Annu Rev Plant Biol , IF:26.379 , 2023 May , V74 : P453-479 doi: 10.1146/annurev-arplant-070722-015329
Plant Hormone Transport and Localization: Signaling Molecules on the Move.
School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel; email: eilonsh@tauex.tau.ac.il.; Current affiliation: College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China; email: zhangyuqin@ucas.ac.cn.
Plant hormones are a group of small signaling molecules produced by plants at very low concentrations that have the ability to move and function at distal sites. Hormone homeostasis is critical to balance plant growth and development and is regulated at multiple levels, including hormone biosynthesis, catabolism, perception, and transduction. In addition, plants move hormones over short and long distances to regulate various developmental processes and responses to environmental factors. Transporters coordinate these movements, resulting in hormone maxima, gradients, and cellular and subcellular sinks. Here, we summarize the current knowledge of most of the characterized plant hormone transporters with respect to biochemical, physiological, and developmental activities. We further discuss the subcellular localizations of transporters, their substrate specificities, and the need for multiple transporters for the same hormone in the context of plant growth and development.
PMID: 36889002
Annu Rev Plant Biol , IF:26.379 , 2023 May , V74 : P387-413 doi: 10.1146/annurev-arplant-102720-033523
Decoding the Auxin Matrix: Auxin Biology Through the Eye of the Computer.
Laboratoire Reproduction et Developpement des Plantes, Universite de Lyon and ENS de Lyon, CNRS, INRAE, Lyon, France; email: raquel.martin@ens-lyon.fr, teva.vernoux@ens-lyon.fr.
The plant hormone auxin is certainly the most studied developmental regulator in plants. The many functions of auxin during development, from the embryo to the root and shoot construction, are mediated by an ever-growing collection of molecular regulators, with an overwhelming degree of both ubiquity and complexity that we are still far from fully understanding and that biological experiments alone cannot grasp. In this review, we discuss how bioinformatics and computational modeling approaches have helped in recent years to explore this complexity and to push the frontiers of our understanding of auxin biology. We focus on how analysis of massive amounts of genomic data and construction of computational models to simulate auxin-regulated processes at different scales have complemented wet experiments to increase the understanding of how auxin acts in the nucleus to regulate transcription and how auxin movement between cells regulates development at the tissular scale.
PMID: 36608348
Trends Plant Sci , IF:18.313 , 2023 May doi: 10.1016/j.tplants.2023.05.003
A complex signaling trio in seed germination: Auxin-JA-ABA.
Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellonska 28, 40-032 Katowice, Poland.; Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellonska 28, 40-032 Katowice, Poland. Electronic address: agata.daszkowska@us.edu.pl.
Recently. Mei et al. discovered the molecular mechanism behind the synergistic action of auxins and jasmonates in enhancing the role of abscisic acid (ABA) in seed germination. They found that JASMONATE-ZIM DOMAIN (JAZ) proteins interact with AUXIN RESPONSE FACTOR (ARF)-16 to mediate auxin-jasmonic acid (JA) crosstalk. Furthermore, they revealed that ARF16 interacts with ABSCISIC ACID INSENSITIVE (ABI)-5 and positively modulates ABA responses at seed germination.
PMID: 37208202
Trends Plant Sci , IF:18.313 , 2023 Jun , V28 (6) : P611-613 doi: 10.1016/j.tplants.2023.03.016
Endoreplication controls cell size via mechanochemical signaling.
Plant & Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, UK. Electronic address: rahul.bhosale@nottingham.ac.uk.; Integrated Molecular Plant Physiology Research (IMPRES), Biology Department, University of Antwerp, 2020 Antwerp, Belgium; Plant Biochemistry & Biotechnology Lab, Department of Agriculture, Hellenic Mediterranean University, Stavromenos PC 71410, Heraklion, Crete, Greece. Electronic address: kris.vissenberg@uantwerpen.be.
During hypocotyl development, an asymmetric auxin gradient causes differential cell elongation, leading to tissue bending and apical hook formation. Recently, Ma et al. identified a molecular pathway that links auxin with endoreplication and cell size through cell wall integrity sensing, cell wall remodeling, and regulation of cell wall stiffness.
PMID: 36997439
Trends Plant Sci , IF:18.313 , 2023 Jun , V28 (6) : P620-622 doi: 10.1016/j.tplants.2023.03.002
Biomolecular condensation: a new player in auxin signaling.
Institute of Biology, University of Graz, Schubertstrasse 51, 8010 Graz, Austria. Electronic address: alicja.gorska@uni-graz.at.; Institute of Biology, University of Graz, Schubertstrasse 51, 8010 Graz, Austria.
Biomolecular condensates are increasingly being recognized as a fundamental mechanism for the organization of the intracellular space. Powers et al. and Jing et al. have demonstrated that a cytoplasmic condensation of AUXIN RESPONSE FACTOR (ARF) transcription factors restrains auxin responses, acting as an additional regulatory layer in the auxin-mediated control of plant development.
PMID: 36959045
Trends Plant Sci , IF:18.313 , 2023 Jul , V28 (7) : P765-775 doi: 10.1016/j.tplants.2023.02.003
The consequences of synthetic auxin herbicide on plant-herbivore interactions.
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.; Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA. Electronic address: rsbaucom@umich.edu.
Although herbicide drift is a common side effect of herbicide application in agroecosystems, its effects on the ecology and evolution of natural communities are rarely studied. A recent shift to dicamba, a synthetic auxin herbicide known for 'drifting' to nontarget areas, necessitates the examination of drift effects on the plant-insect interactions that drive eco-evo dynamics in weed communities. We review current knowledge of direct effects of synthetic auxin herbicides on plant-insect interactions, focusing on plant herbivory, and discuss potential indirect effects, which are cascading effects on organisms that interact with herbicide-exposed plants. We end by developing a framework for the study of plant-insect interactions given drift, highlighting potential changes to plant developmental timing, resource quantity, quality, and cues.
PMID: 36842859
Nucleic Acids Res , IF:16.971 , 2023 Jun doi: 10.1093/nar/gkad521
Spatially resolved transcriptomic analysis of the germinating barley grain.
Department of Animal, Plant and Soil Science, La Trobe Institute for Sustainable Agriculture and Food, School of Agriculture, Biomedical and Environmental Sciences, La Trobe University, Bundoora, Victoria 3086, Australia.; Australian Research Council Research Hub for Medicinal Agriculture, AgriBio Building, La Trobe University, Bundoora, VIC 3086, Australia.; Research Centre for Engineering Biology, College of Life Science, Zhejiang University, 718 East Haizhou Road, Haining, Jiaxing, Zhejiang 314400, China.
Seeds are a vital source of calories for humans and a unique stage in the life cycle of flowering plants. During seed germination, the embryo undergoes major developmental transitions to become a seedling. Studying gene expression in individual seed cell types has been challenging due to the lack of spatial information or low throughput of existing methods. To overcome these limitations, a spatial transcriptomics workflow was developed for germinating barley grain. This approach enabled high-throughput analysis of spatial gene expression, revealing specific spatial expression patterns of various functional gene categories at a sub-tissue level. This study revealed over 14 000 genes differentially regulated during the first 24 h after imbibition. Individual genes, such as the aquaporin gene family, starch degradation, cell wall modification, transport processes, ribosomal proteins and transcription factors, were found to have specific spatial expression patterns over time. Using spatial autocorrelation algorithms, we identified auxin transport genes that had increasingly focused expression within subdomains of the embryo over time, suggesting their role in establishing the embryo axis. Overall, our study provides an unprecedented spatially resolved cellular map for barley germination and identifies specific functional genomics targets to better understand cellular restricted processes during germination. The data can be viewed at https://spatial.latrobe.edu.au/.
PMID: 37351575
Nat Plants , IF:15.793 , 2023 Jun , V9 (6) : P908-925 doi: 10.1038/s41477-023-01406-z
Uncovering the transcriptional regulatory network involved in boosting wheat regeneration and transformation.
Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.; National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, China.; University of Chinese Academy of Sciences, Beijing, China.; Nanjing Agricultural University, Nanjing, China.; National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, China. zhangxs@sdau.edu.cn.; Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China. jxiao@genetics.ac.cn.; University of Chinese Academy of Sciences, Beijing, China. jxiao@genetics.ac.cn.; CAS-JIC Centre of Excellence for Plant and Microbial Science (CEPAMS), Institute of Genetics and Developmental Biology, CAS, Beijing, China. jxiao@genetics.ac.cn.
Genetic transformation is important for gene functional study and crop improvement. However, it is less effective in wheat. Here we employed a multi-omic analysis strategy to uncover the transcriptional regulatory network (TRN) responsible for wheat regeneration. RNA-seq, ATAC-seq and CUT&Tag techniques were utilized to profile the transcriptional and chromatin dynamics during early regeneration from the scutellum of immature embryos in the wheat variety Fielder. Our results demonstrate that the sequential expression of genes mediating cell fate transition during regeneration is induced by auxin, in coordination with changes in chromatin accessibility, H3K27me3 and H3K4me3 status. The built-up TRN driving wheat regeneration was found to be dominated by 446 key transcription factors (TFs). Further comparisons between wheat and Arabidopsis revealed distinct patterns of DNA binding with one finger (DOF) TFs in the two species. Experimental validations highlighted TaDOF5.6 (TraesCS6A02G274000) and TaDOF3.4 (TraesCS2B02G592600) as potential enhancers of transformation efficiency in different wheat varieties.
PMID: 37142750
Nat Plants , IF:15.793 , 2023 May , V9 (5) : P706-719 doi: 10.1038/s41477-023-01396-y
Four class A AUXIN RESPONSE FACTORs promote tomato fruit growth despite suppressing fruit set.
Department of Biology, Duke University, Durham, NC, USA.; School of Grassland Science, Beijing Forestry University, Beijing, P. R. China.; Department of Biology, Duke University, Durham, NC, USA. tps@duke.edu.
In flowering plants, auxin produced in seeds after fertilization promotes fruit initiation. The application of auxin to unpollinated ovaries can also induce parthenocarpy (seedless fruit production). Previous studies have shown that auxin signalling components SlIAA9 and SlARF7 (a class A AUXIN RESPONSE FACTOR (ARF)) are key repressors of fruit initiation in tomato (Solanum lycopersicum). A similar repressive role of class A ARFs in fruit set has also been observed in other plant species. However, evidence is lacking for a role of any class A ARF in promoting fruit development as predicted in the current auxin signalling model. Here we generated higher-order tomato mutants of four class A SlARFs (SlARF5, SlARF7, SlARF8A and SlARF8B) and uncovered their precise combinatorial roles that lead to suppressing and promoting fruit development. All four class A SlARFs together with SlIAA9 inhibited fruit initiation but promoted subsequent fruit growth. Transgenic tomato lines expressing truncated SlARF8A/8B lacking the IAA9-interacting PB1 domain displayed strong parthenocarpy, further confirming the promoting role of SlARF8A/8B in fruit growth. Altering the doses of these four SlARFs led to biphasic fruit growth responses, showing their versatile dual roles as both negative and positive regulators. RNA-seq and chromatin immunoprecipitation-quantitative PCR analyses further identified SlARF8A/8B target genes, including those encoding MADS-BOX transcription factors (AG1, MADS2 and AGL6) that are key repressors of fruit set. These results support the idea that SlIAA9/SlARFs directly regulate the transcription of these MADS-BOX genes to inhibit fruit set. Our study reveals the previously unknown dual function of four class A SlARFs in tomato fruit development and illuminates the complex combinatorial effects of multiple ARFs in controlling auxin-mediated fruit set and fruit growth.
PMID: 37037878
EMBO J , IF:11.598 , 2023 Jun , V42 (11) : Pe111926 doi: 10.15252/embj.2022111926
Auxin-dependent regulation of cell division rates governs root thermomorphogenesis.
Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.; Department of Biology, Institute of Molecular Plant Biology, ETH Zurich, Zurich, Switzerland.; Department of Cell and Metabolic Biology, Leibniz Institute of Plant Biochemistry, Halle (Saale), Germany.; Max Planck Institute for Plant Breeding Research, Cologne, Germany.
Roots are highly plastic organs enabling plants to adapt to a changing below-ground environment. In addition to abiotic factors like nutrients or mechanical resistance, plant roots also respond to temperature variation. Below the heat stress threshold, Arabidopsis thaliana seedlings react to elevated temperature by promoting primary root growth, possibly to reach deeper soil regions with potentially better water saturation. While above-ground thermomorphogenesis is enabled by thermo-sensitive cell elongation, it was unknown how temperature modulates root growth. We here show that roots are able to sense and respond to elevated temperature independently of shoot-derived signals. This response is mediated by a yet unknown root thermosensor that employs auxin as a messenger to relay temperature signals to the cell cycle. Growth promotion is achieved primarily by increasing cell division rates in the root apical meristem, depending on de novo local auxin biosynthesis and temperature-sensitive organization of the polar auxin transport system. Hence, the primary cellular target of elevated ambient temperature differs fundamentally between root and shoot tissues, while the messenger auxin remains the same.
PMID: 37071525
EMBO J , IF:11.598 , 2023 May , V42 (10) : Pe111273 doi: 10.15252/embj.2022111273
TOR acts as a metabolic gatekeeper for auxin-dependent lateral root initiation in Arabidopsis thaliana.
Center for Organismal Studies, Heidelberg University, Heidelberg, Germany.; Institut de Biologie Moleculaire des Plantes (IBMP), UPR CNRS 2357, Strasbourg, France.; Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany.; Centre for Research in Agricultural Genomics, Barcelona, Spain.; Environmental Research Institute, University College Cork, Cork, Ireland.
Plant organogenesis requires matching the available metabolic resources to developmental programs. In Arabidopsis, the root system is determined by primary root-derived lateral roots (LRs), and adventitious roots (ARs) formed from non-root organs. Lateral root formation entails the auxin-dependent activation of transcription factors ARF7, ARF19, and LBD16. Adventitious root formation relies on LBD16 activation by auxin and WOX11. The allocation of shoot-derived sugar to the roots influences branching, but how its availability is sensed for LRs formation remains unknown. We combine metabolic profiling with cell-specific interference to show that LRs switch to glycolysis and consume carbohydrates. The target-of-rapamycin (TOR) kinase is activated in the lateral root domain. Interfering with TOR kinase blocks LR initiation while promoting AR formation. The target-of-rapamycin inhibition marginally affects the auxin-induced transcriptional response of the pericycle but attenuates the translation of ARF19, ARF7, and LBD16. TOR inhibition induces WOX11 transcription in these cells, yet no root branching occurs as TOR controls LBD16 translation. TOR is a central gatekeeper for root branching that integrates local auxin-dependent pathways with systemic metabolic signals, modulating the translation of auxin-induced genes.
PMID: 37021425
Plant Cell , IF:11.277 , 2023 Jun doi: 10.1093/plcell/koad170
MYB112 connects light and circadian clock signals to promote hypocotyl elongation in Arabidopsis.
Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Institute of Plant and Food Science, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China.; National Center for Transgenic Research in Plants, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; Institute of Plant Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing Engineering Research Center for Edible Mushroom, Beijing 100097, China.; School of Life Science, Huizhou University, Huizhou 516007, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, National Center for Soybean Improvement, College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.; State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Advanced Agriculture Sciences and School of Life Sciences, Peking University, Beijing 100871, China.
Ambient light and the endogenous circadian clock play key roles in regulating Arabidopsis (Arabidopsis thaliana) seedling photomorphogenesis. PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) acts downstream of both light and the circadian clock to promote hypocotyl elongation. Several members of the R2R3-MYB transcription factor (TF) family, the most common type of MYB TF family in Arabidopsis, have been shown to be involved in regulating photomorphogenesis. Nonetheless, whether R2R3-MYB TFs are involved in connecting the light and clock signaling pathways during seedling photomorphogenesis remains unknown. Here, we report that MYB112, a member of the R2R3-MYB family, acts as a negative regulator of seedling photomorphogenesis in Arabidopsis. The light signal promotes the transcription and protein accumulation of MYB112. myb112 mutants exhibit short hypocotyls in both constant light and diurnal cycles. MYB112 physically interacts with PIF4 to enhance the transcription of PIF4 target genes involved in the auxin pathway, including YUCCA8 (YUC8), INDOLE-3-ACETIC ACID INDUCIBLE 19 (IAA19) and IAA29. Furthermore, MYB112 directly binds to the promoter of LUX ARRHYTHMO (LUX), the central component of clock oscillators, to repress its expression mainly in the afternoon and relieve LUX-inhibited expression of PIF4. Genetic evidence confirms that LUX acts downstream of MYB112 in regulating hypocotyl elongation. Thus, the enhanced transcript accumulation and transcriptional activation activity of PIF4 by MYB112 additively promotes the expression of auxin-related genes, thereby increasing auxin synthesis and signaling and fine-tuning hypocotyl growth under diurnal cycles.
PMID: 37335905
Plant Cell , IF:11.277 , 2023 May doi: 10.1093/plcell/koad130
The transcriptional hub SHORT INTERNODES1 integrates hormone signals to orchestrate rice growth and development.
State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Plants have evolved sophisticated mechanisms to coordinate their growth and stress responses via integrating various phytohormone signaling pathways. However, the precise molecular mechanisms orchestrating integration of the phytohormone signaling pathways remain largely obscure. In this study, we found that the rice (Oryza sativa) short internodes1 (shi1) mutant exhibits typical auxin-deficient root development and gravitropic response, brassinosteroid (BR)-deficient plant architecture and grain size as well as enhanced abscisic acid (ABA)-mediated drought tolerance. Additionally, we found that the shi1 mutant is also hyposensitive to auxin and BR treatment but hypersensitive to ABA. Further, we showed that OsSHI1 promotes the biosynthesis of auxin and BR by activating the expression of OsYUCCAs and D11, meanwhile dampens ABA signaling by inducing the expression of OsNAC2, which encodes a repressor of ABA signaling. Furthermore, we demonstrated that three classes of transcription factors, AUXIN RESPONSE FACTOR 19 (OsARF19), LEAF AND TILLER ANGLE INCREASED CONTROLLER (LIC), OsZIP26 and OsZIP86, directly bind to the promoter of OsSHI1 and regulate its expression in response to auxin, BR and ABA, respectively. Collectively, our results unravel an OsSHI1-centered transcriptional regulatory hub that orchestrates the integration and self-feedback regulation of multiple phytohormone signaling pathways to coordinate plant growth and stress adaptation.
PMID: 37195873
Plant Cell , IF:11.277 , 2023 May doi: 10.1093/plcell/koad125
SHORT ROOT and INDETERMINATE DOMAIN family members govern PIN-FORMED expression to regulate minor vein differentiation in rice.
Biotechnology Research Institute (BRI), Chinese Academy of Agricultural Sciences (CAAS), Beijing, China.; Joint Laboratory for Photosynthesis Enhancement and C4 Rice Development, BRI, CAAS, Beijing, China.; International Rice Research Institute, Los Banos, Philippines.; Department of Animal and Plant Sciences, University of Sheffield, UK.
C3 and C4 grasses directly and indirectly provide the vast majority of calories to the human diet, yet our understanding of the molecular mechanisms driving photosynthetic productivity in grasses is largely unexplored. Ground meristem cells divide to form mesophyll or vascular initial cells early in leaf development in C3 and C4 grasses. Here we define a genetic circuit composed of SHR (SHORT ROOT), IDD (INDETERMINATE DOMAIN), and PIN (PIN-FORMED) family members that specifies vascular identify and ground cell proliferation in leaves of both C3 and C4 grasses. Ectopic expression and loss-of-function mutant studies of SHR paralogs in the C3 plant Oryza sativa (rice) and the C4 plant Setaria viridis (green millet) revealed the roles of these genes in both minor vein formation and ground cell differentiation. Genetic and in vitro studies further suggested that SHR regulates this process through its interactions with IDD12 and 13. We also revealed direct interactions of these IDD proteins with a putative regulatory element within the auxin transporter gene PIN5c. Collectively, these findings indicate that a SHR-IDD regulatory circuit mediates auxin transport by negatively regulating PIN expression to modulate minor vein patterning in the grasses.
PMID: 37154077
Proc Natl Acad Sci U S A , IF:11.205 , 2023 Jun , V120 (25) : Pe2221313120 doi: 10.1073/pnas.2221313120
The nitrate transporter NRT2.1 directly antagonizes PIN7-mediated auxin transport for root growth adaptation.
State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, Frontiers Science Center for Molecular Design Breeding (MOE), China Agricultural University, Beijing 100193, China.; Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing 100193, China.; College of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding 071002, China.; Institute of Science and Technology Austria, Klosterneuburg 3400, Austria.
As a crucial nitrogen source, nitrate (NO(3)(-)) is a key nutrient for plants. Accordingly, root systems adapt to maximize NO(3)(-) availability, a developmental regulation also involving the phytohormone auxin. Nonetheless, the molecular mechanisms underlying this regulation remain poorly understood. Here, we identify low-nitrate-resistant mutant (lonr) in Arabidopsis (Arabidopsis thaliana), whose root growth fails to adapt to low-NO(3)(-) conditions. lonr2 is defective in the high-affinity NO(3)(-) transporter NRT2.1. lonr2 (nrt2.1) mutants exhibit defects in polar auxin transport, and their low-NO(3)(-)-induced root phenotype depends on the PIN7 auxin exporter activity. NRT2.1 directly associates with PIN7 and antagonizes PIN7-mediated auxin efflux depending on NO(3)(-) levels. These results reveal a mechanism by which NRT2.1 in response to NO(3)(-) limitation directly regulates auxin transport activity and, thus, root growth. This adaptive mechanism contributes to the root developmental plasticity to help plants cope with changes in NO(3)(-) availability.
PMID: 37307446
Proc Natl Acad Sci U S A , IF:11.205 , 2023 May , V120 (19) : Pe2218503120 doi: 10.1073/pnas.2218503120
Dual regulations of cell cycle regulator DPa by auxin in Arabidopsis root distal stem cell maintenance.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, 266237 Qingdao, Shandong, China.; Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, 350002 Fuzhou, Fujian, China.
The plant hormone auxin plays a key role to maintain root stem cell identity which is essential for root development. However, the molecular mechanism by which auxin regulates root distal stem cell (DSC) identity is not well understood. In this study, we revealed that the cell cycle factor DPa is a vital regulator in the maintenance of root DSC identity through multiple auxin signaling cascades. On the one hand, auxin positively regulates the transcription of DPa via AUXIN RESPONSE FACTOR 7 and ARF19. On the other hand, auxin enhances the protein stability of DPa through MITOGEN-ACTIVATED PROTEIN KINASE 3 (MPK3)/MPK6-mediated phosphorylation. Consistently, mutation of the identified three threonine residues (Thr(10), Thr(25), and Thr(227)) of DPa to nonphosphorylated form alanine (DPa(3A)) highly decreased the phosphorylation level of DPa, which decreased its protein stability and affected the maintenance of root DSC identity. Taken together, this study provides insight into the molecular mechanism of how auxin regulates root distal stem cell identity through the dual regulations of DPa at both transcriptional and posttranslational levels.
PMID: 37126711
Curr Biol , IF:10.834 , 2023 Jun , V33 (11) : P2201-2212.e3 doi: 10.1016/j.cub.2023.04.061
Photosynthetic sucrose drives the lateral root clock in Arabidopsis seedlings.
Department of Molecular Plant Physiology, Faculty of Biology, University of Freiburg, Schanzlestr. 1, 79104 Freiburg, Germany. Electronic address: stefan.kircher@biologie.uni-freiburg.de.; Department of Molecular Plant Physiology, Faculty of Biology, University of Freiburg, Schanzlestr. 1, 79104 Freiburg, Germany. Electronic address: peter.schopfer@biologie.uni-freiburg.de.
The development of plant roots is subject to control by light. Here, we show that, similar to monotonous root elongation, the periodic induction of lateral roots (LRs) depends on the activation by light of photomorphogenic and photosynthetic photoreceptors in the shoot in a hierarchical order. The prevailing belief is that the plant hormone auxin serves as a mobile signal transmitter, responsible for interorgan communication, including light-controlled shoot-to-root connections. Alternatively, it has been proposed that the transcription factor HY5 assumes the role as a mobile shoot-to-root signal transmitter. Here, we provide evidence that photosynthetic sucrose produced in the shoot acts as the long-distance signal carrier regulating the local, tryptophan-based biosynthesis of auxin in the LR generation zone of the primary root tip, where the LR clock controls the pace of LR initiation in an auxin-tunable manner. Synchronization of LR formation with primary root elongation allows the adjustment of overall root growth to the photosynthetic performance of the shoot and the maintenance of a constant LR density during light-dark changes in a variable light environment.
PMID: 37207646
Curr Biol , IF:10.834 , 2023 May , V33 (10) : P2008-2023.e8 doi: 10.1016/j.cub.2023.04.029
An LRR receptor kinase controls ABC transporter substrate preferences during plant growth-defense decisions.
Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland.; College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan.; Zentrum fur Molekularbiologie der Pflanzen, Pflanzenphysiologie, Universitat Tubingen, Auf der Morgenstelle 32, 72076 Tubingen, Germany.; Department of Biology, ETH Zurich, Universitatstrasse 2, 8092 Zurich, Switzerland.; Department of Plant Molecular Physiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Z. Noskowskiego 12/14, 61-704 Poznan, Poland; NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, 61-614 Poznan, Poland.; Department Molecular Signal Processing, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120 Halle (Saale), Germany.; Department Biochemistry of Plant Interactions, Leibniz Institute of Plant Biochemistry, Weinberg 3, 06120 Halle (Saale), Germany.; Mendel Centre for Plant Genomics and Proteomics Masaryk University, CEITEC MU Kamenice 5, Building A26, 625 00 Brno, Czech Republic.; Department of Plant Molecular Physiology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Z. Noskowskiego 12/14, 61-704 Poznan, Poland; Department of Biochemistry and Biotechnology, Poznan University of Life Sciences, Dojazd 11, 60-632 Poznan, Poland.; Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland. Electronic address: markus.geisler@unifr.ch.
The exporter of the auxin precursor indole-3-butyric acid (IBA), ABCG36/PDR8/PEN3, from the model plant Arabidopsis has recently been proposed to also function in the transport of the phytoalexin camalexin. Based on these bonafide substrates, it has been suggested that ABCG36 functions at the interface between growth and defense. Here, we provide evidence that ABCG36 catalyzes the direct, ATP-dependent export of camalexin across the plasma membrane. We identify the leucine-rich repeat receptor kinase, QIAN SHOU KINASE1 (QSK1), as a functional kinase that physically interacts with and phosphorylates ABCG36. Phosphorylation of ABCG36 by QSK1 unilaterally represses IBA export, allowing camalexin export by ABCG36 conferring pathogen resistance. As a consequence, phospho-dead mutants of ABCG36, as well as qsk1 and abcg36 alleles, are hypersensitive to infection with the root pathogen Fusarium oxysporum, caused by elevated fungal progression. Our findings indicate a direct regulatory circuit between a receptor kinase and an ABC transporter that functions to control transporter substrate preference during plant growth and defense balance decisions.
PMID: 37146609
J Hazard Mater , IF:10.588 , 2023 Aug , V455 : P131637 doi: 10.1016/j.jhazmat.2023.131637
Indole-3-acetic acid and zinc synergistically mitigate positively charged nanoplastic-induced damage in rice.
Key laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-bioengineering, Guizhou University, Guiyang 550025, PR China.; Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, PR China; National Key Laboratory of Rice Biology, The Advanced Seed Institute, Zhejiang University, Hangzhou 310058, PR China.; National Key Laboratory of Rice Biology, The Advanced Seed Institute, Zhejiang University, Hangzhou 310058, PR China.; Institute of Nuclear Agricultural Sciences, Zhejiang University, Hangzhou 310058, PR China. Electronic address: zhen.yang@zju.edu.cn.; Hainan Institute, Zhejiang University, Yazhou Bay Science and Technology City, Sanya 572025, PR China. Electronic address: mengjiang@zju.edu.cn.
Recent research has shown that polystyrene nanoplastics (PS-NPs) can inhibit plant growth and the development of crops, such as rice. In this study, we aimed to investigate the effects of PS-NPs of different particle sizes (80 nm, 200 nm, and 2 microm) and charges (negative, neutral, and positive) on rice growth, and to explore the underlying mechanisms and potential strategies for mitigating their impacts. Two-week-old rice plants were planted in a standard (1/2) Murashige-Skoog liquid medium holding 50 mg/L of different particle sizes and/or charged PS-NPs for 10 days, and the liquid medium without PS-NPs was used as control. The results showed that positively charged PS-NPs (80 nm PS-NH(2)) had the greatest impact on plant growth and greatly reduced the dry biomass, root length, and plant height of rice by 41.04%, 46.34%, and 37.45%, respectively. The positively charged NPs with a size of 80 nm significantly decreased the zinc (Zn) and indole-3-acetic acid (IAA, auxin) contents by 29.54% and 48.00% in roots, and 31.15% and 64.30% in leaves, respectively, and down-regulated the relative expression level of rice IAA response and biosynthesis genes. Moreover, Zn and/or IAA supplements significantly alleviated the adverse effects of 80 nm PS-NH(2) on rice plant growth. Exogenous Zn and/or IAA increased seedlings' growth, decreased PS-NPs distribution, maintained redox homeostasis, and improved tetrapyrrole biosynthesis in rice treated with 80 nm PS-NH(2). Our findings suggest that Zn and IAA synergistically alleviate positively charged NP-induced damage in rice.
PMID: 37210880
J Hazard Mater , IF:10.588 , 2023 Jun , V452 : P131226 doi: 10.1016/j.jhazmat.2023.131226
Tryptophan pretreatment adjusts transcriptome and metabolome profiles to alleviate cadmium toxicity in Arabidopsis.
Beijing Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement and College of Life Sciences, Capital Normal University, Beijing 100048, China.; Beijing Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement and College of Life Sciences, Capital Normal University, Beijing 100048, China. Electronic address: qixiaoting@cnu.edu.cn.
Cadmium (Cd) is highly toxic to all organisms including plants, and recently tryptophan (Trp) pretreatment of plant seedlings is shown to improve Cd tolerance. But the underlying mechanism remains largely unknown. In this study, we used Arabidopsis (Arabidopsis thaliana) to determine the physiological relevance of Trp pretreatment in alleviating Cd toxicity in plants and explore its molecular mechanism with a focus on the metabolic pathways. The results showed that Trp pretreatment maintained the biomass and root lengths, relieved Cd-induced lipid peroxidation, and reduced Cd transport to the shoots, and eventually improved the response against Cd in Arabidopsis seedlings. The integrative analyses of the transcriptome and metabolome further revealed that Trp pretreatment alleviated Cd toxicity not only through a known mechanism of producing a major auxin indole-3-acetic acid and maintaining its levels, but also through two previously unrecognized mechanisms: increasing the area and strength of cell walls by promoting lignification to further reduce Cd entry, and fine-tuning Cd detoxification products derived from sulfur-containing amino acid metabolism. Our findings thereby provide deep mechanical insights into how Trp alleviates Cd toxicity in plants.
PMID: 36934628
New Phytol , IF:10.151 , 2023 Aug , V239 (3) : P964-978 doi: 10.1111/nph.19004
Ethylene controls cambium stem cell activity via promoting local auxin biosynthesis.
Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, China Agricultural University, Beijing, 100193, China.; College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, Shandong, China.; School of Applied Chemistry and Biotechnology, Shenzhen Polytechnic, Shenzhen, 518055, Guangdong, China.; Core Facilities, College of Life Sciences, Peking University, Beijing, 100871, China.; Faculty of Agriculture, New Valley University, New Valley Governorate, 72511, New Valley, Egypt.; Flower Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, 650205, Yunnan, China.; Crop Pathology and Genetic Research Unit, United States Department of Agriculture, Agricultural Research Service, Davis, CA, 95616, USA.; Department of Plant Sciences, University of California Davis, Davis, CA, 95616, USA.; Plant Biology Section, School of Integrative Plant Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA.
The vascular cambium is the main secondary meristem in plants that produces secondary phloem (outside) and xylem (inside) on opposing sides of the cambium. The phytohormone ethylene has been implicated in vascular cambium activity, but the regulatory network underlying ethylene-mediated cambial activity remains to be elucidated. Here, we found that PETAL MOVEMENT-RELATED PROTEIN1 (RhPMP1), an ethylene-inducible HOMEODOMAIN-LEUCINE ZIPPER I transcription factor in woody plant rose (Rosa hybrida), regulates local auxin biosynthesis and auxin transport to maintain cambial activity. Knockdown of RhPMP1 resulted in smaller midveins and reduced auxin content, while RhPMP1 overexpression resulted in larger midveins and increased auxin levels compared with the wild-type plants. Furthermore, we revealed that Indole-3-pyruvate monooxygenase YUCCA 10 (RhYUC10) and Auxin transporter-like protein 2 (RhAUX2), encoding an auxin biosynthetic enzyme and an auxin influx carrier, respectively, are direct downstream targets of RhPMP1. In summary, our results suggest that ethylene promotes an auxin maximum in the cambium adjacent to the xylem to maintain cambial activity.
PMID: 37282811
New Phytol , IF:10.151 , 2023 Aug , V239 (3) : P949-963 doi: 10.1111/nph.18988
SlMYB99-mediated auxin and abscisic acid antagonistically regulate ascorbic acids biosynthesis in tomato.
Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing, 400044, China.
Ascorbic acid (AsA) is a water-soluble antioxidant that plays important roles in plant development and human health. Understanding the regulatory mechanism underlying AsA biosynthesis is imperative to the development of high AsA plants. In this study, we reveal that the auxin response factor SlARF4 transcriptionally inhibits SlMYB99, which subsequently modulates AsA accumulation via transcriptional activation of AsA biosynthesis genes GPP, GLDH, and DHAR. The auxin-dependent transcriptional cascade of SlARF4-SlMYB99-GPP/GLDH/DHAR modulates AsA synthesis, while mitogen-activated protein kinase SlMAPK8 not only phosphorylates SlMYB99, but also activates its transcriptional activity. Both SlMYB99 and SlMYB11 proteins physically interact with each other, thereby synergistically regulating AsA biosynthesis by upregulating the expression of GPP, GLDH, and DHAR genes. Collectively, these results demonstrate that auxin and abscisic acid antagonistically regulate AsA biosynthesis during development and drought tolerance in tomato via the SlMAPK8-SlARF4-SlMYB99/11 module. These findings provide new insights into the mechanism underlying phytohormone regulation of AsA biosynthesis and provide a theoretical basis for the future development of high AsA plants via molecular breeding.
PMID: 37247338
New Phytol , IF:10.151 , 2023 Jul , V239 (2) : P639-659 doi: 10.1111/nph.18947
Disruption of the amino acid transporter CsAAP2 inhibits auxin-mediated root development in cucumber.
Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing, 100193, China.
Amino acid transporters are the principal mediators of organic nitrogen distribution within plants and are essential for plant growth and development. Despite this importance, relatively few amino acid transporter genes have been explored and elucidated in cucumber (Cucumis sativus). Here, a total of 86 amino acid transporter genes were identified in the cucumber genome. We further identified Amino Acid Permease (AAP) subfamily members that exhibited distinct expression patterns in different tissues. We found that the CsAAP2 as a candidate gene encoding a functional amino acid transporter is highly expressed in cucumber root vascular cells. CsAAP2 knockout lines exhibited arrested development of root meristem, which then caused the delayed initiation of lateral root and the inhibition of root elongation. What is more, the shoot growth of aap2 mutants was strongly retarded due to defects in cucumber root development. Moreover, aap2 mutants exhibited higher concentrations of amino acids and lignin in roots. We found that the mutant roots had a stronger ability to acidize medium. Furthermore, in the aap2 mutants, polar auxin transport was disrupted in the root tip, leading to high auxin levels in roots. Interestingly, slightly alkaline media rescued their severely reduced root growth by stimulating auxin pathway.
PMID: 37129077
New Phytol , IF:10.151 , 2023 Jun , V238 (5) : P1813-1824 doi: 10.1111/nph.18898
Loss-of-function of gynoecium-expressed phospholipase pPLAIIgamma triggers maternal haploid induction in Arabidopsis.
Department of Applied Plant Science, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Korea.; Interdisciplinary Program in IT-Bio Convergence System, Chonnam National University, Gwangju, 61186, Korea.; Laboratoire Reproduction et Developpement des Plantes, Univ Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRAE, Lyon, F-69342, France.
Production of in planta haploid embryos that inherit chromosomes from only one parent can greatly increase breeding efficiency via quickly generating homozygous plants, called doubled haploid. One of the main players of in planta haploid induction is a pollen-specific phospholipase A, which is able, when mutated, to induce in vivo haploid induction in numerous monocots. However, no functional orthologous gene has been identified in dicots plants. Here, we show that loss-of-function of gynoecium-expressed phospholipase AII (pPLAIIgamma) triggers maternal haploid plants in Arabidopsis, at an average rate of 1.07%. Reciprocal crosses demonstrate that haploid plants are triggered from the female side and not from the pollen, and the haploid plants carry the maternal genome. Promoter activity of pPLAIIgamma shows enriched expression in the funiculus of flower development stages 13 and 18, and pPLAIIgamma fused to yellow fluorescent protein reveals a plasma-membrane localization Interestingly, the polar localized PIN1 at the basal plasma membrane of the funiculus was all internalized in pplaIIgamma mutants, suggesting that altered PIN1 localization in female organ could play a role in maternal haploid induction.
PMID: 36967578
New Phytol , IF:10.151 , 2023 Jun , V238 (5) : P1924-1941 doi: 10.1111/nph.18879
AZG1 is a cytokinin transporter that interacts with auxin transporter PIN1 and regulates the root stress response.
Instituto Multidisciplinario de Biologia Vegetal, Velez Sarsfield 249, 5000, Cordoba, Argentina.; Molecular Plant Physiology, Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115, Bonn, Germany.; Institute of Biology II, University of Freiburg, Schanzlestrasse 1, 79104, Freiburg, Germany.; Conservation Ecology, Department Biology, Philipps-Universitat Marburg, Karl-von-Frisch-Strasse 8, 35032, Marburg, Germany.; Laboratory of Growth Regulators, Institute of Experimental Botany ASCR and Palacky, Slechtitelu 27, 783 71, Olomouc, Czech Republic.; Zentrum fur Molekularbiologie der Pflanzen, Universitat Tubingen, Auf der Morgenstelle 1, 72076, Tubingen, Germany.; Faculty of Medicine, Institute of Physiology II, University of Freiburg, Hermann-Herder-Strasse 7, 79104, Freiburg, Germany.; Labormedizinisches Zentrum Ostschweiz, Lagerstrasse 30, 9470, Buchs, SG, Switzerland.; Centre of Biological Systems Analysis, University of Freiburg, 79104, Freiburg, Germany.; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany.
An environmentally responsive root system is crucial for plant growth and crop yield, especially in suboptimal soil conditions. This responsiveness enables the plant to exploit regions of high nutrient density while simultaneously minimizing abiotic stress. Despite the vital importance of root systems in regulating plant growth, significant gaps of knowledge exist in the mechanisms that regulate their architecture. Auxin defines both the frequency of lateral root (LR) initiation and the rate of LR outgrowth. Here, we describe a search for proteins that regulate root system architecture (RSA) by interacting directly with a key auxin transporter, PIN1. The native separation of Arabidopsis plasma membrane protein complexes identified several PIN1 co-purifying proteins. Among them, AZG1 was subsequently confirmed as a PIN1 interactor. Here, we show that, in Arabidopsis, AZG1 is a cytokinin (CK) import protein that co-localizes with and stabilizes PIN1, linking auxin and CK transport streams. AZG1 expression in LR primordia is sensitive to NaCl, and the frequency of LRs is AZG1-dependent under salt stress. This report therefore identifies a potential point for auxin:cytokinin crosstalk, which shapes RSA in response to NaCl.
PMID: 36918499
New Phytol , IF:10.151 , 2023 May , V238 (4) : P1379-1385 doi: 10.1111/nph.18864
Lateral root branching: evolutionary innovations and mechanistic divergence in land plants.
Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India.; Center for Organismal Studies, University of Heidelberg, Heidelberg, 69120, Germany.
The root system architecture in plants is a result of multiple evolutionary innovations over time in response to changing environmental cues. Dichotomy and endogenous lateral branching in the roots evolved in lycophytes lineage but extant seed plants use lateral branching instead. This has led to the development of complex and adaptive root systems, with lateral roots playing a key role in this process exhibiting conserved and divergent features in different plant species. The study of lateral root branching in diverse plant species can shed light on the orderly yet distinct nature of postembryonic organogenesis in plants. This insight provides an overview of the diversity in lateral root (LR) development in various plant species during the evolution of root system in plants.
PMID: 36882384
New Phytol , IF:10.151 , 2023 May , V238 (4) : P1498-1515 doi: 10.1111/nph.18854
PIN-FORMED is required for shoot phototropism/gravitropism and facilitates meristem formation in Marchantia polymorpha.
School of Biological Sciences, Monash University, Melbourne, Vic., 3800, Australia.; ARC Centre of Excellence for Plant Success in Nature and Agriculture, Monash University, Melbourne, Vic., 3800, Australia.
PIN-FORMED auxin efflux transporters, a subclass of which is plasma membrane-localised, mediate a variety of land-plant developmental processes via their polar localisation and subsequent directional auxin transport. We provide the first characterisation of PIN proteins in liverworts using Marchantia polymorpha as a model system. Marchantia polymorpha possesses a single PIN-FORMED gene, whose protein product is predicted to be plasma membrane-localised, MpPIN1. To characterise MpPIN1, we created loss-of-function alleles and produced complementation lines in both M. polymorpha and Arabidopsis. In M. polymorpha, gene expression and protein localisation were tracked using an MpPIN1 transgene encoding a translationally fused fluorescent protein. Overexpression of MpPIN1 can partially complement loss of an orthologous gene, PIN-FORMED1, in Arabidopsis. In M. polymorpha, MpPIN1 influences development in numerous ways throughout its life cycle. Most notably, MpPIN1 is required to establish gemmaling dorsiventral polarity and for orthotropic growth of gametangiophore stalks, where MpPIN1 is basally polarised. PIN activity is largely conserved within land plants, with PIN-mediated auxin flow providing a flexible mechanism to organise growth. Specifically, PIN is fundamentally linked to orthotropism and to the establishment of de novo meristems, the latter potentially involving the formation of both auxin biosynthesis maxima and auxin-signalling minima.
PMID: 36880411
New Phytol , IF:10.151 , 2023 May , V238 (3) : P1146-1162 doi: 10.1111/nph.18775
RRS1 shapes robust root system to enhance drought resistance in rice.
Beijing Key Laboratory of Crop Genetic Improvement, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China.; Sanya Institute of China Agricultural University, Sanya, 572025, China.; Shandong Rice Research Institute, Shandong Academy of Agricultural Sciences, Jinan, 250100, Shandong, China.; Sanya Institute, Hainan Academy of Agricultural Sciences, Sanya, 572025, China.
A strong root system facilitates the absorption of water and nutrients from the soil, to improve the growth of crops. However, to date, there are still very few root development regulatory genes that can be used in crop breeding for agriculture. In this study, we cloned a negative regulator gene of root development, Robust Root System 1 (RRS1), which encodes an R2R3-type MYB family transcription factor. RRS1 knockout plants showed enhanced root growth, including longer root length, longer lateral root length, and larger lateral root density. RRS1 represses root development by directly activating the expression of OsIAA3 which is involved in the auxin signaling pathway. A natural variation in the coding region of RRS1 changes the transcriptional activity of its protein. RRS1(T) allele, originating from wild rice, possibly increases root length by means of weakening regulation of OsIAA3. Knockout of RRS1 enhances drought resistance by promoting water absorption and improving water use efficiency. This study provides a new gene resource for improving root systems and cultivating drought-resistant rice varieties with important values in agricultural applications.
PMID: 36862074
New Phytol , IF:10.151 , 2023 May , V238 (3) : P971-976 doi: 10.1111/nph.18783
Save your TIRs - more to auxin than meets the eye.
John Innes Centre, Norwich, NR4 7UH, UK.; Department of Biology, University of Oxford, Oxford, OX1 3RB, UK.
Auxin has long been known as an important regulator of plant growth and development. Classical studies in auxin biology have uncovered a 'canonical' transcriptional auxin-signalling pathway involving the TRANSPORT INHIBITOR RESPONSE1/AUXIN SIGNALING F-BOX (TIR1/AFB) receptors. TIR1/AFB perception of auxin triggers the degradation of repressors and the derepression of auxin-responsive genes. Nevertheless, the canonical pathway cannot account for all aspects of auxin biology, such as physiological responses that are too rapid for transcriptional regulation. This Tansley insight will explore several 'non-canonical' pathways that have been described in recent years mediating fast auxin responses. We focus on the interplay between a nontranscriptional branch of TIR1/AFB signalling and a TRANSMEMBRANE KINASE1 (TMK1)-mediated pathway in root acid growth. Other developmental aspects involving the TMKs and their association with the controversial AUXIN-BINDING PROTEIN 1 (ABP1) will be discussed. Finally, we provide an updated overview of the ETTIN (ETT)-mediated pathway in contexts outside of gynoecium development.
PMID: 36721296
Plant Biotechnol J , IF:9.803 , 2023 Jul , V21 (7) : P1479-1495 doi: 10.1111/pbi.14054
A systematic dissection in oilseed rape provides insights into the genetic architecture and molecular mechanism of yield heterosis.
Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, China.; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China.; State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, China.; Zhengzhou Fruit Research Institute of the Chinese Academy of Agricultural Sciences, The Laboratory of Melon Crops, Zhengzhou, China.; Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xianyang, China.; Hubei Hongshan Laboratory (HHL), Wuhan, China.; State Agricultural Biotechnology Centre, Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, Murdoch, WA, Australia.
Heterosis refers to the better performance of cross progeny compared with inbred parents, and its utilization contributes greatly to agricultural production. Several hypotheses have been proposed to explain heterosis mainly including dominance, over-dominance (or pseudo-overdominance) and epistasis. However, systematic dissection and verification of these hypotheses are rarely documented. Here, comparison of heterosis level across different traits showed that the strong heterosis of composite traits (such as yield) could be attributed to the multiplicative effects of moderate heterosis of component traits, whether at the genome or locus level. Yield heterosis was regulated by a complex trait-QTL network that was characterized by obvious centre-periphery structure, hub QTL, complex up/downstream and positive/negative feedback relationships. More importantly, we showed that better-parent heterosis on yield could be produced in a cross of two near-isogenic lines by the pyramiding and complementation of two major heterotic QTL showing partial-dominance on yield components. The causal gene (BnaA9.CYP78A9) of QC14 was identified, and its heterotic effect results from the heterozygous status of a CACTA-like transposable element in its upstream regulatory region, which led to partial dominance at expression and auxin levels, thus resulting in non-additive expression of downstream responsive genes involved in cell cycle and proliferation, eventually leading to the heterosis of cell number. Taken together, the results at the phenotypic, genetic and molecular levels were highly consistent, which demonstrated that the pyramiding effect of heterotic QTL and the multiplicative effect of individual component traits could well explain substantial parts of yield heterosis in oilseed rape. These results provide in-depth insights into the genetic architecture and molecular mechanism of yield heterosis.
