Nature , IF:49.962 , 2024 Jul doi: 10.1038/s41586-024-07707-3
Identification of plant transcriptional activation domains.
Department of Biology, Duke University, Durham, NC, USA.; Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, USA.; Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA.; Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO, USA.; Biological Systems Engineering, Virginia Tech, Blacksburg, VA, USA.; Center for Computational Biology, University of California, Berkeley, Berkeley, CA, USA.; Department of Biology, Duke University, Durham, NC, USA. lucia.strader@duke.edu.
Gene expression in Arabidopsis is regulated by more than 1,900 transcription factors (TFs), which have been identified genome-wide by the presence of well-conserved DNA-binding domains. Activator TFs contain activation domains (ADs) that recruit coactivator complexes; however, for nearly all Arabidopsis TFs, we lack knowledge about the presence, location and transcriptional strength of their ADs(1). To address this gap, here we use a yeast library approach to experimentally identify Arabidopsis ADs on a proteome-wide scale, and find that more than half of the Arabidopsis TFs contain an AD. We annotate 1,553 ADs, the vast majority of which are, to our knowledge, previously unknown. Using the dataset generated, we develop a neural network to accurately predict ADs and to identify sequence features that are necessary to recruit coactivator complexes. We uncover six distinct combinations of sequence features that result in activation activity, providing a framework to interrogate the subfunctionalization of ADs. Furthermore, we identify ADs in the ancient AUXIN RESPONSE FACTOR family of TFs, revealing that AD positioning is conserved in distinct clades. Our findings provide a deep resource for understanding transcriptional activation, a framework for examining function in intrinsically disordered regions and a predictive model of ADs.
PMID: 39020176
Annu Rev Plant Biol , IF:26.379 , 2024 Jul , V75 (1) : P377-398 doi: 10.1146/annurev-arplant-062923-030348
Leaf Vein Patterning.
Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada; email: enrico.scarpella@ualberta.ca.
Leaves form veins whose patterns vary from a single vein running the length of the leaf to networks of staggering complexity where huge numbers of veins connect to other veins at both ends. For the longest time, vein formation was thought to be controlled only by the polar, cell-to-cell transport of the plant hormone auxin; recent evidence suggests that is not so. Instead, it turns out that vein patterning features are best accounted for by a combination of polar auxin transport, facilitated auxin diffusion through plasmodesma intercellular channels, and auxin signal transduction-though the latter's precise contribution remains unclear. Equally unclear remain the sites of auxin production during leaf development, on which that vein patterning mechanism ought to depend. Finally, whether that vein patterning mechanism can account for the variety of vein arrangements found in nature remains unknown. Addressing those questions will be the exciting challenge of future research.
PMID: 38382907
Annu Rev Plant Biol , IF:26.379 , 2024 Jul , V75 (1) : P185-209 doi: 10.1146/annurev-arplant-070523-034109
Structure and Function of Auxin Transporters.
School of Life Sciences, Plant Systems Biology, Technical University of Munich, Freising, Germany; email: ulrich.hammes@tum.de.; Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; email: bpp@mbg.au.dk.
Auxins, a group of central hormones in plant growth and development, are transported by a diverse range of transporters with distinct biochemical and structural properties. This review summarizes the current knowledge on all known auxin transporters with respect to their biochemical and biophysical properties and the methods used to characterize them. In particular, we focus on the recent advances that were made concerning the PIN-FORMED family of auxin exporters. Insights derived from solving their structures have improved our understanding of the auxin export process, and we discuss the current state of the art on PIN-mediated auxin transport, including the use of biophysical methods to examine their properties. Understanding the mechanisms of auxin transport is crucial for understanding plant growth and development, as well as for the development of more effective strategies for crop production and plant biotechnology.
PMID: 38211951
Annu Rev Plant Biol , IF:26.379 , 2024 Jul , V75 (1) : P489-519 doi: 10.1146/annurev-arplant-062923-023852
Environmental Control of Hypocotyl Elongation.
Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland; email: christian.fankhauser@unil.ch.; Current affiliation: Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark; email: jkr@plen.ku.dk.
The hypocotyl is the embryonic stem connecting the primary root to the cotyledons. Hypocotyl length varies tremendously depending on the conditions. This developmental plasticity and the simplicity of the organ explain its success as a model for growth regulation. Light and temperature are prominent growth-controlling cues, using shared signaling elements. Mechanisms controlling hypocotyl elongation in etiolated seedlings reaching the light differ from those in photoautotrophic seedlings. However, many common growth regulators intervene in both situations. Multiple photoreceptors including phytochromes, which also respond to temperature, control the activity of several transcription factors, thereby eliciting rapid transcriptional reprogramming. Hypocotyl growth often depends on sensing in green tissues and interorgan communication comprising auxin. Hypocotyl auxin, in conjunction with other hormones, determines epidermal cell elongation. Plants facing cues with opposite effects on growth control hypocotyl elongation through intricate mechanisms. We discuss the status of the field and end by highlighting open questions.
PMID: 38012051
Trends Plant Sci , IF:18.313 , 2024 Jul doi: 10.1016/j.tplants.2024.07.008
BiAux, a newly discovered compound triggering auxin signaling.
University of Silesia in Katowice, Faculty of Natural Sciences, Institute of Biology, Biotechnology, and Environmental Protection, Katowice, Poland.; Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria. Electronic address: jiri.friml@ist.ac.at.; University of Silesia in Katowice, Faculty of Natural Sciences, Institute of Biology, Biotechnology, and Environmental Protection, Katowice, Poland. Electronic address: ewa.mazur@us.edu.pl.
Lateral root (LR) formation, that is vital for plant development, is one of many auxin-modulated processes, but the underlying regulatory mechanism is not yet fully known. Recently, Gonzalez-Garcia et al. discovered the BiAux compound and showed that it is involved in LR development via regulating specific auxin coreceptors.
PMID: 39079770
Trends Plant Sci , IF:18.313 , 2024 Jul doi: 10.1016/j.tplants.2024.07.004
ABLs and transmembrane kinases shape extracellular auxin perception.
Plant Physiology Laboratory, Department of Botany, Chaudhary Mahadeo Prasad (C.M.P.) Degree College, a Constituent Postgraduate College of the University of Allahabad, Prayagraj, Uttar Pradesh 211002, India.; Crop Nanobiology and Molecular Stress Physiology Laboratory, Amity Institute of Organic Agriculture, Amity University, Sector 125, Noida, Uttar Pradesh 201313, India.; Department of Plant Pathology, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing 210095, China.; Plant Physiology Laboratory, Department of Botany, Chaudhary Mahadeo Prasad (C.M.P.) Degree College, a Constituent Postgraduate College of the University of Allahabad, Prayagraj, Uttar Pradesh 211002, India. Electronic address: vijaypratap.au@gmail.com.; College of General Education, Kookmin University, Seoul 02707, South Korea. Electronic address: ravigupta@kookmin.ac.kr.
Auxin is a key phytohormone, but the mechanism underlying apoplastic auxin perception has remained elusive. Yu et al. recently demonstrated that the interaction of two novel apoplast-localized auxin-binding protein 1 (ABP1)-like proteins, ABL1 and ABL2, with transmembrane kinases (TMKs) shapes extracellular auxin perception in both an overlapping and an ABP1-independent manner.
PMID: 39048470
Trends Plant Sci , IF:18.313 , 2024 Jul doi: 10.1016/j.tplants.2024.06.007
Parthenocarpy, a pollination-independent fruit set mechanism to ensure yield stability.
Universite Paris-Saclay, CNRS, INRAE, Universite Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif sur Yvette, France; Vilmorin & Cie, Route d'Ennezat, 63720 Chappes, France.; Vilmorin & Cie, Paraje La Reserva, 04725 La Mojonera, Spain.; Universite Paris-Saclay, CNRS, INRAE, Universite Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif sur Yvette, France; Universite de Paris, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif sur Yvette, France. Electronic address: adnane.boualem@inrae.fr.; Universite Paris-Saclay, CNRS, INRAE, Universite Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif sur Yvette, France; Universite de Paris, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif sur Yvette, France. Electronic address: abdelhafid.bendahmane@inrae.fr.
Fruit development is essential for flowering plants' reproduction and a significant food source. Climate change threatens fruit yields due to its impact on pollination and fertilization processes, especially vulnerable to extreme temperatures, insufficient light, and pollinator decline. Parthenocarpy, the development of fruit without fertilization, offers a solution, ensuring yield stability in adverse conditions and enhancing fruit quality. Parthenocarpic fruits not only secure agricultural production but also exhibit improved texture, appearance, and shelf life, making them desirable for food processing and other applications. Recent research unveils the molecular mechanisms behind parthenocarpy, implicating transcription factors (TFs), noncoding RNAs, and phytohormones such as auxin, gibberellin (GA), and cytokinin (CK). Here we review recent findings, construct regulatory models, and identify areas for further research.
PMID: 39034223
Adv Sci (Weinh) , IF:16.806 , 2024 Jul : Pe2402442 doi: 10.1002/advs.202402442
VIK-Mediated Auxin Signaling Regulates Lateral Root Development in Arabidopsis.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, Shandong, 266237, China.; College of Horticulture, Qingdao Agricultural University, Qingdao, Shandong, 266109, China.
The crucial role of TIR1-receptor-mediated gene transcription regulation in auxin signaling has long been established. In recent years, the significant role of protein phosphorylation modifications in auxin signal transduction has gradually emerged. To further elucidate the significant role of protein phosphorylation modifications in auxin signaling, a phosphoproteomic analysis in conjunction with auxin treatment has identified an auxin activated Mitogen-activated Protein Kinase Kinase Kinase (MAPKKK) VH1-INTERACTING Kinase (VIK), which plays an important role in auxin-induced lateral root (LR) development. In the vik mutant, auxin-induced LR development is significantly attenuated. Further investigations show that VIK interacts separately with the positive regulator of LR development, LATERAL ORGAN BOUNDARIES-DOMAIN18 (LBD18), and the negative regulator of LR emergence, Ethylene Responsive Factor 13 (ERF13). VIK directly phosphorylates and stabilizes the positive transcription factor LBD18 in LR formation. In the meantime, VIK directly phosphorylates the negative regulator ERF13 at Ser168 and Ser172 sites, causing its degradation and releasing the repression by ERF13 on LR emergence. In summary, VIK-mediated auxin signaling regulates LR development by enhancing the protein stability of LBD18 and inducing the degradation of ERF13, respectively.