PMID: 37170717
Plant Biotechnol J , IF:9.803 , 2023 Jul , V21 (7) : P1408-1425 doi: 10.1111/pbi.14046
Auxin inhibits lignin and cellulose biosynthesis in stone cells of pear fruit via the PbrARF13-PbrNSC-PbrMYB132 transcriptional regulatory cascade.
College of Horticulture, State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing, Jiangsu, China.; The New Zealand Institute for Plant and Food Research Ltd, Mt Albert Research Centre, Auckland, New Zealand.; College of Horticultural Science and Engineering, Shandong Agricultural University, Taian, Shandong, China.
Stone cells are often present in pear fruit, and they can seriously affect the fruit quality when present in large numbers. The plant growth regulator NAA, a synthetic auxin, is known to play an active role in fruit development regulation. However, the genetic mechanisms of NAA regulation of stone cell formation are still unclear. Here, we demonstrated that exogenous application of 200 muM NAA reduced stone cell content and also significantly decreased the expression level of PbrNSC encoding a transcriptional regulator. PbrNSC was shown to bind to an auxin response factor, PbrARF13. Overexpression of PbrARF13 decreased stone cell content in pear fruit and secondary cell wall (SCW) thickness in transgenic Arabidopsis plants. In contrast, knocking down PbrARF13 expression using virus-induced gene silencing had the opposite effect. PbrARF13 was subsequently shown to inhibit PbrNSC expression by directly binding to its promoter, and further to reduce stone cell content. Furthermore, PbrNSC was identified as a positive regulator of PbrMYB132 through analyses of co-expression network of stone cell formation-related genes. PbrMYB132 activated the expression of gene encoding cellulose synthase (PbrCESA4b/7a/8a) and lignin laccase (PbrLAC5) binding to their promotors. As expected, overexpression or knockdown of PbrMYB132 increased or decreased stone cell content in pear fruit and SCW thickness in Arabidopsis transgenic plants. In conclusion, our study shows that the 'PbrARF13-PbrNSC-PbrMYB132' regulatory cascade mediates the biosynthesis of lignin and cellulose in stone cells of pear fruit in response to auxin signals and also provides new insights into plant SCW formation.
PMID: 37031416
Plant Biotechnol J , IF:9.803 , 2023 Jun , V21 (6) : P1217-1228 doi: 10.1111/pbi.14031
LAZY3 interacts with LAZY2 to regulate tiller angle by modulating shoot gravity perception in rice.
Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.; University of Chinese Academy of Sciences, Beijing, China.; College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou, China.; State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, China.
Starch biosynthesis in gravity-sensing tissues of rice shoot determines the magnitude of rice shoot gravitropism and thus tiller angle. However, the molecular mechanism underlying starch biosynthesis in rice gravity-sensing tissues is still unclear. We characterized a novel tiller angle gene LAZY3 (LA3) in rice through map-based cloning. Biochemical, molecular and genetic studies further demonstrated the essential roles of LA3 in gravity perception of rice shoot and tiller angle control. The shoot gravitropism and lateral auxin transport were defective in la3 mutant upon gravistimulation. We showed that LA3 encodes a chloroplast-localized tryptophan-rich protein associated with starch granules via Tryptophan-rich region (TRR) domain. Moreover, LA3 could interact with the starch biosynthesis regulator LA2, determining starch granule formation in shoot gravity-sensing tissues. LA3 and LA2 negatively regulate tiller angle in the same pathway acting upstream of LA1 to mediate asymmetric distribution of auxin. Our study defined LA3 as an indispensable factor of starch biosynthesis in rice gravity-sensing tissues that greatly broadens current understanding in the molecular mechanisms underlying the starch granule formation in gravity-sensing tissues, and provides new insights into the regulatory mechanism of shoot gravitropism and rice tiller angle.
PMID: 36789453
Cell Rep , IF:9.423 , 2023 May , V42 (6) : P112565 doi: 10.1016/j.celrep.2023.112565
ERF1 inhibits lateral root emergence by promoting local auxin accumulation and repressing ARF7 expression.
Division of Life Sciences and Medicine, Division of Molecular & Cell Biophysics, Hefei National Science Center for Interdisciplinary Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, The Innovation Academy of Seed Design, Chinese Academy of Sciences, Hefei, Anhui Province 230027, China. Electronic address: zhaopingxia2008@163.com.; Division of Life Sciences and Medicine, Division of Molecular & Cell Biophysics, Hefei National Science Center for Interdisciplinary Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, The Innovation Academy of Seed Design, Chinese Academy of Sciences, Hefei, Anhui Province 230027, China.; College of Life Sciences, Anhui Agricultural University, Hefei, Anhui Province 230036, China.; Division of Life Sciences and Medicine, Division of Molecular & Cell Biophysics, Hefei National Science Center for Interdisciplinary Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, The Innovation Academy of Seed Design, Chinese Academy of Sciences, Hefei, Anhui Province 230027, China. Electronic address: xiangcb@ustc.edu.cn.
Lateral roots (LRs) are crucial for plants to sense environmental signals in addition to water and nutrient absorption. Auxin is key for LR formation, but the underlying mechanisms are not fully understood. Here, we report that Arabidopsis ERF1 inhibits LR emergence by promoting local auxin accumulation with altered distribution and regulating auxin signaling. Loss of ERF1 increases LR density compared with the wild type, whereas ERF1 overexpression causes the opposite phenotype. ERF1 enhances auxin transport by upregulating PIN1 and AUX1, resulting in excessive auxin accumulation in the endodermal, cortical, and epidermal cells surrounding LR primordia. Furthermore, ERF1 represses ARF7 transcription, thereby downregulating the expression of cell-wall remodeling genes that facilitate LR emergence. Together, our study reveals that ERF1 integrates environmental signals to promote local auxin accumulation with altered distribution and repress ARF7, consequently inhibiting LR emergence in adaptation to fluctuating environments.
PMID: 37224012
Plant Physiol , IF:8.34 , 2023 Jun doi: 10.1093/plphys/kiad345
WUSCHEL controls genotype-dependent shoot regeneration capacity in potato.
Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, South Korea.; Department of Crop Science, Chungnam National University, Daejeon 34134, South Korea.; Disease Target Structure Research Center, Korea Research Institute of Bioscience & Biotechnology, Daejeon 34141, South Korea.; Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon 34113, South Korea.; Department of Functional Genomics, KRIBB School of Bioscience, University of Science and Technology, Daejeon 34113, South Korea.; Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Korea.
Plant cells can reprogram their fate. The combinatorial actions of auxin and cytokinin dedifferentiate somatic cells to regenerate organs, which can develop into individual plants. As transgenic plants can be generated from genetically modified somatic cells through these processes, cell fate transition is an unavoidable step in crop genetic engineering. However, regeneration capacity closely depends on the genotype, and the molecular events underlying these variances remain elusive. In the present study, we demonstrated that WUSCHEL (WUS) -a homeodomain transcription factor-determines regeneration capacity in different potato (Solanum tuberosum) genotypes. Comparative analysis of shoot regeneration efficiency and expression of genes related to cell fate transition revealed that WUS expression coincided with regeneration rate in different potato genotypes. Moreover, in a high-efficiency genotype, WUS silencing suppressed shoot regeneration. Meanwhile, in a low-efficiency genotype, regeneration could be enhanced through the supplementation of a different type of cytokinin that promoted WUS expression. Computational modeling of cytokinin receptor-ligand interactions suggested that the docking pose of cytokinins mediated by hydrogen bonding with the core residues may be pivotal for WUS expression and shoot regeneration in potatoes. Furthermore, our whole genome sequencing analysis revealed core sequence variations in the WUS promoters that differentiate low- and high-efficiency genotypes. The present study revealed that cytokinin responses, particularly WUS expression, determine shoot regeneration efficiency in different potato genotypes.
PMID: 37348867
Plant Physiol , IF:8.34 , 2023 Jun doi: 10.1093/plphys/kiad352
Inhibitor AN3661 reveals biological functions of Arabidopsis CLEAVAGE AND POLYADENYLATION SPECIFICITY FACTOR 73.
Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China.; Biomedical Sciences, College of Dental Medicine, Western University of Health Sciences, Pomona, CA 91766, USA.
Cleavage and polyadenylation specificity factor (CPSF) is a protein complex that plays an essential biochemical role in mRNA 3'-end formation, including poly(A) signal recognition and cleavage at the poly(A) site. However, its biological functions at the organismal level are mostly unknown in multicellular eukaryotes. Study of plant CPSF73 has been hampered by the lethality of Arabidopsis (Arabidopsis thaliana) homozygous mutants of AtCPSF73-I and AtCPSF73-II. Here, we used poly(A) tag sequencing (PAT-seq) to investigate the roles of AtCPSF73-I and AtCPSF73-II in Arabidopsis treated with AN3661, an antimalarial drug with specificity for parasite CPSF73 that is homologous to plant CPSF73. Direct seed germination on AN3661-treated medium was lethal; however, 7-day-old seedlings treated with AN3661 survived. AN3661 targeted AtCPSF73-I and AtCPSF73-II, inhibiting growth through coordinating gene expression and poly(A) site choice. Functional enrichment analysis revealed that the accumulation of ethylene and auxin jointly inhibited primary root growth. AN3661 affected poly(A) signaling recognition, resulted in lower U-rich signal usage, caused transcriptional readthrough, and increased the distal poly(A) site usage. Many microRNA targets were found in the 3' UTR lengthened transcripts; these miRNAs may indirectly regulate the expression of these targets through cleavage. Overall, this work demonstrates that AtCPSF73 plays important parts in co-transcriptional regulation, affecting growth and development in Arabidopsis.
PMID: 37335917
Plant Physiol , IF:8.34 , 2023 Jun doi: 10.1093/plphys/kiad321
Axes and Polarities in Leaf Vein Formation.
Department of Biological Sciences, University of Alberta, CW-405 Biological Sciences Building, Edmonton AB T6G 2E9, Canada.
For multicellular organisms to develop, cells must grow, divide, and differentiate along preferential or exclusive orientations or directions. Moreover, those orientations-or axes-and directions-or polarities-must be coordinated between cells within and between tissues. Therefore, how axes and polarities are coordinated between cells is a key question in biology. In animals, such coordination mainly depends on cell migration and direct interaction between proteins protruding from the plasma membrane. Both cell movements and direct cell-cell interactions are prevented in plants by cell walls that surround plant cells and keep them apart and in place. Therefore, plants have evolved unique mechanisms to coordinate their cell axes and polarities. Here I will discuss evidence suggesting that understanding how leaf veins form may uncover those unique mechanisms. Indeed-unlike previously thought-the cell-to-cell, polar transport of the plant hormone auxin along developing veins cannot account for many features of vein patterning. Instead, those features can be accounted for by models of vein patterning that combine polar auxin transport with auxin diffusion through plasmodesmata along the axis of developing veins. Though it remains unclear whether such a combination of polar transport and axial diffusion of auxin can account for the formation of the variety of vein patterns found in plant leaves, evidence suggests that such a combined mechanism may control plant developmental processes beyond vein patterning.
PMID: 37261944
Plant Physiol , IF:8.34 , 2023 May doi: 10.1093/plphys/kiad309
Cell Signaling in the Shoot Apical Meristem.
College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.; State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.; Peking-Tsinghua Center for Life Sciences, Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.; Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences in Weifang, Weifang, Shandong 261325, China.
Distinct from animals, plants maintain organogenesis from specialized tissues termed meristems throughout life. In the shoot apex, the shoot apical meristem (SAM) produces all aerial organs, such as leaves, from its periphery. For this, the SAM needs to precisely balance stem cell renewal and differentiation, which is achieved through dynamic zonation of the SAM, and cell signaling within functional domains is key for SAM functions. The WUSCHEL-CLAVATA feedback loop plays a key role in SAM homeostasis, and recent studies have uncovered new components, expanding our understanding of the spatial expression and signaling mechanism. Advances in polar auxin transport and signaling have contributed to knowledge of the multifaceted roles of auxin in the SAM and organogenesis. Finally, single-cell techniques have expanded our understanding of the cellular functions within the shoot apex at single-cell resolution. In this review, we summarize the most up-to-date understanding of cell signaling in the SAM and focus on the multiple levels of regulation of SAM formation and maintenance.
PMID: 37224874
Plant Physiol , IF:8.34 , 2023 May doi: 10.1093/plphys/kiad293
GmGAMYB-BINDING PROTEIN 1 promotes Small Auxin-Up RNA gene transcription to modulate soybean maturity and height.
Key Laboratory of Soybean Biology of Ministry of Education China, Northeast Agricultural University, Harbin 150030, China.
Flowering time, maturity, and plant height are crucial agronomic traits controlled by photoperiod that affect soybean (Glycine max [L.] Merr.) yield and regional adaptability. It is important to cultivate soybean cultivars of earlier maturity that adapt to high latitudes. GAMYB binding protein 1 (GmGBP1), a member of the SNW/SKIP family of transcriptional co-regulators in soybean, is induced by short days and interacts with transcription factor GAMYB (GmGAMYB) during photoperiod control of flowering time and maturity. In the present study, GmGBP1:GmGBP1 soybean showed the phenotypes of earlier maturity and higher plant height. Chromatin immunoprecipitation sequencing assays (ChIP-seq) of GmGBP1-binding sites and RNA sequencing (RNA-seq) of differentially expressed transcripts in GmGBP1:GmGBP1 further identified potential targets of GmGBP1, including small auxin-up RNA (GmSAUR). GmSAUR:GmSAUR soybean also showed earlier maturity and higher plant height. GmGBP1 interacted with GmGAMYB, bound to the promoter of GmSAUR, and promoted the expression of FLOWER LOCUS T homologs 2a (GmFT2a) and FLOWERING LOCUS D LIKE 19 (GmFDL19). Flowering repressors such as GmFT4 were negatively regulated, resulting in earlier flowering and maturity. Furthermore, the interaction of GmGBP1 with GmGAMYB increased the gibberellin (GA) signal to promote height and hypocotyl elongation by activating GmSAUR; GmSAUR bound to the promoter of the GA-positive activating regulator gibberellic acid-stimulated Arabidopsis 32 (GmGASA32). These results suggested a photoperiod regulatory pathway in which the interaction of GmGBP1 with GmGAMYB directly activated GmSAUR to promote earlier maturity and plant height in soybean.
PMID: 37204820
Plant Physiol , IF:8.34 , 2023 May doi: 10.1093/plphys/kiad289
miR171-targeted SCARECROW-LIKE genes CsSCL2 and CsSCL3 regulate somatic embryogenesis in citrus.
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China.; Hubei Hongshan Laboratory, Wuhan 430070, China.
Somatic embryogenesis (SE) is a key regeneration pathway in various biotechnology approaches to crop improvement, especially for economically important perennial woody crops like citrus. However, maintenance of SE capability has long been a challenge and becomes a bottleneck in biotechnology-facilitated plant improvement. In the embryogenic callus (EC) of citrus, we identified two csi-miR171c targeted SCARECROW-LIKE genes CsSCL2 and CsSCL3 (CsSCL2/3), which exert positive feedback regulation on csi-miR171c expression. Suppression of CsSCL2 expression by RNA interference (RNAi) enhanced SE in citrus callus. A thioredoxin superfamily protein CsClot was identified as an interactive protein of CsSCL2/3. Overexpression of CsClot disturbed reactive oxygen species (ROS) homeostasis in EC and enhanced SE. ChIP-Seq and RNA-Seq identified 660 genes directly suppressed by CsSCL2 that were enriched in biological processes including development related processes, auxin signaling pathway and cell wall organization. CsSCL2/3 bound to the promoters of regeneration-related genes, such as WUSCHEL-RELATED HOMEOBOX 2 (CsWOX2), CsWOX13 and Lateral Organ Boundaries Domain 40 (LBD40), and repressed their expression. Overall, CsSCL2/3 modulate ROS homeostasis through the interactive protein CsClot and directly suppress the expression of regeneration-related genes, thus regulating SE in citrus. We uncovered a regulatory pathway of miR171c-targeted CsSCL2/3 in SE, which shed light on the mechanism of SE and regeneration capability maintenance in citrus.
PMID: 37204807
Plant Physiol , IF:8.34 , 2023 May doi: 10.1093/plphys/kiad264
Computer models of cell polarity establishment in plants.
Centro de Biotecnologia y Genomica de Plantas, Universidad Politecnica de Madrid (UPM) - Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), Pozuelo de Alarcon (Madrid), Spain.
Plant development is a complex task and many processes involve changes in the asymmetric subcellular distribution of cell components that strongly depend on cell polarity. Cell polarity regulates anisotropic growth, and polar localization of membrane proteins, and helps to identify the cell's position relative to its neighbors within an organ. Cell polarity is critical in a variety of plant developmental processes including embryogenesis, cell division, and response to external stimuli. The most conspicuous downstream effect of cell polarity is the polar transport of the phytohormone auxin, which is the only known hormone transported in a polar fashion in and out of cells by specialized exporters and importers. The biological processes behind the establishment of cell polarity are still unknown and researchers have proposed several models which have been tested using computer simulations. The evolution of computer models has progressed in tandem with scientific discoveries, which have highlighted the importance of genetic, chemical, and mechanical input in determining cell polarity and regulating polarity-dependent processes like anisotropic growth, protein subcellular localization, and the development of organ shapes. The purpose of this review is to provide a comprehensive overview of the current understanding of computer models of cell polarity establishment in plants, focusing on the molecular and cellular mechanisms, the proteins involved, and the current state of the field.
PMID: 37144853
Plant Physiol , IF:8.34 , 2023 May , V192 (2) : P1638-1655 doi: 10.1093/plphys/kiad182
The microRNA ppe-miR393 mediates auxin-induced peach fruit softening by promoting ethylene production.
College of Agriculture and Biotechnology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.; Ningbo Fenghua District Peach Research Institute, Ningbo 315502, China.; Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Institute of Pomology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.; Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.; State Agriculture Ministry Laboratory of Horticultural Plant Growth, Development and Quality Improvement, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.; Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
Auxin can inhibit or promote fruit ripening, depending on the species. Melting flesh (MF) peach fruit (Prunus persica L. Batsch) cultivars produce high levels of ethylene caused by high concentrations of indole-3-acetic acid (IAA), which leads to rapid fruit softening at the late stage of development. In contrast, due to the low concentrations of IAA, the fruit of stony hard (SH) peach cultivars does not soften and produces little ethylene. Auxin seems necessary to trigger the biosynthesis of ethylene in peach fruit; however, the mechanism is not well understood. In this study, we identified miRNA gene family members ppe-miR393a and ppe-miR393b that are differentially expressed in SH and MF fruits. RNA ligase-mediated 5' rapid amplification of cDNA ends and transient transformation of Nicotiana benthamiana revealed TRANSPORT INHIBITOR RESPONSE 1 (PpTIR1), part of the auxin perception and response system, as a target of ppe-miR393a and b. Yeast 2-hybrid assay and bimolecular fluorescence complementation assay revealed that PpTIR1 physically interacts with an Aux/IAA protein PpIAA13. The results of yeast 1-hybrid assay, electrophoretic mobility shift assay, and dual-luciferase assay indicated that PpIAA13 could directly bind to and trans-activate the promoter of 1-aminocyclopropane-1-carboxylic acid synthase 1 (PpACS1), required for ethylene biosynthesis. Transient overexpression and suppression of ppe-miR393a and PpIAA13 in peach fruit induced and repressed the expression of PpACS1, confirming their regulatory role in ethylene synthesis. Gene expression analysis in developing MF and SH fruits, combined with postharvest alpha-naphthalene acetic acid (NAA) treatment, supports a role for a ppe-miR393-PpTIR1-PpIAA13-PpACS1 module in regulating auxin-related differences in ethylene production and softening extent in different types of peach.
PMID: 36943294
Plant Physiol , IF:8.34 , 2023 May , V192 (2) : P1449-1465 doi: 10.1093/plphys/kiad103
FAR-RED INSENSITIVE 219 and phytochrome B corepress shade avoidance via modulating nuclear speckle formation.
Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei 106, Taiwan.; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium.; Department of Life Science, College of Life Science, National Taiwan University, Taipei 106, Taiwan.; Master Program in Global Agriculture Technology and Genomic Science, National Taiwan University, Taipei 106, Taiwan.
Plants can sense the shade from neighboring plants by detecting a reduction of the red:far-red light (R:FR) ratio. Phytochrome B (phyB) is the primary photoreceptor that perceives shade light and regulates jasmonic acid (JA) signaling. However, the molecular mechanisms underlying phyB and JA signaling integration in shade responses remain largely unknown. Here, we show the interaction of phyB and FAR-RED INSENSITIVE 219 (FIN219)/JASMONATE RESISTANT1 (JAR1) in a functional demand manner in Arabidopsis (Arabidopsis thaliana) seedling development. Genetic evidence and interaction studies indicated that phyB and FIN219 synergistically and negatively regulate shade-induced hypocotyl elongation. Moreover, phyB interacted with various isoforms of FIN219 under high and low R:FR light. Methyl jasmonate (MeJA) treatment, FIN219 mutation, and PHYBOE digalactosyldiacylglycerol synthase1-1 (dgd1-1) plants, which show increased levels of JA, altered the patterns of phyB-associated nuclear speckles under the same conditions. Surprisingly, PHYBOE dgd1-1 showed a shorter hypocotyl phenotype than its parental mutants under shade conditions. Microarray assays using PHYBOE and PHYBOE fin219-2 indicated that PHYB overexpression substantially affects defense response-related genes under shade light and coregulates expression of auxin-responsive genes with FIN219. Thus, our findings reveal that phyB substantially crosstalks with JA signaling through FIN219 to modulate seedling development under shade light.
PMID: 36869668
Plant Physiol , IF:8.34 , 2023 May , V192 (2) : P1548-1568 doi: 10.1093/plphys/kiad129
MEDIATOR SUBUNIT17 is required for transcriptional optimization of root system architecture in Arabidopsis.
Plant Mediator Lab, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India.; Plant Transcription Regulation, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.; Plant Nutritional Lab, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India.; Molecular Regulation of Plant Development and Adaptation, Institute of Plant Biology, Biological Research Centre, Szeged 6728, Hungary.
Sucrose and auxin are well-known determinants of root system architecture (RSA). However, the factors that connect the signaling pathways evoked by these two critical factors during root development are poorly understood. In this study, we report the role of MEDIATOR SUBUNIT17 (MED17) in RSA and its involvement in the transcriptional integration of sugar and auxin signaling pathways in Arabidopsis (Arabidopsis thaliana). Sucrose regulates root meristem activation through the TARGET OF RAPAMYCIN-E2 PROMOTER BINDING FACTOR A (TOR-E2FA) pathway, and auxin regulates lateral root (LR) development through AUXIN RESPONSE FACTOR-LATERAL ORGAN BOUNDARIES DOMAIN (ARF-LBDs). Both sucrose and auxin play a vital role during primary and LR development. However, there is no clarity on how sucrose is involved in the ARF-dependent regulation of auxin-responsive genes. This study establishes MED17 as a nodal point to connect sucrose and auxin signaling. Transcription of MED17 was induced by sucrose in an E2FA/B-dependent manner. Moreover, E2FA/B interacted with MED17, which can aid in the recruitment of the Mediator complex on the target promoters. Interestingly, E2FA/B and MED17 also occupied the promoter of ARF7, but not ARF19, leading to ARF7 expression, which then activates auxin signaling and thus initiates LR development. MED17 also activated cell division in the root meristem by occupying the promoters of cell-cycle genes, thus regulating their transcription. Thus, MED17 plays an important role in relaying the transcriptional signal from sucrose to auxin-responsive and cell-cycle genes to regulate primary and lateral root development, highlighting the role of the Mediator as the transcriptional processor for optimal root system architecture in Arabidopsis.
PMID: 36852886
Plant Physiol , IF:8.34 , 2023 May , V192 (1) : P28-30 doi: 10.1093/plphys/kiad101
To grow up or not: SUMOylation of IAA7 acts as a key molecular switch of auxin signaling.
School of Biological Sciences, The University of Hong Kong, 999077 Hong Kong, China.; State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, 999077 Hong Kong, China.
PMID: 36797804
Plant Physiol , IF:8.34 , 2023 May , V192 (1) : P25-27 doi: 10.1093/plphys/kiad086
Wheat AUXIN RESPONSE FACTOR 15 delays senescence through interaction at the TaNAM1 locus.
Department of Plant Biology and Genome Center, University of California Davis, Davis, CA 95616, USA.
PMID: 36788762
Plant Physiol , IF:8.34 , 2023 May , V192 (1) : P256-273 doi: 10.1093/plphys/kiad073
Dynamic GOLVEN-ROOT GROWTH FACTOR 1 INSENSITIVE signaling in the root cap mediates root gravitropism.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, B-9052 Ghent, Belgium.; VIB-UGent Center for Plant Systems Biology, Technologiepark 71, B-9052 Ghent, Belgium.
Throughout the exploration of the soil, roots interact with their environment and adapt to different conditions. Directional root growth is guided by asymmetric molecular patterns but how these become established or are dynamically regulated is poorly understood. Asymmetric gradients of the phytohormone auxin are established during root gravitropism, mainly through directional transport mediated by polarized auxin transporters. Upon gravistimulation, PIN-FORMED2 (PIN2) is differentially distributed and accumulates at the lower root side to facilitate asymmetric auxin transport up to the elongation zone where it inhibits cell elongation. GOLVEN (GLV) peptides function in gravitropism by affecting PIN2 abundance in epidermal cells. In addition, GLV signaling through ROOT GROWTH FACTOR 1 INSENSITIVE (RGI) receptors regulates root apical meristem maintenance. Here, we show that GLV-RGI signaling in these 2 processes in Arabidopsis (Arabidopsis thaliana) can be mapped to different cells in the root tip and that, in the case of gravitropism, it operates mainly in the lateral root cap (LRC) to maintain PIN2 levels at the plasma membrane (PM). Furthermore, we found that GLV signaling upregulates the phosphorylation level of PIN2 in an RGI-dependent manner. In addition, we demonstrated that the RGI5 receptor is asymmetrically distributed in the LRC and accumulates in the lower side of the LRC after gravistimulation. Asymmetric GLV-RGI signaling in the root cap likely accounts for differential PIN2 abundance at the PM to temporarily support auxin transport up to the elongation zone, thereby representing an additional level of control on the asymmetrical auxin flux to mediate differential growth of the root.
PMID: 36747317
Plant Physiol , IF:8.34 , 2023 May , V192 (2) : P1268-1288 doi: 10.1093/plphys/kiad038
Causes and consequences of endogenous hypoxia on growth and metabolism of developing maize kernels.
Molecular Genetics Department, Leibniz-Institut fur Pflanzengenetik und Kulturpflanzenforschung, Corrensstrasse, 06466 Seeland-Gatersleben, Germany.; University of Florida, Horticultural Sciences Department, Fifield Hall, 2550 Hull Rd., PO Box 110690, Gainesville, Florida, 32611, USA.; Biosystems Department, KU Leuven-University of Leuven, BIOSYST-MeBioS, Willem de Croylaan 42, B-3001 Leuven, Belgium.
Maize (Zea mays) kernels are the largest cereal grains, and their endosperm is severely oxygen deficient during grain fill. The causes, dynamics, and mechanisms of acclimation to hypoxia are minimally understood. Here, we demonstrate that hypoxia develops in the small, growing endosperm, but not the nucellus, and becomes the standard state, regardless of diverse structural and genetic perturbations in modern maize (B73, popcorn, sweet corn), mutants (sweet4c, glossy6, waxy), and non-domesticated wild relatives (teosintes and Tripsacum species). We also uncovered an interconnected void space at the chalazal pericarp, providing superior oxygen supply to the placental tissues and basal endosperm transfer layer. Modeling indicated a very high diffusion resistance inside the endosperm, which, together with internal oxygen consumption, could generate steep oxygen gradients at the endosperm surface. Manipulation of oxygen supply induced reciprocal shifts in gene expression implicated in controlling mitochondrial functions (23.6 kDa Heat-Shock Protein, Voltage-Dependent Anion Channel 2) and multiple signaling pathways (core hypoxia genes, cyclic nucleotide metabolism, ethylene synthesis). Metabolite profiling revealed oxygen-dependent shifts in mitochondrial pathways, ascorbate metabolism, starch synthesis, and auxin degradation. Long-term elevated oxygen supply enhanced the rate of kernel development. Altogether, evidence here supports a mechanistic framework for the establishment of and acclimation to hypoxia in the maize endosperm.
PMID: 36691698
Plant Physiol , IF:8.34 , 2023 May , V192 (2) : P1420-1434 doi: 10.1093/plphys/kiad034
Auxin-independent effects of apical dominance induce changes in phytohormones correlated with bud outgrowth.
ARC Centre of Excellence for Plant Success in Nature and Agriculture, School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.; School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
The inhibition of shoot branching by the growing shoot tip of plants, termed apical dominance, was originally thought to be mediated by auxin. Recently, the importance of the shoot tip sink strength during apical dominance has re-emerged with recent studies highlighting roles for sugars in promoting branching. This raises many unanswered questions on the relative roles of auxin and sugars in apical dominance. Here we show that auxin depletion after decapitation is not always the initial trigger of rapid cytokinin (CK) increases in buds that are instead correlated with enhanced sugars. Auxin may also act through strigolactones (SLs) which have been shown to suppress branching after decapitation, but here we show that SLs do not have a significant effect on initial bud outgrowth after decapitation. We report here that when sucrose or CK is abundant, SLs are less inhibitory during the bud release stage compared to during later stages and that SL treatment rapidly inhibits CK accumulation in pea (Pisum sativum) axillary buds of intact plants. After initial bud release, we find an important role of gibberellin (GA) in promoting sustained bud growth downstream of auxin. We are, therefore, able to suggest a model of apical dominance that integrates auxin, sucrose, SLs, CKs, and GAs and describes differences in signalling across stages of bud release to sustained growth.
PMID: 36690819
Plant Physiol , IF:8.34 , 2023 May , V192 (1) : P582-600 doi: 10.1093/plphys/kiac581
The Mediator complex subunit MED25 interacts with HDA9 and PIF4 to regulate thermomorphogenesis.
Laboratory of Plant Physiology, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.; Temasek Life Science Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore.; Plant Stress Resilience, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.; Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Trisaia Research Centre, S.S. Ionica, km 419.5, 75026 Rotondella (Matera), Italy.
Thermomorphogenesis is, among other traits, characterized by enhanced hypocotyl elongation due to the induction of auxin biosynthesis genes like YUCCA8 by transcription factors, most notably PHYTOCHROME INTERACTING FACTOR 4 (PIF4). Efficient binding of PIF4 to the YUCCA8 locus under warmth depends on HISTONE DEACETYLASE 9 (HDA9) activity, which mediates histone H2A.Z depletion at the YUCCA8 locus. However, HDA9 lacks intrinsic DNA-binding capacity, and how HDA9 is recruited to YUCCA8, and possibly other PIF4-target sites, is currently not well understood. The Mediator complex functions as a bridge between transcription factors bound to specific promoter sequences and the basal transcription machinery containing RNA polymerase II. Mutants of Mediator component Mediator25 (MED25) exhibit reduced hypocotyl elongation and reduced expression of YUCCA8 at 27 degrees C. In line with a proposed role for MED25 in thermomorphogenesis in Arabidopsis (Arabidopsis thaliana), we demonstrated an enhanced association of MED25 to the YUCCA8 locus under warmth and interaction of MED25 with both PIF4 and HDA9. Genetic analysis confirmed that MED25 and HDA9 operate in the same pathway. Intriguingly, we also showed that MED25 destabilizes HDA9 protein. Based on our findings, we propose that MED25 recruits HDA9 to the YUCCA8 locus by binding to both PIF4 and HDA9.
PMID: 36537119
PLoS Biol , IF:8.029 , 2023 Jun , V21 (6) : Pe3002163 doi: 10.1371/journal.pbio.3002163
Clade-D auxin response factors regulate auxin signaling and development in the moss Physcomitrium patens.
Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, San Diego, California, United States of America.
Auxin response factors (ARFs) are a family of transcription factors that are responsible for regulating gene expression in response to changes in auxin level. The analysis of ARF sequence and activity indicates that there are 2 major groups: activators and repressors. One clade of ARFs, clade-D, is sister to clade-A activating ARFs, but are unique in that they lack a DNA-binding domain. Clade-D ARFs are present in lycophytes and bryophytes but absent in other plant lineages. The transcriptional activity of clade-D ARFs, as well as how they regulate gene expression, is not well understood. Here, we report that clade-D ARFs are transcriptional activators in the model bryophyte Physcomitrium patens and have a major role in the development of this species. Deltaarfddub protonemata exhibit a delay in filament branching, as well as a delay in the chloronema to caulonema transition. Additionally, leafy gametophore development in Deltaarfddub lines lags behind wild type. We present evidence that ARFd1 interacts with activating ARFs via their PB1 domains, but not with repressing ARFs. Based on these results, we propose a model in which clade-D ARFs enhance gene expression by interacting with DNA bound clade-A ARFs. Further, we show that ARFd1 must form oligomers for full activity.
PMID: 37315060
Curr Opin Plant Biol , IF:7.834 , 2023 Jun , V75 : P102405 doi: 10.1016/j.pbi.2023.102405
Turning up the volume: How root branching adaptive responses aid water foraging.
Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, UK. Electronic address: p.mehra@nottingham.ac.uk.; Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, UK.; Plant and Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, UK. Electronic address: malcolm.bennett@nottingham.ac.uk.
Access to water is critical for all forms of life. Plants primarily access water through their roots. Root traits such as branching are highly sensitive to water availability, enabling plants to adapt their root architecture to match soil moisture distribution. Lateral root adaptive responses hydropatterning and xerobranching ensure new branches only form when roots are in direct contact with moist soil. Root traits are also strongly influenced by atmospheric humidity, where a rapid drop leads to a promotion of root growth and branching. The plant hormones auxin and/or abscisic acid (ABA) play key roles in regulating these adaptive responses. We discuss how these signals are part of a novel "water-sensing" mechanism that couples hormone movement with hydrodynamics to orchestrate root branching responses.
PMID: 37379661
Curr Opin Plant Biol , IF:7.834 , 2023 Jun , V75 : P102386 doi: 10.1016/j.pbi.2023.102386
Understanding signaling pathways governing the polar development of root hairs in low-temperature, nutrient-deficient environments.
Fundacion Instituto Leloir and IIBBA-CONICET. Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina; ANID - Millennium Science Initiative Program - Millennium Nucleus for the DeveIopment of Super Adaptable Plants (MN-SAP), Santiago 8370146, Chile.; ANID - Millennium Science Initiative Program - Millennium Nucleus for the DeveIopment of Super Adaptable Plants (MN-SAP), Santiago 8370146, Chile; ANID - Millennium Science Initiative Program - Millennium Institute for Integrative Biology (iBio), Santiago 8331150, Chile; Centro de Biotecnologia Vegetal (CBV), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370146, Chile.; ANID - Millennium Science Initiative Program - Millennium Nucleus for the DeveIopment of Super Adaptable Plants (MN-SAP), Santiago 8370146, Chile; Centro de Biotecnologia Vegetal (CBV), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370146, Chile.; Fundacion Instituto Leloir and IIBBA-CONICET. Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina; ANID - Millennium Science Initiative Program - Millennium Nucleus for the DeveIopment of Super Adaptable Plants (MN-SAP), Santiago 8370146, Chile; ANID - Millennium Science Initiative Program - Millennium Institute for Integrative Biology (iBio), Santiago 8331150, Chile; Centro de Biotecnologia Vegetal (CBV), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370146, Chile. Electronic address: jestevez@leloir.org.ar.
Plants exposed to freezing and above-freezing low temperatures must employ a variety of strategies to minimize fitness loss. There is a considerable knowledge gap regarding how mild low temperatures (around 10 degrees C) affect plant growth and developmental processes, even though the majority of the molecular mechanisms that plants use to adapt to extremely low temperatures are well understood. Root hairs (RH) have become a useful model system for studying how plants regulate their growth in response to both cell-intrinsic cues and environmental inputs. Here, we'll focus on recent advances in the molecular mechanisms underpinning Arabidopsis thaliana RH growth at mild low temperatures and how these discoveries may influence our understanding of nutrient sensing mechanisms by the roots. This highlights how intricately linked mechanisms are necessary for plant development to take place under specific circumstances and to produce a coherent response, even at the level of a single RH cell.
PMID: 37352652
Curr Opin Plant Biol , IF:7.834 , 2023 May , V74 : P102377 doi: 10.1016/j.pbi.2023.102377
How do plants reprogramme the fate of differentiated cells?
RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan. Electronic address: hatsune.morinaka@riken.jp.; RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033, Japan.; RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan; Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology (PRESTO), 7, Gobancho, Chiyoda-ku, Tokyo, 102-0076, Japan.; RIKEN Center for Sustainable Resource Science, 1-7-22 Suehirocho, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-0033, Japan. Electronic address: keiko.sugimoto@riken.jp.
Being able to change cell fate after differentiation highlights the remarkable developmental plasticity of plant cells. Recent studies show that phytohormones, such as auxin and cytokinin, promote cell cycle reactivation, a critical first step to reprogramme mitotically inactive, differentiated cells into organogenic stem cells. Accumulating evidence suggests that wounding provides an additional cue to convert the identity of differentiated cells by promoting the loss of existing cell fate and/or acquisition of new cell fate. Differentiated cells can also alter cell fate without undergoing cell division and in this case, wounding and phytohormones induce master regulators that can directly assign new cell fate.
PMID: 37167921
Curr Opin Plant Biol , IF:7.834 , 2023 Jun , V73 : P102336 doi: 10.1016/j.pbi.2023.102336
Compounds from rhizosphere microbes that promote plant growth.
Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo. Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico.; Facultad de Quimico Farmacobiologia, Universidad Michoacana de San Nicolas de Hidalgo, C. P. 58240, Morelia, Michoacan, Mexico.; Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo. Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico. Electronic address: jbucio@umich.mx.
The rhizosphere is the soil-plant interface colonized by bacterial and fungal species that exert growth-promoting and adaptive benefits. The plant-bacteria relationships rely upon the perception of volatile organic compounds (VOCs), canonical phytohormones such as auxins and cytokinins, and the bacterial quorum sensing-related N-acyl-L-homoserine lactones and cyclodipeptides. On the other hand, plant-beneficial Trichoderma fungi emit highly active VOCs, including 6-pentyl-2H-pyran-2-one (6-PP), and beta-caryophyllene, which contribute to plant morphogenesis, but also into how these microbes spread over roots or live as endophytes. Here, we describe recent findings concerning how compounds from beneficial bacteria and fungi affect root architecture and advance into the signaling events that mediate microbial recognition.
PMID: 36716513
Food Chem , IF:7.514 , 2023 May , V408 : P135215 doi: 10.1016/j.foodchem.2022.135215
A multiomics integrative analysis of color de-synchronization with softening of 'Hass' avocado fruit: A first insight into a complex physiological disorder.
Escuela de Agronomia, Facultad de Ciencias Agronomicas y de los Alimentos, Pontificia Universidad Catolica de Valparaiso, Quillota, Chile.; KU Leuven, Facility for Systems Biology based Mass Spectrometry SYBIOMA, Leuven, Belgium; Biodiversity International, Biodiversity for Food and Agriculture, Leuven, Belgium.; Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Granada, Spain.; Universidad Nacional Agraria La Molina, Instituto de Biotecnologia, Lima, Peru.; Centro de Estudios Postcosecha, Facultad de Ciencias Agronomicas, Universidad de Chile, Santiago, Chile.; Departamento de Fruticultura y Enologia, Facultad de Agronomia e Ingenieria Forestal, Pontificia Universidad Catolica de Chile, Santiago, Chile; Departamento de Genetica Molecular y Microbiologia, Facultad de Ciencias Biologicas, Pontificia Universidad Catolica de Chile, Santiago, Chile; ANID-Millennium Science Initiative Program - Millennium Nucleus for the Development of Super Adaptable Plants (MN-SAP), Santiago, Chile; Millennium Institute Center for Genome Regulation (CRG), Santiago, Chile. Electronic address: claudio.meneses@uc.cl.; Escuela de Agronomia, Facultad de Ciencias Agronomicas y de los Alimentos, Pontificia Universidad Catolica de Valparaiso, Quillota, Chile; Millennium Institute Center for Genome Regulation (CRG), Santiago, Chile. Electronic address: romina.pedreschi@pucv.cl.
Exocarp color de-synchronization with softening of 'Hass' avocado is a relevant recurrent problem for the avocado supply chain. This study aimed to unravel the mechanisms driving this de-synchronization integrating omics datasets from avocado exocarp of different storage conditions and color phenotypes. In addition, we propose potential biomarkers to predict color synchronized/de-synchronized fruit. Integration of transcriptomics, proteomics and metabolomics and network analysis revealed eight transcription factors associated with differentially regulated genes between regular air (RA) and controlled atmosphere (CA) and twelve transcription factors related to avocado fruit color de-synchronization control in ready-to-eat stage. CA was positively correlated to auxins, ethylene, cytokinins and brassinosteroids-related genes, while RA was characterized by enrichment of cell wall remodeling and abscisic acid content associated genes. At ready-to-eat higher contents of flavonoids, abscisic acid and brassinosteroids were associated with color-softening synchronized avocados. In contrast, de-synchronized fruit revealed increases of jasmonic acid, salicylic acid and auxin levels.
PMID: 36528992
Plant Cell Environ , IF:7.228 , 2023 Jun doi: 10.1111/pce.14645
Genetic control underlying the flowering-drought tolerance trade-off in the Antarctic plant Colobanthus quitensis.
Centro de Ecologia Integrativa, Instituto de Ciencias Biologicas, Universidad de Talca, Talca, Chile.; Instituto de Investigaciones Interdisciplinarias (I3), Universidad de Talca, Talca, Chile.; Departamento de Ciencias Naturales, Laboratorio de Genomica y Biodiversidad (LGB), Universidad del Bio-Bio, Chillan, Chile.; IFEVA (CONICET-Facultad de Agronomia, Universidad de Buenos Aires), Buenos Aires, Argentina.; Centro de Investigacion en Estudios Avanzados del Maule (CIEAM), Universidad Catolica del Maule, Talca, Chile.
Plants inhabiting environments with stressful conditions often exhibit a low number of flowers, which can be attributed to the energetic cost associated with reproduction. One of the most stressful environments for plants is the Antarctic continent, characterized by limited soil water availability and low temperatures. Induction of dehydrins like those from the COR gene family and auxin transcriptional response repressor genes (IAAs), which are involved in floral repression, has been described in response to water stress. Here, we investigated the relationship between the water deficit-induced stress response and the number of flowers in Colobanthus quitensis plants collected from populations along a latitudinal gradient. The expression levels of COR47 and IAA12 genes in response to water deficit were found to be associated with the number of flowers. The relationship was observed both in the field and growth chambers. Watering the plants in the growth chambers alleviated the stress and stimualted flowering, thereby eliminating the trade-off observed in the field. Our study provides a mechanistic understanding of the ecological constraints on plant reproduction along a water availability gradient. However, further experiments are needed to elucidate the primary role of water availability in regulating resource allocation to reproduction in plants inhibiting extreme environments.
PMID: 37309267
Plant Cell Environ , IF:7.228 , 2023 Jun , V46 (6) : P1921-1934 doi: 10.1111/pce.14580
SlIAA23-SlARF6 module controls arbuscular mycorrhizal symbiosis by regulating strigolactone biosynthesis in tomato.
Department of Horticulture, Zijingang Campus, Zhejiang University, Hangzhou, China.; Hainan Institute, Zhejiang University, Sanya, China.; Key Laboratory of Horticultural Plants Growth and Development, Agricultural Ministry of China, Hangzhou, China.
Auxins are a class of phytohormones with roles involved in the establishment and maintenance of the arbuscular mycorrhizal symbiosis (AMS). Auxin response factors (ARFs) and Auxin/Indole-acetic acids (AUX/IAAs), as two transcription factors of the auxin signaling pathway, coregulate the transcription of auxin response genes. However, the interrelation and regulatory mechanism of ARFs and AUX/IAAs in regulating AMS are still unclear. In this study, we found that the content of auxin in tomato roots increased sharply and revealed the importance of the auxin signaling pathway in the early stage of AMS. Notably, SlARF6 was found to play a negative role in AMF colonization. Silencing SlARF6 significantly increased the expression of AM-marker genes, as well as AMF-induced phosphorus uptake. SlIAA23 could interact with SlARF6 in vivo and in vitro, and promoted the AMS and phosphorus uptake. Interestingly, SlARF6 and SlIAA23 played a contrary role in strigolactone (SL) synthesis and accumulation in AMF-colonized roots of tomato plants. SlARF6 could directly bind to the AuxRE motif of the SlCCD8 promoter and inhibited its transcription, however, this effect was attenuated by SlIAA23 through interaction with SlARF6. Our results suggest that SlIAA23-SlARF6 coregulated tomato-AMS via an SL-dependent pathway, thus affecting phosphorus uptake in tomato plants.
PMID: 36891914
Plant Cell Environ , IF:7.228 , 2023 May , V46 (5) : P1562-1581 doi: 10.1111/pce.14548
Low light stress promotes new tiller regeneration by changing source-sink relationship and activating expression of expansin genes in wheat.
Key Laboratory of Agricultural Water Resources, Hebei Laboratory of Agricultural Water-Saving, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China.; Jilin Da'an Agro-ecosystem National Observation Research Station, Changchun Jingyuetan Remote Sensing Experiment Station, State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China.
Low light stress seriously decreased wheat grain number through the formation of aborted spike during the reproductive period and induced new tiller regeneration to offset the loss of grain number. However, the mechanism by which plants coordinate spike aborted growth and the regeneration of new tillers remains unknown. To better understand this coordinated process, morphological, physiological and transcriptomic analyses were performed under low light stress at the young microspore stage. Our findings indicated that leaves exhausted most stored carbohydrates in 1 day of darkness. However, spike and uppermost internode (UI) were converted from sink to source, due to increased abscisic acid (ABA) content and decreased cytokinin content. During this process, genes encoding amylases, Sugars Will Eventually be Exported Transporters (SWEET) and sucrose transporters or sucrose carriers (SUT/SUC) were upregulated in spike and UI, which degraded starch into soluble sugars and loaded them into the phloem. Subsequently, soluble sugars were transported to tiller node (TN) where cytokinin and auxin content increased and ABA content decreased, followed by unloading into TN cells by upregulated cell wall invertase (CWINV) genes and highly expressed H(+) /hexose symporter genes. Finally, expansin genes integrated the sugar pathway and hormone pathway, and regulate the formation of new tillers directly.
PMID: 36695201
Chemosphere , IF:7.086 , 2023 Jun , V326 : P138394 doi: 10.1016/j.chemosphere.2023.138394
Waste valorization as low-cost media engineering for auxin production from the newly isolated Streptomyces rubrogriseus AW22: Model development.
Laboratory of Mycology, Biotechnology and Microbial Activity (LaMyBAM), Department of Applied Biology, Constantine 1 University, BP, 325, Ain El Bey, Constantine, 25017, Algeria. Electronic address: wiemalloun@gmail.com.; Biotechnology Laboratory, National Higher School of Biotechnology, Ali Mendjeli University City, BP E66, 25100, Constantine, Algeria. Electronic address: m.berkani@ensbiotech.edu.dz.; Pharmaceutical Research and Sustainable Development Laboratory (ReMeDD), Department of Pharmaceutical Engineering, Faculty of Process Engineering, Constantine 3 University, Constantine, 25000, Algeria.; 3BIO-BioMatter Unit, Ecole Polytechnique de Bruxelles, Universite Libre de Bruxelles (ULB), Avenue F.D. Roosevelt, 50-CP 165/61, 1050, Brussels, Belgium.; Laboratory of Mycology, Biotechnology and Microbial Activity (LaMyBAM), Department of Applied Biology, Constantine 1 University, BP, 325, Ain El Bey, Constantine, 25017, Algeria.; The University of Johannesburg, Department of Chemical Engineering, P.O. Box 17011, Doornfontein, 2088, South Africa. Electronic address: cmdanesh@gmail.com.; Biotechnology Laboratory, National Higher School of Biotechnology, Ali Mendjeli University City, BP E66, 25100, Constantine, Algeria; Research Center in Industrial Technologies CRTI, P.O. Box 64, Cheraga 16014, Algiers, Algeria.; Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.
Indole-3-acetic acid (IAA) represents a crucial phytohormone regulating specific tropic responses in plants and functions as a chemical signal between plant hosts and their symbionts. The Actinobacteria strain of AW22 with high IAA production ability was isolated in Algeria for the first time and was characterized as Streptomyces rubrogriseus through chemotaxonomic analysis and 16 S rDNA sequence alignment. The suitable medium for a maximum IAA yield was engineered in vitro and in silico using machine learning-assisted modeling. The primary low-cost feedstocks comprised various concentrations of spent coffee grounds (SCGs) and carob bean grounds (CBGs) extracts. Further, we combined the Box-Behnken design from response surface methodology (BBD-RSM) with artificial neural networks (ANNs) coupled with the genetic algorithm (GA). The critical process parameters screened via Plackett-Burman design (PBD) served as BBD and ANN-GA inputs, with IAA yield as the output variable. Analysis of the putative IAA using thin-layer chromatography (TLC) and (HPLC) revealed Rf values equal to 0.69 and a retention time of 3.711 min, equivalent to the authentic IAA. AW 22 achieved a maximum IAA yield of 188.290 +/- 0.38 mug/mL using the process parameters generated by the ANN-GA model, consisting of L-Trp, 0.6%; SCG, 30%; T degrees , 25.8 degrees C; and pH 9, after eight days of incubation. An R(2) of 99.98%, adding to an MSE of 1.86 x 10(-5) at 129 epochs, postulated higher reliability of ANN-GA-approach in predicting responses, compared with BBD-RSM modeling exhibiting an R(2) of 76.28%. The validation experiments resulted in a 4.55-fold and 4.46-fold increase in IAA secretion, corresponding to ANN-GA and BBD-RSM models, respectively, confirming the validity of both models.
PMID: 36925000
J Integr Plant Biol , IF:7.061 , 2023 Jun , V65 (6) : P1408-1422 doi: 10.1111/jipb.13460
ESCRT-III component OsSNF7.2 modulates leaf rolling by trafficking and endosomal degradation of auxin biosynthetic enzyme OsYUC8 in rice.
State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genetics and Physiology, Agricultural College of Yangzhou University, Yangzhou, 225009, China.
The endosomal sorting complex required for transport (ESCRT) is highly conserved in eukaryotic cells and plays an essential role in the biogenesis of multivesicular bodies and cargo degradation to the plant vacuole or lysosomes. Although ESCRT components affect a variety of plant growth and development processes, their impact on leaf development is rarely reported. Here, we found that OsSNF7.2, an ESCRT-III component, controls leaf rolling in rice (Oryza sativa). The Ossnf7.2 mutant rolled leaf 17 (rl17) has adaxially rolled leaves due to the decreased number and size of the bulliform cells. OsSNF7.2 is expressed ubiquitously in all tissues, and its protein is localized in the endosomal compartments. OsSNF7.2 homologs, including OsSNF7, OsSNF7.3, and OsSNF7.4, can physically interact with OsSNF7.2, but their single mutation did not result in leaf rolling. Other ESCRT complex subunits, namely OsVPS20, OsVPS24, and OsBRO1, also interact with OsSNF7.2. Further assays revealed that OsSNF7.2 interacts with OsYUC8 and aids its vacuolar degradation. Both Osyuc8 and rl17 Osyuc8 showed rolled leaves, indicating that OsYUC8 and OsSNF7.2 function in the same pathway, conferring leaf development. This study reveals a new biological function for the ESCRT-III components, and provides new insights into the molecular mechanisms underlying leaf rolling.
PMID: 36702785
J Exp Bot , IF:6.992 , 2023 Jun doi: 10.1093/jxb/erad238
Tomato miR156-targeted SlSBP15 represses shoot branching by modulating hormone dynamics and interacting with GOBLET and BRANCHED1b.
Laboratory of Molecular Genetics of Plant Development, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ), University of Sao Paulo (USP), Piracicaba, Sao Paulo, Brazil.; Plant Molecular Genetics Department, Centro Nacional de Biotecnologia-CSIC, Campus Universidad Autonoma de Madrid, Madrid, Spain.; Biosciences Institute, University of Sao Paulo (USP), Sao Paulo, Brazil.
The microRNA156 (miR156)/SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE (SPL/SBP) regulatory hub is highly conserved among phylogenetically distinct species, but how it interconnects multiple pathways to converge to common integrators controlling shoot architecture is still unclear. Here, we demonstrated that the miR156/SlSBP15 node modulates tomato shoot branching (SB) by connecting multiple phytohormones with classical genetic pathways regulating both axillary bud (AB) development and outgrowth. MiR156-overexpressing plants (156-OE) displayed high SB, whereas plants overexpressing a miR156-resistant SlSBP15 allele (rSBP15) showed arrested SB. Importantly, the rSBP15 allele was able to partially restore the wild-type SB phenotype in 156-OE background. rSBP15 plants have tiny ABs, and their activation is dependent on shoot apex-derived auxin transport inhibition. Hormonal measurements revealed that Indole-3-acetic acid (IAA) and abscisic acid (ABA) concentrations were lower in 156-OE and higher in rSBP15 ABs, respectively. Genetic and molecular data indicated that SlSBP15 regulates AB development and outgrowth by inhibiting auxin transport and GOBLET (GOB) activity, and by interacting with tomato BRANCHED1b (SlBRC1b) to control ABA levels within ABs. Collectively, our data provide a new mechanism by which the miR156/SPL/SBP hub regulates SB, and suggest that modulating SlSBP15 activity might have potential applications in shaping tomato shoot architecture.
PMID: 37347477
J Exp Bot , IF:6.992 , 2023 Jun doi: 10.1093/jxb/erad232
Hormonal control of the molecular networks guiding vascular tissue development in the primary root meristem of Arabidopsis thaliana.
Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9052 Ghent, Belgium.; VIB Centre for Plant Systems Biology, Technologiepark 71, 9052 Ghent, Belgium.; Current Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; and University of Chinese Academy of Sciences, Beijing, China.
Vascular tissues serve a dual function in plants providing both physical support as well as controlling the transport of nutrients, water, hormones and other small signaling molecules. Xylem tissues transport water from root to shoot; phloem tissues transfer photosynthates from shoot to root; while divisions of the (pro)cambium increase the number of xylem and phloem cells. Although vascular development constitutes a continuous process from primary growth in the early embryo and meristem regions to secondary growth in the mature plant organs, it can be artificially separated into distinct processes including cell type specification, proliferation, patterning and differentiation. In this review, we focus our attention to how hormonal signals orchestrate the molecular regulation of vascular development in the Arabidopsis thaliana primary root meristem. Although auxin and cytokinin have taken center stage in this aspect since their discovery, other hormones including brassinosteroids, abscisic acid and jasmonic acid are also taking up leading roles during vascular development. All these hormonal cues synergistically or antagonistically participate in the development of vascular tissues, forming a complex hormonal control network.
PMID: 37343122
J Exp Bot , IF:6.992 , 2023 Jun doi: 10.1093/jxb/erad213
Flowering also has to end: knowns and unknowns of reproductive arrest in monocarpic plants.
Instituto de Biologia Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientificas - Universidad Politecnica de Valencia, 46022. Valencia, Spain.
All flowering plants adjust their reproductive period for successful reproduction. Flowering initiation is controlled by a myriad of intensively studied factors, so it can occur in the most favorable conditions. But the end of flowering is also a controlled process, required to optimize the size of the offspring and to maximize resource allocation. Flowering arrest was described and mainly studied in the last century by physiological approaches, but it is much less understood at the genetic or molecular level. In this review, we present an overview of recent progress in this topic, fueled by highly complementary studies that are beginning to provide an integrated view of how the end of flowering is regulated. In this emerging picture, we also highlight key missing aspects that will guide future research and may provide new biotechnological avenues to improve crop yield in annual plants.
PMID: 37280109
J Exp Bot , IF:6.992 , 2023 Jun doi: 10.1093/jxb/erad192
Auxin transport at the ER: Roles and structural similarity of PIN-FORMED and PIN-LIKES.
Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark.; Plant Systems Biology, School of Life Sciences Weihenstephan, Technical University of Munich, 85354 Freising, Germany.; Institute of Biology II, Department of Molecular Plant Physiology (MoPP), University of Freiburg, 79104 Freiburg, Germany.; Center for Integrative Biological Signalling Studies (CIBSS), University of Freiburg, 79104 Freiburg, Germany.
Auxin is a crucial plant hormone that controls a multitude of developmental processes. The directional movement of auxin between cells is largely facilitated by the canonical PIN-FORMED (PIN) proteins in the plasma membrane. In contrast, noncanonical PIN and the PIN-LIKES (PILS) proteins appear to reside mainly in the endoplasmic reticulum (ER). Despite recent progress in identifying the roles of the ER in cellular auxin responses, the transport dynamics of auxin at the ER are not well understood. PILS are structurally related to PINs, and recently structures of PINs opened for new insights into PIN and PILS function. In this review, we summarize the current knowledge on PINs and PILS in intracellular auxin transport. We discuss the physiological properties of the ER and the consequences for transport processes across the ER membrane. Finally, we highlight the emerging role of the ER in the dynamics of cellular auxin signalling and its impact on plant development.
PMID: 37279330
J Exp Bot , IF:6.992 , 2023 May doi: 10.1093/jxb/erad185
PIN structures shed light on their mechanism of auxin efflux.
School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.; Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.
Polar auxin transport is a quintessential feature of higher plant physiology and it has been known for many years that some of the primary drivers of polar auxin transport are the PIN-formed (PIN) auxin efflux proteins. Formative research established many key biochemical features of the transport system and discovered inhibitors such as 1-naphtylphthalamic acid (NPA), but the mechanism of action of PINs has remained elusive. This changed in 2022 with the publication of high-resolution structures of the membrane-spanning domains of three PIN proteins. The atomic structures and associated activity assays reveal that PINs use an elevator mechanism to transport auxin anions out of the cell. NPA was shown to be a competitive inhibitor that traps PINs in their inward-open conformation. The secrets of the hydrophilic cytoplasmic loop of PIN proteins remain to be discovered.
PMID: 37195878
J Exp Bot , IF:6.992 , 2023 May doi: 10.1093/jxb/erad178
Deciphering transcriptional mechanisms of maize internodal elongation by regulatory network analysis.
State Key Laboratory of Plant Physiology and Biochemistry, Engineering Research Center of Plant Growth Regulator, Ministry of Education & College of Agronomy and Biotechnology, China Agricultural University, No.2 Yuanmingyuan West Road, Haidian, Beijing 100193, China.; North China Key Laboratory for Crop Germplasm Resources, Ministry of Education, State Key Laboratory of North China Crop Improvement and Regulation & College of Agronomy, Hebei Agricultural University, Baoding, Hebei 071001, China.; College of Plant Science and Technology, Beijing University of Agriculture, Beijing, 102206, China.
Basal internode length is important for lodging resistance of maize (Zea mays L.). In this study, foliar application of coronatine (COR) at the V8 stage differentially suppressed the length of the eighth internode of 10 cultivars, and three, five, and two cultivars were demonstrated to have strong (SC), moderate (MC), and weak (WC) degrees of internode shortening, respectively. RNA-Seq of the eighth internode of these cultivars revealed a total of 7895 internode elongation-regulating genes (IEGs, including 777 transcription factors (TFs)). Compared with those in WC, the hormone-related genes of cytokinin (CTK), gibberellin (GA), auxin and ethylene (ET) genes in SC were significantly downregulated, and more cell cycle regulatory factors and cell wall related genes showed significant changes, which severely inhibited internode elongation. Furthermore, we explored the direct regulatory relationship between two important TFs and target genes using EMSA, ZmABI7 and ZmMYB117, which regulate the cell cycle and cell wall modification by directly binding to the promoters of ZmCYC1, ZmCYC3, ZmCYC7, and ZmCPP1. The landscape transcriptome atlas reported herein provides a useful resource for studying maize internode development, which may provide a genetic basis for targeted control of internode length to improve lodging tolerance of maize.
PMID: 37170764
J Exp Bot , IF:6.992 , 2023 May doi: 10.1093/jxb/erad174
Auxin as an architect of the pectin matrix.
Umea Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), 90183, Umea, Sweden.; CRRBM, Universite de Picardie Jules Verne, 80000, Amiens, France.
Auxin is a versatile plant growth regulator that triggers multiple signalling pathways at different spatial and temporal resolutions. A plant cell is surrounded by the cell wall, a complex and dynamic network of polysaccharides. The cell wall needs to be rigid to provide mechanical support and protection and highly flexible to allow cell growth and shape acquisition. The modification of the pectin components, among other processes, is a mechanism by which auxin activity alters the mechanical properties of the cell wall. Auxin signalling precisely controls the transcriptional output of several pectin remodelling enzyme-encoded genes, their local activity and pectin deposition and modulation in different developmental contexts. This review examines the mechanism of auxin activity in regulating pectin chemistry at organ, cellular and subcellular levels across diverse plant species and asks questions that remain to be addressed to fully understand the interplay between auxin and pectin in plant growth and development.
PMID: 37166384
J Exp Bot , IF:6.992 , 2023 May doi: 10.1093/jxb/erad166
Loss of S-Nitrosoglutathione reductase disturbs phytohormone homeostasis and regulates shoot side branching and fruit growth in tomato.
Departamento de Botanica, Instituto de Biociencias, Universidade de Sao Paulo, 05508-900, Sao Paulo, SP, Brazil.; Departamento de Biologia Vegetal, Universidade Federal de Vicosa, 36570-900, Vicosa, MG, Brazil.; Departamento de Genetica e Biologia Evolutiva, Instituto de Biociencias, Universidade de Sao Paulo, 05508-900, Sao Paulo, SP, Brazil.; Department of Biochemistry, Cell and Molecular Biology of Plants, Estacion Experimental del Zaidin, Spanish National Research Council (CSIC), Granada, Spain.; Departamento de Ciencias Biologicas, Escola Superior de Agricultura Luiz de Queiroz, Universidade de Sao Paulo, 13418-900, Piracicaba, SP, Brazil.
S-nitrosoglutathione (GSNO) plays a central role in nitric oxide (NO) homeostasis, and GSNO reductase (GSNOR) regulates the cellular levels of GSNO across kingdoms. Here, we investigated the role of endogenous NO in shaping shoot architecture and controlling fruit set and growth in tomato (Solanum lycopersicum). SlGSNOR silencing promoted shoot side branching and led to reduced fruit size, negatively impacting fruit yield. Greatly intensified in slgsnor knockout plants, these phenotypical changes were virtually unaffected by SlGSNOR overexpression. SlGSNOR silencing or knockout intensified protein tyrosine nitration and S-nitrosation and led to aberrant auxin production and signaling in leaf primordia and fruit-setting ovaries, besides restricting the shoot basipetal polar auxin transport stream. SlGSNOR deficiency triggered extensive transcriptional reprogramming at early fruit development, reducing pericarp cell proliferation due to restrictions on auxin, gibberellin and cytokinin production and signaling. Abnormal chloroplast development and carbon metabolism were also detected in early-developing NO-overaccumulating fruits, possibly limiting energy supply and building blocks for fruit growth. These findings provide new insights into the mechanisms by which endogenous NO fine-tunes the delicate hormonal network controlling shoot architecture, fruit set and post-anthesis fruit development, emphasizing the relevance of NO-auxin interaction for plant development and productivity.
PMID: 37157899
J Exp Bot , IF:6.992 , 2023 May doi: 10.1093/jxb/erad168
"The phenomenon of autonomous endosperm in sexual and apomictic plants".
Department of Plant Cytology and Embryology, Faculty of Biology, University of Gdansk, Gdansk, Poland.; School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel.
Endosperm is a key nutritive tissue that supports the developing embryo or seedling, and serves as a major nutritional source for human and livestock feed. In sexual flowering plants, it generally develops after fertilization. However, autonomous endosperm (AE) formation (i.e., independently from fertilization) is also possible. Recent findings of AE loci/ genes and aberrant imprinting in native apomicts, together with a successful initiation of parthenogenesis in rice and lettuce, have enhanced our understanding of the mechanisms bridging sexual and apomictic seed formation. However, the mechanisms driving AE development are not well understood. This review presents novel aspects related to AE development in sexual and asexual plants underlying stress conditions as the primary trigger for AE. Both, application of hormones to unfertilized ovules and mutations that impair epigenetic regulation lead to AE development in sexual Arabidopsis thaliana, which may point to a common pathway for both phenomena. Apomictic-like AE development under experimental conditions can take place due to auxin-dependent gene expression and/or DNA methylation.
PMID: 37155961
J Exp Bot , IF:6.992 , 2023 May doi: 10.1093/jxb/erad163
Local phytochrome signalling limits root growth in light by repressing auxin biosynthesis.
Plant Developmental Genetics, Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE, Leiden, Netherlands.
In nature, plant shoots are exposed to light whereas the roots grow in relative darkness. Surprisingly, many root studies rely on in vitro systems that leave the roots exposed to light whilst ignoring the possible effects of this light on root development. Here, we investigated how direct root illumination affects root growth and development in Arabidopsis and tomato. Our results show that in light-grown Arabidopsis roots activation of local phytochrome A and B by far-red or red light inhibits respectively PHYTOCHROME INTERACTING FACTORs 1 or 4, resulting in decreased YUCCA4 and YUCCA6 expression. As a result, auxin levels in the root apex become suboptimal, ultimately resulting in reduced growth of light-grown roots. These findings highlight once more the importance of using in vitro systems where roots are grown in darkness, for studies that focus on root system architecture. Moreover, we show that the response and components of this mechanism are conserved in tomato roots, thus signifying its importance for horticulture as well. Our findings open up new research possibilities to investigate the importance of light-induced root growth inhibition for plant development, possibly by exploring putative correlations with responses to other abiotic signals, such as temperature, gravity, touch, or salt stress.
PMID: 37140032
J Exp Bot , IF:6.992 , 2023 Jun , V74 (12) : P3579-3594 doi: 10.1093/jxb/erad091
Cytokinin signaling promotes root hair growth by directly regulating RSL4 expression.
Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.; School of Biological Science and Technology, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan.; RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.; Department of Biological Sciences, The University of Tokyo, Tokyo, 119-0033, Japan.; RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Root hairs are single-celled tubular structures produced from the epidermis, which play an essential role in water and nutrient uptake from the soil. Therefore, root hair formation and elongation are controlled not only by developmental programs but also by environmental factors, enabling plants to survive under fluctuating conditions. Phytohormones are key signals that link environmental cues to developmental programs; indeed, root hair elongation is known to be controlled by auxin and ethylene. Another phytohormone, cytokinin, also affects root hair growth, while whether cytokinin is actively involved in root hair growth and, if so, how it regulates the signaling pathway governing root hair development have remained unknown. In this study, we show that the two-component system of cytokinin, which involves the B-type response regulators ARABIDOPSIS RESPONSE REGULATOR 1 (ARR1) and ARR12, promotes the elongation process of root hairs. They directly up-regulate ROOT HAIR DEFECTIVE 6-LIKE 4 (RSL4) encoding a basic helix-loop-helix (bHLH) transcription factor that plays a central role in root hair growth, whereas the ARR1/12-RSL4 pathway does not crosstalk with auxin or ethylene signaling. These results indicate that cytokinin signaling constitutes another input onto the regulatory module governed by RSL4, making it possible to fine-tune root hair growth in changing environments.
PMID: 36912789
J Exp Bot , IF:6.992 , 2023 May , V74 (10) : P3122-3141 doi: 10.1093/jxb/erad094
Maize WRKY28 interacts with the DELLA protein D8 to affect skotomorphogenesis and participates in the regulation of shade avoidance and plant architecture.
State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China.; Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100193, China.
Competition for light from neighboring vegetation can trigger the shade-avoidance response (SAR) in plants, which is detrimental to their yield. The molecular mechanisms regulating SAR are well established in Arabidopsis, and some regulators of skotomorphogenesis have been found to be involved in the regulation of the SAR and plant architecture. However, the role of WRKY transcription factors in this process has rarely been reported, especially in maize (Zea mays). Here, we report that maize Zmwrky28 mutants exhibit shorter mesocotyls in etiolated seedlings. Molecular and biochemical analyses demonstrate that ZmWRKY28 directly binds to the promoter regions of the Small Auxin Up RNA (SAUR) gene ZmSAUR54 and the Phytochrome-Interacting Factor (PIF) gene ZmPIF4.1 to activate their expression. In addition, the maize DELLA protein Dwarf Plant8 (D8) interacts with ZmWRKY28 in the nucleus to inhibit its transcriptional activation activity. We also show that ZmWRKY28 participates in the regulation of the SAR, plant height, and leaf rolling and erectness in maize. Taken together, our results reveal that ZmWRKY28 is involved in GA-mediated skotomorphogenic development and can be used as a potential target to regulate SAR for breeding of high-density-tolerant cultivars.
PMID: 36884355
J Exp Bot , IF:6.992 , 2023 Jun , V74 (12) : P3560-3578 doi: 10.1093/jxb/erad088
LONG HYPOCOTYL IN FAR-RED 1 mediates a trade-off between growth and defence under shade in Arabidopsis.
Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore.; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
Plants respond to vegetative shade with developmental and physiological changes that are collectively known as shade avoidance syndrome (SAS). Although LONG HYPOCOTYL IN FAR-RED 1 (HFR1) is known to be a negative regulator of SAS by forming heterodimers with other basic helix-loop-helix (bHLH) transcription factors to inhibit them, its function in genome-wide transcriptional regulation has not been fully elucidated. Here, we performed RNA-sequencing analyses of Arabidopsis thaliana hfr1-5 mutant and HFR1 overexpression line [HFR1(DeltaN)-OE] to comprehensively identify HFR1-regulated genes at different time points of shade treatment. We found that HFR1 mediates the trade-off between shade-induced growth and shade-repressed defence, by regulating the expression of relevant genes in the shade. Genes involved in promoting growth, such as auxin biosynthesis, transport, signalling and response were induced by shade but suppressed by HFR1 under both short and long durations of shade. Likewise, most ethylene-related genes were shade-induced and HFR1-repressed. However, shade suppressed defence-related genes, while HFR1 induced their expression, especially under long durations of shade treatment. We demonstrated that HFR1 confers increased resistance to bacterial infection under shade.
PMID: 36882154
J Exp Bot , IF:6.992 , 2023 May , V74 (10) : P3047-3059 doi: 10.1093/jxb/erad058
The NIN-LIKE PROTEIN 7 transcription factor modulates auxin pathways to regulate root cap development in Arabidopsis.
Department of Botany and Plant Pathology and Center for Plant Biology, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA.
The root cap is a small tissue located at the tip of the root with critical functions for root growth. Present in nearly all vascular plants, the root cap protects the root meristem, influences soil penetration, and perceives and transmits environmental signals that are critical for root branching patterns. To perform these functions, the root cap must remain relatively stable in size and must integrate endogenous developmental pathways with environmental signals, yet the mechanism is not clear. We previously showed that low pH conditions altered root cap development, and these changes are mediated by the NIN LIKE PROTEIN 7 (NLP7) transcription factor, a master regulator of nitrate signaling. Here we show that in Arabidopsis NLP7 integrates nitrate signaling with auxin pathways to regulate root cap development. We found that low nitrate conditions promote aberrant release of root cap cells. Nitrate deficiency impacts auxin pathways in the last layer of the root cap, and this is mediated in part by NLP7. Mutations in NLP7 abolish the auxin minimum in the last layer of the root cap and alter root cap expression of the auxin carriers PIN-LIKES 3 (PILS3) and PIN-FORMED 7 (PIN7) as well as transcription factors that regulate PIN expression. Together, our data reveal NLP7 as a link between endogenous auxin pathways and nitrate signaling in the root cap.
PMID: 36787214
Int J Biol Macromol , IF:6.953 , 2023 May , V237 : P124061 doi: 10.1016/j.ijbiomac.2023.124061
Small Auxin Up RNA (SAUR) gene family identification and functional genes exploration during the floral organ and fruit developmental stages in pineapple (Ananas comosus L.) and its response to salinity and drought stresses.
College of Life Science, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; Guangxi Key Laboratory of Sugarcane Biology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Agriculture, Guangxi University, Nanning 530004, China.; Fishery Multiplication Management Station of Lijiang River Water Supply Hub Project, Guilin 541001, China.; College of Life Science, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Guangxi Key Laboratory of Sugarcane Biology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Agriculture, Guangxi University, Nanning 530004, China; Pingtan Science and Technology Research Institute of Fujian Agriculture and Forestry University, Pingtan 350400, China. Electronic address: yuanqin@fafu.edu.cn.; College of Life Science, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Guangxi Key Laboratory of Sugarcane Biology, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Agriculture, Guangxi University, Nanning 530004, China. Electronic address: xpniu0613@126.com.
In plants, sexual reproduction relies on the proper development of floral organs that facilitate the successful development of fruits and seeds. Auxin responsive small auxin-up RNA (SAUR) genes play essential roles in floral organ formation and fruit development. However, little is known about the role of SAUR genes in pineapple floral organ formation and fruit development as well as stress responses. In this study, based on genome information and transcriptome datasets, 52 AcoSAUR genes were identified and grouped into 12 groups. The gene structure analysis revealed that most AcoSAUR genes did not have introns, although auxin-acting elements were abundant in the promoter region of AcoSAUR members. The expression analysis across the multiple flower and fruit development stages revealed differential expression of AcoSAUR genes, indicating a tissue and stage-specific function of AcoSAURs. Correlation analysis and pairwise comparisons between gene expression and tissue specificity identified stamen-, petal-, ovule-, and fruit-specific AcoSAURs involved in pineapple floral organs (AcoSAUR4/5/15/17/19) and fruit development (AcoSAUR6/11/36/50). RT-qPCR analysis revealed that AcoSAUR12/24/50 played positive roles in response to the salinity and drought treatment. This work provides an abundant genomic resource for functional analysis of AcoSAUR genes during the pineapple floral organs and fruit development stages. It also highlights the role of auxin signaling involved in pineapple reproductive organ growth.
PMID: 36933586
Development , IF:6.868 , 2023 Jun doi: 10.1242/dev.201762
The Class VIII myosin ATM1 is required for root apical meristem function.
Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50014, USA.; Broad Institute, Cambridge, MA 04212, UK.
Myosins are evolutionarily conserved motor proteins that interact with actin filaments to regulate organelle transport, cytoplasmic streaming and cell growth. Plant-specific Class XI myosin proteins direct cell division and root organogenesis. However, the roles of plant-specific Class VIII myosin proteins in plant growth and development are less understood. Here, we investigated the function of an auxin-regulated Class VIII myosin, Arabidopsis thaliana Myosin 1 (ATM1), using genetics, transcriptomics, and live cell microscopy. ATM1 is associated with the plasma membrane and plasmodesmata within the root apical meristem (RAM). Loss of ATM1 function results in decreased RAM size and reduced cell proliferation in a sugar-dependent manner. Auxin signaling and transcriptional responses were dampened in atm1-1 roots. Complementation of atm1-1 with a tagged ATM1 driven under the native ATM1 promoter restored root growth and cell cycle progression. Genetic analyses of atm1-1 seedlings with gin2 (hexokinase) and target of rapamycin complex 1 (TORC1) overexpression lines indicate that ATM1 is downstream of TOR. Collectively, these results provide novel evidence that ATM1 functions to influence cell proliferation in primary roots in response to auxin and sugar cues.
PMID: 37306290
Development , IF:6.868 , 2023 May , V150 (9) doi: 10.1242/dev.201485
Microbial pattern recognition suppresses de novo organogenesis.
Department of Plant Pathology, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA 30602, USA.
De novo root regeneration (DNRR) is a developmental process that regenerates adventitious roots from wounded tissues. Phytohormone signaling pathways involved in microbial resistance are mobilized after cutting and influence de novo root regeneration. Microbes may positively or negatively influence the development and stress responses of a plant. However, most studies on the molecular mechanisms of de novo organogenesis are performed in aseptic conditions. Thus, the potential crosstalk between organ regeneration and biotic stresses is underexplored. Here, we report the development of a versatile experimental system to study the impact of microbes on DNRR. Using this system, we found that bacteria inhibited root regeneration by activation of, but not limited to, pathogen-associated molecular pattern (PAMP)-triggered immunity. Sensing bacteria-derived flagellin 22 peptide (flg22) inhibited root regeneration by interfering with the formation of an auxin maximum at the wound site. This inhibition relies on the receptor complex that recognizes microbial patterns but may bypass the requirement of salicylic acid signaling.
PMID: 37073949
Development , IF:6.868 , 2023 May , V150 (9) doi: 10.1242/dev.201635
A cornichon protein controls polar localization of the PINA auxin transporter in Physcomitrium patens.
Departamento de Biologia Molecular de Plantas, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico, Av. Universidad 2001, Cuernavaca, Morelos 62210, Mexico.; Department of Biological Sciences, Dartmouth, Hanover, NH 03755, USA.
Newly synthesized membrane proteins pass through the secretory pathway, starting at the endoplasmic reticulum and packaged into COPII vesicles, to continue to the Golgi apparatus before reaching their membrane of residence. It is known that cargo receptor proteins form part of the COPII complex and play a role in the recruitment of cargo proteins for their subsequent transport through the secretory pathway. The role of cornichon proteins is conserved from yeast to vertebrates, but it is poorly characterized in plants. Here, we studied the role of the two cornichon homologs in the secretory pathway of the moss Physcomitrium patens. Mutant analyses revealed that cornichon genes regulate different growth processes during the moss life cycle by controlling auxin transport, with CNIH2 functioning as a specific cargo receptor for the auxin efflux carrier PINA, with the C terminus of the receptor regulating the interaction, trafficking and membrane localization of PINA.
PMID: 37052186
Hortic Res , IF:6.793 , 2023 Jun , V10 (6) : Puhad095 doi: 10.1093/hr/uhad095
Al-induced CsUGT84J2 enhances flavonol and auxin accumulation to promote root growth in tea plants.
State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui, China.; School of Life Science, Anhui Agricultural University, Hefei, Anhui, China.
Although Al is not necessary or even toxic to most plants, it is beneficial for the growth of tea plants. However, the mechanism through which Al promotes root growth in tea plants remains unclear. In the present study, we found that flavonol glycoside levels in tea roots increased following Al treatment, and the Al-induced UDP glycosyltransferase CsUGT84J2 was involved in this mechanism. Enzyme activity assays revealed that rCsUGT84J2 exhibited catalytic activity on multiple types of substrates, including phenolic acids, flavonols, and auxins in vitro. Furthermore, metabolic analysis with UPLC-QqQ-MS/MS revealed significantly increased flavonol and auxin glycoside accumulation in CsUGT84J2-overexpressing Arabidopsis thaliana. In addition, the expression of genes involved in the flavonol pathway as well as in the auxin metabolism, transport, and signaling pathways was remarkably enhanced. Additionally, lateral root growth and exogenous Al stress tolerance were significantly improved in transgenic A. thaliana. Moreover, gene expression and metabolic accumulation related to phenolic acids, flavonols, and auxin were upregulated in CsUGT84J2-overexpressing tea plants but downregulated in CsUGT84J2-silenced tea plants. In conclusion, Al treatment induced CsUGT84J2 expression, mediated flavonol and auxin glycosylation, and regulated endogenous auxin homeostasis in tea roots, thereby promoting the growth of tea plants. Our findings lay the foundation for studying the precise mechanisms through which Al promotes the growth of tea plants.
PMID: 37350798
J Environ Manage , IF:6.789 , 2023 Jul , V337 : P117723 doi: 10.1016/j.jenvman.2023.117723
Integrated biochemical and transcriptomic analysis reveals the effects of Burkholderia sp. SRB-1 on cadmium accumulating in Chrysopogon zizanioides L. under Cd stress.
Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China.; College of Pharmacy, Chengdu Medical College, Chengdu, Sichuan, China.; Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, China.; Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China; Key Laboratory of Environment Protection, Soil Ecological Protection and Pollution Control, Sichuan University & Department of Ecology and Environment of Sichuan, Chengdu, 610065, Sichuan, PR China. Electronic address: xuheng64@sina.com.
Application of plant growth-promoting rhizobacteria plays a vital role in enhancing phytoremediation efficiency. In this study, multiple approaches were employed to investigate the underlying mechanisms of Burkholderia sp. SRB-1 (SRB-1) on elevating Cd uptake and accumulation. Inoculation experiment indicated that SRB-1 could facilitate plant growth and Cd tolerance, as evidenced by the enhanced plant biomass and antioxidative enzymes activities. Cd content in plant shoots and roots increased about 36.56%-39.66% and 25.97%-130.47% assisted with SRB-1 when compared with control. Transcriptomics analysis revealed that SRB-1 upregulated expression of amiE, AAO1-2 and GA2-ox related to auxin and gibberellin biosynthesis in roots. Auxin and gibberellin, as hormone signals, regulated plant Cd tolerance and growth through activating hormone signal transduction pathways, which might also contribute to 67.94% increase of dry weight. The higher expression levels of ATP-binding cassette transporter subfamilies (ABCB, ABCC, ABCD and ABCG) in Chrysopogon zizanioides roots contributed to higher Cd uptake in Cd15 B (323.83 mg kg(-1)) than Cd15 (136.28 mg kg(-1)). Further, SRB-1 facilitated Cd migration from roots to shoots via upregulating the expression of Nramp, ZIP and HMA families. Our integrative analysis provided a molecular-scale perspective on Burkholderia sp. SRB-1 contributing to C. zizanioides performance.
PMID: 36958280
Cells , IF:6.6 , 2023 Jun , V12 (12) doi: 10.3390/cells12121613
Nitrate, Auxin and Cytokinin-A Trio to Tango.
School of Plant Sciences and Food Security, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel.; Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria.
Nitrogen is an important macronutrient required for plant growth and development, thus directly impacting agricultural productivity. In recent years, numerous studies have shown that nitrogen-driven growth depends on pathways that control nitrate/nitrogen homeostasis and hormonal networks that act both locally and systemically to coordinate growth and development of plant organs. In this review, we will focus on recent advances in understanding the role of the plant hormones auxin and cytokinin and their crosstalk in nitrate-regulated growth and discuss the significance of novel findings and possible missing links.
PMID: 37371083
Anal Chim Acta , IF:6.558 , 2023 May , V1256 : P341158 doi: 10.1016/j.aca.2023.341158
Vibration for enhancement of electrochemical analysis of biomolecules in a droplet on the rough surface of a disposable working electrode.
School of Public Health, Nantong University, 9 Seyuan Rd., Nantong, Jiangsu, 226019, China.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China. Electronic address: liuwu@cemps.ac.cn.; School of Public Health, Nantong University, 9 Seyuan Rd., Nantong, Jiangsu, 226019, China. Electronic address: zhugexk@ntu.edu.cn.; School of Public Health, Nantong University, 9 Seyuan Rd., Nantong, Jiangsu, 226019, China. Electronic address: hxl362349@ntu.edu.cn.; School of Public Health, Nantong University, 9 Seyuan Rd., Nantong, Jiangsu, 226019, China. Electronic address: ningbao@ntu.edu.cn.
Although electrochemical detection of microliters-level solutions is attractive for analysis of low-amount biological samples, its performance could be weakened by limited mass transfer due to low Reynolds number and laminar flow. Herein we designed a 3D-printed electroanalytical device to apply vibration for improvement of mass transfer during electrochemical detection. In our approach, the droplet-size sample solution containing Indole-3-acetic acid (IAA, as a model) was directly applied on the effective surface of a disposable working electrode. We demonstrated that vibration could enhance electrochemical responses of IAA more on the rough surface than on the smooth surface of the working electrodes. After optimization, the sensitivity for electrochemical detection of a 20-muL droplet under vibration with the voltage of 7 V increased more than 100% compared with the static condition. The enhanced electrochemical responses brought by vibration could be achieved reproducibly, which could be ascribed to improved mass transfer. Our strategy could be practically applied for differentiation of IAA in different tissues of Marchantia polymorpha with enhanced responses. This study suggested that vibration might become a simple and effective method to improve mass transfer in analysis of microliter-volume solutions, which might be extended for more biochemical assays.
PMID: 37037634
Ying Yong Sheng Tai Xue Bao , IF:6.528 , 2023 May , V34 (5) : P1263-1271 doi: 10.13287/j.1001-9332.202305.013
Effects of 5-HT on the cold resistance of mangrove Kandelia obovata seedlings.
College of Life and Environment Science, Wenzhou University, Wenzhou 325035, Zhejiang, China.; School of Design and Digital Arts, Zhejiang Industry and Trade Vocational College, Wenzhou 325000, Zhejiang, China.; Key Laboratory of Exploitation and Preservation of Coastal Bio-resource, Zhejiang Mariculture Research Institute, Wenzhou 325005, Zhejiang, China.
5-hydroxytryptamine (5-HT) participates in plant growth and development, and can also delay senescence and cope with abiotic stress. To explore the role of 5-HT in regulating the abilities of mangrove in cold resis-tance, we examined the effects of cold acclimation and the spraying of p-chlorophenylalanine (p-CPA, 5-HT synthesis inhibitor) on leaf gas exchange parameters and CO(2) response curves (A/Ca), as well as the endogenous phytohormone content levels in the mangrove species Kandelia obovata seedlings under low temperature stress. The results showed that low temperature stress significantly reduced the contents of 5-HT, chlorophyll, endogenous auxin (IAA), gibberellin (GA), and abscisic acid (ABA). It weakened the CO(2) utilization abilities of plants and reduced net photosynthetic rate, which ultimately reduced carboxylation efficiency (CE). Under low temperature stress, exogenous p-CPA reduced the contents of photosynthetic pigments, endogenous hormones, and 5-HT in the leaves, which aggravated the damages caused by low temperature stress on photosynthesis. By enhancing cold acclimation abilities, the endogenous IAA content in the leaves could was reduced under low temperature stress, promoted the production of 5-HT, improved the contents of photosynthetic pigments, GA, and ABA, as well as enhanced photosynthetic carbon assimilation abilities, which would increase photosynthesis in the K. obovata seedlings. Under cold acclimation conditions, the spraying of p-CPA could significantly inhibit the synthesis of 5-HT, promote the production of IAA, and reduce the contents of photosynthetic pigments, GA, ABA, and CE, which would weaken the effects of cold acclimation by improving the cold resistance of mangroves. In conclusion, cold acclimation could improve the cold resistance abilities of K. obovata seedlings by regulating photosynthetic carbon assimilation capacity and the contents of endogenous phytohormone. 5-HT synthesis is one of the necessary conditions for improving the cold resistance abilities of mangroves.
PMID: 37236943
Environ Res , IF:6.498 , 2023 Jul , V229 : P115966 doi: 10.1016/j.envres.2023.115966
Strigolactones can be a potential tool to fight environmental stresses in arid lands.
Xinjiang Key Desert Plant Roots Ecology and Vegetation Restoration Laboratory, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, China; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, 848300, China. Electronic address: akash.malik786@mails.ucas.ac.cn.; Department of Plant Breeding & Genetics, Gomal University, Dera Ismail Khan, Pakistan.; CSIC, Global Ecology Unit, CREAF-CSIC-UAB, Bellaterra, 08193, Barcelona, Catalonia, Spain; CREAF, Cerdanyola Del Valles, 08193, Catalonia, Spain.; Instituto de Fisiologia Vegetal, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Universidad Nacional de La Plata, Buenos Aires, Argentina.; Department of Botanical and Environmental Sciences, Faculty of Biological Sciences, Kohat University of Science and Technology, Kohat, Pakistan.; Xinjiang Key Desert Plant Roots Ecology and Vegetation Restoration Laboratory, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, China; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, 848300, China.; Xinjiang Key Desert Plant Roots Ecology and Vegetation Restoration Laboratory, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, China; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China; Cele National Station of Observation and Research for Desert-Grassland Ecosystems, Cele, 848300, China. Electronic address: zengfj@ms.xjb.ac.cn.; Key Laboratory of Humid Subtropical Eco-Geographical Process, Ministry of Education, Fujian Normal University, Fuzhou, 350007, China; Institute of Geography, Fujian Normal University, Fuzhou, 350007, China.; Department of Biology, College of Science, University of Tabuk, Tabuk, Saudi Arabia.; State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China.; State Key Laboratory of Phytochemistry and Plant Resources in West China, Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China.
BACKGROUND: Environmental stresses pose a significant threat to plant growth and ecosystem productivity, particularly in arid lands that are more susceptible to climate change. Strigolactones (SLs), carotenoid-derived plant hormones, have emerged as a potential tool for mitigating environmental stresses. METHODS: This review aimed to gather information on SLs' role in enhancing plant tolerance to ecological stresses and their possible use in improving the resistance mechanisms of arid land plant species to intense aridity in the face of climate change. RESULTS: Roots exude SLs under different environmental stresses, including macronutrient deficiency, especially phosphorus (P), which facilitates a symbiotic association with arbuscular mycorrhiza fungi (AMF). SLs, in association with AMF, improve root system architecture, nutrient acquisition, water uptake, stomatal conductance, antioxidant mechanisms, morphological traits, and overall stress tolerance in plants. Transcriptomic analysis revealed that SL-mediated acclimatization to abiotic stresses involves multiple hormonal pathways, including abscisic acid (ABA), cytokinins (CK), gibberellic acid (GA), and auxin. However, most of the experiments have been conducted on crops, and little attention has been paid to the dominant vegetation in arid lands that plays a crucial role in reducing soil erosion, desertification, and land degradation. All the environmental gradients (nutrient starvation, drought, salinity, and temperature) that trigger SL biosynthesis/exudation prevail in arid regions. The above-mentioned functions of SLs can potentially be used to improve vegetation restoration and sustainable agriculture. CONCLUSIONS: Present review concluded that knowledge on SL-mediated tolerance in plants is developed, but still in-depth research is needed on downstream signaling components in plants, SL molecular mechanisms and physiological interactions, efficient methods of synthetic SLs production, and their effective application in field conditions. This review also invites researchers to explore the possible application of SLs in improving the survival rate of indigenous vegetation in arid lands, which can potentially help combat land degradation problems.
PMID: 37100368
Plant J , IF:6.417 , 2023 Jun doi: 10.1111/tpj.16348
ZmXYL modulates auxin-induced maize growth.
National Engineering Laboratory of Crop Stress Resistance, School of Life Science, Anhui Agricultural University, Hefei, 230036, China.; Institute of Advanced Agricultural Technology, Qilu Normal University, Jinan, 250200, China.; State Key Laboratory of Crop Stress Adaptation and Improvement, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, Jinming Road, Kaifeng, 475004, China.; Faculty of Science and Engineering, School of Biological & Marine Sciences, University of Plymouth, Plymouth, PL4 8AA, UK.; Lab of Molecular Breeding by Design in Maize Sanya Institute, Hainan Academy of Agricultural Sciences, Sanya, 572000, China.
Plant architecture, lodging resistance, and yield are closely associated with height. In this paper, we report the identification and characterization of two allelic EMS-induced mutants of Zea mays, xyl-1, and xyl-2 that display dwarf phenotypes. The mutated gene, ZmXYL, encodes an alpha-xylosidase which functions in releasing xylosyl residue from a beta-1,4-linked glucan chain. Total alpha-xylosidase activity in the two alleles is significantly decreased compared to wild-type plants. Loss-of-function mutants of ZmXYL resulted in a decreased xylose content, an increased XXXG content in xyloglucan (XyG), and a reduced auxin content. We show that auxin has an antagonistic effect with XXXG in promoting cell divisions within mesocotyl tissue. xyl-1 and xyl-2 were less sensitive to IAA compared to B73. Based on our study, a model is proposed that places XXXG, an oligosaccharide derived from XyG and the substrate of ZmXYL, as having a negative impact on auxin homeostasis resulting in the dwarf phenotypes of the xyl mutants. Our results provide a insight into the roles of oligosaccharides released from plant cell walls as signals in mediating plant growth and development.
PMID: 37300848
Plant J , IF:6.417 , 2023 May doi: 10.1111/tpj.16333
Auxin biosynthesis gene FveYUC4 is critical for leaf and flower morphogenesis in woodland strawberry.
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, 430070, China.; Hubei Hongshan Laboratory, Wuhan, 430070, China.; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, 20742, USA.
Auxin plays an essential role in plant growth and development, particularly in fruit development. The YUCCA (YUC) genes encode flavin monooxygenases that catalyze a rate-limiting step in auxin biosynthesis. Mutations that disrupt YUC gene function provide useful tools for dissecting general and specific functions of auxin during plant development. In woodland strawberry (Fragaria vesca), two ethyl methanesulfonate mutants, Y422 and Y1011, have been identified that exhibit severe defects in leaves and flowers. In particular, the width of the leaf blade is greatly reduced, and each leaflet in the mutants has fewer and deeper serrations. In addition, the number and shape of the floral organs are altered, resulting in smaller fruits. Mapping by sequencing revealed that both mutations reside in the FveYUC4 gene, and were therefore renamed as yuc4-1 and yuc4-2. Consistent with a role for FveYUC4 in auxin synthesis, free auxin and its metabolites are significantly reduced in the yuc4 leaves and flowers. This role of FveYUC4 in leaf and flower development is supported by its high and specific expression in young leaves and flower buds using GUS reporters. Furthermore, germline transformation of pYUC4::YUC4, which resulted in elevated expression of FveYUC4 in yuc4 mutants, not only rescued the leaf and flower defects but also produced parthenocarpic fruits. Taken together, our data demonstrate that FveYUC4 is essential for leaf and flower morphogenesis in woodland strawberry by providing auxin hormone at the proper time and in the right tissues.
PMID: 37248638
Plant J , IF:6.417 , 2023 May doi: 10.1111/tpj.16330
A very long chain fatty acid responsive transcription factor, MYB93, regulates lateral root development in Arabidopsis.