PMID: 38958531
Adv Sci (Weinh) , IF:16.806 , 2024 Jul , V11 (26) : Pe2402816 doi: 10.1002/advs.202402816
GHCU, a Molecular Chaperone, Regulates Leaf Curling by Modulating the Distribution of KNGH1 in Cotton.
Zhejiang Provincial Key Laboratory of Crop Genetic Resources, Institute of Crop Science, Plant Precision Breeding Academy, College of Agriculture and Biotechnology, Zhejiang University, Zhejiang, 310058, China.; Industrial Crop Research Institute, Sichuan Academy of Agricultural Sciences, Sichuan, 610066, China.; Hainan Institute of Zhejiang University, Sanya, 572025, China.
Leaf shape is considered to be one of the most significant agronomic traits in crop breeding. However, the molecular basis underlying leaf morphogenesis in cotton is still largely unknown. In this study, through genetic mapping and molecular investigation using a natural cotton mutant cu with leaves curling upward, the causal gene GHCU is successfully identified as the key regulator of leaf flattening. Knockout of GHCU or its homolog in cotton and tobacco using CRISPR results in abnormal leaf shape. It is further discovered that GHCU facilitates the transport of the HD protein KNOTTED1-like (KNGH1) from the adaxial to the abaxial domain. Loss of GHCU function restricts KNGH1 to the adaxial epidermal region, leading to lower auxin response levels in the adaxial boundary compared to the abaxial. This spatial asymmetry in auxin distribution produces the upward-curled leaf phenotype of the cu mutant. By analysis of single-cell RNA sequencing and spatiotemporal transcriptomic data, auxin biosynthesis genes are confirmed to be expressed asymmetrically in the adaxial-abaxial epidermal cells. Overall, these findings suggest that GHCU plays a crucial role in the regulation of leaf flattening through facilitating cell-to-cell trafficking of KNGH1 and hence influencing the auxin response level.
PMID: 38666376
Nat Commun , IF:14.919 , 2024 Jul , V15 (1) : P5911 doi: 10.1038/s41467-024-50172-9
Tradeoff between speed and robustness in primordium initiation mediated by auxin-CUC1 interaction.
Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, 14853, USA.; Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA.; Department of Biology, Duke University, Durham, NC, 27708, USA.; Howard Hughes Medical Institute, Duke University, Durham, NC, 27708, USA.; Department of Computational and Systems Biology, John Innes Centre, Norwich, NR4 7UH, UK.; Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, 14853, USA. ahr75@cornell.edu.; Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA. ahr75@cornell.edu.
Robustness is the reproducible development of a phenotype despite stochastic noise. It often involves tradeoffs with other performance metrics, but the mechanisms underlying such tradeoffs were largely unknown. An Arabidopsis flower robustly develops four sepals from four precisely positioned auxin maxima. The development related myb-like 1 (drmy1) mutant generates noise in auxin signaling that disrupts robustness in sepal initiation. Here, we find that increased expression of CUP-SHAPED COTYLEDON1 (CUC1), a boundary specification transcription factor, in drmy1 underlies this loss of robustness. CUC1 surrounds and amplifies stochastic auxin noise in drmy1 to form variably positioned auxin maxima and sepal primordia. Removing CUC1 from drmy1 provides time for noisy auxin signaling to resolve into four precisely positioned auxin maxima, restoring robust sepal initiation. However, removing CUC1 decreases the intensity of auxin maxima and slows down sepal initiation. Thus, CUC1 increases morphogenesis speed but impairs robustness against auxin noise. Further, using a computational model, we find that the observed phenotype can be explained by the effect of CUC1 in repolarizing PIN FORMED1 (PIN1), a polar auxin transporter. Lastly, our model predicts that reducing global growth rate improves developmental robustness, which we validate experimentally. Thus, our study illustrates a tradeoff between speed and robustness during development.
PMID: 39003301
Dev Cell , IF:12.27 , 2024 Jul doi: 10.1016/j.devcel.2024.07.001
Soybean symbiotic-nodule zonation and cell differentiation are defined by NIN2 signaling and GH3-dependent auxin homeostasis.
Haixia Institute of Science and Technology, Horticultural Plant Biology and Metabolomics Center, Fujian Agriculture and Forestry University, Fuzhou, China.; Haixia Institute of Science and Technology, Horticultural Plant Biology and Metabolomics Center, Fujian Agriculture and Forestry University, Fuzhou, China; College of Agriculture and Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China.; Guangdong Provincial Key Laboratory of Plant Adaptation and Molecular Design, Innovative Center of Molecular Genetics and Evolution, School of Life Sciences, Guangzhou University, Guangzhou, 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, Shanghai, China.; Haixia Institute of Science and Technology, Horticultural Plant Biology and Metabolomics Center, Fujian Agriculture and Forestry University, Fuzhou, China. Electronic address: chenxu@fafu.edu.cn.
Symbiotic nodules comprise two classes, indeterminate and determinate, defined by the presence/absence of apical meristem and developmental zonation. Why meristem and zonation are absent from determinate nodules remains unclear. Here, we define cell types in developing soybean nodules, highlighting the undifferentiated infection zones and differentiated nitrogen-fixation zones. Auxin governs infection zone maintenance. GRETCHEN HAGEN 3 (GH3) enzymes deactivate auxin by conjugation and promote cell differentiation. gh3 mutants increased undifferentiated cells and enlarged infection zones. The central symbiosis-transcription factor NIN2a activates GH3.1 to reduce auxin levels and facilitates cell differentiation. High auxin promotes NIN2a protein accumulation and enhances signaling, further deactivating auxin and depleting infection zones. Our findings shed light on the NIN2a-GH3-auxin module that drives soybean nodule cell differentiation. This study challenges our understanding of determinate nodule development and proposes that the regulation of nodule zonation offers valuable insights into broader mechanisms of cell differentiation across plant species.
PMID: 39053471
Dev Cell , IF:12.27 , 2024 Jul doi: 10.1016/j.devcel.2024.06.019
Factors governing cellular reprogramming competence in Arabidopsis adventitious root formation.
Department of Biology, Duke University, Durham, NC 27708, USA; Duke Center for Quantitative BioDesign, Durham, NC 27708, USA.; Department of Biology, Duke University, Durham, NC 27708, USA; Duke Center for Quantitative BioDesign, Durham, NC 27708, USA. Electronic address: lucia.strader@duke.edu.
Developmental reprogramming allows for flexibility in growth and adaptation to changing environmental conditions. In plants, wounding events can result in new stem cell niches and lateral organs. Adventitious roots develop from aerial parts of the plant and are regulated by multiple stimuli, including wounding. Here, we find that Arabidopsis thaliana seedlings wounded at the hypocotyl-root junction reprogram certain pericycle cells to produce adventitious roots proximal to the wound site. We have determined that competence for this reprogramming is controlled; basal cells close to the wound site can produce adventitious roots, whereas cells distal from the wound site mostly cannot. We found that altering cytokinin response or indole-3-butyric acid (IBA)-to-(indole-3-acetic acid) IAA conversion resulted in an expanded adventitious root competence zone and delineated the connection between these pathways. Our work highlights the importance of endogenous IBA-derived auxin and its interaction with cytokinin in adventitious root formation and the regenerative properties of plants.
PMID: 39043189
Plant Cell , IF:11.277 , 2024 Jul doi: 10.1093/plcell/koae212
Strigolactone-induced degradation of SUPPRESSOR OF MORE AXILLARY GROWTH2-LIKE7 (SMXL7) and SMXL8 contributes to gibberellin- and auxin-mediated fiber cell elongation in cotton.
National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.; National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya, Hainan 572024, China.; Zhengzhou Research Base, National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China.
Cotton (Gossypium) fiber length, a key trait determining fiber yield and quality, is highly regulated by a class of recently identified phytohormones, strigolactones (SLs). However, the underlying molecular mechanisms of SL signaling involved in fiber cell development are largely unknown. Here, we show that the SL signaling repressors MORE AXILLARY GROWTH2-LIKE7 (GhSMXL7) and GhSMXL8 negatively regulate cotton fiber elongation. Specifically, GhSMXL7 and GhSMXL8 inhibit the polyubiquitination and degradation of the gibberellin (GA)-triggered DELLA protein (GhSLR1). Biochemical analysis revealed that GhSMXL7 and GhSMXL8 physically interact with GhSLR1, which interferes with the association of GhSLR1 with the E3 ligase GA INSENSITIVE2 (GhGID2), leading to the repression of GA signal transduction. GhSMXL7 also interacts with the transcription factor GhHOX3, preventing its binding to the promoters of essential fiber elongation regulatory genes. Moreover, both GhSMXL7 and GhSMXL8 directly bind to the promoter regions of the AUXIN RESPONSE FACTOR (ARF) genes GhARF18-10A, GhARF18-10D, and GhARF19-7D to suppress their expression. Cotton plants in which GhARF18-10A, GhARF18-10D, and GhARF19-7D transcript levels had been reduced by virus-induced gene silencing (VIGS) displayed reduced fiber length compared with control plants. Collectively, our findings reveal a mechanism illustrating how SL integrates GA and auxin signaling to coordinately regulate plant cell elongation at the single-cell level.
PMID: 39046066
Plant Cell , IF:11.277 , 2024 Jul doi: 10.1093/plcell/koae176
Two PYRIDOXAL PHOSPHATE HOMEOSTASIS PROTEINs are essential for management of the coenzyme pyridoxal 5'-phosphate in Arabidopsis.
Vitamins & Environmental Stress Responses in Plants, Department of Plant Sciences, University of Geneva, 1211 Geneva, Switzerland.
Coenzyme management is important for homeostasis of the pool of active metabolic enzymes. The coenzyme pyridoxal 5'-phosphate (PLP) is involved in diverse enzyme reactions including amino acid and hormone metabolism. Regulatory proteins that contribute to PLP homeostasis remain to be explored in plants. Here we demonstrate the importance of proteins annotated as PLP HOMEOSTASIS PROTEINs (PLPHPs) for controlling PLP in Arabidopsis (Arabidopsis thaliana). A systematic analysis indicates that while most organisms across kingdoms have a single PLPHP homolog, Angiosperms have two. PLPHPs from Arabidopsis bind PLP and exist as monomers, in contrast to reported PLP-dependent enzymes, which exist as multimers. Disrupting the function of both PLPHP homologs perturbs vitamin B6 (pyridoxine) content, inducing a PLP deficit accompanied by light hypersensitive root growth, unlike PLP biosynthesis mutants. Micrografting studies show that the PLP deficit can be relieved distally between shoots and roots. Chemical treatments probing PLP-dependent reactions, notably those for auxin and ethylene, provide evidence that PLPHPs function in the dynamic management of PLP. Assays in vitro show that Arabidopsis PLPHP can coordinate PLP transfer and withdrawal from other enzymes. This study thus expands our knowledge of vitamin B6 biology and highlights the importance of PLP coenzyme homeostasis in plants.
PMID: 38954500
Plant Cell , IF:11.277 , 2024 Jul , V36 (7) : P2668-2688 doi: 10.1093/plcell/koae107
Arabidopsis transcription factor TCP4 controls the identity of the apical gynoecium.
State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.; Zhejiang Lab, Research Institute of Intelligent Computing, Hangzhou 310012, China.; Key Laboratory of Soybean Molecular Design Breeding, National Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100871, China.; Southwest United Graduate School, Kunming 650092, China.
The style and stigma at the apical gynoecium are crucial for flowering plant reproduction. However, the mechanisms underlying specification of the apical gynoecium remain unclear. Here, we demonstrate that Class II TEOSINTE BRANCHED 1/CYCLOIDEA/PCF (TCP) transcription factors are critical for apical gynoecium specification in Arabidopsis (Arabidopsis thaliana). The septuple tcp2 tcp3 tcp4 tcp5 tcp10 tcp13 tcp17 (tcpSEP) and duodecuple tcp2 tcp3 tcp4 tcp5 tcp10 tcp13 tcp17 tcp24 tcp1 tcp12 tcp18 tcp16 (tcpDUO) mutants produce narrower and longer styles, while disruption of TCPs and CRABS CLAW (CRC) or NGATHAs (NGAs) in tcpDUO crc or tcpDUO nga1 nga2 nga4 causes the apical gynoecium to be replaced by lamellar structures with indeterminate growth. TCPs are predominantly expressed in the apex of the gynoecium. TCP4 interacts with CRC to synergistically upregulate the expression level of NGAs, and NGAs further form high-order complexes to control the expression of auxin-related genes in the apical gynoecium by directly interacting with TCP4. Our findings demonstrate that TCP4 physically associates with CRC and NGAs to control auxin biosynthesis in forming fine structures of the apical gynoecium.
PMID: 38581433
Proc Natl Acad Sci U S A , IF:11.205 , 2024 Jul , V121 (29) : Pe2320470121 doi: 10.1073/pnas.2320470121
A transient radial cortical microtubule array primes cell division in Arabidopsis.
Laboratoire de Reproduction et Developpement des Plantes, Universite de Lyon, Ecole Normale Superieure de Lyon, Universite Claude Bernard Lyon 1, Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), CNRS, 69364 Lyon Cedex 07, France.; Department of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.; Faculty of Engineering and Sciences, Universidad Adolfo Ibanez, Vina del Mar 2520000, Chile.; Universite Paris-Saclay, INRAE, AgroParisTech, Institute Jean-Pierre Bourgin for Plant Sciences (IJPB), Versailles 78000, France.
Although the formation of new walls during plant cell division tends to follow maximal tensile stress direction, analyses of individual cells over time reveal a much more variable behavior. The origin of such variability as well as the exact role of interphasic microtubule behavior before cell division have remained mysterious so far. To approach this question, we took advantage of the Arabidopsis stem, where the tensile stress pattern is both highly anisotropic and stable. Although cortical microtubules (CMTs) generally align with maximal tensile stress, we detected a specific time window, ca. 3 h before cell division, where cells form a radial pattern of CMTs. This microtubule array organization preceded preprophase band (PPB) formation, a transient CMT array predicting the position of the future division plane. It was observed under different growth conditions and was not related to cell geometry or polar auxin transport. Interestingly, this cortical radial pattern correlated with the well-documented increase of cytoplasmic microtubule accumulation before cell division. This radial organization was prolonged in cells of the trm678 mutant, where CMTs are unable to form a PPB. Whereas division plane orientation in trm678 is noisier, we found that cell division symmetry was in contrast less variable between daughter cells. We propose that this "radial step" reflects a trade-off in robustness for two essential cell division attributes: symmetry and orientation. This involves a "reset" stage in G2, where an increased cytoplasmic microtubule accumulation transiently disrupts CMT alignment with tissue stress.
PMID: 38990951
Proc Natl Acad Sci U S A , IF:11.205 , 2024 Jul , V121 (28) : Pe2402514121 doi: 10.1073/pnas.2402514121
Multiplexed in situ hybridization reveals distinct lineage identities for major and minor vein initiation during maize leaf development.
Department of Biology, University of Oxford, Oxford OX1 3RB, United Kingdom.; Resolve BioSciences GmbH, 40789 Monheim am Rhein, Germany.
Leaves of flowering plants are characterized by diverse venation patterns. Patterning begins with the selection of vein-forming procambial initial cells from within the ground meristem of a developing leaf, a process which is considered to be auxin-dependent, and continues until veins are anatomically differentiated with functional xylem and phloem. At present, the mechanisms responsible for leaf venation patterning are primarily characterized in the model eudicot Arabidopsis thaliana which displays a reticulate venation network. However, evidence suggests that vein development may proceed via a different mechanism in monocot leaves where venation patterning is parallel. Here, we employed Molecular Cartography, a multiplexed in situ hybridization technique, to analyze the spatiotemporal localization of a subset of auxin-related genes and candidate regulators of vein patterning in maize leaves. We show how different combinations of auxin influx and efflux transporters are recruited during leaf and vein specification and how major and minor vein ranks develop with distinct identities. The localization of the procambial marker PIN1a and the spatial arrangement of procambial initial cells that give rise to major and minor vein ranks further suggests that vein spacing is prepatterned across the medio-lateral leaf axis prior to accumulation of the PIN1a auxin transporter. In contrast, patterning in the adaxial-abaxial axis occurs progressively, with markers of xylem and phloem gradually becoming polarized as differentiation proceeds. Collectively, our data suggest that both lineage- and position-based mechanisms may underpin vein patterning in maize leaves.
PMID: 38959034
J Hazard Mater , IF:10.588 , 2024 Jul , V476 : P135092 doi: 10.1016/j.jhazmat.2024.135092
Methylisothiazolinone pollution inhibited root stem cells and regeneration through auxin transport modification in Arabidopsis thaliana.
Laboratory of Medicinal Plant, Hubei Key Laboratory of Embryonic Stem Cell Research, School of Basic Medicine, Hubei University of Medicine, Shiyan 442000, PR China.; Laboratory of Medicinal Plant, Hubei Key Laboratory of Embryonic Stem Cell Research, School of Basic Medicine, Hubei University of Medicine, Shiyan 442000, PR China; School of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi, China.; Laboratory of Medicinal Plant, Hubei Key Laboratory of Embryonic Stem Cell Research, School of Basic Medicine, Hubei University of Medicine, Shiyan 442000, PR China; State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.; Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry of Ministry of Education, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China.; State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.; Research Center of Environment and Healh of South-to-North Waler Diversion Area, Hubei University of Medicine, Shiyan 442000, China.; College of Ecology, Lishui University, Lishui 323000, China.; Laboratory of Medicinal Plant, Hubei Key Laboratory of Embryonic Stem Cell Research, School of Basic Medicine, Hubei University of Medicine, Shiyan 442000, PR China. Electronic address: lee.childe@qq.com.; State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: juanliu126@126.com.
Methylisothiazolinone (MIT) is a widely used preservative and biocide to prevent product degradation, yet its potential impact on plant growth remains poorly understood. In this study, we investigated MIT's toxic effects on Arabidopsis thaliana root growth. Exposure to MIT significantly inhibited Arabidopsis root growth, associated with reduced root meristem size and root meristem cell numbers. We explored the polar auxin transport pathway and stem cell regulation as key factors in root meristem function. Our findings demonstrated that MIT suppressed the expression of the auxin efflux carrier PIN1 and major root stem cell regulators (PLT1, PLT2, SHR, and SCR). Additionally, MIT hindered root regeneration by downregulating the quiescent center (QC) marker WOX5. Transcriptome analysis revealed MIT-induced alterations in gene expression related to oxidative stress, with physiological experiments confirming elevated reactive oxygen species (ROS) levels and increased cell death in root tips at concentrations exceeding 50 muM. In summary, this study provides critical insights into MIT's toxicity on plant root development and regeneration, primarily linked to modifications in polar auxin transport and downregulation of genes associated with root stem cell regulation.
PMID: 38964040
J Hazard Mater , IF:10.588 , 2024 Jul , V473 : P134719 doi: 10.1016/j.jhazmat.2024.134719
NtARF11 positively regulates cadmium tolerance in tobacco by inhibiting expression of the nitrate transporter NtNRT1.1.
State Key Laboratory of Tobacco Cultivation, College of tobacco Science, Henan Agricultural University, Zhengzhou 450002, China. Electronic address: jiahongfang@126.com.; State Key Laboratory of Tobacco Cultivation, College of tobacco Science, Henan Agricultural University, Zhengzhou 450002, China.; State Key Laboratory of Tobacco Cultivation, College of tobacco Science, Henan Agricultural University, Zhengzhou 450002, China; State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200438, China.; State Key Laboratory of Tobacco Cultivation, College of tobacco Science, Henan Agricultural University, Zhengzhou 450002, China. Electronic address: shf_email2011@126.com.; State Key Laboratory of Tobacco Cultivation, College of tobacco Science, Henan Agricultural University, Zhengzhou 450002, China. Electronic address: ycszp@henau.edu.cn.
Heavy metal cadmium (Cd) is widespread in contaminated soil and an important factor limiting plant growth. NO(3)(-) (nitrate) affects Cd uptake and thus changes Cd tolerance in plants; however, the underlying molecular regulatory mechanisms have not yet been elucidated. Here, we analyzed a novel gene, NtARF11 (auxin response factor), which regulates Cd tolerance in tobacco via the NO(3)(-) uptake pathway, through experiments with NtARF11-knockout and NtARF11-overexpression transgenic tobacco lines. NtARF11 was highly expressed under Cd stress in tobacco plants. Under Cd stress, overexpression of NtARF11 enhanced Cd tolerance in tobacco compared to that in wild-type tobacco, as shown by the low Cd concentration, high chlorophyll concentration, and low accumulation of reactive oxygen species in NtARF11-overexpressing tobacco. Moreover, low NO(3)(-) concentrations were observed in NtARF11-overexpressing tobacco plants. Further analyses revealed direct binding of NtARF11 to the promoter of the nitrate transporter NtNRT1.1, thereby negatively regulating its expression in tobacco. Notably, NtNRT1.1 knockout reduced NO(3)(-) uptake, which resulted in low Cd concentrations in tobacco. Altogether, these results demonstrate that the NtARF11-NtNRT1.1 module functions as a positive regulator of Cd tolerance by reducing the Cd uptake in tobacco, providing new insights for improving Cd tolerance of plants through genetic engineering.