Faculty of Agriculture, Meijo University, 1-501 Shiogamaguchi, Tempaku-ku, Nagoya, Aichi, 468-8502, Japan.; Department of Biological Chemistry, College of Bioscience and Biotechnology, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi, 478-8501, Japan.; Department of Electrical and Electronic Engineering, Faculty of Science and Technology, Meijo University, 1-501 Shiogamaguchi, Tempaku-ku, Nagoya, Aichi, 468-8502, Japan.
Lateral roots (LRs) are critical to root system architecture development in plants. Although the molecular mechanisms by which auxin regulates LR development have been extensively studied, several additional regulatory systems are hypothesized to be involved. Recently, the regulatory role of very long chain fatty acids (VLCFAs) has been shown in LR development. Our analysis showed that LTPG1 and LTPG2, transporters of VLCFAs, are specifically expressed in the developing LR primordium (LRP), while the number of LRs is reduced in the ltpg1/ltpg2 double mutant. Moreover, late LRP development was hindered when the VLCFA levels were reduced by the VLCFA synthesis enzyme mutant, kcs1-5. However, the details of the regulatory mechanisms of LR development controlled by VLCFAs remain unknown. In this study, we propose a novel method to analyze the LRP development stages with high temporal resolution using a deep neural network and identify a VLCFA-responsive transcription factor, MYB93, via transcriptome analysis of kcs1-5. MYB93 showed a carbon chain length-specific expression response following treatment of VLCFAs. Furthermore, myb93 transcriptome analysis suggested that MYB93 regulated the expression of cell wall organization genes. In addition, we also found that LTPG1 and LTPG2 are involved in LR development through the formation of root cap cuticle, which is different from transcriptional regulation by VLCFAs. Our results suggest that VLCFA is a regulator of LRP development through transcription factor-mediated regulation of gene expression and the transportation of VLCFAs is also involved in LR development through root cap cuticle formation.
PMID: 37247130
Plant J , IF:6.417 , 2023 May doi: 10.1111/tpj.16328
ELONGATED HYPOCOTYL5 (HY5) and HY5 HOMOLOGUE (HYH) maintain shade avoidance suppression in UV-B.
School of Biological Sciences, Life Sciences Building, University of Bristol, Bristol, BS8 1TQ, UK.; School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
Reductions in red to far-red ratio (R:FR) provide plants with an unambiguous signal of vegetational shade and are monitored by phytochrome photoreceptors. Plants integrate this information with other environmental cues to determine the proximity and density of encroaching vegetation. Shade-sensitive species respond to reductions in R:FR by initiating a suite of developmental adaptations termed shade avoidance. These include the elongation of stems to facilitate light foraging. Hypocotyl elongation is driven by increased auxin biosynthesis promoted by PHYTOCHROME INTERACTING FACTORs (PIF) 4, 5 and 7. UV-B perceived by the UV RESISTANCE LOCUS 8 (UVR8) photoreceptor rapidly inhibits shade avoidance, in part by suppressing PIF4/5 transcript accumulation and destabilising PIF4/5 protein. Here, we show that longer-term inhibition of shade avoidance is sustained by ELONGATED HYPOCOTYL 5 (HY5) and HY5 HOMOLOGUE (HYH), which regulate transcriptional reprogramming of genes involved in hormone signalling and cell wall modification. HY5 and HYH are elevated in UV-B and suppress the expression of XYLOGLUCAN ENDOTRANSGLUCOSYLASE/HYDROLASE (XTH) genes involved in cell wall loosening. They additionally increase expression GA2-OXIDASE1 (GA2ox1) and GA2ox2, encoding gibberellin catabolism enzymes that act redundantly to stabilise the PIF-inhibiting DELLA proteins. UVR8 therefore regulates temporally distinct signalling pathways to first rapidly inhibit and subsequently maintain suppression of shade avoidance following UV-B exposure.
PMID: 37243898
Plant J , IF:6.417 , 2023 May doi: 10.1111/tpj.16324
PIN2/3/4 auxin carriers mediate root growth inhibition under conditions of boron deprivation in Arabidopsis.
International Research Center for Environmental Membrane Biology & Department of Horticulture, Foshan University, Foshan, 528000, China.; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430000, China.; Microelement Research Center/Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, 430070, China.; Institute of Botany, Plant Science and Biodiversity Center, Slovak Academy of Sciences, Bratislava, Slovakia.; School of Agriculture and Environment & Institute of Agriculture, University of Western Australia, Perth, 6009, Australia.; Tasmanian Institute for Agriculture, College of Science and Engineering, University of Tasmania, Hobart, Tasmania, 7001, Australia.; School of Biological Sciences, University of Western Australia, Perth, 6009, Australia.; Institute of Cellular and Molecular Botany, University of Bonn, D-53115, Bonn, Germany.; Institute of Soil Science Chinese Academy of Sciences, State Key Laboratory of Soil and Sustainable Agriculture, Nanjing, 210018, China.
The mechanistic basis by which boron (B) deprivation inhibits root growth via the mediation of root apical auxin transport and distribution remains elusive. This study showed that B deprivation repressed root growth of wild-type Arabidopsis seedlings, which was related to higher auxin accumulation (observed with DII-VENUS and DR5-GFP lines) in B-deprived roots. Boron deprivation elevated the auxin content in the root apex, coinciding with upregulation of the expression levels of auxin biosynthesis-related genes (TAA1, YUC3, YUC9, and NIT1) in shoots, but not in root apices. Phenotyping experiments using auxin transport-related mutants revealed that the PIN2/3/4 carriers are involved in root growth inhibition caused by B deprivation. B deprivation not only upregulated the transcriptional levels of PIN2/3/4, but also restrained the endocytosis of PIN2/3/4 carriers (observed with PIN-Dendra2 lines), resulting in elevated protein levels of PIN2/3/4 in the plasma membrane. Overall, these results suggest that B deprivation not only enhances auxin biosynthesis in shoots by elevating the expression levels of auxin biosynthesis-related genes but also promotes the polar auxin transport from shoots to roots by upregulating the gene expression levels of PIN2/3/4, as well as restraining the endocytosis of PIN2/3/4 carriers, ultimately resulting in auxin accumulation in root apices and root growth inhibition.
PMID: 37235684
Plant J , IF:6.417 , 2023 Jul , V115 (1) : P155-174 doi: 10.1111/tpj.16218
Salicylic acid inhibits rice endocytic protein trafficking mediated by OsPIN3t and clathrin to affect root growth.
College of Plant Protection, Yunnan Agricultural University, Kunming, 650201, China.; State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, 650201, China.; Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming, 650201, China.; CAS Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China.; National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, 100083, China.; Shanxi Agricultural University/Shanxi Academy of Agricultural Sciences, The Industrial Crop Institute, Fenyang, 032200, China.; Key Lab of Agricultural Biotechnology of Yunnan Province, Biotechnology and Germplasm Resources Research Institute, Yunnan Academy of Agricultural Sciences, Kunming, 650205, Yunnan, China.; Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China.; Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria.; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China.; The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun, Mengla, 666303, Yunnan, China.
Salicylic acid (SA) plays important roles in different aspects of plant development, including root growth, where auxin is also a major player by means of its asymmetric distribution. However, the mechanism underlying the effect of SA on the development of rice roots remains poorly understood. Here, we show that SA inhibits rice root growth by interfering with auxin transport associated with the OsPIN3t- and clathrin-mediated gene regulatory network (GRN). SA inhibits root growth as well as Brefeldin A-sensitive trafficking through a non-canonical SA signaling mechanism. Transcriptome analysis of rice seedlings treated with SA revealed that the OsPIN3t auxin transporter is at the center of a GRN involving the coat protein clathrin. The root growth and endocytic trafficking in both the pin3t and clathrin heavy chain mutants were SA insensitivity. SA inhibitory effect on the endocytosis of OsPIN3t was dependent on clathrin; however, the root growth and endocytic trafficking mediated by tyrphostin A23 (TyrA23) were independent of the pin3t mutant under SA treatment. These data reveal that SA affects rice root growth through the convergence of transcriptional and non-SA signaling mechanisms involving OsPIN3t-mediated auxin transport and clathrin-mediated trafficking as key components.
PMID: 37025008
Plant J , IF:6.417 , 2023 Jun , V114 (6) : P1369-1384 doi: 10.1111/tpj.16198
Hydrogen sulfide alleviates osmotic stress-induced root growth inhibition by promoting auxin homeostasis.
State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
Hydrogen sulfide (H(2) S) promotes plant tolerance against various environmental cues, and d-cysteine desulfhydrase (DCD) is an enzymatic source of H(2) S to enhance abiotic stress resistance. However, the role of DCD-mediated H(2) S production in root growth under abiotic stress remains to be further elucidated. Here, we report that DCD-mediated H(2) S production alleviates osmotic stress-mediated root growth inhibition by promoting auxin homeostasis. Osmotic stress up-regulated DCD gene transcript and DCD protein levels and thus H(2) S production in roots. When subjected to osmotic stress, a dcd mutant showed more severe root growth inhibition, whereas the transgenic lines DCDox overexpressing DCD exhibited less sensitivity to osmotic stress in terms of longer root compared to the wild-type. Moreover, osmotic stress inhibited root growth through repressing auxin signaling, whereas H(2) S treatment significantly alleviated osmotic stress-mediated inhibition of auxin. Under osmotic stress, auxin accumulation was increased in DCDox but decreased in dcd mutant. H(2) S promoted auxin biosynthesis gene expression and auxin efflux carrier PIN-FORMED 1 (PIN1) protein level under osmotic stress. Taken together, our results reveal that mannitol-induced DCD and H(2) S in roots promote auxin homeostasis, contributing to alleviating the inhibition of root growth under osmotic stress.
PMID: 36948886
Plant J , IF:6.417 , 2023 Jun , V114 (6) : P1338-1352 doi: 10.1111/tpj.16196
The AtERF19 gene regulates meristem activity and flower organ size in plants.
Institute of Biotechnology, National Chung Hsing University, Taichung, 40227, Taiwan.; Advanced Plant and Food Crop Biotechnology Center, National Chung Hsing University, Taichung, 40227, Taiwan.
Ethylene-responsive factors (ERFs) have diverse functions in the regulation of various plant developmental processes. Here, we demonstrate the dual role of an Arabidopsis ERF gene, AtERF19, in regulating reproductive meristem activity and flower organ size through the regulation of genes involved in CLAVATA-WUSCHEL (CLV-WUS) and auxin signaling, respectively. We found that AtERF19 stimulated the formation of flower primordia and controlled the number of flowers produced by activating WUS and was negatively regulated by CLV3. 35S::AtERF19 expression resulted in significantly more flowers, whereas 35S::AtERF19 + SRDX dominant-negative mutants produced fewer flowers. In addition, AtERF19 also functioned to control flower organ size by promoting the division/expansion of the cells through activating Small Auxin Up RNA Gene 32 (SAUR32), which positively regulated MYB21/24 in the auxin signaling pathway. 35S::AtERF19 and 35S::SAUR32 resulted in similarly larger flowers, whereas 35S::AtERF19 + SRDX and 35S::SAUR32-RNAi mutants produced smaller flowers than the wild type. The functions of AtERF19 were confirmed by the production of similarly more and larger flowers in 35S::AtERF19 transgenic tobacco (Nicotiana benthamiana) and in transgenic Arabidopsis which ectopically expressed the orchid gene (Nicotiana benthamiana) PaERF19 than in wild-type plants. The finding that AtERF19 regulates genes involved in both CLV-WUS and auxin signaling during flower development significantly expands the current knowledge of the multifunctional evolution of ERF genes in plants. The results presented in this work indicate a dual role for the transcription factor AtERF19 in controlling the number of flowers produced and flower organ size through the regulation of genes involved in CLV-WUS and auxin signaling, respectively. Our findings expand the knowledge of the roles of ERF genes in the regulation of reproductive development.
PMID: 36932949
Plant J , IF:6.417 , 2023 May , V114 (3) : P683-698 doi: 10.1111/tpj.16166
FaMYB123 interacts with FabHLH3 to regulate the late steps of anthocyanin and flavonol biosynthesis during ripening.
Department of Biochemistry and Molecular Biology, University of Cordoba, Edificio Severo Ochoa, Campus de Rabanales, E-14014, Cordoba, Spain.; Max-Planck-Institute of Molecular Plant Physiology, Am Muhlenberg 1, 14476, Potsdam-Golm, Germany.; Department of Agricultural Chemistry, University of Cordoba, Edificio Marie Curie, Campus de Rabanales, E-14014, Cordoba, Spain.; Department of Plant Biology, Instituto de Hortofruticultura Subtropical y Mediterranea La Mayora, University of Malaga, Campus de Teatinos, E-29071, Malaga, Spain.; Department of Plant Biochemistry, Centre for Plant Molecular Biology (ZMBP), Eberhard Karls University, Tubingen, Germany.; Center of Plant Systems Biology and Biotechnology, Ruski Blvd. 139, Plovdiv, 4000, Bulgaria.
In this work, we identified and functionally characterized the strawberry (Fragaria x ananassa) R2R3 MYB transcription factor FaMYB123. As in most genes associated with organoleptic properties of ripe fruit, FaMYB123 expression is ripening-related, receptacle-specific, and antagonistically regulated by ABA and auxin. Knockdown of FaMYB123 expression by RNAi in ripe strawberry fruit receptacles downregulated the expression of enzymes involved in the late steps of anthocyanin/flavonoid biosynthesis. Transgenic fruits showed a parallel decrease in the contents of total anthocyanin and flavonoid, especially malonyl derivatives of pelargonidin and cyanidins. The decrease was concomitant with accumulation of proanthocyanin, propelargonidins, and other condensed tannins associated mainly with green receptacles. Potential coregulation between FaMYB123 and FaMYB10, which may act on different sets of genes for the enzymes involved in anthocyanin production, was explored. FaMYB123 and FabHLH3 were found to interact and to be involved in the transcriptional activation of FaMT1, a gene responsible for the malonylation of anthocyanin components during ripening. Taken together, these results demonstrate that FaMYB123 regulates the late steps of the flavonoid pathway in a specific manner. In this study, a new function for an R2R3 MYB transcription factor, regulating the expression of a gene that encodes a malonyltransferase, has been elucidated.
PMID: 36840368
Ecotoxicol Environ Saf , IF:6.291 , 2023 Jun , V262 : P115128 doi: 10.1016/j.ecoenv.2023.115128
Multiomics reveals Claroideoglomus etunicatum regulates plant hormone signal transduction, photosynthesis and La compartmentalization in maize to promote growth under La stress.
Inner Mongolia Key Laboratory of Environmental Pollution Control and Waste Resource Recycle, Ministry of Education Collaborative Innovation Center for Grassland Ecological Security, Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China; Inner Mongolia Key Laboratory of Environmental Chemistry, School of Chemistry and Environment, Inner Mongolia Normal University, Hohhot 010021, China.; Inner Mongolia Key Laboratory of Environmental Pollution Control and Waste Resource Recycle, Ministry of Education Collaborative Innovation Center for Grassland Ecological Security, Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China.; Service Support Center, Ecology and Environmental Department of Inner Mongolia Autonomous Region, Hohhot 010010, China.; Inner Mongolia Key Laboratory of Environmental Pollution Control and Waste Resource Recycle, Ministry of Education Collaborative Innovation Center for Grassland Ecological Security, Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China. Electronic address: ndguowei@163.com.
Rare earth elements (REEs) have been widely used in traditional and high-tech fields, and high doses of REEs are considered a risk to the ecosystem. Although the influence of arbuscular mycorrhizal fungi (AMF) in promoting host resistance to heavy metal (HM) stress has been well documented, the molecular mechanism by which AMF symbiosis enhances plant tolerance to REEs is still unclear. A pot experiment was conducted to investigate the molecular mechanism by which the AMF Claroideoglomus etunicatum promotes maize (Zea mays) seedling tolerance to lanthanum (La) stress (100 mg.kg(-1) La). C. etunicatum symbiosis significantly improved maize seedling growth, P and La uptake and photosynthesis. Transcriptome, proteome, and metabolome analyses performed alone and together revealed that differentially expressed genes (DEGs) related to auxin /indole-3-acetic acid (AUX/IAA) and the DEGs and differentially expressed proteins (DEPs) related to ATP-binding cassette (ABC) transporters, natural resistance-associated macrophage proteins (Nramp6), vacuoles and vesicles were upregulated. In contrast, photosynthesis-related DEGs and DEPs were downregulated, and 1-phosphatidyl-1D-myo-inositol 3-phosphate (PI(3)P) was more abundant under C. etunicatum symbiosis. C. etunicatum symbiosis can promote plant growth by increasing P uptake, regulating plant hormone signal transduction, photosynthesis and glycerophospholipid metabolism pathways and enhancing La transport and compartmentalization in vacuoles and vesicles. The results provide new insights into the promotion of plant REE tolerance by AMF symbiosis and the possibility of utilizing AMF-maize interactions in REE phytoremediation and recycling.
PMID: 37315361
J Ginseng Res , IF:6.06 , 2023 May , V47 (3) : P469-478 doi: 10.1016/j.jgr.2022.05.009
Nitrate enhances the secondary growth of storage roots in Panax ginseng.
Department of Biology, Chungbuk National University, Cheongju, Republic of Korea.; Department of Biological Sciences, Chungnam National University, Daejeon, Republic of Korea.; Ginseng & Medicinal Plant Research Institute, Chungnam Agricultural Research & Extention Service, Keumsan, Republic of Korea.; Department of Herbal Crop Research, National Institute of Horticultural and Herbal Science, Rural Development Administration, Eumseong, Republic of Korea.; Korea Ginseng Corporation, R&D Headquarters, Daejeon, Republic of Korea.; Theragen Bio Co., Ltd, Suwon, Republic of Korea.; Department of Biological Sciences and Biotechnology, Chungbuk National University, Cheongju, Republic of Korea.
BACKGROUND: Nitrogen (N) is an essential macronutrient for plant growth and development. To support agricultural production and enhance crop yield, two major N sources, nitrate and ammonium, are applied as fertilizers to the soil. Although many studies have been conducted on N uptake and signal transduction, the molecular genetic mechanisms of N-mediated physiological roles, such as the secondary growth of storage roots, remain largely unknown. METHODS: One-year-old P. ginseng seedlings treated with KNO(3) were analyzed for the secondary growth of storage roots. The histological paraffin sections were subjected to bright and polarized light microscopic analysis. Genome-wide RNA-seq and network analysis were carried out to dissect the molecular mechanism of nitrate-mediated promotion of ginseng storage root thickening. RESULTS: Here, we report the positive effects of nitrate on storage root secondary growth in Panax ginseng. Exogenous nitrate supply to ginseng seedlings significantly increased the root secondary growth. Histological analysis indicated that the enhancement of root secondary growth could be attributed to the increase in cambium stem cell activity and the subsequent differentiation of cambium-derived storage parenchymal cells. RNA-seq and gene set enrichment analysis (GSEA) revealed that the formation of a transcriptional network comprising auxin, brassinosteroid (BR)-, ethylene-, and jasmonic acid (JA)-related genes mainly contributed to the secondary growth of ginseng storage roots. In addition, increased proliferation of cambium stem cells by a N-rich source inhibited the accumulation of starch granules in storage parenchymal cells. CONCLUSION: Thus, through the integration of bioinformatic and histological tissue analyses, we demonstrate that nitrate assimilation and signaling pathways are integrated into key biological processes that promote the secondary growth of P. ginseng storage roots.
PMID: 37252286
Int J Mol Sci , IF:5.923 , 2023 Jun , V24 (12) doi: 10.3390/ijms241210410
Integrated Transcriptome and Metabolome Analysis Revealed the Causal Agent of Primary Bud Necrosis in 'Summer Black' Grape.
College of Horticulture, Hunan Agricultural University, Changsha 410128, China.
Primary bud necrosis of grape buds is a physiological disorder that leads to decreased berry yield and has a catastrophic impact on the double cropping system in sub-tropical areas. The pathogenic mechanisms and potential solutions remain unknown. In this study, the progression and irreversibility patterns of primary bud necrosis in 'Summer Black' were examined via staining and transmission electron microscopy observation. Primary bud necrosis was initiated at 60 days after bud break and was characterized by plasmolysis, mitochondrial swelling, and severe damage to other organelles. To reveal the underlying regulatory networks, winter buds were collected during primary bud necrosis progression for integrated transcriptome and metabolome analysis. The accumulation of reactive oxygen species and subsequent signaling cascades disrupted the regulation systems for cellular protein quality. ROS cascade reactions were related to mitochondrial stress that can lead to mitochondrial dysfunction, lipid peroxidation causing damage to membrane structure, and endoplasmic reticulum stress leading to misfolded protein aggregates. All these factors ultimately resulted in primary bud necrosis. Visible tissue browning was associated with the oxidation and decreased levels of flavonoids during primary bud necrosis, while the products of polyunsaturated fatty acids and stilbenes exhibited an increasing trend, leading to a shift in carbon flow from flavonoids to stilbene. Increased ethylene may be closely related to primary bud necrosis, while auxin accelerated cell growth and alleviated necrosis by co-chaperone VvP23-regulated redistribution of auxin in meristem cells. Altogether, this study provides important clues for further study on primary bud necrosis.
PMID: 37373557
Int J Mol Sci , IF:5.923 , 2023 Jun , V24 (12) doi: 10.3390/ijms241210303
RNA-Seq Transcriptome Analysis and Evolution of OsEBS, a Gene Involved in Enhanced Spikelet Number per Panicle in Rice.
State Key Laboratory of Genetic Engineering and MOE Engineering Research Center of Gene Technology, School of Life Sciences, Fudan University, Shanghai 200438, China.; Key Laboratory of Germplasm Innovation and Genetic Improvement of Grain and Oil Crops (Co-Construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Crop Breeding and Cultivation Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.
Spikelet number per panicle (SNP) is one of the most important yield components in rice. Rice ENHANCING BIOMASS AND SPIKELET NUMBER (OsEBS), a gene involved in improved SNP and yield, has been cloned from an accession of Dongxiang wild rice. However, the mechanism of OsEBS increasing rice SNP is poorly understood. In this study, the RNA-Seq technology was used to analyze the transcriptome of wildtype Guichao 2 and OsEBS over-expression line B102 at the heading stage, and analysis of the evolution of OsEBS was also conducted. A total of 5369 differentially expressed genes (DEGs) were identified between Guichao2 and B102, most of which were down-regulated in B102. Analysis of the expression of endogenous hormone-related genes revealed that 63 auxin-related genes were significantly down-regulated in B102. Gene Ontogeny (GO) enrichment analysis showed that the 63 DEGs were mainly enriched in eight GO terms, including auxin-activated signaling pathway, auxin polar transport, auxin transport, basipetal auxin transport, and amino acid transmembrane transport, most of which were directly or indirectly related to polar auxin transport. Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analysis further verified that the down-regulated genes related to polar auxin transport had important effects on increased SNP. Analysis of the evolution of OsEBS found that OsEBS was involved in the differentiation of indica and japonica, and the differentiation of OsEBS supported the multi-origin model of rice domestication. Indica (XI) subspecies harbored higher nucleotide diversity than japonica (GJ) subspecies in the OsEBS region, and XI experienced strong balancing selection during evolution, while selection in GJ was neutral. The degree of genetic differentiation between GJ and Bas subspecies was the smallest, while it was the highest between GJ and Aus. Phylogenetic analysis of the Hsp70 family in O. sativa, Brachypodium distachyon, and Arabidopsis thaliana indicated that changes in the sequences of OsEBS were accelerated during evolution. Accelerated evolution and domain loss in OsEBS resulted in neofunctionalization. The results obtained from this study provide an important theoretical basis for high-yield rice breeding.
PMID: 37373450
Int J Mol Sci , IF:5.923 , 2023 Jun , V24 (12) doi: 10.3390/ijms241210152
Transcriptomic and Metabolomic Analyses Reveal the Roles of Flavonoids and Auxin on Peanut Nodulation.
Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan 250100, China.; Shandong Peanut Research Institute, Qingdao 266100, China.; Shandong Academy of Agricultural Sciences, Jinan 250100, China.
Rhizobia form symbiotic relationships with legumes, fixing atmospheric nitrogen into a plant-accessible form within their root nodules. Nitrogen fixation is vital for sustainable soil improvements in agriculture. Peanut (Arachis hypogaea) is a leguminous crop whose nodulation mechanism requires further elucidation. In this study, comprehensive transcriptomic and metabolomic analyses were conducted to assess the differences between a non-nodulating peanut variety and a nodulating peanut variety. Total RNA was extracted from peanut roots, then first-strand and second-strand cDNA were synthesized and purified. After sequencing adaptors were added to the fragments, the cDNA libraries were sequenced. Our transcriptomic analysis identified 3362 differentially expressed genes (DEGs) between the two varieties. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed that the DEGs were mainly involved in metabolic pathways, hormone signal transduction, secondary metabolic biosynthesis, phenylpropanoid biosynthesis, or ABC transport. Further analyses indicated that the biosynthesis of flavonoids, such as isoflavones, flavonols, and flavonoids, was important for peanut nodulation. A lack of flavonoid transport into the rhizosphere (soil) could prevent rhizobial chemotaxis and the activation of their nodulation genes. The downregulation of AUXIN-RESPONSE FACTOR (ARF) genes and lower auxin content could reduce rhizobia's invasion of peanut roots, ultimately reducing nodule formation. Auxin is the major hormone that influences the cell-cycle initiation and progression required for nodule initiation and accumulates during different stages of nodule development. These findings lay the foundation for subsequent research into the nitrogen-fixation efficiency of peanut nodules.
PMID: 37373299
Int J Mol Sci , IF:5.923 , 2023 Jun , V24 (11) doi: 10.3390/ijms24119613
Genomic Assessment of the Contribution of the Wolbachia Endosymbiont of Eurosta solidaginis to Gall Induction.
Department of Biology, San Francisco State University, San Francisco, CA 94112, USA.; Department of Thoracic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.; Iridian Genomes Inc., Bethesda, MD 20817, USA.
We explored the genome of the Wolbachia strain, wEsol, symbiotic with the plant-gall-inducing fly Eurosta solidaginis with the goal of determining if wEsol contributes to gall induction by its insect host. Gall induction by insects has been hypothesized to involve the secretion of the phytohormones cytokinin and auxin and/or proteinaceous effectors to stimulate cell division and growth in the host plant. We sequenced the metagenome of E. solidaginis and wEsol and assembled and annotated the genome of wEsol. The wEsol genome has an assembled length of 1.66 Mbp and contains 1878 protein-coding genes. The wEsol genome is replete with proteins encoded by mobile genetic elements and shows evidence of seven different prophages. We also detected evidence of multiple small insertions of wEsol genes into the genome of the host insect. Our characterization of the genome of wEsol indicates that it is compromised in the synthesis of dimethylallyl pyrophosphate (DMAPP) and S-adenosyl L-methionine (SAM), which are precursors required for the synthesis of cytokinins and methylthiolated cytokinins. wEsol is also incapable of synthesizing tryptophan, and its genome contains no enzymes in any of the known pathways for the synthesis of indole-3-acetic acid (IAA) from tryptophan. wEsol must steal DMAPP and L-methionine from its host and therefore is unlikely to provide cytokinin and auxin to its insect host for use in gall induction. Furthermore, in spite of its large repertoire of predicted Type IV secreted effector proteins, these effectors are more likely to contribute to the acquisition of nutrients and the manipulation of the host's cellular environment to contribute to growth and reproduction of wEsol than to aid E. solidaginis in manipulating its host plant. Combined with earlier work that shows that wEsol is absent from the salivary glands of E. solidaginis, our results suggest that wEsol does not contribute to gall induction by its host.
PMID: 37298563
Int J Mol Sci , IF:5.923 , 2023 May , V24 (11) doi: 10.3390/ijms24119287
Physiological and Transcriptomic Analyses Reveal the Effects of Carbon-Ion Beam on Taraxacum kok-saghyz Rodin Adventitious Buds.
Biophysics Group, Biomedical Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.; University of Chinese Academy of Sciences, Beijing 100049, China.; Guangdong Key Laboratory for New Technology Research of Vegetables, Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.; Rubber Research Institute, Chinese Academy of Tropical Agricultural Science, Haikou 571101, China.
Taraxacum kok-saghyz Rodin (TKS) has great potential as an alternative natural-rubber (NR)-producing crop. The germplasm innovation of TKS still faces great challenges due to its self-incompatibility. Carbon-ion beam (CIB) irradiation is a powerful and non-species-specific physical method for mutation creation. Thus far, the CIB has not been utilized in TKS. To better inform future mutation breeding for TKS by the CIB and provide a basis for dose-selection, adventitious buds, which not only can avoid high levels of heterozygosity, but also further improve breeding efficiency, were irradiated here, and the dynamic changes of the growth and physiologic parameters, as well as gene expression pattern were profiled, comprehensively. The results showed that the CIB (5-40 Gy) caused significant biological effects on TKS, exhibiting inhibitory effects on the fresh weight and the number of regenerated buds and roots. Then,15 Gy was chosen for further study after comprehensive consideration. CIB-15 Gy resulted in significant oxidative damages (hydroxyl radical (OH(*)) generation activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and malondialdehyde (MDA) content) and activated the antioxidant system (superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX)) of TKS. Based on RNA-seq analysis, the number of differentially expressed genes (DEGs) peaked at 2 h after CIB irradiation. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that DNA-replication-/repair- (mainly up-regulated), cell-death- (mainly up-regulated), plant-hormone- (auxin and cytokinin, which are related to plant morphogenesis, were mainly down-regulated), and photosynthesis- (mainly down-regulated) related pathways were involved in the response to the CIB. Furthermore, CIB irradiation can also up-regulate the genes involved in NR metabolism, which provides an alternative strategy to elevate the NR production in TKS in the future. These findings are helpful to understand the radiation response mechanism and further guide the future mutation breeding for TKS by the CIB.
PMID: 37298239
Int J Mol Sci , IF:5.923 , 2023 May , V24 (11) doi: 10.3390/ijms24119186
Effects of Low Temperature on Pedicel Abscission and Auxin Synthesis Key Genes of Tomato.
College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China.; Modern Protected Horticulture Engineering & Technology Center, Shenyang Agricultural University, Shenyang 110866, China.; National & Local Joint Engineering Research Center of Northern Horticultural Facilities Design & Application Technology (Liaoning), Shenyang 110866, China.; Key Laboratory of Protected Horticulture, Shenyang Agricultural University, Ministry of Education, Shenyang 110866, China.
Cold stress usually causes the abscission of floral organs and a decline in fruit setting rate, seriously reducing tomato yield. Auxin is one of the key hormones that affects the abscission of plant floral organs; the YUCCA (YUC) family is a key gene in the auxin biosynthesis pathway, but there are few research reports on the abscission of tomato flower organs. This experiment found that, under low temperature stress, the expression of auxin synthesis genes increased in stamens but decreased in pistils. Low temperature treatment decreased pollen vigor and pollen germination rate. Low night temperature reduced the tomato fruit setting rate and led to parthenocarpy, and the treatment effect was most obvious in the early stage of tomato pollen development. The abscission rate of tomato pTRV-Slfzy3 and pTRV-Slfzy5 silenced plants was higher than that of the control, which is the key auxin synthesis gene affecting the abscission rate. The expression of Solyc07g043580 was down-regulated after low night temperature treatment. Solyc07g043580 encodes the bHLH-type transcription factor SlPIF4. It has been reported that PIF4 regulates the expression of auxin synthesis and synthesis genes, and is a key protein in the interaction between low temperature stress and light in regulating plant development.
PMID: 37298137
Int J Mol Sci , IF:5.923 , 2023 May , V24 (10) doi: 10.3390/ijms24108748
Comparative Anatomical and Transcriptomics Reveal the Larger Cell Size as a Major Contributor to Larger Fruit Size in Apricot.
State Key Laboratory of Tree Genetics and Breeding, Research Institute of Non-Timber Forestry, Chinese Academy of Forestry, Zhengzhou 450003, China.; College of Forestry, Nanjing Forestry University, Nanjing 210037, China.; Kernel-Apricot Engineering and Technology Research Center of State Forestry and Grassland Administration, Zhengzhou 450003, China.; Key Laboratory of Non-Timber Forest Germplasm Enhancement and Utilization of National Forestry and Grassland Administration, Zhengzhou 450003, China.
Fruit size is one of the essential quality traits and influences the economic value of apricots. To explore the underlying mechanisms of the formation of differences in fruit size in apricots, we performed a comparative analysis of anatomical and transcriptomics dynamics during fruit growth and development in two apricot cultivars with contrasting fruit sizes (large-fruit Prunus armeniaca 'Sungold' and small-fruit P. sibirica 'F43'). Our analysis identified that the difference in fruit size was mainly caused by the difference in cell size between the two apricot cultivars. Compared with 'F43', the transcriptional programs exhibited significant differences in 'Sungold', mainly in the cell expansion period. After analysis, key differentially expressed genes (DEGs) most likely to influence cell size were screened out, including genes involved in auxin signal transduction and cell wall loosening mechanisms. Furthermore, weighted gene co-expression network analysis (WGCNA) revealed that PRE6/bHLH was identified as a hub gene, which interacted with 1 TIR1, 3 AUX/IAAs, 4 SAURs, 3 EXPs, and 1 CEL. Hence, a total of 13 key candidate genes were identified as positive regulators of fruit size in apricots. The results provide new insights into the molecular basis of fruit size control and lay a foundation for future breeding and cultivation of larger fruits in apricot.
PMID: 37240096
Int J Mol Sci , IF:5.923 , 2023 May , V24 (10) doi: 10.3390/ijms24108735
ZmDRR206 Regulates Nutrient Accumulation in Endosperm through Its Role in Cell Wall Biogenesis during Maize Kernel Development.
National Maize Improvement Center, Center for Crop Functional Genomics and Molecular Breeding, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
Dirigent proteins (DIRs) contribute to plant fitness by dynamically reorganizing the cell wall and/or by generating defense compounds during plant growth, development, and interactions with environmental stresses. ZmDRR206 is a maize DIR, it plays a role in maintaining cell wall integrity during seedling growth and defense response in maize, but its role in regulating maize kernel development is unclear. Association analysis of candidate genes indicated that the natural variations of ZmDRR206 were significantly associated with maize hundred-kernel weight (HKW). ZmDRR206 plays a dominant role in storage nutrient accumulation in endosperm during maize kernel development, ZmDRR206 overexpression resulted in small and shrunken maize kernel with significantly reduced starch content and significantly decreased HKW. Cytological characterization of the developing maize kernels revealed that ZmDRR206 overexpression induced dysfunctional basal endosperm transfer layer (BETL) cells, which were shorter with less wall ingrowth, and defense response was constitutively activated in developing maize kernel at 15 and 18 DAP by ZmDRR206 overexpression. The BETL-development-related genes and auxin signal-related genes were down-regulated, while cell wall biogenesis-related genes were up-regulated in developing BETL of the ZmDRR206-overexpressing kernel. Moreover, the developing ZmDRR206-overexpressing kernel had significantly reduced contents of the cell wall components such as cellulose and acid soluble lignin. These results suggest that ZmDRR206 may play a regulatory role in coordinating cell development, storage nutrient metabolism, and stress responses during maize kernel development through its role in cell wall biogenesis and defense response, and provides new insights into understanding the mechanisms of kernel development in maize.
PMID: 37240079
Int J Mol Sci , IF:5.923 , 2023 May , V24 (10) doi: 10.3390/ijms24108692
Griseofulvin Inhibits Root Growth by Targeting Microtubule-Associated Proteins Rather Tubulins in Arabidopsis.
Weed Research Laboratory, Nanjing Agricultural University, Nanjing 210095, China.; Institute of Technology and Life Sciences; National Research Institute, Falenty, Al. Hrabska 3, 05-090 Raszyn, Poland.; Department of Plant Physiology, Institute of Biology, Warsaw University of Life Sciences SGGW, 159 Nowoursynowska 159, 02-776 Warsaw, Poland.
Griseofulvin was considered an effective agent for cancer therapy in past decades. Although the negative effects of griseofulvin on microtubule stability are known, the exact target and mechanism of action in plants remain unclear. Here, we used trifluralin, a well-known herbicide targeting microtubules, as a reference and revealed the differences in root tip morphology, reactive oxygen species production (ROS), microtubule dynamics, and transcriptome analysis between Arabidopsis treated with griseofulvin and trifluralin to elucidate the mechanism of root growth inhibition by griseofulvin. Like trifluralin, griseofulvin inhibited root growth and caused significant swelling of the root tip due to cell death induced by ROS. However, the presence of griseofulvin and trifluralin caused cell swelling in the transition zone (TZ) and meristematic zone (MZ) of root tips, respectively. Further observations revealed that griseofulvin first destroyed cortical microtubules in the cells of the TZ and early elongation zone (EZ) and then gradually affected the cells of other zones. The first target of trifluralin is the microtubules in the root MZ cells. Transcriptome analysis showed that griseofulvin mainly affected the expression of microtubule-associated protein (MAP) genes rather than tubulin genes, whereas trifluralin significantly suppressed the expression of alphabeta-tubulin genes. Finally, it was proposed that griseofulvin could first reduce the expression of MAP genes, meanwhile increasing the expression of auxin and ethylene-related genes to disrupt microtubule alignment in root tip TZ and early EZ cells, induce dramatic ROS production, and cause severe cell death, eventually leading to cell swelling in the corresponding zones and inhibition of root growth.
PMID: 37240033
Int J Mol Sci , IF:5.923 , 2023 May , V24 (10) doi: 10.3390/ijms24108514
Precise Regulation of the TAA1/TAR-YUCCA Auxin Biosynthesis Pathway in Plants.
College of Life Science and Technology, Gansu Agricultural University, Lanzhou 730070, China.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
The indole-3-pyruvic acid (IPA) pathway is the main auxin biosynthesis pathway in the plant kingdom. Local control of auxin biosynthesis through this pathway regulates plant growth and development and the responses to biotic and abiotic stresses. During the past decades, genetic, physiological, biochemical, and molecular studies have greatly advanced our understanding of tryptophan-dependent auxin biosynthesis. The IPA pathway includes two steps: Trp is converted to IPA by TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS/TRYPTOPHAN AMINOTRANSFERASE RELATED PROTEINs (TAA1/TARs), and then IPA is converted to IAA by the flavin monooxygenases (YUCCAs). The IPA pathway is regulated at multiple levels, including transcriptional and post-transcriptional regulation, protein modification, and feedback regulation, resulting in changes in gene transcription, enzyme activity and protein localization. Ongoing research indicates that tissue-specific DNA methylation and miRNA-directed regulation of transcription factors may also play key roles in the precise regulation of IPA-dependent auxin biosynthesis in plants. This review will mainly summarize the regulatory mechanisms of the IPA pathway and address the many unresolved questions regarding this auxin biosynthesis pathway in plants.
PMID: 37239863
Int J Mol Sci , IF:5.923 , 2023 May , V24 (9) doi: 10.3390/ijms24098440
Lateral Root Initiation in Cucumber (Cucumis sativus): What Does the Expression Pattern of Rapid Alkalinization Factor 34 (RALF34) Tell Us?
Laboratory of Cellular and Molecular Mechanisms of Plant Development, Komarov Botanical Institute, Russian Academy of Sciences, 197022 Saint Petersburg, Russia.; Department of Ecology, Environment and Plant Sciences, Stockholm University, 10691 Stockholm, Sweden.
In Arabidopsis, the small signaling peptide (peptide hormone) RALF34 is involved in the gene regulatory network of lateral root initiation. In this study, we aimed to understand the nature of the signals induced by RALF34 in the non-model plant cucumber (Cucumis sativus), where lateral root primordia are induced in the apical meristem of the parental root. The RALF family members of cucumber were identified using phylogenetic analysis. The sequence of events involved in the initiation and development of lateral root primordia in cucumber was examined in detail. To elucidate the role of the small signaling peptide CsRALF34 and its receptor CsTHESEUS1 in the initial stages of lateral root formation in the parental root meristem in cucumber, we studied the expression patterns of both genes, as well as the localization and transport of the CsRALF34 peptide. CsRALF34 is expressed in all plant organs. CsRALF34 seems to differ from AtRALF34 in that its expression is not regulated by auxin. The expression of AtRALF34, as well as CsRALF34, is regulated in part by ethylene. CsTHESEUS1 is expressed constitutively in cucumber root tissues. Our data suggest that CsRALF34 acts in a non-cell-autonomous manner and is not involved in lateral root initiation in cucumber.
PMID: 37176146
Front Bioeng Biotechnol , IF:5.89 , 2023 , V11 : P1188119 doi: 10.3389/fbioe.2023.1188119
Conditional protein degradation in Yarrowia lipolytica using the auxin-inducible degron.
Department of Molecular Biosciences and Bioengineering, University of Hawai'i at Manoa, Honolulu, HI, United States.; Department of Energy, Environmental and Chemical Engineering, Washington University, Saint Louis, MO, United States.
Conditional protein degradation is a powerful tool for controlled protein knockdown. The auxin-inducible degron (AID) technology uses a plant auxin to induce depletion of degron-tagged proteins, and it has been shown to be functional in several non-plant eukaryotes. In this study, we demonstrated AID-based protein knockdown in an industrially important oleaginous yeast Yarrowia lipolytica. Using the mini-IAA7 (mIAA7) degron derived from Arabidopsis IAA7, coupled with an Oryza sativa TIR1 (OsTIR1) plant auxin receptor F-box protein (expressed from the copper-inducible MT2 promoter), C-terminal degron-tagged superfolder GFP could be degraded in Yarrowia lipolytica upon addition of copper and the synthetic auxin 1-Naphthaleneacetic acid (NAA). However, leaky degradation of the degron-tagged GFP in the absence of NAA was also noted. This NAA-independent degradation was largely eliminated by replacing the wild-type OsTIR1 and NAA with the OsTIR1(F74A) variant and the auxin derivative 5-Ad-IAA, respectively. Degradation of the degron-tagged GFP was rapid and efficient. However, Western blot analysis revealed cellular proteolytic cleavage within the mIAA7 degron sequence, leading to the production of a GFP sub-population lacking an intact degron. The utility of the mIAA7/OsTIR1(F74A) system was further explored in controlled degradation of a metabolic enzyme, beta-carotene ketolase, which converts beta-carotene to canthaxanthin via echinenone. This enzyme was tagged with the mIAA7 degron and expressed in a beta-carotene producing Y. lipolytica strain that also expressed OsTIR1(F74A) controlled by the MT2 promoter. By adding copper and 5-Ad-IAA at the time of culture inoculation, canthaxanthin production was found to be reduced by about 50% on day five compared to the control culture without adding 5-Ad-IAA. This is the first report that demonstrates the efficacy of the AID system in Y. lipolytica. Further improvement of AID-based protein knockdown in Y. lipolytica may be achieved by preventing proteolytic removal of the mIAA7 degron tag.
PMID: 37324427
Microb Biotechnol , IF:5.813 , 2023 Jun doi: 10.1111/1751-7915.14296
Regulation of indole-3-acetic acid biosynthesis and consequences of auxin production deficiency in Serratia plymuthica.
Department of Biotechnology and Environmental Protection, Estacion Experimental del Zaidin, Consejo Superior de Investigaciones Cientificas, Granada, Spain.
Indole-3-acetic acid (IAA) is emerging as a key intra- and inter-kingdom signal molecule that modulates a wide range of processes of importance during plant-microorganism interaction. However, the mechanisms by which IAA carries out its functions in bacteria as well as the regulatory processes by which bacteria modulate auxin production are largely unknown. Here, we found that IAA synthesis deficiency results in important global transcriptional changes in the broad-range antibiotic-producing rhizobacterium Serratia plymuthica A153. Most pronounced transcriptional changes were observed in various gene clusters for aromatic acid metabolism, including auxin catabolism. To delve into the corresponding molecular mechanisms, different regulatory proteins were biochemically characterized. Among them, a TyrR orthologue was essential for IAA production through the activation of the ipdc gene encoding a key enzyme for IAA biosynthesis. We showed that TyrR specifically recognizes different aromatic amino acids which, in turn, alters the interactions of TyrR with the ipdc promoter. Screening of mutants defective in various transcriptional and post-transcriptional regulators allowed the identification of additional regulators of IAA production, including PigP and quorum sensing-related genes. Advancing our knowledge on the mechanisms that control the IAA biosynthesis in beneficial phytobacteria is of biotechnological interest for improving agricultural productivity and sustainable agricultural development.
PMID: 37345981
Front Plant Sci , IF:5.753 , 2023 , V14 : P1172816 doi: 10.3389/fpls.2023.1172816
Genome-wide association analysis for emergence of deeply sown rice (Oryza sativa) reveals novel aus-specific phytohormone candidate genes for adaptation to dry-direct seeding in the field.
Department of Crop Sciences, University of Illinois Urbana-Champaign, Urbana, IL, United States.; International Rice Research Institute (IRRI), Los Banos, Philippines.; International Rice Research Institute (IRRI), South Asia Regional Centre (ISARC), Varanasi, India.; Africa Rice Center (AfricaRice), Abidjan, Cote d'Ivoire.; Seattle Children's Research Institute, Seattle, WA, United States.
Dry direct-seeded rice (dry-DSR) is typically sown deeply to circumvent the need for irrigation, and thus seedling emergence is a crucial trait affecting plant stand and yield. To breed elite cultivars that use less water and are climate-resilient, an understanding of the genomic regions and underlying genes that confer emergence in deeply sown dry-DSR would be highly advantageous. A combined diversity panel of 470 rice accessions (RDP1 plus aus subset of 3K RGP) was evaluated with 2.9 million single nucleotide polymorphisms (SNPs) to identify associations with dry-DSR traits in the field and component traits in a controlled-environment experiment. Using genome-wide association study (GWAS) analyses, we identified 18 unique QTLs on chromosomes 1, 2, 4, 5, 6, 7, 9, 10, and 11, explaining phenotypic variance ranging from 2.6% to 17.8%. Three QTLs, namely, qSOE-1.1, qEMERG-AUS-1.2, and qEMERG-AUS-7.1, were co-located with previously reported QTLs for mesocotyl length. Among the identified QTLs, half were associated with the emergence of aus, and six were unique to the aus genetic group. Based on functional annotation, we identified eleven compelling candidate genes that primarily regulate phytohormone pathways such as cytokinin, auxin, gibberellic acid, and jasmonic acid. Prior studies indicated that these phytohormones play a critical role in mesocotyl length under deep sowing. This study provides new insight into the importance of aus and indica as desirable genetic resources to mine favorable alleles for deep-sowing tolerance in rice. The candidate genes and marker-tagged desirable alleles identified in this study should benefit rice breeding programs directly.
PMID: 37377815
Front Plant Sci , IF:5.753 , 2023 , V14 : P1192340 doi: 10.3389/fpls.2023.1192340
Transcriptome analysis reveals that auxin promotes strigolactone-induced adventitious root growth in the hypocotyl of melon seedlings.
College of Horticulture, Hebei Agricultural University, Baoding, China.; Collaborative Innovation Center of Vegetable Industry in Hebei, Baoding, China.; Hebei Key Laboratory of Vegetable Germplasm Innovation and Utilization, Baoding, China.