PMID: 38797073
J Hazard Mater , IF:10.588 , 2024 Jul , V473 : P134587 doi: 10.1016/j.jhazmat.2024.134587
Suppression of OsSAUR2 gene expression immobilizes soil arsenic bioavailability by modulating root exudation and rhizosphere microbial assembly in rice.
The Key Laboratory for Quality Improvement of Agricultural Products of Zhejiang Province, College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou 311300, People's Republic of China.; The Key Laboratory for Quality Improvement of Agricultural Products of Zhejiang Province, College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou 311300, People's Republic of China. Electronic address: liuqp@zafu.edu.cn.
One of the factors influencing the behavior of arsenic (As) in environment is microbial-mediated As transformation. However, the detailed regulatory role of gene expression on the changes of root exudation, rhizosphere microorganisms, and soil As occurrence forms remains unclear. In this study, we evidence that loss-of-function of OsSAUR2 gene, a member of the SMALL AUXIN-UP RNA family in rice, results in significantly higher As uptake in roots but greatly lower As accumulation in grains via affecting the expression of OsLsi1, OsLsi2 in roots and OsABCC1 in stems. Further, the alteration of OsSAUR2 expression extensively affects the metabolomic of root exudation, and thereby leading to the variations in the composition of rhizosphere microbial communities in rice. The microbial community in the rhizosphere of Ossaur2 plants strongly immobilizes the occurrence forms of As in soil. Interestingly, Homovanillic acid (HA) and 3-Coumaric acid (CA), two differential metabolites screened from root exudation, can facilitate soil iron reduction, enhance As bioavailability, and stimulate As uptake and accumulation in rice. These findings add our further understanding in the relationship of OsSAUR2 expression with the release of root exudation and rhizosphere microbial assembly under As stress in rice, and provide potential rice genetic resources and root exudation in phytoremediation of As-contaminated paddy soil.
PMID: 38772107
New Phytol , IF:10.151 , 2024 Jul doi: 10.1111/nph.19959
Actin-bundling protein fimbrin serves as a new auxin biosynthesis orchestrator in Arabidopsis root tips.
Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, College of Life Sciences, Northwest University, Xi'an, 710069, China.; National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China.
Plants delicately regulate endogenous auxin levels through the coordination of transport, biosynthesis, and inactivation, which is crucial for growth and development. While it is well-established that the actin cytoskeleton can regulate auxin levels by affecting polar transport, its potential role in auxin biosynthesis has remained largely unexplored. Using LC-MS/MS-based methods combined with fluorescent auxin marker detection, we observed a significant increase in root auxin levels upon deletion of the actin bundling proteins AtFIM4 and AtFIM5. Fluorescent observation, immunoblotting analysis, and biochemical approaches revealed that AtFIM4 and AtFIM5 affect the protein abundance of the key auxin synthesis enzyme YUC8 in roots. AtFIM4 and AtFIM5 regulate the auxin synthesis enzyme YUC8 at the protein level, with its degradation mediated by the 26S proteasome. This regulation modulates auxin synthesis and endogenous auxin levels in roots, consequently impacting root development. Based on these findings, we propose a molecular pathway centered on the 'actin cytoskeleton-26S proteasome-YUC8-auxin' axis that controls auxin levels. Our findings shed light on a new pathway through which plants regulate auxin synthesis. Moreover, this study illuminates a newfound role of the actin cytoskeleton in regulating plant growth and development, particularly through its involvement in maintaining protein homeostasis via the 26S proteasome.
PMID: 39044442
New Phytol , IF:10.151 , 2024 Jul doi: 10.1111/nph.19967
Tip of the iceberg? Three novel TOPLESS-interacting effectors of the gall-inducing fungus Ustilago maydis.
Department of Plant Pathology, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Nussallee 9, Bonn, 53115, Germany.; Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Vienna Bio Center (VBC), Dr. Bohr-Gasse 3, Vienna, 1030, Austria.
Ustilago maydis is a biotrophic pathogen causing smut disease in maize. It secretes a cocktail of effector proteins, which target different host proteins during its biotrophic stages in the host plant. One such class of proteins we identified previously is TOPLESS (TPL) and TOPLESS-RELATED (TPR) transcriptional corepressors. Here, we screened 297 U. maydis effector candidates for their ability to interact with maize TPL protein RAMOSA 1 ENHANCER LOCUS 2 LIKE 2 (RELK2) and their ability to induce auxin signaling and thereby identified three novel TPL-interacting protein effectors (Tip6, Tip7, and Tip8). Structural modeling and mutational analysis allowed the identification of TPL-interaction motifs of Tip6 and Tip7. In planta interaction between Tip6 and Tip7 with RELK2 occurs mainly in nuclear compartments, whereas Tip8 colocalizes with RELK2 in a compartment outside the nucleus. Overexpression of Tip8 in nonhost plants leads to cell death, indicating recognition of the effector or its activity. By performing infection assays with single and multideletion mutants of U. maydis, we demonstrate a positive role of Tip6 and Tip7 in U. maydis virulence. Transcriptional profiling of maize leaves infected with Tip effector mutants in comparison with SG200 strain suggests Tip effector activities are not merely redundant.
PMID: 39021059
New Phytol , IF:10.151 , 2024 Jul doi: 10.1111/nph.19970
A transcriptional repressor HVA regulates vascular bundle formation through auxin transport in Arabidopsis stem.
Department of Plant Science and Landscape Architecture, University of Connecticut, 1376 Storrs Rd, Storrs, CT, 06269, USA.; Institute for System Genomics, University of Connecticut, Storrs, CT, 06269, USA.
Vascular bundles transport water and photosynthate to all organs, and increased bundle number contributes to crop lodging resistance. However, the regulation of vascular bundle formation is poorly understood in the Arabidopsis stem. We report a novel semi-dominant mutant with high vascular activity, hva-d, showing increased vascular bundle number and enhanced cambium proliferation in the stem. The activation of a C2H2 zinc finger transcription factor, AT5G27880/HVA, is responsible for the hva-d phenotype. Genetic, biochemical, and fluorescent microscopic analyses were used to dissect the functions of HVA. HVA functions as a repressor and interacts with TOPLESS via the conserved Ethylene-responsive element binding factor-associated Amphiphilic Repression motif. In contrast to the HVA activation line, knockout of HVA function with a CRISPR-Cas9 approach or expression of HVA fused with an activation domain VP16 (HVA-VP16) resulted in fewer vascular bundles. Further, HVA directly regulates the expression of the auxin transport efflux facilitator PIN1, as a result affecting auxin accumulation. Genetics analysis demonstrated that PIN1 is epistatic to HVA in controlling bundle number. This research identifies HVA as a positive regulator of vascular initiation through negatively modulating auxin transport and sheds new light on the mechanism of bundle formation in the stem.
PMID: 39014537
New Phytol , IF:10.151 , 2024 Jul doi: 10.1111/nph.19949
The biosynthesis of storage reserves and auxin is coordinated by a hierarchical regulatory network in maize endosperm.
State Key Laboratory of Maize Bio-breeding, Frontiers Science Center for Molecular Design Breeding, Joint International Research Laboratory of Crop Molecular Breeding, National Maize Improvement Center, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China.; State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.; Shanghai Key Laboratory of Bio-Energy Crops, Plant Science Center, School of Life Sciences, Shanghai University, Shanghai, 200444, China.
Grain filling in maize (Zea mays) is intricately linked to cell development, involving the regulation of genes responsible for the biosynthesis of storage reserves (starch, proteins, and lipids) and phytohormones. However, the regulatory network coordinating these biological functions remains unclear. In this study, we identified 1744 high-confidence target genes co-regulated by the transcription factors (TFs) ZmNAC128 and ZmNAC130 (ZmNAC128/130) through chromatin immunoprecipitation sequencing coupled with RNA-seq analysis in the zmnac128/130 loss-of-function mutants. We further constructed a hierarchical regulatory network using DNA affinity purification sequencing analysis of downstream TFs regulated by ZmNAC128/130. In addition to target genes involved in the biosynthesis of starch and zeins, we discovered novel target genes of ZmNAC128/130 involved in the biosynthesis of lipids and indole-3-acetic acid (IAA). Consistently, the number of oil bodies, as well as the contents of triacylglycerol, and IAA were significantly reduced in zmnac128/130. The hierarchical regulatory network centered by ZmNAC128/130 revealed a significant overlap between the direct target genes of ZmNAC128/130 and their downstream TFs, particularly in regulating the biosynthesis of storage reserves and IAA. Our results indicated that the biosynthesis of storage reserves and IAA is coordinated by a multi-TFs hierarchical regulatory network in maize endosperm.
PMID: 38962989
New Phytol , IF:10.151 , 2024 Aug , V243 (4) : P1299-1300 doi: 10.1111/nph.19879
Dior R. Kelley.
PMID: 38837388
Plant Biotechnol J , IF:9.803 , 2024 Aug , V22 (8) : P2201-2215 doi: 10.1111/pbi.14339
PagARGOS promotes low-lignin wood formation in poplar.
State Key Laboratory of Efficient Production of Forest Resources, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.; National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China.; Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Singapore.; Beijing Key Laboratory of Lignocellulosic Chemistry, College of Materials Science and Technology, Beijing Forestry University, Beijing, China.; National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China.; Shandong Provincial Key Laboratory of Energy Genetics and CAS Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.
Wood formation, which occurs mainly through secondary xylem development, is important not only for supplying raw material for the 'ligno-chemical' industry but also for driving the storage of carbon. However, the complex mechanisms underlying the promotion of xylem formation remain to be elucidated. Here, we found that overexpression of Auxin-Regulated Gene involved in Organ Size (ARGOS) in hybrid poplar 84 K (Populus alba x Populus tremula var. glandulosa) enlarged organ size. In particular, PagARGOS promoted secondary growth of stems with increased xylem formation. To gain further insight into how PagARGOS regulates xylem development, we further carried out yeast two-hybrid screening and identified that the auxin transporter WALLS ARE THIN1 (WAT1) interacts with PagARGOS. Overexpression of PagARGOS up-regulated WAT1, activating a downstream auxin response promoting cambial cell division and xylem differentiation for wood formation. Moreover, overexpressing PagARGOS caused not only higher wood yield but also lower lignin content compared with wild-type controls. PagARGOS is therefore a potential candidate gene for engineering fast-growing and low-lignin trees with improved biomass production.
PMID: 38492213
Plant Biotechnol J , IF:9.803 , 2024 Jul , V22 (7) : P2054-2074 doi: 10.1111/pbi.14325
CaIAA2-CaARF9 module mediates the trade-off between pepper growth and immunity.
Collaborative Innovation Center for Efficient and Green Production of Agriculture in Mountainous Areas of Zhejiang Province, College of Horticulture Science, Zhejiang A&F University, Hangzhou, Zhejiang, China.; Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable, Ministry of Agriculture and Rural Affairs, Zhejiang A&F University, Hangzhou, Zhejiang, China.; Agricultural College, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China.; Institute of Biological Chemistry, Washington State University, Pullman, Washington, USA.
To challenge the invasion of various pathogens, plants re-direct their resources from plant growth to an innate immune defence system. However, the underlying mechanism that coordinates the induction of the host immune response and the suppression of plant growth remains unclear. Here we demonstrate that an auxin response factor, CaARF9, has dual roles in enhancing the immune resistance to Ralstonia solanacearum infection and in retarding plant growth by repressing the expression of its target genes as exemplified by Casmc4, CaLBD37, CaAPK1b and CaRROP1. The expression of these target genes not only stimulates plant growth but also negatively impacts pepper resistance to R. solanacearum. Under normal conditions, the expression of Casmc4, CaLBD37, CaAPK1b and CaRROP1 is active when promoter-bound CaARF9 is complexed with CaIAA2. Under R. solanacearum infection, however, degradation of CaIAA2 is triggered by SA and JA-mediated signalling defence by the ubiquitin-proteasome system, which enables CaARF9 in the absence of CaIAA2 to repress the expression of Casmc4, CaLBD37, CaAPK1b and CaRROP1 and, in turn, impeding plant growth while facilitating plant defence to R. solanacearum infection. Our findings uncover an exquisite mechanism underlying the trade-off between plant growth and immunity mediated by the transcriptional repressor CaARF9 and its deactivation when complexed with CaIAA2.
PMID: 38450864
Cell Rep , IF:9.423 , 2024 Jul , V43 (8) : P114524 doi: 10.1016/j.celrep.2024.114524
Single-cell RNA sequencing reveals dynamics of gene expression for 2D elongation and 3D growth in Physcomitrium patens.
State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, China.; CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China.; National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, 85 Minglun Street, Kaifeng 475001, China.; Mid-Florida Research and Education Center, Department of Environmental Horticulture, University of Florida, 2725 South Binion Road, Apopka, FL 32703, USA.; State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, China. Electronic address: liuli2020@hubu.edu.cn.
The transition from two-dimensional (2D) to 3D growth likely facilitated plants to colonize land, but its heterogeneity is not well understood. In this study, we utilized single-cell RNA sequencing to analyze the moss Physcomitrium patens, whose morphogenesis involves a transition from 2D to 3D growth. We profiled over 17,000 single cells covering all major vegetative tissues, including 2D filaments (chloronema and caulonema) and 3D structures (bud and gametophore). Pseudotime analyses revealed larger numbers of candidate genes that determine cell fates for 2D tip elongation or 3D bud differentiation. Using weighted gene co-expression network analysis, we identified a module that connects beta-type carbonic anhydrases (betaCAs) with auxin. We further validated the cellular expression patterns of betaCAs and demonstrated their roles in 3D gametophore development. Overall, our study provides insights into cellular heterogeneity in a moss and identifies molecular signatures that underpin the 2D-to-3D growth transition at single-cell resolution.
PMID: 39046878
Plant Physiol , IF:8.34 , 2024 Jul doi: 10.1093/plphys/kiae370
Cell wall integrity modulates HOOKLESS1 and PHYTOCHROME INTERACTING FACTOR4 expression controlling apical hook formation.
Dipartimento di Biologia e biotecnologie "Charles Darwin", Sapienza Universita di Roma, Rome, Italy.; Umea Plant Science Centre (UPSC), Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden.; IRBV, Department of Biological Sciences, University of Montreal, Montreal, Quebec, Canada.; Laboratory of Growth Regulators, Institute of Experimental Botany, Czech Academy of Sciences and Faculty of Science, Palacky University Olomouc, CZ-78371 Olomouc, Czech Republic.; Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom.; Umea Plant Science Centre (UPSC), Department of Plant Physiology, Umea University, 901 87 Umea, Sweden.
Formation of the apical hook in etiolated dicot seedlings results from differential growth in the hypocotyl apex and is tightly controlled by environmental cues and hormones, among which auxin and gibberellins (GAs) play an important role. Cell expansion is tightly regulated by the cell wall, but whether and how feedback from this structure contributes to hook development is still unclear. Here, we show that etiolated seedlings of the Arabidopsis (Arabidopsis thaliana) quasimodo2-1 (qua2) mutant, defective in pectin biosynthesis, display severe defects in apical hook formation and maintenance, accompanied by loss of asymmetric auxin maxima and of differential cell expansion. Moreover, qua2 seedlings show reduced expression of HOOKLESS 1 (HLS1) and PHYTOCHROME INTERACTING FACTOR 4 (PIF4), which are positive regulators of hook formation. Treatment of wild-type seedlings with the cellulose inhibitor isoxaben (isx) also prevents hook development and represses HLS1 and PIF4 expression. Exogenous GAs, loss of DELLA proteins or HLS1 overexpression partially restore hook development in qua2 and isx-treated seedlings. Interestingly, increased agar concentration in the medium restores, both in qua2 and isx-treated seedlings, hook formation, asymmetric auxin maxima and PIF4 and HLS1 expression. Analysis of plants expressing a FRET-based GA sensor indicate that isx reduces accumulation of GAs in the apical hook region in a turgor-dependent manner. Lack of the cell wall integrity sensor THESEUS 1, which modulates turgor loss point, restores hook formation in qua2 and isx-treated seedlings. We propose that turgor-dependent signals link changes in cell wall integrity to the PIF4-HLS1 signalling module to control differential cell elongation during hook formation.
PMID: 38976579
Sci Total Environ , IF:7.963 , 2024 Jul , V948 : P174663 doi: 10.1016/j.scitotenv.2024.174663
Non-pathogenic microbiome associated to aquatic plants and anthropogenic impacts on this interaction.
Ecotoxicology of Aquatic Microorganisms Laboratory, GRIL, EcotoQ, TOXEN, Department of Biological Sciences, Universite du Quebec a Montreal, Montreal Succ. Centre-Ville, H3C 3P8 Montreal, QC, Canada.; Institut national de la recherche scientifique - Centre Eau Terre Environnement, 490 Couronne St, Quebec City, Quebec G1K 9A9, Canada.; Ecotoxicology of Aquatic Microorganisms Laboratory, GRIL, EcotoQ, TOXEN, Department of Biological Sciences, Universite du Quebec a Montreal, Montreal Succ. Centre-Ville, H3C 3P8 Montreal, QC, Canada. Electronic address: juneau.philippe@uqam.ca.
The microbiota associated with aquatic plants plays a crucial role in promoting plant growth and development. The structure of the plant microbiome is shaped by intricate interactions among hosts, microbes, and environmental factors. Consequently, anthropogenic pressures that disrupt these interactions can indirectly impact the ecosystem services provided by aquatic plants, such as CO(2) fixation, provision of food resources, shelter to animals, nutrient cycling, and water purification. Presently, studies on plant-microbiota interactions primarily focus on terrestrial hosts and overlook aquatic environments with their unique microbiomes. Therefore, there is a pressing need for a comprehensive understanding of plant microbiomes in aquatic ecosystems. This review delves into the overall composition of the microbiota associated with aquatic plant, with a particular emphasis on bacterial communities, which have been more extensively studied. Subsequently, the functions provided by the microbiota to their aquatic plants hosts are explored, including the acquisition and mobilization of nutrients, production of auxin and related compounds, enhancement of photosynthesis, and protection against biotic and abiotic stresses. Additionally, the influence of anthropogenic stressors, such as climate change and aquatic contamination, on the interaction between microbiota and aquatic plants is discussed. Finally, knowledge gaps are highlighted and future directions in this field are suggested.
PMID: 38992379
Sci Total Environ , IF:7.963 , 2024 Oct , V946 : P174198 doi: 10.1016/j.scitotenv.2024.174198
Plant metabolic responses to soil herbicide residues differ under herbivory in two woodland strawberry genotypes.
Biodiversity Unit, University of Turku, 20014 Turku, Finland. Electronic address: Benjamin.fuchs@utu.fi.; Department of Biology, University of Turku, 20014 Turku, Finland.; Biodiversity Unit, University of Turku, 20014 Turku, Finland.; Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojova 263, 16502 Prague, Czech Republic.; Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, 70211 Kuopio, Finland.; Natural Chemistry Research Group, Department of Chemistry, FI-20014, University of Turku, Finland.; Biodiversity Unit, University of Turku, 20014 Turku, Finland; Division of Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research, As, Norway.
The use of glyphosate-based herbicides (GBHs) to control weeds has increased exponentially in recent decades, and their residues and degradation products have been found in soils across the globe. GBH residues in soil have been shown to affect plant physiology and specialised metabolite biosynthesis, which, in turn, may impact plant resistance to biotic stressors. In a greenhouse study, we investigated the interactive effects between soil GBH residues and herbivory on the performance, phytohormone concentrations, phenolic compound concentrations and volatile organic compound (VOC) emissions of two woodland strawberry (Fragaria vesca) genotypes, which were classified as herbivore resistant and herbivore susceptible. Plants were subjected to herbivory by strawberry leaf beetle (Galerucella tenella) larvae, and to GBH residues by growing in soil collected from a field site with GBH treatments twice a year over the past eight years. Soil GBH residues reduced the belowground biomass of the susceptible genotype and the aboveground biomass of both woodland strawberry genotypes. Herbivory increased the belowground biomass of the resistant genotype and the root-shoot ratio of both genotypes. At the metabolite level, herbivory induced the emission of several VOCs. Jasmonic acid, abscisic acid and auxin concentrations were induced by herbivory, in contrast to salicylic acid, which was only induced by herbivory in combination with soil GBH residues in the resistant genotype. The concentrations of phenolic compounds were higher in the resistant genotype compared to the susceptible genotype and were induced by soil GBH residues in the resistant genotype. Our results indicate that soil GBH residues can differentially affect plant performance, phytohormone concentrations and phenolic compound concentrations under herbivore attack, in a genotype-dependent manner. Soil GBH altered plant responses to herbivory, which may impact plant resistance traits and species interactions. With ongoing agrochemical pollution, we need to consider plant cultivars with better resistance to polluted soils while maintaining plant resilience under challenging environmental conditions.