INTRODUCTION: Strigolactone (SL) and auxin are two important phytohormones involved in plant root development, but whether they show synergistic or mutual promotion effects during adventitious root (AR) formation has not been adequately explored. METHODS: In this study, we investigated the mechanisms of GR24 (synthetic SL) and indole-3-acetic acid (IAA; a type of auxin) in the formation of ARs using melon as the study material. RESULTS: Morphological measurements showed that the AR number, length, superficial area, and volume under the GR24 treatment were 1.60-3.27, 1.58-3.99, 2.06-3.42, and 3.00-6.11 times greater than those of the control group, respectively, at 6-10 days; the GR24+IAA treatment further promoted AR formation in melon seedlings, and the AR number, length, superficial area, and volume under the GR24+IAA treatment were 1.44-1.51, 1.28-1.73, 1.19-1.83, and 1.31-1.87 times greater than those obtained with the GR24 treatment, respectively. Transcriptome analysis revealed 2,742, 3,352, and 2,321 differentially expressed genes (DEGs) identified from the GR24 vs. control, GR24+IAA vs. control, and GR24+IAA vs. GR24 comparisons, respectively. The GR24 treatment and GR24+IAA treatment affected auxin and SL synthesis as well as components of the phytohormone signal transduction pathway, such as auxin, brassinosteroid (BR), ethylene (ETH), cytokinin (CK), gibberellin (GA), and abscisic acid (ABA). The concentrations of auxin, GA, zeatin (ZT), and ABA were evaluated using high-performance liquid chromatography (HPLC). From 6 to 10 days, the auxin, GA, and ZT contents in the GR24 treatment group were increased by 11.48%-15.34%, 11.83%-19.50%, and 22.52%-66.17%, respectively, compared to the control group, and these features were increased by 22.00%-31.20%, 21.29%-25.75%, 51.76%-98.96%, respectively, in the GR24+IAA treatment group compared with the control group. Compared to that in the control, the ABA content decreased by 10.30%-11.83% in the GR24 treatment group and decreased by 18.78%-24.00% in the GR24+IAA treatment group at 6-10 days. DISCUSSION: Our study revealed an interaction between strigolactone and auxin in the induction of AR formation in melon seedlings by affecting the expression of genes related to plant hormone pathways and contents.
PMID: 37377810
Front Plant Sci , IF:5.753 , 2023 , V14 : P1193042 doi: 10.3389/fpls.2023.1193042
Transcriptome profiles of rice roots under simulated microgravity conditions and following gravistimulation.
Institute of Crop Science, National Agriculture and Food Research Organization, Tsukuba, Japan.; Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Japan.
Root system architecture affects the efficient uptake of water and nutrients in plants. The root growth angle, which is a critical component in determining root system architecture, is affected by root gravitropism; however, the mechanism of root gravitropism in rice remains largely unknown. In this study, we conducted a time-course transcriptome analysis of rice roots under conditions of simulated microgravity using a three-dimensional clinostat and following gravistimulation to detect candidate genes associated with the gravitropic response. We found that HEAT SHOCK PROTEIN (HSP) genes, which are involved in the regulation of auxin transport, were preferentially up-regulated during simulated microgravity conditions and rapidly down-regulated by gravistimulation. We also found that the transcription factor HEAT STRESS TRANSCRIPTION FACTOR A2s (HSFA2s) and HSFB2s, showed the similar expression patterns with the HSPs. A co-expression network analysis and an in silico motif search within the upstream regions of the co-expressed genes revealed possible transcriptional control of HSPs by HSFs. Because HSFA2s are transcriptional activators, whereas HSFB2s are transcriptional repressors, the results suggest that the gene regulatory networks governed by HSFs modulate the gravitropic response through transcriptional control of HSPs in rice roots.
PMID: 37360733
Front Plant Sci , IF:5.753 , 2023 , V14 : P1136445 doi: 10.3389/fpls.2023.1136445
An auxin-mediated ultradian rhythm positively influences root regeneration via EAR1/EUR1 in Arabidopsis.
Center for Plant Aging Research, Institute for Basic Science, Daegu, Republic of Korea.; Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
Ultradian rhythms have been proved to be critical for diverse biological processes. However, comprehensive understanding of the short-period rhythms remains limited. Here, we discover that leaf excision triggers a gene expression rhythm with ~3-h periodicity, named as the excision ultradian rhythm (UR), which is regulated by the plant hormone auxin. Promoter-luciferase analyses showed that the spatiotemporal patterns of the excision UR were positively associated with de novo root regeneration (DNRR), a post-embryonic developmental process. Transcriptomic analysis indicated more than 4,000 genes including DNRR-associated genes were reprogramed toward ultradian oscillation. Genetic studies showed that EXCISION ULTRADIAN RHYTHM 1 (EUR1) encoding ENHANCER OF ABSCISIC ACID CO-RECEPTOR1 (EAR1), an abscisic acid signaling regulator, was required to generate the excision ultradian rhythm and enhance root regeneration. The eur1 mutant exhibited the absence of auxin-induced excision UR generation and partial failure during rescuing root regeneration. Our results demonstrate a link between the excision UR and adventitious root formation via EAR1/EUR1, implying an additional regulatory layer in plant regeneration.
PMID: 37351216
Front Plant Sci , IF:5.753 , 2023 , V14 : P1184020 doi: 10.3389/fpls.2023.1184020
Functional specialization of chloroplast vesiculation (CV) duplicated genes from soybean shows partial overlapping roles during stress-induced or natural senescence.
Laboratorio de Biologia Molecular Vegetal, Instituto de Quimica Biologica, Facultad de Ciencias, Universidad de la Republica, Montevideo, Uruguay.; Department of Plant Sciences, University of California, Davis, Davis, CA, United States.
Soybean is a globally important legume crop which is highly sensitive to drought. The identification of genes of particular relevance for drought responses provides an important basis to improve tolerance to environmental stress. Chloroplast Vesiculation (CV) genes have been characterized in Arabidopsis and rice as proteins participating in a specific chloroplast-degradation vesicular pathway (CVV) during natural or stress-induced leaf senescence. Soybean genome contains two paralogous genes encoding highly similar CV proteins, CV1 and CV2. In this study, we found that expression of CV1 was differentially upregulated by drought stress in soybean contrasting genotypes exhibiting slow-wilting (tolerant) or fast-wilting (sensitive) phenotypes. CV1 reached higher induction levels in fast-wilting plants, suggesting a negative correlation between CV1 gene expression and drought tolerance. In contrast, autophagy (ATG8) and ATI-PS (ATI1) genes were induced to higher levels in slow-wilting plants, supporting a pro-survival role for these genes in soybean drought tolerance responses. The biological function of soybean CVs in chloroplast degradation was confirmed by analyzing the effect of conditional overexpression of CV2-FLAG fusions on the accumulation of specific chloroplast proteins. Functional specificity of CV1 and CV2 genes was assessed by analyzing their specific promoter activities in transgenic Arabidopsis expressing GUS reporter gene driven by CV1 or CV2 promoters. CV1 promoter responded primarily to abiotic stimuli (hyperosmolarity, salinity and oxidative stress), while the promoter of CV2 was predominantly active during natural senescence. Both promoters were highly responsive to auxin but only CV1 responded to other stress-related hormones, such as ABA, salicylic acid and methyl jasmonate. Moreover, the dark-induced expression of CV2, but not of CV1, was strongly inhibited by cytokinin, indicating similarities in the regulation of CV2 to the reported expression of Arabidopsis and rice CV genes. Finally, we report the expression of both CV1 and CV2 genes in roots of soybean and transgenic Arabidopsis, suggesting a role for the encoded proteins in root plastids. Together, the results indicate differential roles for CV1 and CV2 in development and in responses to environmental stress, and point to CV1 as a potential target for gene editing to improve crop performance under stress without compromising natural development.
PMID: 37346131
Front Plant Sci , IF:5.753 , 2023 , V14 : P1176705 doi: 10.3389/fpls.2023.1176705
Allelic variation in the indoleacetic acid-lysine synthase gene of the bacterial pathogen Pseudomonas savastanoi and its role in auxin production.
Area de Genetica, Facultad de Ciencias, Universidad de Malaga (UMA), Malaga, Spain.; Instituto de Hortofruticultura Subtropical y Mediterranea "La Mayora", Consejo Superior de Investigaciones Cientificas (IHSM-UMA-CSIC), Malaga, Spain.; Department of Biology, Biochemistry and Natural Sciences, Universitat Jaume I (UJI), Castello de la Plana, Spain.; Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, NC, United States.; Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA, United States.
Indole-3-acetic acid (IAA) production is a pathogenicity/virulence factor in the Pseudomonas syringae complex, including Pseudomonas savastanoi. P. savastanoi pathovars (pvs.) genomes contain the iaaL gene, encoding an enzyme that catalyzes the biosynthesis of the less biologically active compound 3-indole-acetyl-ϵ-L-lysine (IAA-Lys). Previous studies have reported the identification of IAA-Lys in culture filtrates of P. savastanoi strains isolated from oleander (pv. nerii), but the conversion of IAA into a conjugate was not detectable in olive strains (pv. savastanoi). In this paper, we show the distribution of iaaL alleles in all available P. savastanoi genomes of strains isolated from woody hosts. Most strains encode two different paralogs, except for those isolated from broom (pv. retacarpa), which contain a single allele. In addition to the three previously reported iaaL alleles (iaaL (Psv), iaaL (Psn) and iaaL (Pto)), we identified iaaL (Psf), an exclusive allele of strains isolated from ash (pv. fraxini). We also found that the production of IAA-Lys in P. savastanoi pv. savastanoi and pv. nerii depends on a functional iaaL (Psn) allele, whereas in pv. fraxini depends on iaaL (Psf). The production of IAA-Lys was detected in cultures of an olive strain heterologously expressing IaaL(Psn-1), IaaL(Psf-1) and IaaL(Psf-3), but not when expressing IaaL(Psv-1). In addition, Arabidopsis seedlings treated with the strains overproducing the conjugate, and thus reducing the free IAA content, alleviated the root elongation inhibitory effect of IAA. IAA-Lys synthase activity assays with purified allozymes confirmed the functionality and specificity of lysine as a substrate of IaaL(Psn-1) and IaaL(Psf-3), with IaaL(Psf-3) showing the highest catalytic efficiency for both substrates. The IAA-Lys synthase activity of IaaL(Psn-1) was abolished by the insertion of two additional tyrosine residues encoded in the inactive allozyme IaaL(Psv-1). These results highlight the relevance of allelic variation in a phytohormone-related gene for the modulation of auxin production in a bacterial phytopathogen.
PMID: 37346122
Front Plant Sci , IF:5.753 , 2023 , V14 : P1166728 doi: 10.3389/fpls.2023.1166728
Genetic dissection of thousand-seed weight in linseed (Linum usitatissimum L.) using multi-locus genome-wide association study.
Division of Genomic Resources, Indian Council of Agricultural Research (ICAR)-National Bureau of Plant Genetic Resources, New Delhi, India.; ICAR-National Bureau of Plant Genetic Resources, Regional Station Akola, Maharashtra, India.; Division of Germplasm Evaluation, ICAR-National Bureau of Plant Genetic Resources, New Delhi, India.; Division of Germplasm Conservation, ICAR-National Bureau of Plant Genetic Resources, New Delhi, India.; ICAR-National Bureau of Plant Genetic Resources, New Delhi, India.
Flaxseed/linseed is an important oilseed crop having applications in the food, nutraceutical, and paint industry. Seed weight is one of the most crucial determinants of seed yield in linseed. Here, quantitative trait nucleotides (QTNs) associated with thousand-seed weight (TSW) have been identified using multi-locus genome-wide association study (ML-GWAS). Field evaluation was carried out in five environments in multi-year-location trials. SNP genotyping information of the AM panel of 131 accessions comprising 68,925 SNPs was employed for ML-GWAS. From the six ML-GWAS methods employed, five methods helped identify a total of 84 unique significant QTNs for TSW. QTNs identified in >/= 2 methods/environments were designated as stable QTNs. Accordingly, 30 stable QTNs have been identified for TSW accounting up to 38.65% trait variation. Alleles with positive effect on trait were analyzed for 12 strong QTNs with r (2) >/= 10.00%, which showed significant association of specific alleles with higher trait value in three or more environments. A total of 23 candidate genes have been identified for TSW, which included B3 domain-containing transcription factor, SUMO-activating enzyme, protein SCARECROW, shaggy-related protein kinase/BIN2, ANTIAUXIN-RESISTANT 3, RING-type E3 ubiquitin transferase E4, auxin response factors, WRKY transcription factor, and CBS domain-containing protein. In silico expression analysis of candidate genes was performed to validate their possible role in different stages of seed development process. The results from this study provide significant insight and elevate our understanding on genetic architecture of TSW trait in linseed.
PMID: 37332700
Front Plant Sci , IF:5.753 , 2023 , V14 : P1187634 doi: 10.3389/fpls.2023.1187634
How plants cope with fast primary root elongation inhibition.
College of Bioscience and Bioengineering, Jiangxi Agricultural University, Jiangxi, Nanchang, China.
PMID: 37324686
Front Plant Sci , IF:5.753 , 2023 , V14 : P1082094 doi: 10.3389/fpls.2023.1082094
Inactivation of tomato WAT1 leads to reduced susceptibility to Clavibacter michiganensis through downregulation of bacterial virulence factors.
Plant Breeding, Wageningen University & Research, Wageningen, Netherlands.; Graduate School Experimental Plant Sciences Wageningen University & Research, Wageningen, Netherlands.; Cluster of Plant Developmental Biology, Laboratory of Molecular Biology, Wageningen University & Research, Wageningen, Netherlands.; Biointeractions & Plant Health, Wageningen University & Research, Wageningen, Netherlands.
Tomato bacterial canker caused by Clavibacter michiganensis (Cm) is considered to be one of the most destructive bacterial diseases of tomato. To date, no resistance to the pathogen has been identified. While several molecular studies have identified (Cm) bacterial factors involved in disease development, the plant genes and mechanisms associated with susceptibility of tomato to the bacterium remain largely unknown. Here, we show for the first time that tomato gene SlWAT1 is a susceptibility gene to Cm. We inactivated the gene SlWAT1 through RNAi and CRISPR/Cas9 to study changes in tomato susceptibility to Cm. Furthermore, we analysed the role of the gene in the molecular interaction with the pathogen. Our findings demonstrate that SlWAT1 functions as an S gene to genetically diverse Cm strains. Inactivation of SlWAT1 reduced free auxin contents and ethylene synthesis in tomato stems and suppressed the expression of specific bacterial virulence factors. However, CRISPR/Cas9 slwat1 mutants exhibited severe growth defects. The observed reduced susceptibility is possibly a result of downregulation of bacterial virulence factors and reduced auxin contents in transgenic plants. This shows that inactivation of an S gene may affect the expression of bacterial virulence factors.
PMID: 37324660
Front Plant Sci , IF:5.753 , 2023 , V14 : P1166226 doi: 10.3389/fpls.2023.1166226
Size regulation of the lateral organ initiation zone and its role in determining cotyledon number in conifers.
Mathematics Department, British Columbia Institute of Technology, Burnaby, BC, Canada.; Biotechnology Department, British Columbia Institute of Technology, Burnaby, BC, Canada.
INTRODUCTION: Unlike monocots and dicots, many conifers, particularly Pinaceae, form three or more cotyledons. These are arranged in a whorl, or ring, at a particular distance from the embryo tip, with cotyledons evenly spaced within the ring. The number of cotyledons, n(c), varies substantially within species, both in clonal cultures and in seed embryos. n(c) variability reflects embryo size variability, with larger diameter embryos having higher n(c). Correcting for growth during embryo development, we extract values for the whorl radius at each n(c). This radius, corresponding to the spatial pattern of cotyledon differentiation factors, varies over three-fold for the naturally observed range of n(c). The current work focuses on factors in the patterning mechanism that could produce such a broad variability in whorl radius. Molecularly, work in Arabidopsis has shown that the initiation zone for leaf primordia occurs at a minimum between inhibitor zones of HD-ZIP III at the shoot apical meristem (SAM) tip and KANADI (KAN) encircling this farther from the tip. PIN1-auxin dynamics within this uninhibited ring form auxin maxima, specifying primordia initiation sites. A similar mechanism is indicated in conifer embryos by effects on cotyledon formation with overexpression of HD-ZIP III inhibitors and by interference with PIN1-auxin patterning. METHODS: We develop a mathematical model for HD-ZIP III/KAN spatial localization and use this to characterize the molecular regulation that could generate (a) the three-fold whorl radius variation (and associated n(c) variability) observed in conifer cotyledon development, and (b) the HD-ZIP III and KAN shifts induced experimentally in conifer embryos and in Arabidopsis. RESULTS: This quantitative framework indicates the sensitivity of mechanism components for positioning lateral organs closer to or farther from the tip. Positional shifting is most readily driven by changes to the extent of upstream (meristematic) patterning and changes in HD-ZIP III/KAN mutual inhibition, and less efficiently driven by changes in upstream dosage or the activation of HD-ZIP III. Sharper expression boundaries can also be more resistant to shifting than shallower expression boundaries. DISCUSSION: The strong variability seen in conifer n(c) (commonly from 2 to 10) may reflect a freer variation in regulatory interactions, whereas monocot (n(c) = 1) and dicot (n(c) = 2) development may require tighter control of such variation. These results provide direction for future quantitative experiments on the positional control of lateral organ initiation, and consequently on plant phyllotaxy and architecture.
PMID: 37265639
Front Plant Sci , IF:5.753 , 2023 , V14 : P1142868 doi: 10.3389/fpls.2023.1142868
Transcriptome profiling of high and low somatic embryogenesis rate of oil palm (Elaeis guineensis Jacq. var. Tenera).
Biotechnology Department, Plant Production and Biotechnology Division, PT SMART Tbk, Bogor, Indonesia.; Agronomy and Horticulture Department, Agriculture Faculty, Bogor Agricultural University, Bogor, Indonesia.
Oil palm micropropagation through tissue culture is a technique to provide elite oil palms to meet the desired traits. This technique is commonly carried out through somatic embryogenesis. However, the oil palm's somatic embryogenesis rate is quite low. Several approaches have been made to overcome this problem, including transcriptome profiling through RNA-seq to identify key genes involved in oil palm somatic embryogenesis. RNA sequencing was applied in high- and low-embryogenic ortets of Tenera varieties based on the somatic embryoid rate at the callus, globular, scutellar, and coleoptilar embryoid stages. Cellular analysis of embryoid inductions and proliferations showed that high-embryogenic ortets resulted in higher embryoid proliferation and germinations than low-embryogenic ortets. Transcriptome profiling showed that there are a total of 1,911 differentially expressed genes (DEGs) between high- and low-embryogenic ortets. ABA signaling-related genes such as LEA, DDX28, and vicilin-like protein are upregulated in high-embryogenic ortets. Furthermore, DEGs associated with other hormone signaling, such as HD-ZIP associated with brassinosteroids and NPF associated with auxin, are upregulated in high-embryogenic ortets. This result suggests a physiological difference between high- and low-embryogenic ortets that is connected to their capacity for somatic embryogenesis. These DEGs will be used as potential biomarkers for high-embryogenic ortets and will be validated in further studies.
PMID: 37251752
Theor Appl Genet , IF:5.699 , 2023 Jun , V136 (7) : P160 doi: 10.1007/s00122-023-04404-z
Photoperiod and gravistimulation-associated Tiller Angle Control 1 modulates dynamic changes in rice plant architecture.
State Key Laboratory of Rice Biology and Breeding, Key Laboratory for Zhejiang Super Rice Research, China National Center for Rice Improvement, China National Rice Research Institute, Hangzhou, 311401, China.; Rice Research Institute, Key Laboratory of Application and Safety Control of Genetically Modified Crops, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, China.; State Key Laboratory of Rice Biology and Breeding, Key Laboratory for Zhejiang Super Rice Research, China National Center for Rice Improvement, China National Rice Research Institute, Hangzhou, 311401, China. caoliyong@caas.cn.; State Key Laboratory of Rice Biology and Breeding, Key Laboratory for Zhejiang Super Rice Research, China National Center for Rice Improvement, China National Rice Research Institute, Hangzhou, 311401, China. zhangyingxin@caas.cn.; State Key Laboratory of Rice Biology and Breeding, Key Laboratory for Zhejiang Super Rice Research, China National Center for Rice Improvement, China National Rice Research Institute, Hangzhou, 311401, China. chengshihua@caas.cn.
TAC1 is involved in photoperiodic and gravitropic responses to modulate rice dynamic plant architecture likely by affecting endogenous auxin distribution, which could explain TAC1 widespread distribution in indica rice. Plants experience a changing environment throughout their growth, which requires dynamic adjustments of plant architecture in response to these environmental cues. Our previous study demonstrated that Tiller Angle Control 1 (TAC1) modulates dynamic changes in plant architecture in rice; however, the underlying regulatory mechanisms remain largely unknown. In this study, we show that TAC1 regulates plant architecture in an expression dose-dependent manner, is highly expressed in stems, and exhibits dynamic expression in tiller bases during the growth period. Photoperiodic treatments revealed that TAC1 expression shows circadian rhythm and is more abundant during the dark period than during the light period and under short-day conditions than under long-day conditions. Therefore, it contributes to dynamic plant architecture under long-day conditions and loose plant architecture under short-day conditions. Gravity treatments showed that TAC1 is induced by gravistimulation and negatively regulates shoot gravitropism, likely by affecting auxin distribution. Notably, the tested indica rice containing TAC1 displayed dynamic plant architecture under natural long-day conditions, likely explaining the widespread distribution of TAC1 in indica rice. Our results provide new insights into TAC1-mediated regulatory mechanisms for dynamic changes in rice plant architecture.
PMID: 37347301
Front Microbiol , IF:5.64 , 2023 , V14 : P1152597 doi: 10.3389/fmicb.2023.1152597
Biocontrol and plant growth promoting traits of two avocado rhizobacteria are orchestrated by the emission of diffusible and volatile compounds.
Red de Estudios Moleculares Avanzados, Instituto de Ecologia, A.C., Xalapa, Veracruz, Mexico.; CONACyT - Escuela Nacional de Estudios Superiores, Unidad Morelia, Laboratorio Nacional de Analisis y Sintesis Ecologica, Universidad Nacional Autonoma de Mexico, Morelia, Michoacan, Mexico.; CONACyT - Red de Diversidad Biologica del Occidente Mexicano, Centro Regional del Bajio, Instituto de Ecologia, A.C., Patzcuaro, Michoacan, Mexico.; Facultad de Medicina, Universidad Nacional Autonoma de Mexico, Ciudad de Mexico, Mexico.; Escuela Nacional de Estudios Superiores Unidad Morelia, Laboratorio Nacional de Analisis y Sintesis Ecologica, Universidad Nacional Autonoma de Mexico, Morelia, Mexico.; Red de Diversidad Biologica del Occidente Mexicano, Centro Regional del Bajio, Instituto de Ecologia, A.C., Patzcuaro, Michoacan, Mexico.
Avocado (Persea americana Mill.) is a tree crop of great social and economic importance. However, the crop productivity is hindered by fast-spreading diseases, which calls for the search of new biocontrol alternatives to mitigate the impact of avocado phytopathogens. Our objectives were to evaluate the antimicrobial activity of diffusible and volatile organic compounds (VOCs) produced by two avocado rhizobacteria (Bacillus A8a and HA) against phytopathogens Fusarium solani, Fusarium kuroshium, and Phytophthora cinnamomi, and assess their plant growth promoting effect in Arabidopsis thaliana. We found that, in vitro, VOCs emitted by both bacterial strains inhibited mycelial growth of the tested pathogens by at least 20%. Identification of bacterial VOCs by gas chromatography coupled to mass spectrometry (GC-MS) showed a predominance of ketones, alcohols and nitrogenous compounds, previously reported for their antimicrobial activity. Bacterial organic extracts obtained with ethyl acetate significantly reduced mycelial growth of F. solani, F. kuroshium, and P. cinnamomi, the highest inhibition being displayed by those from strain A8a (32, 77, and 100% inhibition, respectively). Tentative identifications carried out by liquid chromatography coupled to accurate mass spectrometry of diffusible metabolites in the bacterial extracts, evidenced the presence of some polyketides such as macrolactins and difficidin, hybrid peptides including bacillaene, and non-ribosomal peptides such as bacilysin, which have also been described in Bacillus spp. for antimicrobial activities. The plant growth regulator indole-3-acetic acid was also identified in the bacterial extracts. In vitro assays showed that VOCs from strain HA and diffusible compounds from strain A8a modified root development and increased fresh weight of A. thaliana. These compounds differentially activated several hormonal signaling pathways involved in development and defense responses in A. thaliana, such as auxin, jasmonic acid (JA) and salicylic acid (SA); genetic analyses suggested that developmental stimulation of the root system architecture by strain A8a was mediated by the auxin signaling pathway. Furthermore, both strains were able to enhance plant growth and decreased the symptoms of Fusarium wilt in A. thaliana when soil-inoculated. Collectively, our results evidence the potential of these two rhizobacterial strains and their metabolites as biocontrol agents of avocado pathogens and as biofertilizers.
PMID: 37206331
Biology (Basel) , IF:5.079 , 2023 May , V12 (6) doi: 10.3390/biology12060787
Effect of Low Light Stress on Distribution of Auxin (Indole-3-acetic Acid) between Shoot and Roots and Development of Lateral Roots in Barley Plants.
Ufa Institute of Biology, Ufa Federal Research Centre RAS, 69 Pr. Octyabrya, 450054 Ufa, Russia.; K.A. Timiryazev Institute of Plant Physiology RAS, 35 Botanicheskaya St., 127276 Moscow, Russia.
Depending on their habitat conditions, plants can greatly change the growth rate of their roots. However, the mechanisms of such responses remain insufficiently clear. The influence of a low level of illumination on the content of endogenous auxins, their localization in leaves and transport from shoots to roots were studied and related to the lateral root branching of barley plants. Following two days' reduction in illumination, a 10-fold reduction in the emergence of lateral roots was found. Auxin (IAA, indole-3-acetic acid) content decreased by 84% in roots and by 30% in shoots, and immunolocalization revealed lowered IAA levels in phloem cells of leaf sections. The reduced content of IAA found in the plants under low light suggests an inhibition of production of this hormone under these conditions. At the same time, two-fold downregulation of the LAX3 gene expression, facilitating IAA influx into the cells, was detected in the roots, as well as a decline in auxin diffusion from shoots through the phloem by about 60%. It was suggested that the reduced emergence of lateral roots in barley under a low level of illumination was due to a disturbance of auxin transport through the phloem and down-regulation of the genes responsible for auxin transport in plant roots. The results confirm the importance of the long distance transport of auxins for the control of the growth of roots under conditions of low light. Further study of the mechanisms that control the transport of auxins from shoots to roots in other plant species is required.
PMID: 37372072
Pest Manag Sci , IF:4.845 , 2023 May doi: 10.1002/ps.7541
Nontarget-site resistance due to rapid physiological response in 2,4-D resistant Conyza sumatrensis: reduced 2,4-D translocation and auxin-induced gene expression.
Federal Rural University of Rio de Janeiro, Department of Crop, Seropedica, Brazil.; Colorado State University, Department of Agricultural Biology, Fort Collins, Colorado, USA.; Corteva Agriscience, Field Scientist, Sao Paulo, Brazil.
BACKGROUND: Resistance to 2,4-Dichlorophenoxyacetic acid (2,4-D) has been reported in several weed species since the 1950s; however, a biotype of Conyza sumatrensis showing a novel physiology of the rapid response minutes after herbicide application was reported in 2017. The objective of this research was to investigate the mechanisms of resistance and identify transcripts associated with the rapid physiological response of C. sumatrensis to 2,4-D herbicide. RESULTS: Differences were found in 2,4-D absorption between the resistant and susceptible biotypes. Herbicide translocation was reduced in the resistant biotype compared to the susceptible. In resistant plants 98.8% of [(14) C] 2,4-D was found in the treated leaf, whereas approximately 13% translocated to other plant parts in the susceptible biotype at 96 h after treatment. Resistant plants did not metabolize [(14) C] 2,4-D and had only intact [(14) C] 2,4-D at 96 h after application, whereas susceptible plants metabolized [(14) C] 2,4-D into four detected metabolites, consistent with reversible conjugation metabolites found in other 2,4-D sensitive plant species. Pre-treatment with the cytochrome P450 inhibitor malathion did not enhance 2,4-D sensitivity in either biotype. Following treatment with 2,4-D, resistant plants showed increased expression of transcripts within plant defense response and hypersensitivity pathways, whereas both sensitive and resistant plants showed increased expression of auxin-response transcripts. CONCLUSION: Our results demonstrate that reduced 2,4-D translocation contributes to resistance in the C. sumatrensis biotype. The reduction in 2,4-D transport is likely to be a consequence of the rapid physiological response to 2,4-D in resistant C. sumatrensis. Resistant plants had increased expression of auxin-responsive transcripts, indicating that a target-site mechanism is unlikely. (c) 2023 Society of Chemical Industry.
PMID: 37178347
Rice (N Y) , IF:4.783 , 2023 Jun , V16 (1) : P28 doi: 10.1186/s12284-023-00645-0
Pan-transcriptomic Profiling Demarcates Serendipita Indica-Phosphorus Mediated Tolerance Mechanisms in Rice Exposed to Arsenic Toxicity.
Zhejiang Key Laboratory of Crop Germplasm Resource, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China.; Dow International Medical College, Dow University of Health Sciences, Karachi, 74200, Pakistan.; Zhejiang Key Laboratory of Crop Germplasm Resource, Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China. drimran@zju.edu.cn.
Inadvertent accumulation of arsenic (As) in rice (Oryza sativa L.) is a concern for people depending on it for their subsistence, as it verily causes epigenetic alterations across the genome as well as in specific cells. To ensure food safety, certain attempts have been made to nullify this highest health hazard encompassing physiological, chemical and biological methods. Albeit, the use of mycorrhizal association along with nutrient reinforcement strategy has not been explored yet. Mechanisms of response and resistance of two rice genotypes to As with or without phosphorus (P) nutrition and Serendipita indica (S. indica; S.i) colonization were explored by root transcriptome profiling in the present study. Results revealed that the resistant genotype had higher auxin content and root plasticity, which helped in keeping the As accumulation and P starvation response to a minimum under alone As stress. However, sufficient P supply and symbiotic relationship switched the energy resources towards plant's developmental aspects rather than excessive root proliferation. Higher As accumulating genotype (GD-6) displayed upregulation of ethylene signaling/biosynthesis, root stunting and senescence related genes under As toxicity. Antioxidant defense system and cytokinin biosynthesis/signaling of both genotypes were strengthened under As + S.i + P, while the upregulation of potassium (K) and zinc (Zn) transporters depicted underlying cross-talk with iron (Fe) and P. Differential expression of phosphate transporters, peroxidases and GSTs, metal detoxification/transport proteins, as well as phytohormonal metabolism were responsible for As detoxification. Taken together, S. indica symbiosis fortified with adequate P-fertilizer can prove to be effective in minimizing As acquisition and accumulation in rice plants.
PMID: 37354226
Plant Sci , IF:4.729 , 2023 Jul , V332 : P111726 doi: 10.1016/j.plantsci.2023.111726
Short-term exposition to acute cadmium toxicity induces the loss of root gravitropic stimuli perception through PIN2-mediated auxin redistribution in Arabidopsis thaliana (L.) Heynh.
Department of Agricultural and Environmental Sciences, University of Milano, Milan 20133, Italy.; Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Arcavacata of Rende, CS 87036, Italy.; Universidade de Vigo, Departamento de Bioloxia Vexetal e Ciencias do Solo, Facultade de Bioloxia, Campus Lagoas-Marcosende s/n, 36310 Vigo, Spain.; Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Arcavacata of Rende, CS 87036, Italy. Electronic address: leonardo.bruno@unical.it.
Cadmium (Cd), one of the most widespread and water-soluble polluting heavy metals, has been widely studied on plants, even if the mechanisms underlying its phytotoxicity remain elusive. Indeed, most experiments are performed using extensive exposure time to the toxicants, not observing the primary targets affected. The present work studied Cd effects on Arabidopsis thaliana (L.) Heynh's root apical meristem (RAM) exposed for short periods (24 h and 48 h) to acute phytotoxic concentrations (100 and 150 microM). The effects were studied through integrated morpho-histological, molecular, pharmacological and metabolomic analyses, highlighting that Cd inhibited primary root elongation by affecting the meristem zone via altering cell expansion. Moreover, Cd altered Auxin accumulation in RAM and affected PINs polar transporters, particularly PIN2. In addition, we observed that high Cd concentration induced accumulation of reactive oxygen species (ROS) in roots, which resulted in an altered organization of cortical microtubules and the starch and sucrose metabolism, altering the statolith formation and, consequently, the gravitropic root response. Our results demonstrated that short Cd exposition (24 h) affected cell expansion preferentially, altering auxin distribution and inducing ROS accumulation, which resulted in an alteration of gravitropic response and microtubules orientation pattern.
PMID: 37149227
Plant Sci , IF:4.729 , 2023 Jul , V332 : P111718 doi: 10.1016/j.plantsci.2023.111718
Indole-3-acetaldoxime delays root iron-deficiency responses and modify auxin homeostasis in Medicago truncatula.
Department of Pomology, Aula Dei Experimental Station, Consejo Superior de Investigaciones Cientificas (CSIC), Avda. de Montanana 1005, E-50059 Zaragoza, Spain.; Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA), Avda. de Pamplona 123, E-31192 Mutilva, Spain.; Institute for Advanced Materials and Mathematics (INAMAT2), Department of Sciences, Public University of Navarre (UPNA), Campus de Arrosadia, E-31006 Pamplona, Spain.; Department of Pomology, Aula Dei Experimental Station, Consejo Superior de Investigaciones Cientificas (CSIC), Avda. de Montanana 1005, E-50059 Zaragoza, Spain. Electronic address: aoiz@eead.csic.es.
Iron (Fe) is an essential plant micronutrient, being a major limiting growth factor in calcareous soils. To increase Fe uptake, plants induce lateral roots growth, the expression of a Fe(III)-chelate reductase (FCR), a Fe(II)-transporter and a H(+)-ATPase and the secretion of flavins. Furthermore, auxin hormone family is involved in the Fe-deficiency responses but the action mechanism remains elusive. In this work, we evaluated the effect of the auxin-precursor indole-3-acetaldoxime (IAOx) on hydroponically grown Medicago truncatula plants under different Fe conditions. Upon 4-days of Fe starvation, the pH of the nutrient solution decreased, while both the FCR activity and the presence of flavins increased. Exogenous IAOx increased lateral roots growth contributing to superroot phenotype, decreased chlorosis, and delayed up to 3-days the pH-decrease, the FCR-activity increase, and the presence of flavins, compared to Fe-deficient plants. Gene expression levels were in concordance with the physiological responses. RESULTS: showed that IAOx was immediately transformed to IAN in roots and shoots to maintain auxin homeostasis. IAOx plays an active role in iron homeostasis delaying symptoms and responses in Fe-deficient plants. We may speculate that IAOx or its derivatives remobilize Fe from root cells to alleviate Fe-deficiency. Overall, these results point out that the IAOx-derived phenotype may have advantages to overcome nutritional stresses.
PMID: 37105378
Plant Sci , IF:4.729 , 2023 Jul , V332 : P111699 doi: 10.1016/j.plantsci.2023.111699
Role of EIN2-mediated ethylene signaling in regulating petal senescence, abscission, reproductive development, and hormonal crosstalk in tobacco.
Department of Biology, University of Texas Rio Grande Valley, 1201 W. University Dr, Edinburg, TX 78539, USA. Electronic address: manohar.chakrabarti@utrgv.edu.; Department of Biology, University of Texas Rio Grande Valley, 1201 W. University Dr, Edinburg, TX 78539, USA.
Ethylene plays a pivotal role in a wide range of developmental, physiological, and defense processes in plants. EIN2 (ETHYLENE INSENSITIVE2) is a key player in the ethylene signaling pathway. To characterize the role of EIN2 in processes, such as petal senescence, where it has been found to play important roles along with various other developmental and physiological processes, the tobacco (Nicotiana tabacum) ortholog of EIN2 (NtEIN2) was isolated and NtEIN2 silenced transgenic lines were generated using RNA interference (RNAi). Silencing of NtEIN2 compromised plant defense against pathogens. NtEIN2 silenced lines displayed significant delays in petal senescence, and pod maturation, and adversely affected pod and seed development. This study further dissected the petal senescence in ethylene insensitive lines, that displayed alteration in the pattern of petal senescence and floral organ abscission. Delay in petal senescence was possibly because of delayed aging processes within petal tissues. Possible crosstalk between EIN2 and AUXIN RESPONSE FACTOR 2 (ARF2) in regulating the petal senescence process was also investigated. Overall, these experiments indicated a crucial role for NtEIN2 in controlling diverse developmental and physiological processes, especially in petal senescence.
PMID: 37028457
Plant Sci , IF:4.729 , 2023 Jun , V331 : P111686 doi: 10.1016/j.plantsci.2023.111686
Conservation and divergence of flg22, pep1 and nlp20 in activation of immune response and inhibition of root development.
College of Life Sciences, Sichuan Agricultural University, Ya'an, Sichuan, PR China.; College of Horticulture, FAFU-UCR Joint Center and Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.; Lusyno Biotech Ltd., Chengdu, Sichuan, PR China.; College of Horticulture, FAFU-UCR Joint Center and Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China. Electronic address: wus@fafu.edu.cn.; College of Life Sciences, Sichuan Agricultural University, Ya'an, Sichuan, PR China. Electronic address: yicai@sicau.edu.cn.
Many pattern-recognition receptors (PRRs) and their corresponding ligands have been identified. However, it is largely unknown how similar and different these ligands are in inducing plant innate immunity and affecting plant development. In this study, we examined three well characterized ligands in Arabidopsis thaliana, namely flagellin 22 (flg22), plant elicitor peptide 1 (pep1) and a conserved 20-amino-acid fragment found in most necrosis and ethylene-inducing peptide 1-like proteins (nlp20). Our quantitative analyses detected the differences in amplitude in the early immune responses of these ligands, with nlp20-induced responses typically being slower than those mediated by flg22 and pep1. RNA sequencing showed the shared differentially expressed genes (DEGs) was mostly enriched in defense response, whereas nlp20-regulated genes represent only a fraction of those genes differentially regulated by flg22 and pep1. The three elicitors all inhibited primary root growth, especially pep1, which inhibited both auxin transport and signaling pathway. In addition, pep1 significantly inhibited the cell division and genes involved in cell cycle. Compared with flg22 and nlp20, pep1 induced much stronger expression of its receptor in roots, suggesting a potential positive feedback regulation in the activation of immune response. Despite PRRs and their co-receptor BAK1 were necessary for both PAMP induced immune response and root growth inhibition, bik1 mutant only showed impaired defense response but relatively normal root growth inhibition, suggesting BIK1 acts differently in these two biological processes.
PMID: 36963637
Plant Sci , IF:4.729 , 2023 Jun , V331 : P111677 doi: 10.1016/j.plantsci.2023.111677
Dysfunction of GmVPS8a causes compact plant architecture in soybean.
Soybean Research Institute, Key Laboratory of Biology and Genetic Improvement of Soybean, National Center for Soybean Improvement (Ministry of Agriculture), National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.; National Soybean Improvement Center Shijiazhuang Sub-Center, North China Key Laboratory of Biology and Genetic Improvement of Soybean, Ministry of Agriculture, Laboratory of Crop Genetics and Breeding of Hebei, Cereal & Oil Crop Institute, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang, China.; The National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China. Electronic address: liubin05@caas.cn.; Soybean Research Institute, Key Laboratory of Biology and Genetic Improvement of Soybean, National Center for Soybean Improvement (Ministry of Agriculture), National Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: tjzhao@njau.edu.cn.
Vacuolar Protein Sorting 8 (Vps8) protein is a specific subunit of the class C core vacuole/endosome tethering (CORVET) complex that plays a key role in endosomal trafficking in yeast (Saccharomyces cerevisiae). However, its functions remain largely unclear in plant vegetative growth. Here, we identified a soybean (Glycine max) T4219 mutant characterized with compact plant architecture. Map-based cloning targeted to a candidate gene GmVPS8a (Glyma.07g049700) and further found that two nucleotides deletion in the first exon of GmVPS8a causes a premature termination of the encoded protein in the T4219 mutant. Its functions were validated by CRISPR/Cas9-engineered mutation in the GmVPS8a gene that recapitulated the T4219 mutant phenotypes. Furthermore, NbVPS8a-silenced tobacco (Nicotiana benthamiana) plants exhibited similar phenotypes to the T4219 mutant, suggesting its conserved roles in plant growth. The GmVPS8a is widely expressed in multiple organs and its protein interacts with GmAra6a and GmRab5a. Combined analysis of transcriptomic and proteomic data revealed that dysfunction of GmVPS8a mainly affects pathways on auxin signal transduction, sugar transport and metabolism, and lipid metabolism. Collectively, our work reveals the function of GmVPS8a in plant architecture, which may extend a new way for genetic improvement of ideal plant-architecture breeding in soybean and other crops.
PMID: 36931563
Plant Sci , IF:4.729 , 2023 May , V330 : P111666 doi: 10.1016/j.plantsci.2023.111666
Genome-wide identification and characterization of long non-coding RNA in barley roots in response to Piriformospora indica colonization.
School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China. Electronic address: liangli@hebut.edu.cn.; School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China.; School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China. Electronic address: jackeikee@hebut.edu.cn.
Currently, there is very limited information about long noncoding RNAs (lncRNAs) found in barley. It remains unclear whether barley lncRNAs are responsive to Piriformospora indica (P. indica) colonization.We found that barley roots exhibited fast development and that large roots branched after P. indica colonization. Genome-wide high-throughput RNA-seq and bioinformatic analysis showed that 4356 and 5154 differentially expressed LncRNAs (DELs) were found in response to P. indica at 3 and 7 days after colonization (dai), respectively, and 2456 DELs were found at 7 dai compared to 3 dai. Based on the coexpression correlation of lncRNAmRNA, we found that 98.6% of lncRNAs were positively correlated with 3430 mRNAs at 3 dai and 7 dai. Further GO analysis showed that 30 lncRNAs might be involved in the regulation of gene transcription; 23 lncRNAs might participate in cell cycle regulation. Moreover, the metabolite analysis indicated that chlorophyll a, sucrose, protein, gibberellin, and auxin were in accordance with the results of the transcriptome, and the respective lncRNAs were positively correlated with these target RNAs. Gene silencing suggested that lncRNA TCONS_00262342 is probably a key regulator of GA(3) synthesis pathway, which participates in P. indica and barley interactions. We concluded that acting as a molecular material basis and resource, lncRNAs respond to P. indica colonization by regulating metabolite content in barley and coordinate the complex regulatory process of higher life by constructing highly positive correlations with their target mRNAs.
PMID: 36858207
Plant Sci , IF:4.729 , 2023 May , V330 : P111638 doi: 10.1016/j.plantsci.2023.111638
SlGH3.15, a member of the GH3 gene family, regulates lateral root development and gravitropism response by modulating auxin homeostasis in tomato.
National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.; Vegetable Research Institute, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, 530007, China.; Department of Plant Sciences, University of Idaho, Moscow, ID 83844, USA.; National Key Laboratory for Germplasm Innovation and Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei, 430070, China. Electronic address: zhangjunhng@mail.hzau.edu.cn.
Multiple Gretchen Hagen 3 (GH3) genes have been implicated in a range of processes in plant growth and development through their roles in maintaining hormonal homeostasis. However, there has only been limited study on the functions of GH3 genes in tomato (Solanum lycopersicum). In this work, we investigated the important function of SlGH3.15, a member of the GH3 gene family in tomato. Overexpression of SlGH3.15 led to severe dwarfism in both the above- and below-ground sections of the plant, accompanied by a substantial decrease in free IAA content and reduction in the expression of SlGH3.9, a paralog of SlGH3.15. Exogenous supply of IAA negatively affected the elongation of the primary root and partially restored the gravitropism defects in SlGH3.15-overexpression lines. While no phenotypic change was observed in the SlGH3.15 RNAi lines, double knockout lines of SlGH3.15 and SlGH3.9 were less sensitive to treatments with the auxin polar transport inhibitor. Overall, these findings revealed important roles of SlGH3.15 in IAA homeostasis and as a negative regulator of free IAA accumulation and lateral root formation in tomato.
PMID: 36796648
Front Genet , IF:4.599 , 2023 , V14 : P1193953 doi: 10.3389/fgene.2023.1193953
Genome-wide identification, evolution and expression profiles analysis of bHLH gene family in Castanea mollissima.
Engineering Research Center of Chestnut Industry Technology, Ministry of Education, Hebei Normal University of Science and Technology, Qinhuangdao, Hebei, China.; Hebei Collaborative Innovation Center of Chestnut Industry, Qinhuangdao, Hebei, China.; Hebei Key Laboratory of Horticultural Germplasm Excavation and Innovative Utilization, Qinhuangdao, Hebei, China.
The basic helix-loop-helix (bHLH) transcription factors (TFs) gene family is an important gene family in plants, and participates in regulation of plant apical meristem growth, metabolic regulation and stress resistance. However, its characteristics and potential functions have not been studied in chestnut (Castanea mollissima), an important nut with high ecological and economic value. In the present study, 94 CmbHLHs were identified in chestnut genome, of which 88 were unevenly distributed on chromosomes, and other six were located on five unanchored scaffolds. Almost all CmbHLH proteins were predicted in the nucleus, and subcellular localization demonstrated the correctness of the above predictions. Based on the phylogenetic analysis, all of the CmbHLH genes were divided into 19 subgroups with distinct features. Abundant cis-acting regulatory elements related to endosperm expression, meristem expression, and responses to gibberellin (GA) and auxin were identified in the upstream sequences of CmbHLH genes. This indicates that these genes may have potential functions in the morphogenesis of chestnut. Comparative genome analysis showed that dispersed duplication was the main driving force for the expansion of the CmbHLH gene family inferred to have evolved through purifying selection. Transcriptome analysis and qRT-PCR experiments showed that the expression patterns of CmbHLHs were different in different chestnut tissues, and revealed some members may have potential functions in chestnut buds, nuts, fertile/abortive ovules development. The results from this study will be helpful to understand the characteristics and potential functions of the bHLH gene family in chestnut.
PMID: 37252667
Plant Cell Rep , IF:4.57 , 2023 May doi: 10.1007/s00299-023-03030-9
The SMC5/6 complex subunit MMS21 regulates stem cell proliferation in rice.
College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.; Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing, 210095, China.; Jiangsu Collaborative Innovation Centre for Modern Crop Production, Nanjing, 210095, China.; College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China. dingcq@njau.edu.cn.; Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing, 210095, China. dingcq@njau.edu.cn.; Jiangsu Collaborative Innovation Centre for Modern Crop Production, Nanjing, 210095, China. dingcq@njau.edu.cn.