PMID: 38914330
Sci Total Environ , IF:7.963 , 2024 Sep , V942 : P173775 doi: 10.1016/j.scitotenv.2024.173775
High-throughput 16S rRNA gene-based amplicon sequencing reveals the functional divergence of halophilic bacterial communities in the Suaeda salsa root compartments on the eastern coast of China.
Biofuels Institute, School of Environment & Safety Engineering, Jiangsu University, Zhenjiang 212013, China.; Biofuels Institute, School of Environment & Safety Engineering, Jiangsu University, Zhenjiang 212013, China; School of Life Sciences, Jiangsu University, Zhenjiang 212013, China; Department of Zoology & Environmental Biology, University of Nigeria, Nsukka 410001, Nigeria.; Biofuels Institute, School of Environment & Safety Engineering, Jiangsu University, Zhenjiang 212013, China. Electronic address: jxjiang@ujs.edu.cn.
The rhizosphere environment of plants, which harbors halophilic bacterial communities, faces significant challenges in coping with environmental stressors, particularly saline soil properties. This study utilizes a high-throughput 16S rRNA gene-based amplicon sequencing to investigate the variations in bacterial community dynamics in rhizosphere soil (RH), root surface soil (RS), root endophytic bacteria (PE) compartments of Suaeda salsa roots, and adjoining soils (CK) across six locations along the eastern coast of China: Nantong (NT), Yancheng (YC), Dalian (DL), Tianjin (TJ), Dongying (DY), and Qingdao (QD), all characterized by chloride-type saline soil. Variations in the physicochemical properties of the RH compartment were also evaluated. The results revealed significant changes in pH, electrical conductivity, total salt content, and ion concentrations in RH samples from different locations. Notably, the NT location exhibited the highest alkalinity and nitrogen availability. The pH variations were linked to HCO(3)(-) accumulation in S. salsa roots, while salinity stress influenced soil pH through H(+) discharge. Despite salinity stress, enzymatic activities such as catalase and urease were higher in soils from various locations. The diversity and richness of bacterial communities were higher in specific locations, with Proteobacteria dominating PE samples from the DL location. Additionally, Vibrio and Marinobacter were prevalent in RH samples. Significant correlations were found between soil pH, salinity, nutrient content, and the abundance and diversity of bacterial taxa in RH samples. Bioinformatics analysis revealed the prevalence of halophilic bacteria, such as Bacillus, Halomonas, and Streptomyces, with diverse metabolic functions, including amino acid and carbohydrate metabolisms. Essential genes, such as auxin response factor (ARF) and GTPase-encoding genes, were abundant in RH samples, suggesting adaptive strategies for harsh environments. Likewise, proline/betaine transport protein genes were enriched, indicating potential bioremediation mechanisms against high salt stress. These findings provide insight into the metabolic adaptations facilitating resilience in saline ecosystems and contribute to understanding the complex interplay between soil conditions, bacterial communities, and plant adaptation.
PMID: 38844238
Curr Opin Plant Biol , IF:7.834 , 2024 Jul , V81 : P102589 doi: 10.1016/j.pbi.2024.102589
Putting heads together: Developmental genetics of the Asteraceae capitulum.
Department of Biological Sciences, Auburn University, 36849, Auburn, AL, USA.; Department of Biological Sciences, Auburn University, 36849, Auburn, AL, USA. Electronic address: danielsjones@auburn.edu.
Inflorescence architecture is highly variable across plant lineages yet is critical for facilitating reproductive success. The capitulum-type inflorescence of the Asteraceae is marked as a key morphological innovation that preceded the family's diversification and expansion. Despite its evolutionary significance, our understanding of capitulum development and evolution is limited. This review highlights our current perspective on capitulum evolution through the lens of both its molecular and developmental underpinnings. We attempt to summarize our understanding of the capitulum by focusing on two key characteristics: patterning (arrangement of florets on a capitulum) and floret identity specification. Note that these two features are interconnected such that the identity of florets depends on their position along the inflorescence axis. Phytohormones such as auxin seemingly determine both pattern progression and floret identity specification through unknown mechanisms. Floret morphology in a head is controlled by differential expression of floral symmetry genes regulating floret identity specification. We briefly summarize the applicability of the ABCE quartet model of flower development in regulating the floret organ identity of a capitulum in Asteraceae. Overall, there have been promising advancements in our understanding of capitula; however, comprehensive functional genetic analyses are necessary to fully dissect the molecular pathways and mechanisms involved in capitulum development.
PMID: 38955094
Plant Cell Environ , IF:7.228 , 2024 Jul doi: 10.1111/pce.15050
Water wisteria genome reveals environmental adaptation and heterophylly regulation in amphibious plants.
The State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China.; Laboratory of Marine Biological Resources Development and Utilization, Zhejiang Marine Development Research Institute, Zhoushan, Zhejiang, China.; Joseph Gottlieb Kolreuter Institute for Plant Sciences, Karlsruhe Institute of Technology, Karlsruhe, Germany.; Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan.; Center for Plant Sciences, Kyoto Sangyo University, Kyoto, Japan.; Department of Life Science, Pohang University of Science and Technology, Pohang, South Korea.; Institute of Transformative Biomolecules (WPI-ITbM), Nagoya University, Nagoya, Aichi, Japan.; Howard Hughes Medical Institute, The University of Texas at Austin, Austin, Texas, USA.; Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA.
Heterophylly is a phenomenon whereby an individual plant dramatically changes leaf shape in response to the surroundings. Hygrophila difformis (Acanthaceae; water wisteria), has recently emerged as a model plant to study heterophylly because of its striking leaf shape variation in response to various environmental factors. When submerged, H. difformis often develops complex leaves, but on land it develops simple leaves. Leaf complexity is also influenced by other factors, such as light density, humidity, and temperature. Here, we sequenced and assembled the H. difformis chromosome-level genome (scaffold N50: 60.43 Mb, genome size: 871.92 Mb), which revealed 36 099 predicted protein-coding genes distributed over 15 pseudochromosomes. H. difformis diverged from its relatives during the Oligocene climate-change period and expanded gene families related to its amphibious habit. Genes related to environmental stimuli, leaf development, and other pathways were differentially expressed in submerged and terrestrial conditions, possibly modulating morphological and physiological acclimation to changing environments. We also found that auxin plays a role in H. difformis heterophylly. Finally, we discovered candidate genes that respond to different environmental conditions and elucidated the role of LATE MERISTEM IDENTITY 1 (LMI1) in heterophylly. We established H. difformis as a model for studying interconnections between environmental adaptation and morphogenesis.
PMID: 39076061
Plant Cell Environ , IF:7.228 , 2024 Jul doi: 10.1111/pce.15039
Sextuple knockouts of a highly conserved and coexpressed AUXIN/INDOLE-3-ACETIC ACID gene set confer shade avoidance-like responses in Arabidopsis.
Institute of Genetics and Regenerative Biology, College of Life Sciences, Zhejiang University, Hangzhou, China.; School of Pharmacy, Hangzhou Normal University, Hangzhou, China.
AUXIN/INDOLE-3-ACETIC ACIDs are transcriptional repressors for auxin signalling. Aux/IAAs of Arabidopsis thaliana display some functional redundancy. The IAA3/SHY2 clade (IAA1, IAA2, IAA3 and IAA4) show strong sequence similarity, but no higher-order mutants have been reported. Here, through CRISPR/Cas9 genome editing, we generated loss-of-function iaa1/2/3/4 mutants. The quadruple mutants only exhibited a weak phenotype. Thus, we additionally knocked out IAA7/AXR2 and IAA16, which are coexpressed with IAA1/2/3/4. Remarkably, under white light control conditions, the iaa1/2/3/4/7/16 mutants exhibited a shade avoidance-like phenotype with over-elongated hypocotyls and petioles and hyponastic leaves. The sextuple mutants were highly sensitive to low light intensity, and the hypocotyl cells of the mutants were excessively elongated. Transcriptome profiling and qRT-PCR analyses revealed that the sextuple mutation upregulated IAA19/MSG2 and IAA29, two shared shade/auxin signalling targets. Besides, genes encoding cell wall-remodelling proteins and shade-responsive transcription regulators were upregulated. Using dual-luciferase reporter assays, we verified that IAA2/IAA7 targeted the promoters of cell wall-remodelling genes to inhibit their transcription. Our work indicates that the IAA1/2/3/4/7/16 gene set is required for the optimal integration of auxin and shade signalling. The mutants generated here should be valuable for exploring the complex interactions among signal sensors, transcription activators and transcription repressors during hormone/environmental responses.
PMID: 39012193
Plant Cell Environ , IF:7.228 , 2024 Jul doi: 10.1111/pce.15031
Glycosylation mode of phloretin affects the morphology and stress resistance of apple plant.
State Key Laboratory for Crop Stress Resistance and High-Efficiency/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, China.
Phloretin has different glycosylation modes in plants. Phlorizin (phloretin 2'-O-glucoside) is one of the glycosylation products of phloretin, and accumulates abundantly in apple plants. However, it is still unclear whether phlorizin is more beneficial for apple plants compared with other glycosylation products of phloretin. We created transgenic apple plants with different glycosylation modes of phloretin. In transgenic plants, the accumulation of phlorizin was partly replaced by that of trilobatin (phloretin 4'-O-glucoside) or phloretin 3',5'-di-C-glycoside. Compared with wild type, transgenic plants with less phlorizin showed dwarf phenotype, larger stomatal size, higher stomatal density and less tolerance to drought stress. Transcriptome and phytohormones assay indicate that phlorizin might regulate stomatal development and behaviour via controlling auxin and abscisic acid signalling pathways as well as carbonic anhydrase expressions. Transgenic apple plants with less phlorizin also showed less resistance to spider mites. Apple plants may hydrolyse phlorizin to produce phloretin, but cannot hydrolyse trilobatin or phloretin 3',5'-di-C-glycoside. Compared with its glycosylation products, phloretin is more toxic to spider mites. These results suggest that the glycosylation of phloretin to produce phlorizin is the optimal glycosylation mode in apple plants, and plays an important role in apple resistance to stresses.