SMC5/6 complex subunit OsMMS21 is involved in cell cycle and hormone signaling and required for stem cell proliferation during shoot and root development in rice. The structural maintenance of chromosome (SMC)5/6 complex is required for nucleolar integrity and DNA metabolism. Moreover, METHYL METHANESULFONATE SENSITIVITY GENE 21 (MMS21), a SUMO E3 ligase that is part of the SMC5/6 complex, is essential for the root stem cell niche and cell cycle transition in Arabidopsis. However, its specific role in rice remains unclear. Here, OsSMC5 and OsSMC6 single heterozygous mutants were generated using CRISPR/Cas9 technology to elucidate the function of SMC5/6 subunits, including OsSMC5, OsSMC6, and OsMMS21, in cell proliferation in rice. ossmc5/ + and ossmc6/ + heterozygous single mutants did not yield homozygous mutants in their progeny, indicating that OsSMC5 and OsSMC6 both play necessary roles during embryo formation. Loss of OsMMS21 caused severe defects in both the shoot and roots in rice. Transcriptome analysis showed a significant decrease in the expression of genes involved in auxin signaling in the roots of osmms21 mutants. Moreover, the expression levels of the cycB2-1 and MCM genes, which are involved the cell cycle, were significantly lower in the shoots of the mutants, indicating that OsMMS21 was involved in both hormone signaling pathways and the cell cycle. Overall, these findings indicate that the SUMO E3 ligase OsMMS21 is required for both shoot and root stem cell niches, improving the understanding of the function of the SMC5/6 complex in rice.
PMID: 37178216
Plant Cell Rep , IF:4.57 , 2023 Jul , V42 (7) : P1217-1231 doi: 10.1007/s00299-023-03025-6
Transcription elongation factors OsSPT4 and OsSPT5 are essential for rice growth and development and act with APO2.
College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.; Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing, 210095, People's Republic of China.; Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry, Nanjing, 210095, People's Republic of China.; College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China. dingcq@njau.edu.cn.; Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing, 210095, People's Republic of China. dingcq@njau.edu.cn.; Collaborative Innovation Center for Modern Crop Production Co-Sponsored by Province and Ministry, Nanjing, 210095, People's Republic of China. dingcq@njau.edu.cn.
The transcription elongation factor SPT4/SPT5 complex is essential for rice vegetative and reproductive growth and that OsSPT5-1, with its interactor APO2, is involved in multiple phytohormone pathways. The SPT4/SPT5 complex is a transcription elongation factor that regulates the processivity of transcription elongation. However, our understanding of the role of SPT4/SPT5 complex in developmental regulation remains limited. Here, we identified three SPT4/SPT5 genes (OsSPT4, OsSPT5-1, and OsSPT5-2) in rice, and investigated their roles in vegetative and reproductive growth. These genes are highly conserved with their orthologs in other species. OsSPT4 and OsSPT5-1 are widely expressed in various tissues. By contrast, OsSPT5-2 is expressed at a relatively low level, which could cause osspt5-2 null mutants have no phenotypes. Loss-of-function mutants of OsSPT4 and OsSPT5-1 could not be obtained; their heterozygotes showed severe reproductive growth defects. An incomplete mutant line (osspt5-1#12) displayed gibberellin-related dwarfed defects and a weak root system at an early vegetative phase, and a short life cycle in different planting environments. Furthermore, OsSPT5-1 interacts with the transcription factor ABERRANT PANICLE ORGANIZATION 2 (APO2) and plays a similar role in regulating the growth of rice shoots. RNA sequencing analysis verified that OsSPT5-1 is involved in multiple phytohormone pathways, including gibberellin, auxin, and cytokinin. Therefore, the SPT4/SPT5 complex is essential for both vegetative and reproductive growth in rice.
PMID: 37148321
Plant Cell Rep , IF:4.57 , 2023 Jul , V42 (7) : P1163-1177 doi: 10.1007/s00299-023-03019-4
A methane-cGMP module positively influences adventitious rooting.
College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.; Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, 210014, China.; College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China. wbshenh@njau.edu.cn.
Endogenous cGMP operates downstream of CH(4) control of adventitious rooting, following by the regulation in the expression of cell cycle regulatory and auxin signaling-related genes. Methane (CH(4)) is a natural product from plants and microorganisms. Although exogenously applied CH(4) and cyclic guanosine monophosphate (cGMP) are separately confirmed to be involved in the control of adventitious root (AR) formation, the possible interaction still remains elusive. Here, we observed that exogenous CH(4) not only rapidly promoted cGMP synthesis through increasing the activity of guanosine cyclase (GC), but also induced cucumber AR development. These responses were obviously impaired by the removal of endogenous cGMP with two GC inhibitors. Anatomical evidence showed that the emerged stage (V) among AR primordia development might be the main target of CH(4)-cGMP module. Genetic evidence revealed that the transgenic Arabidopsis that overexpressed the methyl-coenzyme M reductase gene (MtMCR) from Methanobacterium thermoautotrophicum not only increased-cGMP production, but also resulted in a pronounced AR development compared to wild-type (WT), especially with the addition of CH(4) or the cell-permeable cGMP derivative 8-Br-cGMP. qPCR analysis confirmed that some marker genes associated with cell cycle regulatory and auxin signaling were closely related to the brand-new CH(4)-cGMP module in AR development. Overall, our results clearly revealed an important function of cGMP in CH(4) governing AR formation by modulating auxin-dependent pathway and cell cycle regulation.
PMID: 37084115
Plant Cell Rep , IF:4.57 , 2023 Jun , V42 (6) : P961-974 doi: 10.1007/s00299-023-03013-w
Abscisic acid in plants under abiotic stress: crosstalk with major phytohormones.
Department of Biotechnology, St. Xavier's College (Autonomous), 30 Mother Teresa Sarani, Kolkata, 700016, West Bengal, India.; Discipline of Life Sciences, School of Sciences, Indira Gandhi National Open University, Maidan Garhi, New Delhi, 110068, India. aryadeep.rc@gmail.com.
Extensive crosstalk exists among ABA and different phytohormones that modulate plant tolerance against different abiotic stress. Being sessile, plants are exposed to a wide range of abiotic stress (drought, heat, cold, salinity and metal toxicity) that exert unwarranted threat to plant life and drastically affect growth, development, metabolism, and yield of crops. To cope with such harsh conditions, plants have developed a wide range of protective phytohormones of which abscisic acid plays a pivotal role. It controls various physiological processes of plants such as leaf senescence, seed dormancy, stomatal closure, fruit ripening, and other stress-related functions. Under challenging situations, physiological responses of ABA manifested in the form of morphological, cytological, and anatomical alterations arise as a result of synergistic or antagonistic interaction with multiple phytohormones. This review provides new insight into ABA homeostasis and its perception and signaling crosstalk with other phytohormones at both molecular and physiological level under critical conditions including drought, salinity, heavy metal toxicity, and extreme temperature. The review also reveals the role of ABA in the regulation of various physiological processes via its positive or negative crosstalk with phytohormones, viz., gibberellin, melatonin, cytokinin, auxin, salicylic acid, jasmonic acid, ethylene, brassinosteroids, and strigolactone in response to alteration of environmental conditions. This review forms a basis for designing of plants that will have an enhanced tolerance capability against different abiotic stress.
PMID: 37079058
Plant Cell Rep , IF:4.57 , 2023 May , V42 (5) : P921-937 doi: 10.1007/s00299-023-03001-0
Comparative transcriptome analysis reveals the function of SlPRE2 in multiple phytohormones biosynthesis, signal transduction and stomatal development in tomato.
Institute of Jiangxi Oil-Tea Camellia, Jiujiang University, Jiujiang, 332000, Jiangxi, China. zhuzhiguo@jju.edu.cn.; College of Pharmacy and Life Sciences, Jiujiang University, Jiujiang, 332000, Jiangxi, China. zhuzhiguo@jju.edu.cn.; Institute of Jiangxi Oil-Tea Camellia, Jiujiang University, Jiujiang, 332000, Jiangxi, China.; College of Pharmacy and Life Sciences, Jiujiang University, Jiujiang, 332000, Jiangxi, China.; College of Biological Science and Agriculture, Qiannan Normal University for Nationalities, Duyun, 558000, Guizhou, China.
Transcriptomic, physiological, and qRT-PCR analysis revealed the potential mechanism by which SlPRE2 regulates plant growth and stomatal size via multiple phytohormone pathways in tomato. Paclobutrazol resistance proteins (PREs) are atypical members of the basic/helix-loop-helix (bHLH) transcription factor family that regulate plant morphology, cell size, pigment metabolism and abiotic stress in response to different phytohormones. However, little is known about the network regulatory mechanisms of PREs in plant growth and development in tomato. In this study, the function and mechanism of SlPRE2 in tomato plant growth and development were investigated. The quantitative RT-PCR results showed that the expression of SlPRE2 was regulated by multiple phytohormones and abiotic stresses. It showed light-repressed expression during the photoperiod. The RNA-seq results revealed that SlPRE2 regulated many genes involved in photosynthesis, chlorophyll metabolism, phytohormone metabolism and signaling, and carbohydrate metabolism, suggesting the role of SlPRE2 in gibberellin, brassinosteroid, auxin, cytokinin, abscisic acid and salicylic acid regulated plant development processes. Moreover, SlPRE2 overexpression plants showed widely opened stomata in young leaves, and four genes involved in stomatal development showed altered expression. Overall, the results demonstrated the mechanism by which SlPRE2 regulates phytohormone and stress responses and revealed the function of SlPRE2 in stomatal development in tomato. These findings provide useful clues for understanding the molecular mechanisms of SlPRE2-regulated plant growth and development in tomato.
PMID: 37010556
Plant Cell Rep , IF:4.57 , 2023 May , V42 (5) : P939-952 doi: 10.1007/s00299-023-03002-z
Fusion gene 4CL-CCR promotes lignification in tobacco suspension cells.
State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology , Beijing Forestry University, Beijing, 100083, China.; The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing, 100083, China.; State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology , Beijing Forestry University, Beijing, 100083, China. gaiying@bjfu.edu.cn.; The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing, 100083, China. gaiying@bjfu.edu.cn.; State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology , Beijing Forestry University, Beijing, 100083, China. jiangxn@bjfu.edu.cn.; The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, Beijing, 100083, China. jiangxn@bjfu.edu.cn.
The fusion gene 4CL-CCR promotes lignification and activates lignin-related MYB expression in tobacco but inhibits auxin-related gene expression and hinders the auxin absorption of cells. Given the importance of lignin polymers in plant growth and their industrial value, it is necessary to investigate how plants synthesize monolignols and regulate the level of lignin in cell walls. In our previous study, expression of the Populus tomentosa fusion gene 4CL-CCR significantly promoted the production of 4-hydroxycinnamyl alcohols. However, the function of 4CL-CCR in organisms remains poorly understood. In this study, the fusion gene 4CL-CCR was heterologously expressed in tobacco suspension cells. We found that the transgenic suspension cells exhibited lignification earlier. Furthermore, 4CL-CCR significantly reduced the content of phenolic acids and increased the content of aldehydes in the medium, which led to an increase in lignin deposition. Moreover, transcriptome results showed that the genes related to lignin synthesis, such as PAL, 4CL, CCoAOMT and CAD, were significantly upregulated in the 4CL-CCR group. The expression of genes related to auxin, such as ARF3, ARF5 and ARF6, was significantly downregulated. The downregulation of auxin affected the expression of transcription factor MYBs. We hypothesize that the upregulated genes MYB306 and MYB315 are involved in the regulation of cell morphogenesis and lignin biosynthesis and eventually enhance lignification in tobacco suspension cells. Our findings provide insight into the function of 4CL-CCR in lignification and how secondary cell walls are formed in plants.
PMID: 36964306
Genetics , IF:4.562 , 2023 Jun doi: 10.1093/genetics/iyad102
How flower development genes were identified using forward genetic screens in Arabidopsis thaliana.
School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia.
In the later part of the 1980s, the time was ripe for identifying genes controlling flower development. In that pregenomic era, the easiest way to do this was to induce random mutations in seeds by chemical mutagens (or irradiation) and to screen thousands of plants for those with phenotypes specifically defective in floral morphogenesis. Here, we discuss the results of premolecular screens for flower development mutants in Arabidopsis thaliana, carried out at Caltech and Monash University, emphasizing the usefulness of saturation mutagenesis, multiple alleles to identify full loss-of-function, conclusions based on multiple mutant analyses, and from screens for enhancer and suppressor modifiers of original mutant phenotypes. One outcome was a series of mutants that led to the ABC floral organ identity model (AP1, AP2, AP3, PI, and AG). In addition, genes controlling flower meristem identity (AP1, CAL, and LFY), floral meristem size (CLV1 and CLV3), development of individual floral organ types (CRC, SPT, and PTL), and inflorescence meristem properties (TFL1, PIN1, and PID) were defined. These occurrences formed targets for cloning that eventually helped lead to an understanding of transcriptional control of the identity of floral organs and flower meristems, signaling within meristems, and the role of auxin in initiating floral organogenesis. These findings in Arabidopsis are now being applied to investigate how orthologous and paralogous genes act in other flowering plants, allowing us to wander in the fertile fields of evo-devo.
PMID: 37294732
Microb Ecol , IF:4.552 , 2023 Jul , V86 (1) : P431-445 doi: 10.1007/s00248-022-02080-y
Screening of Phosphate Solubilization Identifies Six Pseudomonas Species with Contrasting Phytostimulation Properties in Arabidopsis Seedlings.
Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico.; Catedratico CONACYT-Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico.; Instituto de Ecologia, Red de Estudios Moleculares Avanzados, Cluster BioMimic(R), Carretera Antigua a Coatepec 351, El Haya, A.C, 91073, Veracruz, Mexico.; Catedratico CONACYT-Instituto de Ecologia, Red de Estudios Moleculares Avanzados, Cluster BioMimic(R), Carretera Antigua a Coatepec 351, El Haya, A.C, 91073, Veracruz, Mexico.; Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacan, Mexico. jbucio@umich.mx.
The interaction of plants with bacteria and the long-term success of their adaptation to challenging environments depend upon critical traits that include nutrient solubilization, remodeling of root architecture, and modulation of host hormonal status. To examine whether bacterial promotion of phosphate solubilization, root branching and the host auxin response may account for plant growth, we isolated and characterized ten bacterial strains based on their high capability to solubilize calcium phosphate. All strains could be grouped into six Pseudomonas species, namely P. brassicae, P. baetica, P. laurylsulfatiphila, P. chlororaphis, P. lurida, and P. extremorientalis via 16S rRNA molecular analyses. A Solibacillus isronensis strain was also identified, which remained neutral when interacting with Arabidopsis roots, and thus could be used as inoculation control. The interaction of Arabidopsis seedlings with bacterial streaks from pure cultures in vitro indicated that their phytostimulation properties largely differ, since P. brassicae and P. laurylsulfatiphila strongly increased shoot and root biomass, whereas the other species did not. Most bacterial isolates, except P. chlororaphis promoted lateral root formation, and P. lurida and P. chlororaphis strongly enhanced expression of the auxin-inducible gene construct DR5:GUS in roots, but the most bioactive probiotic bacterium P. brassicae could not enhance the auxin response. Inoculation with P. brassicae and P. lurida improved shoot and root growth in medium supplemented with calcium phosphate as the sole Pi source. Collectively, our data indicate the differential responses of Arabidopsis seedlings to inoculation with several Pseudomonas species and highlight the potential of P. brassicae to manage phosphate nutrition and plant growth in a more eco-friendly manner.
PMID: 35867140
Microb Ecol , IF:4.552 , 2023 May , V85 (4) : P1396-1411 doi: 10.1007/s00248-022-01998-7
Microorganisms Associated with the Ambrosial Beetle Xyleborus affinis with Plant Growth-Promotion Activity in Arabidopsis Seedlings and Antifungal Activity Against Phytopathogenic Fungus Fusarium sp. INECOL_BM-06.
Red de Estudios Moleculares Avanzados, Instituto de Ecologia A.C, Xalapa, 91073, Veracruz, Mexico.; Red de Biodiversidad Y Sistematica, Instituto de Ecologia A.C, Carretera Antigua a Coatepec 351, El Haya, 91073, Xalapa, Veracruz, Mexico.; Red de Estudios Moleculares Avanzados, Instituto de Ecologia A.C, Xalapa, 91073, Veracruz, Mexico. randy.ortiz@inecol.mx.; Catedra CONACyT en el Instituto de Ecologia, A.C., Carretera Antigua a Coatepec 351, El Haya, C.P. 91073, Xalapa, Veracruz, Mexico. randy.ortiz@inecol.mx.
Plants interact with a great diversity of microorganisms or insects throughout their life cycle in the environment. Plant and insect interactions are common; besides, a great variety of microorganisms associated with insects can induce pathogenic damage in the host, as mutualist phytopathogenic fungus. However, there are other microorganisms present in the insect-fungal association, whose biological/ecological activities and functions during plant interaction are unknown. In the present work evaluated, the role of microorganisms associated with Xyleborus affinis, an important beetle species within the Xyleborini tribe, is characterized by attacking many plant species, some of which are of agricultural and forestry importance. We isolated six strains of microorganisms associated with X. affinis shown as plant growth-promoting activity and altered the root system architecture independent of auxin-signaling pathway in Arabidopsis seedlings and antifungal activity against the phytopathogenic fungus Fusarium sp. INECOL_BM-06. In addition, evaluating the tripartite interaction plant-microorganism-fungus, interestingly, we found that microorganisms can induce protection against the phytopathogenic fungus Fusarium sp. INECOL_BM-06 involving the jasmonic acid-signaling pathway and independent of salicylic acid-signaling pathway. Our results showed the important role of this microorganisms during the plant- and insect-microorganism interactions, and the biological potential use of these microorganisms as novel agents of biological control in the crops of agricultural and forestry is important.
PMID: 35357520
Physiol Plant , IF:4.5 , 2023 May-Jun , V175 (3) : Pe13937 doi: 10.1111/ppl.13937
A stratagem for primary root elongation under moderate salt stress in the halophyte Schrenkiella parvula.
Graduate School of Life Sciences, Tohoku University, Sendai, Japan.; Department of Biology, Faculty of Science, Ege University, Izmir, Turkiye.
Schrenkiella parvula, an Arabidopsis-related halophyte, grows around Lake Tuz (Salt) in Turkey and can survive up to 600 mM NaCl. Here, we performed physiological studies on the roots of S. parvula and A. thaliana seedlings cultivated under a moderate salt condition (100 mM NaCl). Interestingly, S. parvula germinated and grew at 100 mM NaCl, but germination did not occur at salt concentrations above 200 mM. In addition, primary roots elongated much faster at 100 mM NaCl, while being thinner with fewer roots hair, than under NaCl-free conditions. Salt-induced root elongation was due to epidermal cell elongation, but meristem size and meristematic DNA replication were reduced. The expression of genes related to auxin response and biosynthesis was also reduced. Application of exogenous auxin abolished the changes in primary root elongation, suggesting that auxin reduction is the main trigger for root architectural changes in response to moderate salinity in S. parvula. In A. thaliana seeds, germination was maintained up to 200 mM NaCl, but post-germination root elongation was significantly inhibited. Furthermore, primary roots did not promote elongation even under fairly low salt conditions. Compared to A. thaliana, cell death and ROS content in primary roots of salt-stressed plants were significantly lower in S. parvula. These changes in the roots of S. parvula seedlings may be an adaptive strategy to reach lower salinity by advancing into deeper soils, while being impaired by moderate salt stress.
PMID: 37243856
Sci Rep , IF:4.379 , 2023 Jun , V13 (1) : P9635 doi: 10.1038/s41598-023-36500-x
Cis-regulatory elements and transcription factors related to auxin signaling in the streptophyte algae Klebsormidium nitens.
School of Life Science and Technology, Tokyo Institute of Technology, 4259 B-65, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8501, Japan.; School of Life Science and Technology, Tokyo Institute of Technology, 4259 B-65, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8501, Japan. hori.k@lipid.bio.titech.ac.jp.; School of Life Science and Technology, Tokyo Institute of Technology, 4259 B-65, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8501, Japan. ohta.h.ab@m.titech.ac.jp.
The phytohormone auxin affects numerous processes in land plants. The central auxin signaling machinery, called the nuclear auxin pathway, is mediated by its pivotal receptor named TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALING F-BOX (TIR1/AFB). The nuclear auxin pathway is widely conserved in land plants, but auxin also accumulates in various algae. Although auxin affects the growth of several algae, the components that mediate auxin signaling have not been identified. We previously reported that exogenous auxin suppresses cell proliferation in the Klebsormidium nitens that is a member of streptophyte algae, a paraphyletic group sharing the common ancestor with land plants. Although K. nitens lacks TIR1/AFB, auxin affects the expression of numerous genes. Thus, elucidation of the mechanism of auxin-inducible gene expression in K. nitens would provide important insights into the evolution of auxin signaling. Here, we show that some motifs are enriched in the promoter sequences of auxin-inducible genes in K. nitens. We also found that the transcription factor KnRAV activates several auxin-inducible genes and directly binds the promoter of KnLBD1, a representative auxin-inducible gene. We propose that KnRAV has the potential to regulate auxin-responsive gene expression in K. nitens.
PMID: 37322074
Sci Rep , IF:4.379 , 2023 Jun , V13 (1) : P8932 doi: 10.1038/s41598-023-29402-5
Comparative transcriptomic analysis of transcription factors and hormones during flower bud differentiation in 'Red Globe' grape under red‒blue light.
College of Agriculture, Ningxia University, Yinchuan, 750021, China.; College of Agriculture, Ningxia University, Yinchuan, 750021, China. zhyhcau@sina.com.
Grape is a globally significant fruit-bearing crop, and the grape flower bud differentiation essential to fruit production is closely related to light quality. To investigate the regulatory mechanism of grape flower bud differentiation under red‒blue light, the transcriptome and hormone content were determined at four stages of flower bud differentiation. The levels of indole-3-acetic acid (IAA) and abscisic acid (ABA) in grape flower buds at all stages of differentiation under red‒blue light were higher than those in the control. However, the levels of cytokinins (CKs) and gibberellic acid (giberellins, GAs) fluctuated continuously over the course of flower bud differentiation. Moreover, many differentially expressed genes were involved in auxin, CK, GA, and the ABA signal transduction pathways. There were significant differences in the AUX/IAA, SAUR, A-RR, and ABF gene expression levels between the red‒blue light treatment and the control buds, especially in regard to the ABF genes, the expression levels of which were completely different between the two groups. The expression of GBF4 and AI5L2 in the control was always low, while the expression under red‒blue light increased. AI5L7 and AI5L5 expression levels showed an upwards trend in the control plant buds and gradually decreased in red‒blue light treatment plant buds. Through weighted gene coexpression network analysis, we determined that the transcription factors WRK48 (WRKY family), EF110 (ERF family), ABR1, CAMTA3 (CAMTA family), and HSFA3 (HSF family) may be involved in the regulation of the GBF4 gene. This study lays a foundation for further analysis of grape flower bud differentiation regulation under red‒blue light.
PMID: 37264033
Ann Bot , IF:4.357 , 2023 Jun doi: 10.1093/aob/mcad071
Stomatal development and orientation - a phylogenetic and ecophysiological perspective.
Royal Botanic Gardens, Kew, Richmond, UK.
BACKGROUND: Oriented patterning of epidermal cells is achieved primarily by transverse protodermal cell divisions perpendicular to the organ axis, followed by axial cell elongation. In linear leaves with parallel venation, most stomata are regularly aligned with the veins. This longitudinal patterning operates under a strong developmental constraint and has demonstrable physiological benefits, especially in grasses. However, transversely oriented stomata characterise a few groups, both among living angiosperms and extinct Mesozoic seed plants. SCOPE: This review examines comparative and developmental data on stomatal patterning in a broad phylogenetic context, focusing on the evolutionary and ecophysiological significance of guard-cell orientation. It draws from a diverse range of literature to explore the pivotal roles of the plant growth hormone auxin in establishing polarity and chemical gradients that enable cellular differentiation. CONCLUSIONS: Transverse stomata evolved iteratively in a few seed-plant groups during the Mesozoic era, especially among parasitic or xerophytic taxa, such as the hemiparasitic mistletoe genus Viscum and the xerophytic shrub Casuarina, indicating a possible link with ecological factors such as the Cretaceous CO2 decline and changing water availability. The discovery of this feature in some extinct seed-plant taxa known only from fossils could represent a useful phylogenetic marker.
PMID: 37288594
Foods , IF:4.35 , 2023 Jun , V12 (12) doi: 10.3390/foods12122297
Metabolome, Plant Hormone, and Transcriptome Analyses Reveal the Mechanism of Spatial Accumulation Pattern of Anthocyanins in Peach Flesh.
Jinhua Academy of Agricultural Sciences (Zhejiang Institute of Agricultural Machinery), Jinhua 321000, China.; Sanya Nanfan Research Institute of Hainan University, Sanya 572025, China.; Key Laboratory of Quality Regulation of Tropical Horticultural Crop in Hainan Province, Department of Horticulture, School of Horticulture, Haidian Campus, Hainan University, Haikou 570228, China.
Anthocyanins are important secondary metabolites in fruits, and anthocyanin accumulation in the flesh of peach exhibits a spatial pattern, but the relevant mechanism is still unknown. In this study, the yellow-fleshed peach, cv. 'Jinxiu', with anthocyanin accumulation in the mesocarp around the stone was used as the experimental material. Red flesh (RF) and yellow flesh (YF) were sampled separately for flavonoid metabolite (mainly anthocyanins), plant hormone, and transcriptome analyses. The results showed that the red coloration in the mesocarp was due to the accumulation of cyanidin-3-O-glucoside, with an up-regulation of anthocyanin biosynthetic genes (F3H, F3'H, DFR, and ANS), transportation gene GST, and regulatory genes (MYB10.1 and bHLH3). Eleven ERFs, nine WRKYs, and eight NACs were also defined as the candidate regulators of anthocyanin biosynthesis in peach via RNA-seq. Auxin, cytokinin, abscisic acid (ABA), salicylic acid (SA), and 1-aminocyclopropane-1-carboxylic acid (ACC, ethylene precursor) were enriched in the peach flesh, with auxin, cytokinin, ACC, and SA being highly accumulated in the RF, but ABA was mainly distributed in the YF. The activators and repressors in the auxin and cytokinin signaling transduction pathways were mostly up-regulated and down-regulated, respectively. Our results provide new insights into the regulation of spatial accumulation pattern of anthocyanins in peach flesh.
PMID: 37372513
Foods , IF:4.35 , 2023 Jun , V12 (12) doi: 10.3390/foods12122303
Unraveling the Mechanism of StWRKY6 in Potato (Solanum tuberosum)'s Cadmium Tolerance for Ensuring Food Safety.
College of Agriculture, Guizhou University, Guiyang 550025, China.; Guizhou Provincial Academy of Agricultural Sciences, Animal Husbandry and Veterinary Research Institute, Guiyang 550005, China.; Department of Biological Sciences, Alabama State University, Office 314, 1627 Harris Way, Montgomery, AL 36104, USA.; National Products Research Center of Guizhou Province, Guiyang 550025, China.
The WRKY transcription factor plays a crucial role in plant stress adaptation. Our research has found that WRKY6 in Solanum tuberosum (potatoes) is closely related to cadmium (Cd) tolerance. Therefore, investigating the mechanism of StWRKY6 in plant resistance to Cd toxicity is of great scientific importance for food safety. This research further analyzed the gene structure and functional regions of the nuclear transcription factor WRKY6 in potatoes, discovering that StWRKY6 contains W box, GB/box, ABRE, and other elements that can act as a nuclear transcription regulatory factor to execute multiple functional regulations. The results of the heterologous expression of StWRKY6 in Arabidopsis under Cd stress showed that the overexpression line (StWRKY6-OE) had significantly higher SAPD values and content of reactive oxygen species scavenging enzymes than the wild type, indicating that StWRKY6 plays a crucial role in protecting the photosynthetic system and promoting carbohydrate synthesis. Transcriptome analysis also revealed that the Cd-induced expression of StWRKY6 up-regulated many potential gene targets, including APR2, DFRA, ABCG1, VSP2, ERF013, SAUR64/67, and BBX20, which are involved in Cd chelation (APR2, DFRA), plant defense (VSP2, PDF1.4), toxic substance efflux (ABCG1), light morphology development (BBX20), and auxin signal (SAUR64/67). These genes coordinate the regulation of Cd tolerance in the StWRKY6 overexpression line. In summary, this study identified a potential gene set of the co-expression module of StWRKY6, providing useful evidence for the remediation of Cd-contaminated soil and the genetic breeding of low Cd-accumulating crops, thereby ensuring food safety.
PMID: 37372512
Plant Physiol Biochem , IF:4.27 , 2023 Jun , V201 : P107827 doi: 10.1016/j.plaphy.2023.107827
Mutant IAA21 genes from Dendrocalamus sinicus Chia et J. L. Sun inhibit stem and root growth in transgenic tobacco by interacting with ARF5.
College of Life Science, Xinjiang Normal University, Xinyi Road, Shayibake District, Urumqi, 830054, PR China; Institute of Highland Forest Science, Chinese Academy of Forestry, Bailongsi, Panlong District, Kunming, 650233, PR China.; Institute of Highland Forest Science, Chinese Academy of Forestry, Bailongsi, Panlong District, Kunming, 650233, PR China.; College of Life Science, Xinjiang Normal University, Xinyi Road, Shayibake District, Urumqi, 830054, PR China; Xinjiang Key Laboratory of Special Species Conservation and Regulatory Biology, Xinyi Road, Shayibake District, Urumqi, 830054, PR China.; Institute of Highland Forest Science, Chinese Academy of Forestry, Bailongsi, Panlong District, Kunming, 650233, PR China. Electronic address: yanghanqikm@aliyun.com.
Woody bamboos are important resource of industrial fibres. Auxin signaling plays a key role in multiple plant developmental processes, as yet the role of auxin/indole acetic acid (Aux/IAA) in culm development of woody bamboos has not been previously characterized. Dendrocalamus sinicus Chia et J. L. Sun is the largest woody bamboo documented in the world. Here, we identified two alleles of DsIAA21 gene (sIAA21 and bIAA21) from the straight- and bent-culm variants of D. sinicus, respectively, and studied how the domains I, i, and II of DsIAA21 affect the gene transcriptional repression. The results showed that bIAA21 expression was rapidly induced by exogenous auxin in D. sinicus. In transgenic tobacco, sIAA21 and bIAA21 mutated in domains i, and II significantly regulated plant architecture and root development. Stem cross sections revealed that parenchyma cells were smaller in transgenic plants than that in wild type plants. Domain i mutation changed the leucine and proline at position 45 to proline and leucine (siaa21(L45P) and biaa21(P45L)) strongly repressed cell expansion and root elongation by reducing the gravitropic response. Substitution of isoleucine with valine in domain II of the full length DsIAA21 resulted in dwarf stature in transgenic tobacco plants. Furthermore, the DsIAA21 interacted with auxin response factor 5 (ARF5) in transgenic tobacco plants, suggesting that DsIAA21 might inhibit stem and root elongation via interacting with ARF5. Taken together, our data indicated that DsIAA21 was a negative regulator of plant development and suggested that amino acid differences in domain i of sIAA21 versus bIAA21 affected their response to auxin, and might play a key role in the formation of the bent culm variant in D. sinicus. Our results not only shed a light on the morphogenetic mechanism in D. sinicus, but also provided new insights into versatile function of Aux/IAAs in plants.
PMID: 37329689
Plant Physiol Biochem , IF:4.27 , 2023 Jun , V201 : P107832 doi: 10.1016/j.plaphy.2023.107832
Wheat type one protein phosphatase promotes salt and osmotic stress tolerance in arabidopsis via auxin-mediated remodelling of the root system.
Plant Physiology and Functional Genomics Research Unit, Higher Institute of Biotechnology, University of Sfax, BP "1175", 3038, Sfax, Tunisia.; Plant Physiology and Functional Genomics Research Unit, Higher Institute of Biotechnology, University of Sfax, BP "1175", 3038, Sfax, Tunisia. Electronic address: chantal.ebel@isbs.usf.tn.
The control of optimal root growth and plant stress responses depends largely on a variety of phytohormones among which auxin and brassinosteroids (BRs) are the most influential. We have previously reported that the durum wheat type 1 protein phosphatase TdPP1 participates in the control of root growth by modulating BR signaling. In this study, we pursue our understanding of how TdPP1 fulfills this regulatory function on root growth by evaluating the physiological and molecular responses of Arabidopsis TdPP1 over-expressing lines to abiotic stresses. Our results showed that when exposed to 300 mM Mannitol or 100 mM NaCl, the seedlings of TdPP1 over-expressors exhibit modified root architecture with higher lateral root density, and longer root hairs concomitant with a lower inhibition of the primary root growth. These lines also exhibit faster gravitropic response and a decrease in primary root growth inhibition when exposed to high concentrations of exogenous IAA. On another hand, a cross between TdPP1 overexpressors and DR5:GUS marker line was performed to monitor auxin accumulation in roots. Remarkably, the TdPP1 overexpression resulted in an enhanced auxin gradient under salt stress with a higher accumulation in primary and lateral root tips. Moreover, TdPP1 transgenics exhibit a significant induction of a subset of auxin-responsive genes under salt stress conditions. Therefore, our results reveal a role of PP1 in enhancing auxin signaling to help shape greater root plasticity thus improving plant stress resilience.
PMID: 37327648
Plant Physiol Biochem , IF:4.27 , 2023 Jun , V201 : P107808 doi: 10.1016/j.plaphy.2023.107808
Advances in nanoparticle and organic formulations for prolonged controlled release of auxins.
Southern Federal University, ul. Bolshaya Sadovaya 105/42, Rostov-on-Don, 344006, Russian Federation; Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia, 1113, Bulgaria. Electronic address: vbutova@sfedu.ru.; Southern Federal University, ul. Bolshaya Sadovaya 105/42, Rostov-on-Don, 344006, Russian Federation.
Plant hormones have been well known since Charles Darwin as signaling molecules directing plant metabolism. Their action and transport pathways are at the top of scientific interest and were reviewed in many research articles. Modern agriculture applies phytohormones as supplements to achieve desired physiological plant response. Auxins are a class of plant hormones extensively used for crop management. Auxins stimulate the formation of lateral roots and shoots, seed germination, while extensively high concentrations of these chemicals act as herbicides. Natural auxins are unstable; light or enzyme action leads to their degradation. Moreover, the concentration dependant action of phytohormones denier one-shot injection of these chemicals and require constant slow additive of supplement. It obstructs the direct introduction of auxins. On the other hand, delivery systems can protect phytohormones from degradation and provide a slow release of loaded drugs. Moreover, this release can be managed by external stimuli like pH, enzymes, or temperature. The present review is focused on three auxins: indole-3-acetic, indole-3-butyric, and 1-naphthaleneacetic acids. We collected some examples of inorganic (oxides, Ag, layered double hydroxides) and organic (chitosan, organic formulations) delivery systems. The action of carriers can enhance auxin effects via protection and targeted delivery of loaded molecules. Moreover, nanoparticles can act as nano fertilizers, intensifying the phytohormone effect, providing slow controlled release. So delivery systems for auxins are extremely attractive for modern agriculture opening sustainable management of plant metabolism and morphogenesis.
PMID: 37290135
Plant Physiol Biochem , IF:4.27 , 2023 May , V198 : P107683 doi: 10.1016/j.plaphy.2023.107683
Cytokinins act synergistically with heat acclimation to enhance rice thermotolerance affecting hormonal dynamics, gene expression and volatile emission.
Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, 165 02, Prague, Czech Republic. Electronic address: prerostova@ueb.cas.cz.; Laboratory of Plant Biotechnologies, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 313, 165 02, Prague, Czech Republic. Electronic address: rezek@ueb.cas.cz.; Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, 165 02, Prague, Czech Republic. Electronic address: jarosova@ueb.cas.cz.; Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, 165 02, Prague, Czech Republic. Electronic address: lacek@ueb.cas.cz.; Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, 165 02, Prague, Czech Republic. Electronic address: dobrev@ueb.cas.cz.; Laboratory of Plant Biotechnologies, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 313, 165 02, Prague, Czech Republic. Electronic address: marsik@ueb.cas.cz.; Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, 165 02, Prague, Czech Republic. Electronic address: gaudinova@ueb.cas.cz.; Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, 165 02, Prague, Czech Republic. Electronic address: knirsch@ueb.cas.cz.; Laboratory of Growth Regulators, Institute of Experimental Botany, Czech Academy of Sciences, Slechtitelu 27, 783 71, Olomouc, Czech Republic; Department of Chemical Biology, Faculty of Science, Palacky University, 17. listopadu 1192/12, 779 00, Olomouc, Czech Republic. Electronic address: karel.dolezal@upol.cz.; Laboratory of Growth Regulators, Institute of Experimental Botany, Czech Academy of Sciences, Slechtitelu 27, 783 71, Olomouc, Czech Republic; Department of Chemical Biology, Faculty of Science, Palacky University, 17. listopadu 1192/12, 779 00, Olomouc, Czech Republic. Electronic address: lucie.plihalova@upol.cz.; Laboratory of Plant Biotechnologies, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 313, 165 02, Prague, Czech Republic. Electronic address: vanek@ueb.cas.cz.; Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA. Electronic address: jkieber@bio.unc.edu.; Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, Rozvojova 263, 165 02, Prague, Czech Republic. Electronic address: vankova@ueb.cas.cz.
Heat stress is a frequent environmental constraint. Phytohormones can significantly affect plant thermotolerance. This study compares the effects of exogenous cytokinin meta-topolin-9-(tetrahydropyran-2-yl)purine (mT9THP) on rice (Oryza sativa) under control conditions, after acclimation by moderate temperature (A; 37 degrees C, 2h), heat stress (HS; 45 degrees C, 6h) and their combination (AHS). mT9THP is a stable cytokinin derivative that releases active meta-topolin gradually, preventing the rapid deactivation reported after exogenous cytokinin application. Under control conditions, mT9THP negatively affected jasmonic acid in leaves and abscisic and salicylic acids in crowns (meristematic tissue crucial for tillering). Exogenous cytokinin stimulated the emission of volatile organic compounds (VOC), especially 2,3-butanediol. Acclimation upregulated trans-zeatin, expression of stress- and hormone-related genes, and VOC emission. The combination of acclimation and mT9THP promoted the expression of stress markers and antioxidant enzymes and moderately increased VOC emission, including 2-ethylhexyl salicylate or furanones. AHS and HS responses shared some common features, namely, increase of ethylene precursor aminocyclopropane-1-carboxylic acid (ACC), cis-zeatin and cytokinin methylthio derivatives, as well as the expression of heat shock proteins, alternative oxidases, and superoxide dismutases. AHS specifically induced jasmonic acid and auxin indole-3-acetic acid levels, diacylglycerolipids with fewer double bonds, and VOC emissions [e.g., acetamide, lipoxygenase (LOX)-derived volatiles]. Under direct HS, exogenous cytokinin mimicked some positive acclimation effects. The combination of mT9THP and AHS had the strongest thermo-protective effect, including a strong stimulation of VOC emissions (including LOX-derived ones). These results demonstrate for the first time the crucial contribution of volatiles to the beneficial effects of cytokinin and AHS on rice thermotolerance.
PMID: 37062127
BMC Plant Biol , IF:4.215 , 2023 Jun , V23 (1) : P342 doi: 10.1186/s12870-023-04356-y
Genome-wide identification and expression analysis of the AUX/IAA gene family in turnip (Brassica rapa ssp. rapa).
College of Agriculture and Biotechnology, Wenzhou Vocational College of Science and Technology (Wenzhou Academy of Agricultural Sciences), Wenzhou, Zhejiang, 325006, China.; Southern Zhejiang Key Laboratory of Crop Breeding, Wenzhou Vocational College of Science and Technology (Wenzhou Academy of Agricultural Sciences), Wenzhou, Zhejiang, 325006, China.; Wenzhou Key Laboratory of Resource Plant Innovation and Utilization, Zhejiang Institute of Subtropical Crops, Zhejiang Academy of Agricultural Sciences, Wenzhou, Zhejiang, 325005, China.; Wenzhou Lucheng District Agricultural Industry Institute, Wenzhou, Zhejiang, 325000, China.; College of Agriculture and Biotechnology, Wenzhou Vocational College of Science and Technology (Wenzhou Academy of Agricultural Sciences), Wenzhou, Zhejiang, 325006, China. sunji@wzvcst.edu.cn.; Southern Zhejiang Key Laboratory of Crop Breeding, Wenzhou Vocational College of Science and Technology (Wenzhou Academy of Agricultural Sciences), Wenzhou, Zhejiang, 325006, China. sunji@wzvcst.edu.cn.
BACKGROUND: Auxin/indoleacetic acid (AUX/IAA) genes encoding short-lived proteins participate in AUX signaling transduction and play crucial roles in plant growth and development. Although the AUX/IAA gene family has been identified in many plants, a systematic analysis of AUX/IAA genes in Brassica rapa ssp. rapa has not yet been reported. RESULTS: We performed a comprehensive genome-wide analysis and found 89 AUX/IAA genes in turnip based on the conserved AUX/IAA domain (pfam02309). Phylogenetic analysis of AUX/IAA genes from turnip, Arabidopsis, and cabbage revealed that these genes cluster into six subgroups (A1, A2, A3, A4, B1, and B2). The motif distribution was also conservative among the internal members of the clade. Enhanced yellow fluorescent protein (EYFP) signals of BrrIAA-EYFPs showed that BrrIAA members functioned as nucleoproteins. Moreover, transcriptional analysis revealed that the expression patterns of AUX/IAA genes in turnip were tissue-dependent. Because orthologs have similar biological functions and interaction networks in plant growth and development, BrrIAA66 in turnip possibly played a role in embryo axis formation, vascular development, lateral root formation, and floral organ development by interacting with BrrARF19 and BrrTIR1. CONCLUSION: These results provide a theoretical basis for further investigation of BrrAUX/IAA genes and lay the foundation for functional analysis of BrrIAA66 in turnip.
PMID: 37370022
BMC Plant Biol , IF:4.215 , 2023 Jun , V23 (1) : P322 doi: 10.1186/s12870-023-04319-3
Circular RNAs modulate the floral fate acquisition in soybean shoot apical meristem.
Plant Molecular Biology and Biotechnology Laboratory, Faculty of Science, The University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia.; Plant Molecular Biology and Biotechnology Laboratory, Faculty of Science, The University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia. premlb@unimelb.edu.au.
BACKGROUND: Soybean (Glycine max), a major oilseed and protein source, requires a short-day photoperiod for floral induction. Though key transcription factors controlling flowering have been identified, the role of the non-coding genome is limited. Circular RNAs (circRNAs) recently emerged as a novel class of RNAs with critical regulatory functions. However, a study on circRNAs during the floral transition of a crop plant is lacking. We investigated the expression and potential function of circRNAs in floral fate acquisition by soybean shoot apical meristem in response to short-day treatment. RESULTS: Using deep sequencing and in-silico analysis, we denoted 384 circRNAs, with 129 exhibiting short-day treatment-specific expression patterns. We also identified 38 circRNAs with predicted binding sites for miRNAs that could affect the expression of diverse downstream genes through the circRNA-miRNA-mRNA network. Notably, four different circRNAs with potential binding sites for an important microRNA module regulating developmental phase transition in plants, miR156 and miR172, were identified. We also identified circRNAs arising from hormonal signaling pathway genes, especially abscisic acid, and auxin, suggesting an intricate network leading to floral transition. CONCLUSIONS: This study highlights the gene regulatory complexity during the vegetative to reproductive transition and paves the way to unlock floral transition in a crop plant.
PMID: 37328881
BMC Plant Biol , IF:4.215 , 2023 Jun , V23 (1) : P325 doi: 10.1186/s12870-023-04339-z
Indirect regeneration in Ficus lyrata Warb. and metabolite profiles influenced by nitric oxide and Plant growth regulators.
Department of Horticultural Science, College of Agriculture, Shiraz University, Box 65186-71441, Shiraz, Iran. r.abdolinejad@gmail.com.; Department of Horticultural Science, Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, IR 6341773637, Khuzestan, Iran. Salehi@asnrukh.ac.ir.
BACKGROUND: To establish an indirect regeneration protocol in Ficus lyrata, a three-phase experiment (callus induction, morphogenic callus induction, and plant regeneration) based on auxin, cytokinin, and nitric oxide interactions was designed and implemented using leaf explants. The metabolite profiles (amino acid profile, total phenolic content, total soluble sugars, and total antioxidant activity) alteration patterns were also investigated to determine the metabolites contributing to the progress of each phase. RESULTS: Results demonstrated that 11 out of 48 implemented treatments resulted in morphogenic callus induction (morphogenic treatments), and nitric oxide played a key role in increasing efficiency from 13 to 100%. More importantly, nitric oxide cross-talk with cytokinins was necessary for shoot regeneration from morphogenic calli. Only 4 out of all 48 implemented treatments were capable of shoot regeneration (regenerative treatments), and among them, PR42 treatment led to the highest shoot regeneration rate (86%) and maximum mean number of shoot/explant (10.46). Metabolite analyses revealed that the morphogenic and regenerative treatments followed similar metabolite alterations, which were associated with increased biosynthesis of arginine, lysine, methionine, asparagine, glutamine, histidine, threonine, leucine, glycine, serine amino acids, total soluble sugars content, and total antioxidant activity. On the contrary, non-morphogenic and non-regenerative treatments caused the accumulation of a significantly greater total phenolic content and malondialdehyde in the explant cells, which reflexed the stressful condition of the explants. CONCLUSIONS: It could be concluded that the proper interactions of auxin, cytokinins, and nitric oxide could result in metabolite biosynthesis alterations, leading to triggering cell proliferation, morphogenic center formation, and shoot regeneration.
PMID: 37328837
BMC Plant Biol , IF:4.215 , 2023 Jun , V23 (1) : P319 doi: 10.1186/s12870-023-04320-w
Overexpression of a novel small auxin-up RNA gene, OsSAUR11, enhances rice deep rootedness.
Shanghai Agrobiological Gene Center, Shanghai, 201106, China.; Key Laboratory of Grain Crop Genetic Resources Evaluation and Utilization, Ministry of Agriculture and Rural Affairs, Beijing, China.; College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China.; Shanghai Agrobiological Gene Center, Shanghai, 201106, China. lijun@sagc.org.cn.; Key Laboratory of Grain Crop Genetic Resources Evaluation and Utilization, Ministry of Agriculture and Rural Affairs, Beijing, China. lijun@sagc.org.cn.; College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430070, China. lijun@sagc.org.cn.; Shanghai Agrobiological Gene Center, Shanghai, 201106, China. cl@sagc.org.cn.; Key Laboratory of Grain Crop Genetic Resources Evaluation and Utilization, Ministry of Agriculture and Rural Affairs, Beijing, China. cl@sagc.org.cn.
BACKGROUND: Deep rooting is an important factor affecting rice drought resistance. However, few genes have been identified to control this trait in rice. Previously, we identified several candidate genes by QTL mapping of the ratio of deep rooting and gene expression analysis in rice. RESULTS: In the present work, we cloned one of these candidate genes, OsSAUR11, which encodes a small auxin-up RNA (SAUR) protein. Overexpression of OsSAUR11 significantly enhanced the ratio of deep rooting of transgenic rice, but knockout of this gene did not significantly affect deep rooting. The expression of OsSAUR11 in rice root was induced by auxin and drought, and OsSAUR11-GFP was localized both in the plasma membrane and cell nucleus. Through an electrophoretic mobility shift assay and gene expression analysis in transgenic rice, we found that the transcription factor OsbZIP62 can bind to the promoter of OsSAUR11 and promote its expression. A luciferase complementary test showed that OsSAUR11 interacts with the protein phosphatase OsPP36. Additionally, expression of several auxin synthesis and transport genes (e.g., OsYUC5 and OsPIN2) were down-regulated in OsSAUR11-overexpressing rice plants. CONCLUSIONS: This study revealed a novel gene OsSAUR11 positively regulates deep rooting in rice, which provides an empirical basis for future improvement of rice root architecture and drought resistance.
PMID: 37316787
BMC Plant Biol , IF:4.215 , 2023 Jun , V23 (1) : P310 doi: 10.1186/s12870-023-04330-8
GhPYL9-5D and GhPYR1-3 A positively regulate Arabidopsis and cotton responses to ABA, drought, high salinity and osmotic stress.
National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Life Sciences, College of Agriculture, Henan University, Kaifeng, 475004, China.; National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Life Sciences, College of Agriculture, Henan University, Kaifeng, 475004, China. haofsh@henu.edu.cn.
BACKGROUND: Abscisic acid (ABA) receptor pyrabactin resistance 1/PYR1-like/regulatory components of ABA receptor proteins (PYR/PYL/RCARs) have been demonstrated to play pivotal roles in ABA signaling and in response to diverse environmental stimuli including drought, salinity and osmotic stress in Arabidopsis. However, whether and how GhPYL9-5D and GhPYR1-3A, the homologues of Arabidopsis PYL9 and PYR1 in cotton, function in responding to ABA and abiotic stresses are still unclear. RESULTS: GhPYL9-5D and GhPYR1-3A were targeted to the cytoplasm and nucleus. Overexpression of GhPYL9-5D and GhPYR1-3A in Arabidopsis wild type and sextuple mutant pyr1pyl1pyl2pyl4pyl5pyl8 plants resulted in ABA hypersensitivity in terms of seed germination, root growth and stomatal closure, as well as seedling tolerance to water deficit, salt and osmotic stress. Moreover, the VIGS (Virus-induced gene silencing) cotton plants, in which GhPYL9-5D or GhPYR1-3A were knocked down, showed clearly reduced tolerance to polyethylene glycol 6000 (PEG)-induced drought, salinity and osmotic stresses compared with the controls. Additionally, transcriptomic data revealed that GhPYL9-5D was highly expressed in the root, and GhPYR1-3A was strongly expressed in the fiber and stem. GhPYL9-5D, GhPYR1-3A and their homologs in cotton were highly expressed after treatment with PEG or NaCl, and the two genes were co-expressed with redox signaling components, transcription factors and auxin signal components. These results suggest that GhPYL9-5D and GhPYR1-3A may serve important roles through interplaying with hormone and other signaling components in cotton adaptation to salt or osmotic stress. CONCLUSIONS: GhPYL9-5D and GhPYR1-3A positively regulate ABA-mediated seed germination, primary root growth and stomatal closure, as well as tolerance to drought, salt and osmotic stresses likely through affecting the expression of multiple downstream stress-associated genes in Arabidopsis and cotton.
PMID: 37296391
BMC Plant Biol , IF:4.215 , 2023 May , V23 (1) : P265 doi: 10.1186/s12870-023-04253-4
Different evolutionary patterns of TIR1/AFBs and AUX/IAAs and their implications for the morphogenesis of land plants.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China. zcheng@utk.edu.
BACKGROUND: The plant hormone auxin is widely involved in plant growth, development, and morphogenesis, and the TIR1/AFB and AUX/IAA proteins are closely linked to rapid auxin response and signal transmission. However, their evolutionary history, historical patterns of expansion and contraction, and changes in interaction relationships are still unknown. RESULTS: Here, we analyzed the gene duplications, interactions, and expression patterns of TIR1/AFBs and AUX/IAAs to understand their underlying mechanisms of evolution. The ratios of TIR1/AFBs to AUX/IAAs range from 4:2 in Physcomitrium patens to 6:29 in Arabidopsis thaliana and 3:16 in Fragaria vesca. Whole-genome duplication (WGD) and tandem duplication have contributed to the expansion of the AUX/IAA gene family, but numerous TIR1/AFB gene duplicates were lost after WGD. We further analyzed the expression profiles of TIR1/AFBs and AUX/IAAs in different tissue parts of Physcomitrium patens, Selaginella moellendorffii, Arabidopsis thaliana and Fragaria vesca, and found that TIR1/AFBs and AUX/IAAs were highly expressed in all tissues in P. patens, S. moellendorffii. In A. thaliana and F. vesca, TIR1/AFBs maintained the same expression pattern as the ancient plants with high expression in all tissue parts, while AUX/IAAs appeared tissue-specific expression. In F. vesca, 11 AUX/IAAs interacted with TIR1/AFBs with different interaction strengths, and the functional specificity of AUX/IAAs was related to their ability to bind TIR1/AFBs, thus promoting the development of specific higher plant organs. Verification of the interactions among TIR1/AFBs and AUX/IAAs in Marchantia polymorpha and F. vesca also showed that the regulation of AUX/IAA members by TIR1/AFBs became more refined over the course of plant evolution. CONCLUSIONS: Our results indicate that specific interactions and specific gene expression patterns both contributed to the functional diversification of TIR1/AFBs and AUX/IAAs.
PMID: 37202746
Tree Physiol , IF:4.196 , 2023 Jun doi: 10.1093/treephys/tpad073
Modulation of Polar Auxin Transport Identifies the Molecular Determinants of Source-Sink Carbon Relationships and Sink Strength in Poplar.
Environmental Molecular Sciences Laboratory (EMSL), Pacific Northwest National Laboratory (PNNL), Richland, Washington USA.; Current Address: Department of Ecology and Forest Genetics, Forest Sciences Institute (ICIFOR), National Institute for Agricultural and Food Research and Technology (INIA-CSIC), Madrid, Spain.; Current Address: Departments of Integrative Biology and Plant, Soil and Microbial Sciences, Michigan State University (MSU), East Lansing, Michigan, USA.; Adjoint Faculty, School of Biological Science (SBS), Washington State University (WSU), Pullman, WA.
Source-to-sink carbon (C) allocation driven by the sink strength, i.e., the ability of a sink organ to import C, plays a central role in tissue growth and biomass productivity. However, molecular drivers of sink strength have not been thoroughly characterized in trees. Auxin, as a major plant phytohormone, regulates the mobilization of photoassimilates in source tissues and elevates the translocation of carbohydrates toward sink organs, including roots. In this study, we used an 'auxin-stimulated carbon sink' approach to understand the molecular processes involved in the long-distance source-sink C allocation in poplar. Poplar cuttings were foliar sprayed with polar auxin transport modulators, including auxin enhancers (AE) (i.e., IBA and IAA) and auxin inhibitor (AI) (i.e., NPA), followed by a comprehensive analysis of leaf, stem, and root tissues using biomass evaluation, phenotyping, C isotope labeling, metabolomics, and transcriptomics approaches. Auxin modulators altered root dry weight and branching pattern, and AE increased photosynthetically fixed C allocation from leaf to root tissues. The transcriptome analysis identified highly expressed genes in root tissue under AE condition including transcripts encoding polygalacturonase and beta-amylase that could increase the sink size and activity. Metabolic analyses showed a shift in overall metabolism including an altered relative abundance levels of galactinol, and an opposite trend in citrate levels in root tissue under AE and AI conditions. In conclusion, we postulate a model suggesting that the source-sink C relationships in poplar could be fueled by mobile sugar alcohols, starch metabolism-derived sugars, and TCA-cycle intermediates as key molecular drivers of sink strength.
PMID: 37265358
Tree Physiol , IF:4.196 , 2023 May doi: 10.1093/treephys/tpad060
Comparative transcriptomics provides insights into the pathogenic immune response of brown leaf spots in weeping forsythia.
School of Pharmacy, Henan University, Kaifeng, Henan 475004, China.; Henan Province Engineering Research Center of High Value Utilization to Natural Medical Resource in Yellow River Basin, Kaifeng 475004, China.; School of Life Sciences, Henan University, Kaifeng, Henan 475004, China.; College of Life Science and Technology, Inner Mongolia Normal University, Huhehaote, China.; State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China.
Weeping forsythia is an important ornamental, ecological, and medicinal plant. Brown leaf spots reduce the large-scale production of weeping forsythia as a medicinal crop. Alternaria alternata is a pathogen causing brown leaf spots in weeping forsythia; however, its pathogenesis and the immune response mechanisms of weeping forsythia remain unclear. In this study, we identified the two mechanisms based on morphological anatomy, physiological indexes, and gene expression analyses. Our results showed that A. alternata induced leaf stomata to open, invaded the mesophyll, dissolved the cell wall, destroyed the cell membrane, and decreased the number of chloroplasts by up-regulating the expression of auxin-activated signaling pathway genes. A. alternata also down-regulated iron ion homeostasis and binding-related genes, which caused an increase in the levels of iron ions and reactive oxygen species in leaves. These processes eventually led to programmed cell death, destroying palisade and spongy tissues and causing the formation of iron rust spots. A. alternata also caused defense and hypersensitive responses in weeping forsythia through signaling pathways mediated by flg22-like and elf18-like polypeptides, ethylene, H2O2, and bacterial secretion systems. Our study provides a theoretical basis for the control of brown leaf spots in weeping forsythia.
PMID: 37171622
Tree Physiol , IF:4.196 , 2023 May , V43 (5) : P851-866 doi: 10.1093/treephys/tpac149
Physiological and transcriptome analyses of the effects of excessive water deficit on malic acid accumulation in apple.
College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China.
Acidity is a determinant of the organoleptic quality of apple, whereas its regulatory mechanism under water stress remains obscure. Fruit from apple 'Yanfu 3' of Fuji trees grown under normal water irrigation (CK), excessive water deficit treatment (DRT) and excessive water irrigation treatment (WAT) were sampled at 85, 100, 115, 130, 145, 160 and 175 days after full bloom designated stages S1, S2, S3, S4, S5, S6 and S7, respectively. DRT treatment reduced the individual fruit weight and fruit moisture content, and increased fruit firmness. The malate content of DRT treatment was higher than that of CK and WAT from stages S1 to S7. RNA sequencing (RNA-seq) analysis of the transcriptome at stages S4, S6 and S7 indicated that malate anabolism was associated with cysteine and methionine, auxin signaling, glyoxylate and dicarboxylate and pyruvate metabolism. Overexpression of MdPEPC4 increased the malate content in apple calli induced by 4% PEG. Our study provides novel insights into the effects of water stress on the molecular mechanism underlying apple fruit acidity.
PMID: 36579825
Microorganisms , IF:4.128 , 2023 Jun , V11 (6) doi: 10.3390/microorganisms11061615
Symbiotic Variations among Wheat Genotypes and Detection of Quantitative Trait Loci for Molecular Interaction with Auxin-Producing Azospirillum PGPR.
Univ Lyon, Universite Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR5557 Ecologie Microbienne, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne, France.; GDEC, INRAE, UCA, F-63000 Clermont-Ferrand, France.
Crop varieties differ in their ability to interact with Plant Growth-Promoting Rhizobacteria (PGPR), but the genetic basis for these differences is unknown. This issue was addressed with the PGPR Azospirillum baldaniorum Sp245, using 187 wheat accessions. We screened the accessions based on the seedling colonization by the PGPR and the expression of the phenylpyruvate decarboxylase gene ppdC (for synthesis of the auxin indole-3-acetic acid), using gusA fusions. Then, the effects of the PGPR on the selected accessions stimulating Sp245 (or not) were compared in soil under stress. Finally, a genome-wide association approach was implemented to identify the quantitative trait loci (QTL) associated with PGPR interaction. Overall, the ancient genotypes were more effective than the modern genotypes for Azospirillum root colonization and ppdC expression. In non-sterile soil, A. baldaniorum Sp245 improved wheat performance for three of the four PGPR-stimulating genotypes and none of the four non-PGPR-stimulating genotypes. The genome-wide association did not identify any region for root colonization but revealed 22 regions spread on 11 wheat chromosomes for ppdC expression and/or ppdC induction rate. This is the first QTL study focusing on molecular interaction with PGPR bacteria. The molecular markers identified provide the possibility to improve the capacity of modern wheat genotypes to interact with Sp245, as well as, potentially, other Azospirillum strains.
PMID: 37375117
Microorganisms , IF:4.128 , 2023 May , V11 (5) doi: 10.3390/microorganisms11051227
Influence of Plant Growth-Promoting Rhizobacteria on the Formation of Apoplastic Barriers and Uptake of Water and Potassium by Wheat Plants.
Ufa Institute of Biology, Ufa Federal Research Centre, Russian Academy of Sciences, Prospekt Oktyabrya, 69, 450054 Ufa, Russia.; Group of Culture of Beneficial Microorganisms, All-Russia Research Institute for Agricultural Microbiology, Podbelskogo sh. 3, Pushkin, 196608 Saint-Petersburg, Russia.
The formation of apoplastic barriers is important for controlling the uptake of water and ions by plants, thereby influencing plant growth. However, the effects of plant growth-promoting bacteria on the formation of apoplastic barriers, and the relationship between these effects and the ability of bacteria to influence the content of hormones in plants, have not been sufficiently studied. The content of cytokinins, auxins and potassium, characteristics of water relations, deposition of lignin and suberin and the formation of Casparian bands in the root endodermis of durum wheat (Triticum durum Desf.) plants were evaluated after the introduction of the cytokinin-producing bacterium Bacillus subtilis IB-22 or the auxin-producing bacterium Pseudomonas mandelii IB-Ki14 into their rhizosphere. The experiments were carried out in laboratory conditions in pots with agrochernozem at an optimal level of illumination and watering. Both strains increased shoot biomass, leaf area and chlorophyll content in leaves. Bacteria enhanced the formation of apoplastic barriers, which were most pronounced when plants were treated with P. mandelii IB-Ki14. At the same time, P. mandelii IB-Ki14 caused no decrease in the hydraulic conductivity, while inoculation with B. subtilis IB-22, increased hydraulic conductivity. Cell wall lignification reduced the potassium content in the roots, but did not affect its content in the shoots of plants inoculated with P. mandelii IB-Ki14. Inoculation with B. subtilis IB-22 did not change the potassium content in the roots, but increased it in the shoots.
PMID: 37317202
Planta , IF:4.116 , 2023 Jun , V258 (2) : P33 doi: 10.1007/s00425-023-04193-1
Comparative transcriptome analysis reveals the regulatory effects of exogenous auxin on lateral root development and tanshinone accumulation in Salvia miltiorrhiza.
Joint International Research Laboratory of Agriculture and Agri-Product Safety, Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China. zhangsc@yzu.edu.cn.; Joint International Research Laboratory of Agriculture and Agri-Product Safety, Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China.; Shaanxi Origin Agricultural Science and Technology Co., Ltd, Tongchuan, 727000, People's Republic of China.; Key Laboratory of Plant Secondary Metabolism and Regulation of Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, People's Republic of China. ydf807@sina.com.
The physiological and transcriptome analysis revealed that auxin was a positive regulator of lateral root development and tanshinone accumulation in Salvia miltiorrhiza. Roots of S. miltiorrhiza are widely used as medicinal materials in China, and the root morphology and content of bioactive compounds [such as phenolic acids and diterpenoid quinones (tanshinones)] are the main factors to determine the quality of this herb. Auxin regulates root development and secondary metabolism in many plant species, but little is known about its function in S. miltiorrhiza. In this study, S. miltiorrhiza seedlings were treated (exogenous application) with the auxin indole-3-acetic acid (IAA) and the polar auxin transport inhibitor N-1-naphthylphthalamic acid (NPA) to investigate the regulatory roles of auxin in S. miltiorrhiza. The results indicated that exogenous IAA promoted both lateral root development and tanshinones biosynthesis in S. miltiorrhiza. The NPA application suppressed the lateral root development but showed no obvious effects on tanshinones accumulation. Based on the RNA-seq analysis, expressions of genes related to auxin biosynthesis and signaling transduction were altered in both treated groups. Coincidental with the enhanced content of tanshinones, transcripts of several key enzyme genes in the tanshinones biosynthetic pathway were stimulated after the exogenous IAA application. The expression profiles of seven common transcription factor domain-containing gene families were analyzed, and the results implied that some AP2/ERF genes were probably responsible for the auxin-induced lateral root development in S. miltiorrhiza. These findings shed new light on the regulatory roles of auxin on root development and bioactive compounds biosynthesis in S. miltiorrhiza, and lay the groundwork for future research into the detailed molecular mechanism underlying these biological functions.
PMID: 37378716
Planta , IF:4.116 , 2023 Jun , V258 (2) : P26 doi: 10.1007/s00425-023-04183-3
LBD18 and IAA14 antagonistically interact with ARF7 via the invariant Lys and acidic residues of the OPCA motif in the PB1 domain.
Department of Bioenergy Science and Technology, Chonnam National University, Buk-Gu, Gwangju, 61186, South Korea.; Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Buk-Gu, Gwangju, 61186, South Korea.; Department of Bioenergy Science and Technology, Chonnam National University, Buk-Gu, Gwangju, 61186, South Korea. jungmkim@jnu.ac.kr.; Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Buk-Gu, Gwangju, 61186, South Korea. jungmkim@jnu.ac.kr.; Kumho Life Science Laboratory, Chonnam National University, Buk-Gu, Gwangju, 500-757, South Korea. jungmkim@jnu.ac.kr.
LBD18 and IAA14 antagonistically interact with ARF7 through the electrostatic faces in the ARF7PB1 domain, modulating ARF7 transcriptional activity. Auxin Response Factor 7 (ARF7)/ARF19 control lateral root development by directly activating Lateral Organ Boundaries Domain 16 (LBD16)/LBD18 genes in Arabidopsis. LBD18 upregulates ARF19 expression by binding to the ARF19 promoter. It also interacts with ARF7 through the Phox and Bem1 (PB1) domain to enhance the ARF7 transcriptional activity, forming a dual mode of positive feedback loop. LBD18 competes with the repressor indole-3-acetic acid 14 (IAA14) for ARF7 binding through the PB1 domain. In this study, we examined the molecular determinant of the ARF7 PB1 domain for interacting with LBD18 and showed that the electronic faces in the ARF7 PB1 domain are critical for interacting with LBD18 and IAA14/17. We used a luminescence complementation imaging assay to determine protein-protein interactions. The results showed that mutation of the invariant lysine residue and the OPCA motif in the PB1 domain in ARF7 significantly reduces the protein interaction between ARF7 and LBD18. Transient gene expression assays with Arabidopsis protoplasts showed that IAA14 suppressed transcription-enhancing activity of LBD18 on the LUC reporter gene fused to the ARF19 promoter harboring an auxin response element, but mutation of the invariant lysine residue and OPCA motif in the PB1 domain of IAA14 reduced the repression capability of IAA14 for transcription-enhancing activity of LBD18. We further showed that the same mutation in the PB1 domain of IAA14 reduces its repression capability, thereby increasing the LUC activity induced by both ARF7 and LBD18 compared with IAA14. These results suggest that LBD18 competes with IAA14 for ARF7 binding via the electrostatic faces of the ARF7 PB1 domain to modulate ARF7 transcriptional activity.
PMID: 37354348
Planta , IF:4.116 , 2023 May , V257 (6) : P120 doi: 10.1007/s00425-023-04144-w
The inhibition of maize (Zea mays L.) root stem cell regeneration by low oxygen is attenuated by Phytoglobin 1 (Pgb1) through changes in auxin and jasmonic acid.
Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.; Department of Botany, Faculty of Science, Tanta University, Tanta, 31527, Egypt.; Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada. stasolla@ms.umanitoba.ca.
Over-expression of Phytoglobin1 increases the viability of maize root stem cells to low oxygen stress through changes in auxin and jasmonic acid responses. Hypoxia inhibits maize (Zea mays L.) root growth by deteriorating the quiescent center (QC) stem cells of the root apical meristem. Over-expression of the Phytoglobin1 ZmPgb1.1 alleviates these effects through the retention of the auxin flow along the root profile required for the specification of the QC stem cells. To identify QC-specific hypoxia responses and determine whether ZmPgb1.1 exercises a direct role on QC stem cells, we performed a QC functionality test. This was done by estimating the ability of QCs to regenerate a root in vitro in a hypoxic environment. Hypoxia decreased the functionality of the QCs by depressing the expression of several genes participating in the synthesis and response of auxin. This was accompanied by a decrease in DR5 signal, a suppression of PLETHORA and WOX5, two markers of QC cell identity, and a reduction in expression of genes participating in JA synthesis and signaling. Over-expression of ZmPgb1.1 was sufficient to mitigate all these responses. Through pharmacological alterations of auxin and JA, it is demonstrated that both hormones are required for QC functionality under hypoxia, and that JA acts downstream of auxin during QC regeneration. A model is proposed whereby the ZmPgb1.1 maintenance of auxin synthesis in hypoxic QCs is determinant for the retention of their functionality, with JA supporting the regeneration of roots from the QCs.
PMID: 37178357
Planta , IF:4.116 , 2023 May , V257 (6) : P108 doi: 10.1007/s00425-023-04136-w
Advances in the study of the function and mechanism of the action of flavonoids in plants under environmental stresses.
School of Environmental Science, Liaoning University, Shenyang, 110036, China. wujieting@lnu.edu.cn.; School of Environmental Science, Liaoning University, Shenyang, 110036, China.; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.; Kerchin District Branch Office, Tongliao City Ecological Environment Bureau, Tongliao, 028006, China.; Dalian Neusoft University of Information, Dalian, 116032, China.
This review summarizes the anti-stress effects of flavonoids in plants and highlights its role in the regulation of polar auxin transport and free radical scavenging mechanism. As secondary metabolites widely present in plants, flavonoids play a vital function in plant growth, but also in resistance to stresses. This review introduces the classification, structure and synthetic pathways of flavonoids. The effects of flavonoids in plant stress resistance were enumerated, and the mechanism of flavonoids in plant stress resistance was discussed in detail. It is clarified that plants under stress accumulate flavonoids by regulating the expression of flavonoid synthase genes. It was also determined that the synthesized flavonoids are transported in plants through three pathways: membrane transport proteins, vesicles, and bound to glutathione S-transferase (GST). At the same time, the paper explores that flavonoids regulate polar auxin transport (PAT) by acting on the auxin export carrier PIN-FORMED (PIN) in the form of ATP-binding cassette subfamily B/P-glycoprotein (ABCB/PGP) transporter, which can help plants to respond in a more dominant form to stress. We have demonstrated that the number and location of hydroxyl groups in the structure of flavonoids can determine their free radical scavenging ability and also elucidated the mechanism by which flavonoids exert free radical removal in cells. We also identified flavonoids as signaling molecules to promote rhizobial nodulation and colonization of arbuscular mycorrhizal fungi (AMF) to enhance plant-microbial symbiosis in defense to stresses. Given all this knowledge, we can foresee that the in-depth study of flavonoids will be an essential way to reveal plant tolerance and enhance plant stress resistance.
PMID: 37133783
Genes (Basel) , IF:4.096 , 2023 Jun , V14 (6) doi: 10.3390/genes14061215
Identification of Key Genes Regulating Sorghum Mesocotyl Elongation through Transcriptome Analysis.
Shanxi Key Laboratory of Sorghum Genetic and Germplasm Innovation, Sorghum Research Institute, Shanxi Agricultural University, Jinzhong 030600, China.; College of Agriculture, Shanxi Agricultural University, Jinzhong 030600, China.
Sorghum with longer mesocotyls is beneficialfor improving its deep tolerance, which is important for the seedling rates. Here, we perform transcriptome analysis between four different sorghum lines, with the aim of identifying the key genes regulating sorghum mesocotyl elongation. According to the mesocotyl length (ML) data, we constructed four comparison groups for the transcriptome analysis and detected 2705 common DEGs. GO and KEGG enrichment analysis showed that the most common category of DEGs were involved in cell wall, microtubule, cell cycle, phytohormone, and energy metabolism-related pathways. In the cell wall biological processes, the expression of SbEXPA9-1, SbEXPA9-2, SbXTH25, SbXTH8-1, and SbXTH27 are increased in the sorghum lines with long ML. In the plant hormone signaling pathway, five auxin-responsive genes and eight cytokinin/zeatin/abscisic acid/salicylic acid-related genes showed a higher expression level in the long ML sorghum lines. In addition, five ERF genes showed a higher expression level in the sorghum lines with long ML, whereas two ERF genes showed a lower expression level in these lines. Furthermore, the expression levels of these genes were further analyzed using real-time PCR (RT-qPCR), which showed similar results. This work identified the candidate gene regulating ML, which may provide additional evidence to understand the regulatory molecular mechanisms of sorghum mesocotyl elongation.
PMID: 37372395
Genes (Basel) , IF:4.096 , 2023 May , V14 (6) doi: 10.3390/genes14061206
Regulatory Mechanisms of ArAux/IAA13 and ArAux/IAA16 in the Rooting Process of Acer rubrum.
Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing University of Agriculture, Beijing 102206, China.; College of Landscape Architecture, Beijing University of Agriculture, Beijing 102206, China.; Beijing Laboratory of Urban and Rural Ecological Environment, Beijing 102206, China.
Acer rubrum is difficult to root during cutting propagation. Auxin/indole-acetic acids (Aux/IAA) proteins, which are encoded by the early response genes of auxin, are transcriptional repressors that play important roles in auxin-mediated root growth and development. In this study, ArAux/IAA13 and ArAux/IAA16, which were significantly differentially expressed after 300 mg/L indole butyric acid treatment, were cloned. Heatmap analysis revealed that they might be associated with the process of adventitious root (AR) growth and development mediated by auxin. Subcellular localization analysis showed that they performed their function in the nucleus. Bimolecular fluorescence complementation assays revealed the interactions between them and two auxin response factor (ARF) proteins, ArARF10 and ArARF18, confirming their relevance to AR growth and development. Overexpression of transgenic plants confirmed that the overexpression of ArAux/IAA13 and ArAux/IAA16 inhibited AR development. These results help elucidate the mechanisms of auxin-mediated AR growth and development during the propagation of A. rubrum and provide a molecular basis for the rooting of cuttings.
PMID: 37372386
Plant Genome , IF:4.089 , 2023 May : Pe20343 doi: 10.1002/tpg2.20343
Proteomic analysis of near-isogenic lines reveals key biomarkers on wheat chromosome 4B conferring drought tolerance.
UWA School of Agriculture and Environment, The University of Western Australia, Crawley, Western Australia, Australia.; The UWA Institute of Agriculture, The University of Western Australia, Crawley, Western Australia, Australia.; Department of Primary Industries and Regional Development, South Perth, Western Australia, Australia.; Proteomics International, Crawley, Western Australia, Australia.; Harry Perkins Institute of Medical Research, QEII Medical Centre, The University of Western Australia, Crawley, Western Australia, Australia.
Drought is a major constraint for wheat production that is receiving increased attention due to global climate change. This study conducted isobaric tags for relative and absolute quantitation proteomic analysis on near-isogenic lines to shed light on the underlying mechanism of qDSI.4B.1 quantitative trait loci (QTL) on the short arm of chromosome 4B conferring drought tolerance in wheat. Comparing tolerant with susceptible isolines, 41 differentially expressed proteins were identified to be responsible for drought tolerance with a p-value of < 0.05 and fold change >1.3 or <0.7. These proteins were mainly enriched in hydrogen peroxide metabolic activity, reactive oxygen species metabolic activity, photosynthetic activity, intracellular protein transport, cellular macromolecule localization, and response to oxidative stress. Prediction of protein interactions and pathways analysis revealed the interaction between transcription, translation, protein export, photosynthesis, and carbohydrate metabolism as the most important pathways responsible for drought tolerance. The five proteins, including 30S ribosomal protein S15, SRP54 domain-containing protein, auxin-repressed protein, serine hydroxymethyltransferase, and an uncharacterized protein with encoding genes on 4BS, were suggested as candidate proteins responsible for drought tolerance in qDSI.4B.1 QTL. The gene coding SRP54 protein was also one of the differentially expressed genes in our previous transcriptomic study.
PMID: 37199103
Plant Mol Biol , IF:4.076 , 2023 May doi: 10.1007/s11103-023-01355-3
Ectopic overexpression of TaHsfA5 promotes thermomorphogenesis in Arabidopsis thaliana and thermotolerance in Oryza sativa.
Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.; Department of Plant Molecular Biology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India. param@genomeindia.org.
Heat stress transcription factors (Hsfs) play an important role in regulating the heat stress response in plants. Among the Hsf family members, the group A members act upstream in initiating the response upon sensing heat stress and thus, impart thermotolerance to the plants. In the present study, wheat HsfA5 (TaHsfA5) was found to be one of the Hsfs, which was upregulated both in heat stress and during the recovery period after the stress. TaHsfA5 was found to interact with TaHsfA3 and TaHsfA4, both of which are known to positively regulate the heat stress-responsive genes. Apart from these, TaHsfA5 also interacted with TaHSBP2 protein, whose role has been implicated in attenuating the heat stress response. Further, its heterologous overexpression in Arabidopsis and Oryza sativa promoted thermotolerance in these plants. This indicated that TaHsfA5 positively regulated the heat stress response. Interestingly, the TaHsfA5 overexpression Arabidopsis plants when grown at warm temperatures showed a hyper-thermomorphogenic response in comparison to the wild-type plants. This was found to be consistent with the higher expression of PIF4 and its target auxin-responsive genes in these transgenics in contrast to the wild-type plants. Thus, these results suggest the involvement of TaHsfA5 both in the heat stress response as well as in the thermomorphogenic response in plants.
PMID: 37166615
Plant Mol Biol , IF:4.076 , 2023 May , V112 (1-2) : P85-98 doi: 10.1007/s11103-023-01354-4
Identification and transcriptome data analysis of ARF family genes in five Orchidaceae species.
International Center for Bamboo and Rattan, Chaoyang District, Beijing, China.; Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo & Rattan Science and Technology, Chaoyang District, Beijing, China.; Pingxiang Bamboo Forest Ecosystem Research Station, Pingxiang, Guangxi, China.; International Center for Bamboo and Rattan, Chaoyang District, Beijing, China. hutao@icbr.ac.cn.; Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo & Rattan Science and Technology, Chaoyang District, Beijing, China. hutao@icbr.ac.cn.; Pingxiang Bamboo Forest Ecosystem Research Station, Pingxiang, Guangxi, China. hutao@icbr.ac.cn.
The Orchidaceae is a large family of perennial herbs especially noted for the exceptional diversity of specialized flowers. Elucidating the genetic regulation of flowering and seed development of orchids is an important research goal with potential utility in orchid breeding programs. Auxin Response Factor (ARF) genes encode auxin-responsive transcription factors, which are involved in the regulation of diverse morphogenetic processes, including flowering and seed development. However, limited information on the ARF gene family in the Orchidaceae is available. In this study, 112 ARF genes were identified in the genomes of 5 orchid species (Apostasia shenzhenica, Dendrobium catenatum, Phalaenopsis aphrodite, Phalaenopsis equestris and Vanilla planifolia,). These genes were grouped into 7 subfamilies based on their phylogenetic relationships. Compared with the ARF family in model plants, such as Arabidopsis thaliana and Oryza sativa, one group of ARF genes involved in pollen wall synthesis has been lost during evolution of the Orchidaceae. This loss corresponds with absence of the exine in the pollinia. Through mining of the published genomic and transcriptomic data for the 5 orchid species: the ARF genes of subfamily 4 may play an important role in flower formation and plant growth, whereas those of subfamily 3 are potentially involved in pollen wall development. the study results provide novel insights into the genetic regulation of unique morphogenetic phenomena of orchids, which lay a foundation for further analysis of the regulatory mechanisms and functions of sexual reproduction-related genes in orchids.
PMID: 37103774
Plant Mol Biol , IF:4.076 , 2023 May , V112 (1-2) : P1-18 doi: 10.1007/s11103-023-01341-9
Coordination of floral and fiber development in cotton (Gossypium) by hormone- and flavonoid-signalling associated regulatory miRNAs.
School of Biotechnology, Gautam Buddha University, Greater Noida, 201312, India.; Center for Genetic Manipulation of Crop Plants, University of Delhi South Campus, New Delhi, 110021, India.; School of Biotechnology, Gautam Buddha University, Greater Noida, 201312, India. bhupendra@gbu.ac.in.
Various plant development activities and stress responses are tightly regulated by various microRNAs (miRNA) and their target genes, or transcription factors in a spatiotemporal manner. Here, to exemplify how flowering-associated regulatory miRNAs synchronize their expression dynamics during floral and fiber development in cotton, constitutive expression diminution transgenic lines of auxin-signaling regulatory Gh-miR167 (35S-MIM167) were developed through target mimicry approach. 'Moderate' (58% to 80%)- and 'high' (> 80%)-Gh-miR167 diminution mimic lines showed dosage-dependent developmental deformities in anther development, pollen maturation, and fruit (= boll) formation. Cross pollination of 'moderate' 35S-MIM167 mimic lines with wild type (WT) plant partially restored boll formation and emergence of fiber initials on the ovule surface. Gh-miR167 diminution favored organ-specific transcription biases in miR159, miR166 as well as miR160, miR164, and miR172 along with their target genes during anther and petal development, respectively. Similarly, accumulative effect of percent Gh-miR167 diminution, cross regulation of its target ARF6/8 genes, and temporal mis-expression of hormone signaling- and flavonoid biosynthesis-associated regulatory miRNAs at early fiber initiation stage caused irregular fiber formation. Spatial and temporal transcription proportions of regulatory miRNAs were also found crucial for the execution of hormone- and flavonoid-dependent progression of floral and fiber development. These observations discover how assorted regulatory genetic circuits get organized in response to Gh-miR167 diminution and converge upon ensuing episodes of floral and fiber development in cotton.
PMID: 37067671
BMC Genomics , IF:3.969 , 2023 Jun , V24 (1) : P329 doi: 10.1186/s12864-023-09399-x
Genome-wide analysis of MdPLATZ genes and their expression during axillary bud outgrowth in apple (Malus domestica Borkh.).
College of Horticulture, Hebei Agricultural University, Hebei, 071000, China.; College of Horticulture, Hebei Agricultural University, Hebei, 071000, China. yysjz@hebau.edu.cn.; College of Horticulture, Hebei Agricultural University, Hebei, 071000, China. tanming@hebau.edu.cn.
BACKGROUND: Branching is a plastic character that affects plant architecture and spatial structure. The trait is controlled by a variety of plant hormones through coordination with environmental signals. Plant AT-rich sequence and zinc-binding protein (PLATZ) is a transcription factor that plays an important role in plant growth and development. However, systematic research on the role of the PLATZ family in apple branching has not been conducted previously. RESULTS: In this study, a total of 17 PLATZ genes were identified and characterized from the apple genome. The 83 PLATZ proteins from apple, tomato, Arabidopsis, rice, and maize were classified into three groups based on the topological structure of the phylogenetic tree. The phylogenetic relationships, conserved motifs, gene structure, regulatory cis-acting elements, and microRNAs of the MdPLATZ family members were predicted. Expression analysis revealed that MdPLATZ genes exhibited distinct expression patterns in different tissues. The expression patterns of the MdPLATZ genes were systematically investigated in response to treatments that impact apple branching [thidazuron (TDZ) and decapitation]. The expression of MdPLATZ1, 6, 7, 8, 9, 15, and 16 was regulated during axillary bud outgrowth based on RNA-sequencing data obtained from apple axillary buds treated by decapitation or exogenous TDZ application. Quantitative real-time PCR analysis showed that MdPLATZ6 was strongly downregulated in response to the TDZ and decapitation treatments, however, MdPLATZ15 was significantly upregulated in response to TDZ, but exhibited little response to decapitation. Furthermore, the co-expression network showed that PLATZ might be involved in shoot branching by regulating branching-related genes or mediating cytokinin or auxin pathway. CONCLUSION: The results provide valuable information for further functional investigation of MdPLATZ genes in the control of axillary bud outgrowth in apple.
PMID: 37322464
Pestic Biochem Physiol , IF:3.963 , 2023 Jun , V193 : P105450 doi: 10.1016/j.pestbp.2023.105450
Multiple resistance of Echinochloa phyllopogon to synthetic auxin, ALS-, and ACCase-inhibiting herbicides in Northeast China.
Shenyang Agricultural University, College of Plant Protection, Shenyang, Liaoning 110866, China.; Agricultural and Rural Bureau of Caofeidian District, Tangshan, Hebei 063299, China.; Shenyang Agricultural University, College of Plant Protection, Shenyang, Liaoning 110866, China. Electronic address: jimingshan@163.com.
Echinochloa phyllopogon is a self-pollinating allotetraploid weed and a serious threat to global rice production. One sensitive and three multiple-resistant populations collected from two provinces of Northeast China were used to analyze the mechanism of multiple resistance of E. phyllopogon to penoxsulam, metamifop, and quinclorac. Compared with the sensitive population LN12, LN1 showed higher resistance to these three herbicides; LN24 showed medium resistance to penoxsulam and metamifop and higher resistance to quinclorac (274-fold); HLJ4 showed low resistance to penoxsulam and high resistance to metamifop and quinclorac. Target sequence analysis showed no mutations in acetolactate synthase or acetyl-CoA carboxylase genes. In-vitro enzyme activity analysis showed that the activity of the target enzyme of multiple herbicide-resistant populations was similar to that of the sensitive population. The P450 inhibitor, malathion, noticeably increased the sensitivity of LN1, LN24, and HLJ4 to penoxsulam, LN1 to metamifop, and HLJ4 to quinclorac. Under all four treatments, the GSTs activities of resistant and sensitive populations showed an increasing trend from day 1 to day 5, but the sensitivity and activity of GSTs were higher in the multiple-resistant population than that in the sensitive population LN12. This study identified the development of multiple-resistant E. phyllopogon populations that pose a serious threat to rice production in rice fields in Northeast China, preliminarily confirming that multiple-resistance was likely due to non-target-site resistance mechanisms. These populations of E. phyllopogon are likely to be more difficult to control.
PMID: 37248019
Plants (Basel) , IF:3.935 , 2023 Jun , V12 (12) doi: 10.3390/plants12122280
Characterization of the PIN Auxin Efflux Carrier Gene Family and Its Expression during Zygotic Embryogenesis in Persea americana.
Centro de Investigacion Cientifica de Yucatan, Unidad de Bioquimica y Biologia Molecular de Plantas, Calle 43 No. 130 x 32 y 34, Chuburna de Hidalgo, Merida CP 97205, Yucatan, Mexico.; Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Avenida Itzaes, No. 490 x Calle 59, Col. Centro, Merida CP 97000, Yucatan, Mexico.
Auxins are responsible for a large part of the plant development process. To exert their action, they must move throughout the plant and from cell to cell, which is why plants have developed complex transport systems for indole-3-acetic acid (IAA). These transporters involve proteins that transport IAA into cells, transporters that move IAA to or from different organelles, mainly the endoplasmic reticulum, and transporters that move IAA out of the cell. This research determined that Persea americana has 12 PIN transporters in its genome. The twelve transporters are expressed during different stages of development in P. americana zygotic embryos. Using different bioinformatics tools, we determined the type of transporter of each of the P. americana PIN proteins and their structure and possible location in the cell. We also predict the potential phosphorylation sites for each of the twelve-PIN proteins. The data show the presence of highly conserved sites for phosphorylation and those sites involved in the interaction with the IAA.
PMID: 37375905
Plants (Basel) , IF:3.935 , 2023 May , V12 (11) doi: 10.3390/plants12112173
Evidence That PbrSAUR72 Contributes to Iron Deficiency Tolerance in Pears by Facilitating Iron Absorption.
State Key Laboratory of Fruit Biology, School of Horticulture, Anhui Agricultural University, Hefei 230036, China.; Agricultural Experimental Center of Guiyang, Guiyang Agriculture and Rural Bureau, Guiyang 550018, China.; Singleron Biotechnology Co., Ltd., Nanjing 210000, China.
Iron is an essential trace element for plants; however, low bioactive Fe in soil continuously places plants in an Fe-deficient environment, triggering oxidative damage. To cope with this, plants make a series of alterations to increase Fe acquisition; however, this regulatory network needs further investigation. In this study, we found notably decreased indoleacetic acid (IAA) content in chlorotic pear (Pyrus bretschneideri Rehd.) leaves caused by Fe deficiency. Furthermore, IAA treatment slightly induced regreening by increasing chlorophyll synthesis and Fe(2+) accumulation. At that point, we identified PbrSAUR72 as a key negative effector output of auxin signaling and established its close relationship to Fe deficiency. Furthermore, the transient PbrSAUR72 overexpression could form regreening spots with increased IAA and Fe(2+) content in chlorotic pear leaves, whereas its transient silencing does the opposite in normal pear leaves. In addition, cytoplasm-localized PbrSAUR72 exhibits root expression preferences and displays high homology to AtSAUR40/72. This promotes salt tolerance in plants, indicating a putative role for PbrSAUR72 in abiotic stress responses. Indeed, transgenic plants of Solanum lycopersicum and Arabidopsis thaliana overexpressing PbrSAUR72 displayed less sensitivity to Fe deficiency, accompanied by substantially elevated expression of Fe-induced genes, such as FER/FIT, HA, and bHLH39/100. These result in higher ferric chelate reductase and root pH acidification activities, thereby hastening Fe absorption in transgenic plants under an Fe-deficient condition. Moreover, the ectopic overexpression of PbrSAUR72 inhibited reactive oxygen species production in response to Fe deficiency. These findings contribute to a new understanding of PbrSAURs and its involvement in Fe deficiency, providing new insights for the further study of the regulatory mechanisms underlying the Fe deficiency response.
PMID: 37299155
Plants (Basel) , IF:3.935 , 2023 May , V12 (11) doi: 10.3390/plants12112175
Efficient Plant Regeneration System from Leaf Explant Cultures of Daphne genkwa via Somatic Embryogenesis.
Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea.; Department of Industrial Plant Science and Technology, Chungbuk National University, Cheongju 28644, Republic of Korea.; Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 56212, Republic of Korea.
This study aimed to establish an efficient plant regeneration system from leaf-derived embryogenic structure cultures of Daphne genkwa. To induce embryogenic structures, fully expanded leaf explants of D. genkwa were cultured on Murashige and Skoog (MS) medium supplemented with 0, 0.1, 0.5, 1, 2, and 5 mg.L(-1) 2,4-dichlorophenoxyacetic acid (2,4-D), respectively. After 8 weeks of incubation, the highest frequency of embryogenic structure formation reached 100% when the leaf explants were cultivated on MS medium supplemented with 0.1 to 1 mg.L(-1) 2,4-D. At higher concentrations of 2,4-D (over 2 mg.L(-1) 2,4-D), the frequency of embryogenic structure formation significantly declined. Similar to 2,4-D, indole butyric acid (IBA) and alpha-naphthaleneacetic acid (NAA) treatments were also able to form embryogenic structures. However, the frequency of embryogenic structure formation was lower than that of 2,4-D. In particular, the yellow embryonic structure (YES) and white embryonic structure (WES) were simultaneously developed from the leaf explants of D. genkwa on culture medium containing 2,4-D, IBA, and NAA, respectively. Embryogenic calluses (ECs) were formed from the YES after subsequent rounds of subculture on MS medium supplemented with 1 mg.L(-1) 2,4-D. To regenerate whole plants, the embryogenic callus (EC) and the two embryogenic structures (YES and WES) were transferred onto MS medium supplemented with 0.1 mg.L(-1) 6-benzyl aminopurine (BA). The YES had the highest plant regeneration potential via somatic embryo and shoot development compared to the EC and WES. To our knowledge, this is the first successful report of a plant regeneration system via the somatic embryogenesis of D. genkwa. Thus, the embryogenic structures and plant regeneration system of D. genkwa could be applied to mass proliferation and genetic modification for pharmaceutical metabolite production in D. genkwa.
PMID: 37299152
Plants (Basel) , IF:3.935 , 2023 May , V12 (11) doi: 10.3390/plants12112119
Convergent Adaptation of Multiple Herbicide Resistance to Auxin Mimics and ALS- and EPSPS-Inhibitors in Brassica rapa from North and South America.
Department of Agricultural Parasitology, Chapingo Autonomous University, Texcoco 56230, Mexico.; Department Agroforestry, Biochemistry and Molecular Biology, University of Cordoba, 14014 Cordoba, Spain.; Chacra Experimental Integrada Barrow (MDA-INTA), National Scientific and Technical Research Council (CONICET), Faculty of Agronomy, National University of La Pampa, Santa Rosa L6300, Argentina.; Private Consultant in Weed Control, Buenos Aires C1033, Argentina.; Departamento de Quimica, Universidade Federal de Sao Carlos, Sao Carlos 13565-905, Brazil.; Biosciences Department, Polytechnic Institute of Beja, 7800-000 Beja, Portugal.; VALORIZA-Research Centre for Endogenous Resource Valorization, Polytechnic Institute of Portalegre, 7300-555 Portalegre, Portugal.
Herbicide-resistant weeds have been identified and recorded on every continent where croplands are available. Despite the diversity of weed communities, it is of interest how selection has led to the same consequences in distant regions. Brassica rapa is a widespread naturalized weed that is found throughout temperate North and South America, and it is a frequent weed among winter cereal crops in Argentina and in Mexico. Broadleaf weed control is based on glyphosate that is used prior to sowing and sulfonylureas or mimic auxin herbicides that are used once the weeds have already emerged. This study was aimed at determining whether a convergent phenotypic adaptation to multiple herbicides had occurred in B. rapa populations from Mexico and Argentina by comparing the herbicide sensitivity to inhibitors of the acetolactate synthase (ALS), 5-enolpyruvylshikimate-3-phosphate (EPSPS), and auxin mimics. Five B. rapa populations were analyzed from seeds collected in wheat fields in Argentina (Ar1 and Ar2) and barley fields in Mexico (Mx1, Mx2 and MxS). Mx1, Mx2, and Ar1 populations presented multiple resistance to ALS- and EPSPS-inhibitors and to auxin mimics (2,4-D, MCPA, and fluroxypyr), while the Ar2 population showed resistance only to ALS-inhibitors and glyphosate. Resistance factors ranged from 947 to 4069 for tribenuron-methyl, from 1.5 to 9.4 for 2,4-D, and from 2.7 to 42 for glyphosate. These were consistent with ALS activity, ethylene production, and shikimate accumulation analyses in response to tribenuron-methyl, 2,4-D, and glyphosate, respectively. These results fully support the evolution of the multiple- and cross-herbicide resistance to glyphosate, ALS-inhibitors, and auxinic herbicides in B. rapa populations from Mexico and Argentina.
PMID: 37299097
Plants (Basel) , IF:3.935 , 2023 Apr , V12 (9) doi: 10.3390/plants12091854
Ethylene Inhibition Reduces De Novo Shoot Organogenesis and Subsequent Plant Development from Leaf Explants of Solanum betaceum Cav.