PMID: 38995178
Plant Cell Environ , IF:7.228 , 2024 Jul doi: 10.1111/pce.15027
A molecular module connects abscisic acid with auxin signals to facilitate seasonal wood formation in Populus.
Yuelushan Laboratory, College of Life and Environmental Sciences, Central South University of Forestry and Technology, Changsha, China.; Key Laboratory of Plant Carbon Capture, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.
Perennial trees have a recurring annual cycle of wood formation in response to environmental fluctuations. However, the precise molecular mechanisms that regulate the seasonal formation of wood remain poorly understood. Our prior study indicates that VCM1 and VCM2 play a vital role in regulating the activity of the vascular cambium by controlling the auxin homoeostasis of the cambium zone in Populus. This study indicates that abscisic acid (ABA) affects the expression of VCM1 and VCM2, which display seasonal fluctuations in relation to photoperiod changes. ABA-responsive transcription factors AREB4 and AREB13, which are predominantly expressed in stem secondary vascular tissue, bind to VCM1 and VCM2 promoters to induce their expression. Seasonal changes in the photoperiod affect the ABA amount, which is linked to auxin-regulated cambium activity via the functions of VCM1 and VCM2. Thus, the study reveals that AREB4/AREB13-VCM1/VCM2-PIN5b acts as a molecular module connecting ABA and auxin signals to control vascular cambium activity in seasonal wood formation.
PMID: 38963121
Plant Cell Environ , IF:7.228 , 2024 Aug , V47 (8) : P3030-3045 doi: 10.1111/pce.14916
Cytosolic ABA Receptor Kinases phosphorylate the D6 PROTEIN KINASE leading to its stabilization which promotes Arabidopsis growth.
Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, State Key Laboratory of Hydraulics and Mountain River Engineering, College of Life Sciences, Sichuan University, Chengdu, China.
The polar auxin transport is required for proper plant growth and development. D6 PROTEIN KINASE (D6PK) is required for the phosphorylation of PIN-FORMED (PIN) auxin efflux carriers to regulate auxin transport, while the regulation of D6PK stabilization is still poorly understood. Here, we found that Cytosolic ABA Receptor Kinases (CARKs) redundantly interact with D6PK, and the interactions are dependent on CARKs' kinase activities. Similarly, CARK3 also could interact with paralogs of D6PK, including D6PKL1, D6PKL2, and D6PKL3. The genetic analysis shows that D6PK acts the downstream of CARKs to regulate Arabidopsis growth, including hypocotyl, leaf area, vein formation, and the length of silique. Loss-of-function of CARK3 in overexpressing GFP-D6PK plants leads to reduce the level of D6PK protein, thereby rescues plant growth. In addition, the cell-free degradation assays indicate that D6PK is degraded through 26 S proteasome pathway, while the phosphorylation by CARK3 represses this process in cells. In summary, D6PK stabilization by the CARK family is required for auxin-mediated plant growth and development.
PMID: 38644762
Plant Cell Environ , IF:7.228 , 2024 Aug , V47 (8) : P2895-2910 doi: 10.1111/pce.14913
The 'Candidatus phytoplasma ziziphi' effectors SJP1 and SJP2 destabilise the bifunctional regulator ZjTCP7 to modulate floral transition and shoot branching.
Anhui Province Key Laboratory of Horticultural Crop Quality Biology, College of Horticulture, Anhui Agricultural University, Hefei, China.; Horticulture Research Institute, Anhui Academy of Agricultural Sciences, Hefei, China.
Phytoplasmic SAP11 effectors alter host plant architecture and flowering time. However, the exact mechanisms have yet to be elucidated. Two SAP11-like effectors, SJP1 and SJP2, from 'Candidatus Phytoplasma ziziphi' induce shoot branching proliferation. Here, the transcription factor ZjTCP7 was identified as a central target of these two effectors to regulate floral transition and shoot branching. Ectopic expression of ZjTCP7 resulted in enhanced bolting and earlier flowering than did the control. Interaction and expression assays demonstrated that ZjTCP7 interacted with the ZjFT-ZjFD module, thereby enhancing the ability of these genes to directly bind to the ZjAP1 promoter. The effectors SJP1 and SJP2 unravelled the florigen activation complex by specifically destabilising ZjTCP7 and ZjFD to delay floral initiation. Moreover, the shoot branching of the ZjTCP7-SRDX transgenic Arabidopsis lines were comparable to those of the SJP1/2 lines, suggesting the involvement of ZjTCP7 in the regulation of shoot branching. ZjTCP7 interacted with the branching repressor ZjBRC1 to enhance suppression of the auxin efflux carrier ZjPIN3 expression. ZjTCP7 also directly bound to and upregulated the auxin biosynthesis gene ZjYUCCA2, thereby promoting auxin accumulation. Our findings confirm that ZjTCP7 serves as a bifunctional regulator destabilised by the effectors SJP1 and SJP2 to modulate plant development.
PMID: 38623040
J Integr Plant Biol , IF:7.061 , 2024 Jul doi: 10.1111/jipb.13745
Simultaneous mutations in ITPK4 and MRP5 genes result in a low phytic acid level without compromising salt tolerance in Arabidopsis.
Key Laboratory of Plant Design, National Key Laboratory of Plant Molecular Genetics, Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, the Chinese Academy of Sciences, Shanghai, 200032, China.; University of Chinese Academy of Sciences, Beijing, 100190, China.; State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.; Institute of Advanced Biotechnology and School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518055, China.; Ministry of Agriculture and Rural Affairs Key Laboratory of Gene Editing Technologies, Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya, 572024, China.
Generation of crops with low phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate (InsP(6))) is an important breeding direction, but such plants often display less desirable agronomic traits. In this study, through ethyl methanesulfonate-mediated mutagenesis, we found that inositol 1,3,4-trisphosphate 5/6-kinase 4 (ITPK4), which is essential for producing InsP(6), is a critical regulator of salt tolerance in Arabidopsis. Loss of function of ITPK4 gene leads to reduced root elongation under salt stress, which is primarily because of decreased root meristem length and reduced meristematic cell number. The itpk4 mutation also results in increased root hair density and increased accumulation of reactive oxygen species during salt exposure. RNA sequencing assay reveals that several auxin-responsive genes are down-regulated in the itpk4-1 mutant compared to the wild-type. Consistently, the itpk4-1 mutant exhibits a reduced auxin level in the root tip and displays compromised gravity response, indicating that ITPK4 is involved in the regulation of the auxin signaling pathway. Through suppressor screening, it was found that mutation of Multidrug Resistance Protein 5 (MRP5)5 gene, which encodes an ATP-binding cassette (ABC) transporter required for transporting InsP(6) from the cytoplasm into the vacuole, fully rescues the salt hypersensitivity of the itpk4-1 mutant, but in the itpk4-1 mrp5 double mutant, InsP(6) remains at a very low level. These results imply that InsP(6) homeostasis rather than its overall amount is beneficial for stress tolerance in plants. Collectively, this study uncovers a pair of gene mutations that confer low InsP(6) content without impacting stress tolerance, which offers a new strategy for creating "low-phytate" crops.
PMID: 39031490
J Integr Plant Biol , IF:7.061 , 2024 Jul doi: 10.1111/jipb.13736
Light-stabilized GIL1 suppresses PIN3 activity to inhibit hypocotyl gravitropism.
Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.; Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China.; School of Advanced Agricultural Sciences and School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.; Department of Biology, University of Fribourg, Fribourg, 1700, Switzerland.
Light and gravity coordinately regulate the directional growth of plants. Arabidopsis Gravitropic in the Light 1 (GIL1) inhibits the negative gravitropism of hypocotyls in red and far-red light, but the underlying molecular mechanisms remain elusive. Our study found that GIL1 is a plasma membrane-localized protein. In endodermal cells of the upper part of hypocotyls, GIL1 controls the negative gravitropism of hypocotyls. GIL1 directly interacts with PIN3 and inhibits the auxin transport activity of PIN3. Mutation of PIN3 suppresses the abnormal gravitropic response of gil1 mutant. The GIL1 protein is unstable in darkness but it is stabilized by red and far-red light. Together, our data suggest that light-stabilized GIL1 inhibits the negative gravitropism of hypocotyls by suppressing the activity of the auxin transporter PIN3, thereby enhancing the emergence of young seedlings from the soil.
PMID: 38990128
J Integr Plant Biol , IF:7.061 , 2024 Jul , V66 (7) : P1351-1369 doi: 10.1111/jipb.13656
The miR159a-DUO1 module regulates pollen development by modulating auxin biosynthesis and starch metabolism in citrus.
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, 430070, China.; Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of the Ministry of Education and Key Laboratory of Non-Wood Forest Products of the Forestry Ministry, Central South University of Forestry and Technology, Changsha, 410004, China.
Achieving seedlessness in citrus varieties is one of the important objectives of citrus breeding. Male sterility associated with abnormal pollen development is an important factor in seedlessness. However, our understanding of the regulatory mechanism underlying the seedlessness phenotype in citrus is still limited. Here, we determined that the miR159a-DUO1 module played an important role in regulating pollen development in citrus, which further indirectly modulated seed development and fruit size. Both the overexpression of csi-miR159a and the knocking out of DUO1 in Hong Kong kumquat (Fortunella hindsii) resulted in small and seedless fruit phenotypes. Moreover, pollen was severely aborted in both transgenic lines, with arrested pollen mitotic I and abnormal pollen starch metabolism. Through additional cross-pollination experiments, DUO1 was proven to be the key target gene for miR159a to regulate male sterility in citrus. Based on DNA affinity purification sequencing (DAP-seq), RNA-seq, and verified interaction assays, YUC2/YUC6, SS4 and STP8 were identified as downstream target genes of DUO1, those were all positively regulated by DUO1. In transgenic F. hindsii lines, the miR159a-DUO1 module down-regulated the expression of YUC2/YUC6, which decreased indoleacetic acid (IAA) levels and modulated auxin signaling to repress pollen mitotic I. The miR159a-DUO1 module reduced the expression of the starch synthesis gene SS4 and sugar transport gene STP8 to disrupt starch metabolism in pollen. Overall, this work reveals a new mechanism by which the miR159a-DUO1 module regulates pollen development and elucidates the molecular regulatory network underlying male sterility in citrus.