Centre for Functional Ecology, TERRA Associate Laboratory, Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal.; InnovPlantProtect CoLab, 7350-478 Elvas, Portugal.
In de novo shoot organogenesis (DNSO) plant cells develop into new shoots, without the need of an existing meristem. Generally, this process is triggered by wounding and specific growth regulators, such as auxins and cytokinins. Despite the potential significance of the plant hormone ethylene in DNSO, its effect in regeneration processes of woody species has not been thoroughly investigated. To address this gap, Solanum betaceum Cav. was used as an experimental model to explore the role of this hormone on DNSO and potentially extend the findings to other woody species. In this work it was shown that ethylene positively regulates DNSO from tamarillo leaf explants. Ethylene precursors ACC and ethephon stimulated shoot regeneration by increasing the number of buds and shoots regenerated. In contrast, the inhibition of ethylene biosynthesis or perception by AVG and AgNO(3) decreased shoot regeneration. Organogenic callus induced in the presence of ethylene precursors showed an upregulated expression of the auxin efflux carrier gene PIN1, suggesting that ethylene may enhance shoot regeneration by affecting auxin distribution prior to shoot development. Additionally, it was found that the de novo shoot meristems induced in explants in which ethylene biosynthesis and perception was suppressed were unable to further develop into elongated shoots. Overall, these results imply that altering ethylene levels and perception could enhance shoot regeneration efficiency in tamarillo. Moreover, we offer insights into the possible molecular mechanisms involved in ethylene-induced shoot regeneration.
PMID: 37176912
Gene , IF:3.688 , 2023 Jun , V871 : P147434 doi: 10.1016/j.gene.2023.147434
Comparative transcriptome analysis reveals hormone, transcriptional and epigenetic regulation involved in prickle formation in Zanthoxylum armatum.
Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: sabrina-0810@hotmail.com.; College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, China. Electronic address: Caozhengyan1998@163.com.; College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, China. Electronic address: wupeiyin718@163.com.; College of Biology and Food Engineering, Chongqing Three Georges University, Chongqing 404100, China. Electronic address: liuyn9523@163.com.; Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: loujuan1981@163.com.; Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: 18580561843@163.com.; Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: sunxiaofan2022@163.com.; Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: ztmysishuo@163.com.; Chongqing Key Laboratory of Economic Plant Biotechnology, Chongqing University of Arts and Sciences, Chongqing 402160, China. Electronic address: chenzexiong1979@163.com.
Zanthoxylum armatum is an evergreen plant with high economical and medicinal values. The presence of prickles on stems and leaves is undesirable for them make picking difficult. To date, little is known of prickle formation in Z. armatum. Herein, the morphological and molecular features of prickle initiation in prickless (WC) and three types of prickly Z. armatum were characterized. Compared to WC, the levels of cytokinin and auxin were increased, while GA and JA declined in prickly Z. armatum. Transcriptome analysis identified 6258 differentially expressed genes (DEGs) between prickless and prickly Z. armatum. Among them, several DEGs related to hormone metabolism and signaling, including LOG7, CKX3, AHK1, three DELLAs, six JAZs and TIR1, were candidate genes involved in prickle formation. Transcription factors associated with prickle formation were screened, including MYB6-1/MYB6-2, WER, GL3-2, SPL4/5, SOC1, and SCL32. Of them, MYB6-1 and WER might negatively regulate prickles initiation via interacting with GL3-2. Additionally, the histone acetylation and DNA methylation levels, the transcripts of histone acetyltransferase/deacetylase and DNA methyltransferases showed significant differences between prickless and prickly plants, indicating their involvements in prickle initiation. These findings illustrate the regulation of prickle formation might be mediated by phytohormones (especially cytokinin), transcription factors and epigenetic modifications in Z. armatum.
PMID: 37068692
J Plant Physiol , IF:3.549 , 2023 May , V287 : P154003 doi: 10.1016/j.jplph.2023.154003
Comparison of two contrasting Leymus chinensis accessions reveals the roles of the cell wall and auxin in rhizome development.
Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010010, China.; Grassland Work Station of East Ujimqin Banner of Xilin Gol League of Inner Mongolia, East Ujimqin Banner, 026300, China.; Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010010, China. Electronic address: 111986015@imu.edu.cn.; Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010010, China. Electronic address: kangyan105@imu.edu.cn.; Key Laboratory of Forage and Endemic Crop Biology, Ministry of Education, School of Life Sciences, Inner Mongolia University, Hohhot, 010010, China. Electronic address: qizhi@imu.edu.cn.
Leymus chinensis, a perennial native forage grass, is widely distributed in the steppes of Inner Mongolia as the dominant species. The main reproductive strategy of this grass is clonal propagation, which occurs via the proliferation of subterranean horizontal stems known as rhizomes. To elucidate the mechanism underlying rhizome development in this grass, we collected 60 accessions of L. chinensis and evaluated their rhizome development. One accession, which we named SR-74 (Strong Rhizomes), had significantly better rhizome development capacity than the accession WR-16 (Weak Rhizomes) in terms of rhizome number, total and primary rhizome length, and number of rhizome seedlings. Rhizome elongation was positively correlated with the number of internodes in the rhizome, which affected plant biomass. Compared to WR-16, SR-74 had higher rhizome tip hardness, higher abundance of transcripts participating in the biosynthesis of cell wall components, and higher levels of the metabolites L-phenylalanine, trans-cinnamic acid, 3-coumaric acid, ferulic acid, and coniferin. These metabolites in the phenylpropanoid biosynthesis pathway are precursors of lignin. In addition, SR-74 rhizomes contained higher amounts of auxin and auxin metabolites, including L-Trp, IPA, IBA, IAA and IAA-Asp, as well as upregulated expression of the auxin biosynthesis and signaling genes YUCCA6, YUCCA8, YUCCA10, YUCCA11, PIN1, PIN2, UGT1, UGT2, UGT4, UGT10, GH3, IAA7, IAA23, and IAA30. We propose a network between auxin signaling and the cell wall underlying rhizome development in L. chinensis.
PMID: 37301035
J Plant Physiol , IF:3.549 , 2023 Jun , V285 : P153995 doi: 10.1016/j.jplph.2023.153995
Integrative transcriptome and metabolome revealed the molecular mechanism of Bacillus megaterium BT22-mediated growth promotion in Arabidopsis thaliana.
Biophysics Group, Biomedical Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China.; College of Life Science, Lanzhou University, Lanzhou, 730000, China.; College of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, 730050, China.; Biophysics Group, Biomedical Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Kejin Innovation Institute of Heavy Ion Beam Biological Industry, Baiyin, 730900, China.; College of Pharmacy, Gansu University of Chinese Medicine, Lanzhou, 730000, China.; Lueyang County Jinxiu Agricultural Development Co., Ltd, Lueyang, Hanzhong, 724300, China.; Biophysics Group, Biomedical Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Kejin Innovation Institute of Heavy Ion Beam Biological Industry, Baiyin, 730900, China. Electronic address: libinzhoulz@gmail.com.
Plant growth-promoting rhizobacteria (PGPR) can promote plant growth and protect plants from pathogens, which contributes to sustainable agricultural development. Several studies have reported their beneficial characteristics in facilitating plant growth and development and enhancing plant stress resistance through different mechanisms. However, there is still a challenge to study the molecular mechanism of plant response to PGPR. We integrated the transcriptome and metabolome of Arabidopsis thaliana (Arabidopsis) to understand its responses to the inoculation with an isolated PGPR strain (BT22) of Bacillus megaterium. Fresh shoot weight, dry shoot weight and leaf number of Arabidopsis were increased by BT22 treatment, showing a positive growth-promoting effect. According multi-omics analysis, 878 differentially expressed genes (296 up-regulated, 582 down-regulated) and 139 differentially expressed metabolites (66 up-regulated, 73 down-regulated) response to BT22 inoculation. GO enrichment results indicate that the up-regulated genes mainly enriched in the regulation of growth and auxin response pathways. In contrast, the down-regulated genes mainly enriched in wounding response, jasmonic acid and ethylene pathways. BT22 inoculation regulated plant hormone signal transduction of Arabidopsis, including auxin and cytokinin response genes AUX/IAA, SAUR, and A-ARR related to cell enlargement and cell division. The contents of nine flavonoids and seven phenylpropanoid metabolites were increased, which help to induce systemic resistance in plants. These results suggest that BT22 promoted Arabidopsis growth by regulating plant hormone homeostasis and inducing metabolome reprogramming.
PMID: 37163868
Protoplasma , IF:3.356 , 2023 Jul , V260 (4) : P1233-1251 doi: 10.1007/s00709-023-01844-8
Light intensity-mediated auxin homeostasis in spikelets links carbohydrate metabolism enzymes with grain filling rate in rice.
Crop Physiology and Biochemistry Division, ICAR-National Rice Research Institute, Cuttack, 753006, Odisha, India.; Crop Improvement Division, ICAR-National Rice Research Institute, Cuttack, 753006, Odisha, India.; Crop Improvement Division, ICAR-National Rice Research Institute, Cuttack, 753006, Odisha, India. lambodarjamujhadi@gmail.com.
Low light (LL) stress during the grain-filling stage acutely impairs the quality and quantity of starch accumulation in rice grains. Here, we observed that LL-induced poor starch biosynthesis is modulated by auxin homeostasis, which regulates the activities of major carbohydrate metabolism enzymes such as starch synthase (SS) and ADP-glucose pyrophosphorylase (AGPase) in rice. Further, during the grain-filling period under LL, the starch/sucrose ratio increased in leaves but significantly decreased in the developing spikelets. This suggests poor sucrose biosynthesis in leaves and starch in the grains of the rice under LL. A lower grain starch was found to be correlated with the depleted AGPase and SS activities in the developing rice grains under LL. Further, under LL, the endogenous auxin (IAA) level in the spikelets was found to be synchronized with the expression of a heteromeric G protein gene, RGB1. Interestingly, under LL, the expression of OsYUC11 was significantly downregulated, which subsequently resulted in reduced IAA in the developing rice spikelets, followed by poor activation of grain-filling enzymes. This resulted in lowered grain starch accumulation, grain weight, panicle number, spikelet fertility, and eventually grain yield, which was notably higher in the LL-susceptible (GR4, IR8) than in the LL-tolerant (Purnendu, Swarnaprabha) rice genotypes. Therefore, we hypothesize that depletion in auxin biosynthesis under LL stress is associated with the downregulation of RBG1, which discourages the expression and activities of grain-filling enzymes, resulting in lower starch production, panicle formation, and grain yield in rice.
PMID: 36847862
Protoplasma , IF:3.356 , 2023 Jul , V260 (4) : P1109-1133 doi: 10.1007/s00709-022-01833-3
Auxin- and pH-induced guttation in Phycomyces sporangiophores: relation between guttation and diminished elongation growth.
Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11030, Belgrade, Serbia. vunduk@imsi.bg.ac.rs.; Max Planck Institute for Evolutionary Biology, Department of Evolutionary Biology, August Thienemann Str. 2, 24306, Plon, Germany.; Institute for Multidisciplinary Research, University of Belgrade, Kneza Viseslava 1, 11030, Belgrade, Serbia.; Singidunum University, Danijelova 32, 11010, Belgrade, Serbia.; Faculty of Biology, Philipps-University Marburg, Karl-Von-Frisch Str. 8, 35032, Marburg, Germany.
Guttation, the formation of exudation water, is widespread among plants and fungi, yet the underlying mechanisms remain largely unknown. We describe the conditions for inducing guttation in sporangiophores of the mucoracean fungus, Phycomyces blakesleeanus. Cultivation on peptone-enriched potato dextrose agar elicits vigorous guttation mainly below the apical growing zone, while sporangiophores raised on a glucose-mineral medium manifest only moderate guttation. Mycelia do not guttate irrespective of the employed media. The topology of guttation droplets allows identifying the non-growing part of the sporangiophore as a guttation zone, which responds to humidity and medium composition in ways that become relevant for turgor homeostasis and thus the sensor physiology of the growing zone. Apparently, the entire sporangiophore, rather than exclusively the growing zone, participates in signal reception and integration to generate a common growth output. Exogenous auxin applied to the growing zones elicits two correlated responses: (i) formation of guttation droplets in the growing and transition zones below the sporangium and (ii) a diminution of the growth rate. In sporangiophore populations, guttation-induction by exogenous control buffer occurs at low frequencies; the bias for guttation increases with increasing auxin concentration. Synthetic auxins and the transport inhibitor NPA suppress guttation completely, but leave growth rates largely unaffected. Mutants C2 carA and C148 carA madC display higher sensitivities for auxin-induced guttation compared to wild type. A working model for guttation includes aquaporins and mechanosensitive ion channels that we identified in Phycomyces by sequence domain searches.
PMID: 36622433
Protoplasma , IF:3.356 , 2023 May , V260 (3) : P955-966 doi: 10.1007/s00709-022-01826-2
Phytotoxicity and the molecular response in yttrium oxide nanoparticle-treated Arabidopsis thaliana seedlings.
Higher Education Key Laboratory of Plant Molecular and Environment Stress Response, Shanxi Normal University, Taiyuan, 030000, Shanxi, China.; College of Life Sciences, Shanxi Normal University, Taiyuan, 030000, Shanxi, China.; Higher Education Key Laboratory of Plant Molecular and Environment Stress Response, Shanxi Normal University, Taiyuan, 030000, Shanxi, China. jinlin_feng@163.com.; College of Life Sciences, Shanxi Normal University, Taiyuan, 030000, Shanxi, China. jinlin_feng@163.com.; Higher Education Key Laboratory of Plant Molecular and Environment Stress Response, Shanxi Normal University, Taiyuan, 030000, Shanxi, China. hhwrsl@163.com.; College of Life Sciences, Shanxi Normal University, Taiyuan, 030000, Shanxi, China. hhwrsl@163.com.
Due to the widespread application of rare earth oxide nanoparticles in various fields, their release into the environment is inevitable, and their potential toxicity and ecological impact have become a concern. Yttrium oxide nanoparticles are important rare earth oxide nanoparticles; however, their impact on plants and the molecular mechanism underlying their influence on plant growth and development are unclear. In this study, we found that yttrium oxide nanoparticles at concentrations exceeding 2 mM significantly inhibited the growth of Arabidopsis seedlings. Using Arabidopsis marker lines for auxin signaling, we found that the application of yttrium oxide nanoparticles resulted in disordered auxin signaling in root cells. Auxin signaling in the cells of the quiescent center and columella stem cells decreased, while auxin signaling in the cells of the stele was enhanced. In addition, trypan blue staining showed that yttrium oxide nanoparticles induced root cell death. Transcriptome analysis showed that the nanoparticles specifically inhibited the expression of lignin synthesis-related genes, activated the MAPK signaling pathway, and enhanced the ethylene and abscisic acid signaling pathways in plants. This study demonstrates the phytotoxicity of yttrium oxide nanoparticles at the molecular level in Arabidopsis, and it provides a new perspective on how plants respond to rare earth oxide stress.
PMID: 36445485
Protoplasma , IF:3.356 , 2023 May , V260 (3) : P723-739 doi: 10.1007/s00709-022-01808-4
Insights of auxin signaling F-box genes in wheat (Triticum aestivum L.) and their dynamic expression during the leaf rust infection.
Department of Bioengineering and Biotechnology, Birla Institute of Technology, Mesra, Ranchi, 835215, Jharkhand, India.; Division of Genetics, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.; Department of Bioengineering and Biotechnology, Birla Institute of Technology, Mesra, Ranchi, 835215, Jharkhand, India. kmukhopadhyay@bitmesra.ac.in.
The TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALING F-BOX (TIR1/AFB) protein serves as auxin receptor and links with Aux/IAA repressor protein leading to its degradation via SKP-Cullin-F box (SCF(TIR1/AFB)) complex in the auxin signaling pathway. Present study revealed 11 TIR1/AFB genes in wheat by genome-wide search using AFB HMM profile. Phylogenetic analysis clustered these genes in two classes. Several phytohormone, abiotic, and biotic stress responsive cis-elements were detected in promoter regions of TIR1/AFB genes. These genes were localized on homoeologous chromosome groups 2, 3, and 5 showing orthologous relation with other monocot plants. Most genes were interrupted by introns and the gene products were localized in cytoplasm, nucleus, and cell organelles. TaAFB3, TaAFB5, and TaAFB8 had nuclear localization signals. The evolutionary constraint suggested paralogous sister pairs and orthologous genes went through strong purifying selection process and are slowly evolving at protein level. Functional annotation revealed all TaAFB genes participated in auxin activated signaling pathway and SCF-mediated ubiquitination process. Furthermore, in silico expression study revealed their diverse expression profiles during various developmental stages in different tissues and organs as well as during biotic and abiotic stress. QRT-PCR based studies suggested distinct expression pattern of TIR1-1, TIR1-3, TaAFB1, TaAFB2, TaAFB3, TaAFB4, TaAFB5, TaAFB7, and TaAFB8 displaying maximum expression at 24 and 48 h post inoculation in both susceptible and resistant near isogenic wheat lines infected with leaf rust pathogen. Importantly, this also reflects coordinated responses in expression patterns of wheat TIR1/AFB genes during progression stages of leaf rust infection.
PMID: 36100728
PLoS One , IF:3.24 , 2023 , V18 (5) : Pe0286140 doi: 10.1371/journal.pone.0286140
Comparative analysis of microRNA expression profiles in shoot and root tissues of contrasting rice cultivars (Oryza sativa L.) with different salt stress tolerance.
Institute of Genome Research, Vietnam Academy of Science and Technology, Hanoi, Vietnam.; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
Rice is the second-most important primary crop in the world and one of the most susceptible crops to salt stress. Soil salinization hinders seedling growth and decreases crop yield by inducing ionic and osmotic imbalances, photosynthesis disturbances, cell wall alterations, and gene expression inhibition. Plants have developed a range of defense mechanisms to adapt to salt stress. One of the most effective means is to make use of plant microRNAs (miRNAs) as post-transcriptional regulators to regulate the expression of developmental genes in order to mitigate the detrimental effects of salt stress. In this study, the miRNA sequencing data between two contrasting rice cultivars, salt-tolerant Doc Phung (DP) and salt-sensitive IR28 seedlings, were compared under control and salt stress (150 mM NaCl) conditions to determine the salt stress-responsive miRNAs. Comparative analysis of miRNA sequencing data detected a total of 69 differentially expressed miRNAs in response to salt stress treatment. Among them, 18 miRNAs from 13 gene families, MIR156, MIR164, MIR167, MIR168, MIR171, MIR396, MIR398, MIR1432, MIR1846, MIR1857, MIR1861, MIR3979, and MIR5508, were identified to be specifically and significantly expressed in the shoot and root tissues of DP seedlings. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses further revealed that these detected miRNAs regulate a range of essential biological and stress response processes, including gene transcription, osmotic homeostasis, root formation, ROS scavenger synthesis, and auxin and abscisic acid signaling pathways. Our findings provide more insight into the miRNA-mediated responsive mechanisms of rice under salt stress and should benefit the improvement of salt stress tolerance in rice.
PMID: 37224116
Int J Phytoremediation , IF:3.212 , 2023 May : P1-18 doi: 10.1080/15226514.2023.2216311
2,4-D mediated moderation of aluminum tolerance in Salvinia molesta D. Mitch. with regards to bioexclusion and related physiological and metabolic changes.
Department of Botany, Plant Physiology, Biochemistry and Plant Molecular Biology Research Unit, University of Kalyani, Kalyani, India.; Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh.; Laboratory of Plant Stress Responses, Faculty of Agriculture, Kagawa University, Takamatsu, Japan.
We examined the efficacy of 2,4-dichlorophenoxy acetic acid (2,4-D; 500 microM) in enhancing the potential of Salvinia species for tolerance to aluminum (Al) toxicity (240 and 480 microM, seven days). Salvinia showed better efficacy in removal of toxicity of Al by sorption mechanism with changes of bond energy shifting on cell wall residues and surface structure. Plants recorded tolerance to Al concentration (480 microM) when pretreated with 2,4-D through adjustment of relative water content, proline content, osmotic potential, and improved the pigment fluorescence for energy utilization under Al stress. Photosynthetic activities with regards to NADP-malic enzyme and malic dehydrogenase and sugar metabolism with wall and cytosolic invertase activities were strongly correlated with compatible solutes. A less membrane peroxidation and protein carbonylation had reduced ionic loss over the membrane that was studied with reduced electrolyte leakage with 2,4-D pretreated plants. Membrane stabilization was also recorded with higher ratio of K(+) to Na(+), thereby suggesting roles of 2,4-D in ionic balance. Better sustenance of enzymatic antioxidation with peroxidase and glutathione metabolism reduced reactive oxygen species accumulation and save the plant for oxidative damages. Moreover, gene polymorphism for antioxidant, induced by 2,4-D varied through Al concentrations would suggest an improved biomarker for tolerance. Collectively, analysis and discussion of plant's responses assumed that auxin herbicide could be a potential phytoprotectant for Salvinia as well as improving the stability to Al toxicity and its bioremediation efficacy.
PMID: 37259532
PeerJ , IF:2.984 , 2023 , V11 : Pe15440 doi: 10.7717/peerj.15440
Physiological response and transcriptome analyses of leguminous Indigofera bungeana Walp. to drought stress.
College of Forestry and Prataculture, Ningxia University, Yinchuan, Ningxia, China.; Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration of North-Western China, Ningxia University, Yinchuan, Ningxia, China.
OBJECTIVE: Indigofera bungeana is a shrub with high quality protein that has been widely utilized for forage grass in the semi-arid regions of China. This study aimed to enrich the currently available knowledge and clarify the detailed drought stress regulatory mechanisms in I. bungeana, and provide a theoretical foundation for the cultivation and resistance breeding of forage crops. METHODS: This study evaluates the response mechanism to drought stress by exploiting multiple parameters and transcriptomic analyses of a 1-year-old seedlings of I. bungeana in a pot experiment. RESULTS: Drought stress significantly caused physiological changes in I. bungeana. The antioxidant enzyme activities and osmoregulation substance content of I. bungeana showed an increase under drought. Moreover, 3,978 and 6,923 differentially expressed genes were approved by transcriptome in leaves and roots. The transcription factors, hormone signal transduction, carbohydrate metabolism of regulatory network were observed to have increased. In both tissues, genes related to plant hormone signaling transduction pathway might play a more pivotal role in drought tolerance. Transcription factors families like basic helix-loop-helix (bHLH), vian myeloblastosis viral oncogene homolog (MYB), basic leucine zipper (bZIP) and the metabolic pathway related-genes like serine/threonine-phosphatase 2C (PP2C), SNF1-related protein kinase 2 (SnRK2), indole-3-acetic acid (IAA), auxin (AUX28), small auxin up-regulated rna (SAUR), sucrose synthase (SUS), sucrosecarriers (SUC) were highlighted for future research about drought stress resistance in Indigofera bungeana. CONCLUSION: Our study posited I. bungeana mainly participate in various physiological and metabolic activities to response severe drought stress, by regulating the expression of the related genes in hormone signal transduction. These findings, which may be valuable for drought resistance breeding, and to clarify the drought stress regulatory mechanisms of I. bungeana and other plants.
PMID: 37334133
Chem Biodivers , IF:2.408 , 2023 May , V20 (5) : Pe202201243 doi: 10.1002/cbdv.202201243
22-Oxocholestanes SPGP4 and SPGP8: in Silico and in Vitro Study as Activators of Plant Growth Promotion.
Laboratorio de Elucidacion y Sintesis en Quimica Organica, Facultad de Ciencias Quimicas, Benemerita Universidad Autonoma de Puebla, 72570, Puebla, Mexico.; Centro de Investigacion en Biotecnologia Aplicada-IPN, Tepetitla de Lardizabal, 90700, Tlaxcala, Mexico.; Laboratorio de Sintesis y Modificacion de Productos Naturales, Facultad de Ciencias Quimicas, Benemerita Universidad Autonoma de Puebla, 72570, Puebla, Mexico.
The 22-oxocholestanes compounds have shown an outstanding plant growth promoting activity; they have similar bioactivity as brassinosteroids, so they are normally named as brassinosteroid analogs thinking that they also impact on the known receptor BRI1. However, in silico studies allow us to predict interactions with other receptors and thus it's possible to evaluate them, through receptors of gibberellins, auxins, jasmonates, strigolactones and the protein associated with the BRI1 gene. This article describes the bioactivity of structures SPGP4 and SPGP8 as plant growth-promoting compounds. Both structures present coupling energies and interactions at the same level as epibrassinolide in the protein associated with BRI1 gene. Additionally, interactions through the auxin pathway and to strigolactone receptor were found using selected tests. In the rice lamina tilt, a higher effect was obtained when SPGP4 and SPGP8 were compared to epibrassinolide, although in a lesser level vis a vis to homobrassinolide. In the same way, when SPGP4 and SPGP8 were tested in the Growth Root Model an activity as strigonolactones was observed, enhancing the relationship between the main and secondary roots. However, the growth of coleptiles, when applying auxins, compounds SPGP4 and SPGP8 did not reach the same level as controls. In the tests associated to gibberellins and jasmonic acid, an increased bioactivity was observed, although this behavior was not reflected from the in silico study, possibly due to secondary signaling cascades. This work demonstrates that the 22-oxocolestane compounds SPGP4 and SPGP8 could be used as plant growth hormones, promoting several pathways.
PMID: 37062704
3 Biotech , IF:2.406 , 2023 May , V13 (5) : P132 doi: 10.1007/s13205-023-03546-7
Regulatory networks of hormone-involved transcription factors and their downstream pathways during somatic embryogenesis of Arabidopsis thaliana.
Department of Biotechnology and Plant Breeding, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran. GRID: grid.411301.6. ISNI: 0000 0001 0666 1211
Somatic embryogenesis (SE) depends on a variety of developmental pathways that are influenced by several environmental factors. Therefore, it is important to understand the relationship between environmental and genetic factors by identifying the gene networks involved in SE through gene set enrichment analysis (GSEA). For determination of SE effective transcription factors, upstream sequences of core-enriched genes were analyzed. The results indicated that response to hormones is one of the biological pathways activated by the enriched TFs at all stages of somatic embryogenesis and about half of the hormonal pathways were enriched. On the fifth day after 2,4-Dichlorophenoxyacetic acid (2,4-D) treatment, the activity of hormone-affecting genes reached its maximum. At this time, more transcription factors regulated the enriched genes compared to the other stages of somatic embryogenesis. MYBs, AT-HOOKs, and HSFs are the main families of transcription factors which affect core-enriched genes during SE. CCA1, PRR7, and TOC1 and their related genes at the center of protein-protein interaction of SE-key transcription factors, involved in the regulation of the circadian clock. Gene expression analysis of CCA1, PRR7, and TOC1 revealed that the genes involved in circadian clock reached their maximum activity when embryonic cells formed. Also, auxin response elements were identified at the upstream of SE-circadian clock transcription factors, indicating that they might mediate between auxin signaling and SE-related hormonal pathways as well as SE marker genes such as AGL15, BBM, and LECs. Based on these results, it is possible that the cellular circadian rhythm activates various developmental pathways under the influence of auxin signal transduction and their interactions determine the induction of somatic embryogenesis. According to the results of this study, modifying pathways affected by SE-related transcription factors such as circadian rhythm may result in cell reprogramming and increase somatic embryogenesis efficiency. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-023-03546-7.
PMID: 37091499
Mol Biol Rep , IF:2.316 , 2023 Jun doi: 10.1007/s11033-023-08563-6
Transcriptome analysis provides insights into the stress response in cultivated peanut (Arachis hypogaea L.) subjected to drought-stress.
Department of Biosciences, Saurashtra University Rajkot, Christ Campus, 360005, Vidya Niketan, Gujarat, India.; Christ Campus, Saurashtra University, 360005, Vidya Niketan, Rajkot, Gujarat, India.; Bionivid Technology Private Limited, Bengaluru, Karnataka, India.; Department of Biotechnology and Biochemistry, Junagadh Agricultural University, 362001, Junagadh, Gujarat, India.; Department of Biotechnology and Biochemistry, Junagadh Agricultural University, 362001, Junagadh, Gujarat, India. rukam@jau.in.
BACKGROUND: Peanut (Arachis hypogaea L.) is one of the valuable oilseed crops grown in drought-prone areas worldwide. Drought severely limits peanut production and productivity significantly. METHOD AND RESULTS: In order to decipher the drought tolerance mechanism in peanut under drought stress, RNA sequencing was performed in TAG - 24 (drought tolerant genotype) and JL-24 (drought susceptible genotype). Approximately 51 million raw reads were generated from four different libraries of two genotypes subjected to drought stress exerted by 20% PEG 6000 stress and control conditions, of which ~ 41 million (80.87%) filtered reads were mapped to the Arachis hypogaea L. reference genome. The transcriptome analysis detected 1,629 differentially expressed genes (DEGs), 186 genes encoding transcription factors (TFs) and 30,199 SSR among the identified DEGs. Among the differentially expressed TF encoding genes, the highest number of genes were WRKY followed by bZIP, C2H2, and MYB during drought stress. The comparative analysis between the two genotypes revealed that TAG-24 exhibits activation of certain key genes and transcriptional factors that are involved in essential biological processes. Specifically, TAG-24 showed activation of genes involved in the plant hormone signaling pathway such as PYL9, Auxin response receptor gene, and ABA. Additionally, genes related to water deprivation such as LEA protein and those involved in combating oxidative damage such as Glutathione reductase were also found to be activated in TAG-24. CONCLUSION: This genome-wide transcription map, therefore, provides a valuable tool for future transcript profiling under drought stress and enriches the genetic resources available for this important oilseed crop.
PMID: 37378750
Mol Biol Rep , IF:2.316 , 2023 Jun , V50 (6) : P5319-5343 doi: 10.1007/s11033-023-08429-x
Comparative transcriptome analysis of Zea mays upon mechanical wounding.
Department of Botany, Hansraj College, University of Delhi, Delhi, India.; J C Bose Center for Plant Genomics, Hansraj College, University of Delhi, Delhi, India.; Department of Botany, North-Eastern Hill University, Shillong, India.; Department of Zoology, Deshbandhu College, University of Delhi, New Delhi, India. iksingh@db.du.ac.in.; Department of Botany, Hansraj College, University of Delhi, Delhi, India. archanasingh@hrc.du.ac.in.; J C Bose Center for Plant Genomics, Hansraj College, University of Delhi, Delhi, India. archanasingh@hrc.du.ac.in.; Delhi School of Climate Change and Sustainability, Institution of Eminence, Maharishi Karnad Bhawan, University of Delhi, New Delhi, India. archanasingh@hrc.du.ac.in.
BACKGROUND: Mechanical wounding (MW) is mainly caused due to high wind, sand, heavy rains and insect infestation, leading to damage to crop plants and an increase in the incidences of pathogen infection. Plants respond to MW by altering expression of genes, proteins, and metabolites that help them to cope up with the stress. METHODS AND RESULTS: In order to characterize maize transcriptome in response to mechanical wounding, a microarray analysis was executed. The study revealed 407 differentially expressed genes (DEGs) (134 upregulated and 273 downregulated). The upregulated genes were engaged in protein synthesis, transcription regulation, phytohormone signaling-mediated by salicylic acid, auxin, jasmonates, biotic and abiotic stress including bacterial, insect, salt and endoplasmic reticulum stress, cellular transport, on the other hand downregulated genes were involved in primary metabolism, developmental processes, protein modification, catalytic activity, DNA repair pathways, and cell cycle. CONCLUSION: The transcriptome data present here can be further utilized for understanding inducible transcriptional response during mechanical injury and their purpose in biotic and abiotic stress tolerance. Furthermore, future study concentrating on the functional characterization of the selected key genes (Bowman Bird trypsin inhibitor, NBS-LRR-like protein, Receptor-like protein kinase-like, probable LRR receptor-like ser/thr-protein kinase, Cytochrome P450 84A1, leucoanthocyanidin dioxygenase, jasmonate O-methyltransferase) and utilizing them for genetic engineering for crop improvement is strongly recommended.
PMID: 37155015
Antonie Van Leeuwenhoek , IF:2.271 , 2023 Jun doi: 10.1007/s10482-023-01850-z
Ancylobacter radicis sp. nov., a novel aerobic methylotrophic bacteria associated with plants.
G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Federal Research Center <
The two novel bacterial strains, designated as VT(T) and ML, were isolated from roots of cinquefoil (Potentilla sp.) and leaves of meadow-grass (Poa sp.) on the flooded bank of lake, respectively. These isolates were Gram-negative, non-spore-forming, non-motile, rod-shaped cells, utilized methanol, methylamine, and polycarbon compounds as carbon and energy sources. In the whole-cell fatty acid pattern of strains prevailed C(18:1)omega7c and C(19:0cyc). Based on the phylogenetic analysis of 16S rRNA gene sequences, strains VT(T) and ML were closely related to the representatives of the genus Ancylobacter (98.3-98.5%). The assembled genome of strain VT(T) has a total length of 4.22 Mbp, and a G + C content is 67.3%. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values between strain VT(T) and closely related type strains of genus Ancylobacter were 78.0-80.6%, 73.8-78.3% and 22.1-24.0%, respectively, that clearly lower than proposed thresholds for species. On the basis of the phylogenetic, phenotypic, and chemotaxonomic analysis, isolates VT(T) and ML represent a novel species of the genus Ancylobacter, for which the name Ancylobacter radicis sp. nov. is proposed. The type strain is VT(T) (= VKM B-3255(T) = CCUG 72400(T)). In addition, novel strains were able to dissolve insoluble phosphates, to produce siderophores and plant hormones (auxin biosynthesis). According to genome analysis genes involved in the biosynthesis of siderophores, polyhydroxybutyrate, exopolysaccharides and phosphorus metabolism, as well as the genes involved in the assimilation of C(1)-compounds (natural products of plant metabolism) were found in the genome of type strain VT(T).
PMID: 37270429
Antonie Van Leeuwenhoek , IF:2.271 , 2023 Jul , V116 (7) : P615-630 doi: 10.1007/s10482-023-01828-x
Lysinibacillus spp.: an IAA-producing endospore forming-bacteria that promotes plant growth.
Universidad de Antioquia, Instituto de Biologia, Medellin, Colombia. manuel.pantojag@udea.edu.co.; Facultad de Ciencias Agropecuarias, Unilasallista Corporacion Universitaria, Caldas - Antioquia, Colombia. manuel.pantojag@udea.edu.co.; Plant Response Biotech, Plant City, FL, USA.; United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, Crop Bioprotection Research Unit, 1815 N University, Peoria, IL, USA.; Universidad de Antioquia, Instituto de Biologia, Medellin, Colombia.
Lysinibacillus is a bacterial genus that has generated recent interest for its biotechnological potential in agriculture. Strains belonging to this group are recognized for their mosquitocidal and bioremediation activity. However, in recent years some reports indicate its importance as plant growth promoting rhizobacteria (PGPR). This research sought to provide evidence of the PGP activity of Lysinibacillus spp. and the role of the indole-3-acetic acid (IAA) production associated with this activity. Twelve Lysinibacillus spp. strains were evaluated under greenhouse conditions, six of which increased the biomass and root architecture of corn plants. In most cases, growth stimulation was evident at 10(8) CFU/mL inoculum concentration. All strains produced IAA with high variation between them (20-70 microg/mL). The bioinformatic identification of predicted genes associated with IAA production allowed the detection of the indole pyruvic acid pathway to synthesize IAA in all strains; additionally, genes for a tryptamine pathway were detected in two strains. Extracellular filtrates from all strain's cultures increased the corn coleoptile length in an IAA-similar concentration pattern, which demonstrates the filtrates had an auxin-like effect on plant tissue. Five of the six strains that previously showed PGPR activity in corn also promoted the growth of Arabidopsis thaliana (col 0). These strains induced changes in root architecture of Arabidopsis mutant plants (aux1-7/axr4-2), the partial reversion of mutant phenotype indicated the role of IAA on plant growth. This work provided solid evidence of the association of Lysinibacillus spp. IAA production with their PGP activity, which constitutes a new approach for this genus. These elements contribute to the biotechnological exploration of this bacterial genus for agricultural biotechnology.
PMID: 37138159
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2218670 doi: 10.1080/15592324.2023.2218670
ChIFNalpha regulates adventitious root development in Lotus japonicus via an auxin-mediated pathway.
Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-Bioengineering, Guizhou University, Guiyang, Guizhou Province, China.; Department of Genetics, University of Georgia, Athens, GA, USA.
Adventitious roots (ARs), developing from non-root tissue, play an important role in some plants. Here, the molecular mechanism of AR differentiation in Lotus japonicus L. (L. japonicus) with the transformed chicken interferon alpha gene (ChIFNalpha) encoding cytokine was studied. ChIFNalpha transgenic plants (TP) were identified by GUS staining, PCR, RT-PCR, and ELISA. Up to 0.175 mug/kg rChIFNalpha was detected in TP2 lines. Expressing rChIFNalpha promotes AR development by producing longer roots than controls. We found that the effect was enhanced with the auxin precursor IBA treatment in TP. IAA contents, POD, and PPO activities associated with auxin regulation were higher than wild type (WT) in TP and exogenous ChIFNalpha treatment plants. Transcriptome analysis revealed 48 auxin-related differentially expressed genes (DEGs) (FDR < 0.05), which expression levels were verified by RT-qPCR analysis. GO enrichment analysis of DEGs also highlighted the auxin pathway. Further analysis found that ChIFNalpha significantly enhanced auxin synthesis and signaling mainly with up-regulated genes of ALDH, and GH3. Our study reveals that ChIFNalpha can promote plant AR development by mediating auxin regulation. The findings help explore the role of ChIFNalpha cytokines and expand animal gene sources for the molecular breeding of growth regulation of forage plants.
PMID: 37288791
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2207845 doi: 10.1080/15592324.2023.2207845
Mendel-200: Pea as a model system to analyze hormone-mediated stem elongation.
I- Cultiver, Inc, Manteca, CA 95336 & Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA.
In a recent Review Article on Gregor Mendel's (1822-1884) work with pea (Pisum sativum)-plants, it was proposed that this crop species should be re-vitalized as a model organism for the study of cell- and organ growth. Here, we describe the effect of exogenous gibberellic acid (GA(3)) on the growth of the second internode in 4-day-old light-grown pea seedlings (Pisum sativum, large var. "Senator"). lnjection of glucose into the internode caused a growth-promoting effect similar to that of the hormone GA(3). Imbibition of dry pea seeds in GA(3), or water as control, resulted in a drastic enhancement in organ development in this tall variety. Similar results were reported for dwarf peas. These "classical" experimental protocols are suitable to study the elusive effect of gibberellins (which act in coordination with auxin) on the regulation of plant development at the biochemical and molecular levels.
PMID: 37166004
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2163342 doi: 10.1080/15592324.2022.2163342
Cloning and expression study of a high-affinity nitrate transporter gene from Zea mays L.
Heilongjiang Academy of Agricultural Sciences, Harbin, Heilongjiang, China.; Key Laboratory of Saline-Alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, Heilongjiang, China.; Aulin College, Northeast Forestry University, Harbin, Heilongjiang, China.
A nitrate transporter gene, named B46NRT2.1, from salt-tolerant Zea mays L. B46 has been cloned. B46NRT2.1 contained the same domain belonging to the major facilitator superfamily (PLN00028). The results of the phylogenetic tree indicated that B46NRT2.1 exhibits sequence similarity and the closest relationship with those known nitrate transporters of the NRT2 family. Through RT-qPCR, we found that the expression of B46NRT2.1 mainly happens in the root and leaf. Moreover, the treatment with NaCl, Na(2)CO(3), and NaHCO(3) could significantly increase the expression of B46NRT2.1. B46NRT2.1 was located in the plasma membrane. Through the study of yeast and plant salt response brought by B46NRT2.1 overexpression, we have preliminary knowledge that the expression of B46NRT2.1 makes yeast and plants respond to salt shock. There are 10 different kinds of cis-acting regulatory elements (CRES) in the promotor sequences of B46NRT2.1 gene using the PlantCARE web server to analyze. It mainly includes hormone response, abscisic acid, salicylic acid, gibberellin, methyl jasmonate, and auxin. The B46NRT2.1 gene's co-expression network showed that it was co-expressed with a number of other genes in several biological pathways, including regulation of NO(3) long-distance transit, modulation of nitrate sensing and metabolism, nitrate assimilation, and transduction of Jasmonic acid-independent wound signal. The results of this work should serve as a good scientific foundation for further research on the functions of the NRT2 gene family in plants (inbred line B46), and this research adds to our understanding of the molecular mechanisms under salt tolerance.
PMID: 36645908
Genome , IF:2.166 , 2023 Jun , V66 (6) : P131-149 doi: 10.1139/gen-2022-0072
Paenibacillus terrae NK3-4 regulates the transcription of growth-related and stress resistance-related genes in rice.
College of Life Science, Shangrao Normal University, Shangrao, Jiangxi 334001, China.; Heilongjiang Academy of Agricultural Reclamation Sciences, Haerbin, Heilongjiang 150038, China.
Paenibacillus terrae NK3-4 is a plant growth-promoting rhizobacterium. In this study, the effects of NK3-4 on rice growth and gene transcription were determined. The results indicated that a seed soaking treatment and a pre-germination seed treatment using NK3-4 promoted rice growth, especially spraying rice seedlings with NK3-4 increased the root number and root length by 34.2% and 34.1%, respectively. Moreover, NK3-4 induced the differential transcription of genes annotated with gene ontology (GO) terms; the number of up-regulated genes was 4.38-times higher than the number of down-regulated genes. The NK3-4 treatment induced the differential transcription of genes in 1794 GO functional groups, with 1531 functional groups containing up-regulated genes. Specific growth-related genes up-regulated by NK3-4 are involved in biological processes, including responses to auxin, hormone biosynthesis, cellular component biogenesis, root system development, and other functions. Furthermore, stress resistance-related genes were up-regulated, some of which encode WRKYs, NPK1-related protein kinase, NPR1-like 4, CaM-like proteins, MYBs, ERFs, TIFYs, NACs, EL5s, PR1s, PR2, PR8, PODs, and PAD4. Considered together, these findings imply that NK3-4 may promote plant growth and enhance stress resistance by regulating gene expression, making it a potentially useful microbe for regulating rice growth and stress resistance.
PMID: 36927123
Biosci Biotechnol Biochem , IF:2.043 , 2023 May , V87 (6) : P592-604 doi: 10.1093/bbb/zbad029
Analysis of the effect of each plant hormone on the maturation of woodland strawberry fruit in auxin-induced parthenocarpic fruit.
Kihara Institute for Biological Research, Yokohama City University, Kanagawa, Japan.; Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.; Faculty of Agriculture, Utsunomiya University, Tochigi, Japan.
Evaluation of individual roles of plant hormones in fruit development is difficult because various plant hormones function simultaneously. In this study, to analyze the effect of plant hormones on fruit maturation one by one, plant hormones were applied to auxin-induced parthenocarpic woodland strawberry (Fragaria vesca) fruits. As a result, auxin, gibberellin (GA), and jasmonate, but, not abscisic acid and ethylene increased the proportion of ultimately mature fruits. So far, to produce comparable fruit with pollinated fruit in size, auxin with GA treatment was required in woodland strawberry. Picrolam (Pic), the most potent auxin in inducing parthenocarpic fruit, induced fruit which is comparable in size with pollinated fruit without GA. The endogenous GA level and the result of the RNA interference analysis of the main GA biosynthetic gene suggest that a basal level of endogenous GA is essential for fruit development. The effect of other plant hormones was also discussed.
PMID: 36914217
Plant Commun , 2023 May : P100632 doi: 10.1016/j.xplc.2023.100632
Chemical inhibition of Arabidopsis PIN-FORMED auxin transporters by the anti-inflammatory drug naproxen.
MOE Key Laboratory for Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China.; Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria.; MOE Key Laboratory for Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China. Electronic address: wengjp@ustc.edu.cn.; MOE Key Laboratory for Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China. Electronic address: lx023@ustc.edu.cn.; MOE Key Laboratory for Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China. Electronic address: sunlf17@ustc.edu.cn.; MOE Key Laboratory for Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China; Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China. Electronic address: sttan@ustc.edu.cn.
The phytohormone auxin plays central roles in many growth and developmental processes in plants. Development of chemical tools targeting the auxin pathway is useful for both plant biology and agriculture. Here we uncover that naproxen, a synthetic compound with anti-inflammatory activity in humans, acts as an auxin transport inhibitor targeting PIN-FORMED (PIN) transporters in plants. Physiological experiments indicate that exogenous naproxen treatment affects pleiotropic auxin-regulated developmental processes. Further cellular and biochemical evidence supports that naproxen suppresses auxin transport, specifically PIN-mediated auxin efflux. Moreover, biochemical and structural analysis confirms that naproxen binds directly to PIN1 protein, via the same binding cavity as the IAA substrate. Thus, by combining cellular, biochemical, and structural approaches, this study well establishes that naproxen is a PIN inhibitor and elucidates the underlying mechanisms. Further use of the compound may advance our understanding on the molecular mechanisms of PIN-mediated auxin transport, and expand our toolkit in auxin biology and agriculture.
PMID: 37254481
J Genet Genomics , 2023 May doi: 10.1016/j.jgg.2023.05.001
Nitric oxide-mediated S-nitrosylation of IAA17 protein in intrinsically disordered region represses auxin signaling.
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Department of Biology, Duke University, Durham, NC 27008, USA. Electronic address: hongwei.jing@duke.edu.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA; Center for Biomolecular Condensates (CBC), Washington University in St. Louis, St. Louis, MO 63130, USA.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; Department of Biology, Duke University, Durham, NC 27008, USA.; Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA 24061, USA.; Department of Biological Systems Engineering, Virginia Tech, Blacksburg, VA 24061, USA; The Translational Plant Sciences Center (TPSC), Virginia Tech, Blacksburg, VA 24061, USA.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: jrzuo@genetics.ac.cn.
The phytohormone auxin plays crucial roles in nearly every aspect of plant growth and development. Auxin signaling is activated through the phytohormone-induced proteasomal degradation of the Auxin/INDOLE-3-ACETIC ACID (Aux/IAA) family of transcriptional repressors. Notably, many auxin-modulated physiological processes are also regulated by nitric oxide (NO) that executes its biological effects predominantly through protein S-nitrosylation at specific cysteine residues. However, little is known about the molecular mechanisms in regulating the interactive NO and auxin networks. Here, we show that NO represses auxin signaling by inhibiting IAA17 protein degradation. NO induces the S-nitrosylation of Cys-70 located in the intrinsically disordered region of IAA17, which inhibits the TIR1-IAA17 interaction and consequently the proteasomal degradation of IAA17. The accumulation of a higher level of IAA17 attenuates auxin response. Moreover, an IAA17(C70W) nitrosomimetic mutation renders the accumulation of a higher level of the mutated protein, thereby causing partial resistance to auxin and defective lateral root development. Taken together, these results suggest that S-nitrosylation of IAA17 at Cys-70 inhibits its interaction with TIR1, thereby negatively regulating auxin signaling. This study provides unique molecular insights into the redox-based auxin signaling in regulating plant growth and development.
PMID: 37187411