PMID: 38578168
J Exp Bot , IF:6.992 , 2024 Jul doi: 10.1093/jxb/erae315
Phenylboronic acid interacts with pectic rhamnogalacturonan-II and displays anti-auxinic effects during Arabidopsis thaliana root growth and development.
Universite de Rouen Normandie, GLYCOMEV UR 4358, SFR Normandie Vegetal FED 4277, Innovation Chimie Carnot, IRIB, F-76000 Rouen, France.; Universite Paris-Saclay, CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 91198, Gif-sur-Yvette, France.; Department of Biology, The Pennsylvania State University, University Park, PA, USA.
Boron dimerizes RG-II in the plant cell wall and is crucial for plant cell elongation. However, studying RG-II dimerization in plants is challenging because of the severe phenotypes or lethality of RG-II mutants. Boron deprivation abrogates both RG-II dimerization and plant growth, but whether or how these phenotypes are functionally linked has remained unclear. Boric acid analogues can serve as experimental tools to interfere with RG-II cross-linking. Here, we investigated RG-II dimerization and developmental phenotypes in Arabidopsis thaliana seedlings treated with a boric acid analogue, phenylboronic acid (PBA), to test whether the observed developmental phenotypes are attributable to alteration of RG-II dimerization or to other putative functions of boron in plants. We found that PBA treatment altered root development in seedlings while RG-II dimerization and distribution were not affected. Surprisingly, under low boron conditions, PBA treatment i) had no effect on root size but still prevented lateral root development and ii) restored RG-II dimerization. PBA treatment also disrupted auxin levels, potentially explaining the absence of lateral roots in seedlings treated with this analogue. We conclude that PBA interacts both with RG-II and other cellular targets such as auxin signaling components, and that the phenotypes caused by PBA arise from interference with multiple functions of boron.
PMID: 39058275
J Exp Bot , IF:6.992 , 2024 Jul doi: 10.1093/jxb/erae305
Alternate bearing in 'Hass' avocado - Fruit load-induced changes in bud auxin homeostasis are associated with flowering repression.
Institute of Plant Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion 7505101, Israel.; The Robert H. Smith Faculty of Agriculture, Food and Environment, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
In 'Hass' avocado (Persea americana), fruit presence reduces next season flowering. Recent fruit tree studies proposed that heavy fruit load (HFL) generates an auxin (IAA) signal in the buds, which represses flowering. However, the nature of this signal remains unknown. Here, we investigated the effect of avocado HFL on bud IAA accumulation and flowering transition. We found that IAA-aspartate and IAA-glutamate conjugate levels were significantly higher in buds from 'on' (fully loaded) than 'off' (low-loaded) trees, hinting that free IAA levels were higher in the former. Expression analysis showed that coinciding with flowering reduction, HFL induced the floral repressor PaTFL1, and suggested that accumulation of IAA in buds as imposed by HFL was associated with its conjugation to aspartate and glutamate and resulted both from de novo IAA synthesis, as well as from reduced IAA export. Accordingly, experiments involving radiolabelled 14C-IAA demonstrated that HFL reduced shoot basipetal IAA transport. Lastly, we confirmed the negative effects of IAA on flowering, showing that IAA and PAT blocker (TIBA) treatments delayed 'off' trees inflorescence development, reducing their inflorescence axis and inducing PaTFL1 transcript. Together, our data suggest that avocado HFL generates IAA signalling in buds that induces PaTFL1, which represses inflorescence development.
PMID: 39011888
J Exp Bot , IF:6.992 , 2024 Jul doi: 10.1093/jxb/erae307
New insights into plasmodesmata: complex 'protoplasmic connecting threads'.
Donald Danforth Plant Science Center, Saint Louis, Missouri, 63132, USA.
Intercellular communication in plants, as in other multicellular organisms, allows cells in tissues to coordinate their responses for development and in response to environmental stimuli. Much of this communication is facilitated by plasmodesmata (PD), consisting of membranes and cytoplasm, that connect adjacent cells to each other. PD have long been viewed as passive conduits for the movement of a variety of metabolites and molecular cargoes, but this perception has been changing over the last two decades or so. Research from the last few years has revealed the importance of PD as signaling hubs and as crucial players in hormone signaling. The adoption of advanced biochemical approaches, molecular tools and high-resolution imaging modalities have led to several recent breakthroughs in our understanding of the roles of PD, revealing the structural and regulatory complexity of these 'protoplasmic connecting threads'. We highlight several of these findings that we think well illustrate the current understanding of PD as functioning at the nexus of plant physiology, development, and acclimation to the environment.
PMID: 39001658
J Exp Bot , IF:6.992 , 2024 Jul , V75 (13) : P3778-3796 doi: 10.1093/jxb/erae162
Crosstalk between Rho of Plants GTPase signalling and plant hormones.
Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610064, P. R. China.
Rho of Plants (ROPs) constitute a plant-specific subset of small guanine nucleotide-binding proteins within the Cdc42/Rho/Rac family. These versatile proteins regulate diverse cellular processes, including cell growth, cell division, cell morphogenesis, organ development, and stress responses. In recent years, the dynamic cellular and subcellular behaviours orchestrated by ROPs have unveiled a notable connection to hormone-mediated organ development and physiological responses, thereby expanding our knowledge of the functions and regulatory mechanisms of this signalling pathway. This review delineates advancements in understanding the interplay between plant hormones and the ROP signalling cascade, focusing primarily on the connections with auxin and abscisic acid pathways, alongside preliminary discoveries in cytokinin, brassinosteroid, and salicylic acid responses. It endeavours to shed light on the intricate, coordinated mechanisms bridging cell- and tissue-level signals that underlie plant cell behaviour, organ development, and physiological processes, and highlights future research prospects and challenges in this rapidly developing field.
PMID: 38616410
J Exp Bot , IF:6.992 , 2024 Jul , V75 (14) : P4180-4194 doi: 10.1093/jxb/erae105
Genetic and epigenetic basis of phytohormonal control of floral transition in plants.
Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
The timing of the developmental transition from the vegetative to the reproductive stage is critical for angiosperms, and is fine-tuned by the integration of endogenous factors and external environmental cues to ensure successful reproduction. Plants have evolved sophisticated mechanisms to response to diverse environmental or stress signals, and these can be mediated by hormones to coordinate flowering time. Phytohormones such as gibberellin, auxin, cytokinin, jasmonate, abscisic acid, ethylene, and brassinosteroids and the cross-talk among them are critical for the precise regulation of flowering time. Recent studies of the model flowering plant Arabidopsis have revealed that diverse transcription factors and epigenetic regulators play key roles in relation to the phytohormones that regulate floral transition. This review aims to summarize our current knowledge of the genetic and epigenetic mechanisms that underlie the phytohormonal control of floral transition in Arabidopsis, offering insights into how these processes are regulated and their implications for plant biology.
PMID: 38457356
J Exp Bot , IF:6.992 , 2024 Jul , V75 (14) : P4171-4179 doi: 10.1093/jxb/erad419
New molecular components that regulate the transcriptional hub in root hairs: coupling environmental signals with endogenous hormones to coordinate growth.
Fundacion Instituto Leloir and IIBBA-CONICET. Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina.; ANID-Millennium Science Initiative Program-Millennium Nucleus for the Development of Super Adaptable Plants (MN-SAP), Santiago 8370146, Chile.; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.; 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.
Root hairs have become an important model system for studying plant growth, and in particular how plants modulate their growth in response to cell-intrinsic and environmental stimuli. In this review, we discuss recent advances in our understanding of the molecular mechanisms underlying the growth of Arabidopsis root hairs in the interface between responses to environmental cues (e.g. nutrients such as nitrates and phosphate, and microorganisms) and hormonal stimuli (e.g. auxin). Growth of root hairs is under the control of several transcription factors that are also under strong regulation at different levels. We highlight recent new discoveries along these transcriptional pathways that might have the potential to increase our capacity to enhance nutrient uptake by the roots in the context of abiotic stresses. We use the text-mining capacities of the PlantConnectome database to generate an up-to-date view of root hairs growth within these complex biological contexts.
PMID: 37875460
Int J Biol Macromol , IF:6.953 , 2024 Aug , V274 (Pt 2) : P133446 doi: 10.1016/j.ijbiomac.2024.133446
Systematic identification and functional analysis of root meristem growth factors (RGFs) reveals role of PgRGF1 in modulation of root development and ginsenoside production in Panax ginseng.
School of Pharmacy, Shihezi University, Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, Xinjiang, Shihezi 832000, China.; State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.; Laboratory of Medicinal Plant, Hubei Key Laboratory of Embryonic Stem Cell Research, School of Basic Medicine, Hubei University of Medicine, Shiyan 442000, PR China.; College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China.; School of Pharmacy, Shihezi University, Key Laboratory of Xinjiang Phytomedicine Resource and Utilization, Ministry of Education, Xinjiang, Shihezi 832000, China. Electronic address: 20945549@qq.com.; Laboratory of Medicinal Plant, Hubei Key Laboratory of Embryonic Stem Cell Research, School of Basic Medicine, Hubei University of Medicine, Shiyan 442000, PR China. Electronic address: lee.childe@qq.com.; State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: juanliu126@126.com.
Panax ginseng C.A. Mey., known for its medicinal and dietary supplement properties, primarily contains pharmacologically active ginsenosides. However, the regulatory mechanisms linking ginseng root development with ginsenoside biosynthesis are still unclear. Root meristem growth factors (RGFs) are crucial for regulating plant root growth. In our study, we identified five ginseng RGF peptide sequences from the ginseng genome and transcriptome libraries. We treated Arabidopsis and ginseng adventitious roots with exogenous Panax ginseng RGFs (PgRGFs) to assess their activities. Our results demonstrate that PgRGF1 influences gravitropic responses and reduces lateral root formation in Arabidopsis. PgRGF1 has been found to restrict the number and length of ginseng adventitious root branches in ginseng. Given the medicinal properties of ginseng, We determined the ginsenoside content and performed transcriptomic analysis of PgRGF1-treated ginseng adventitious roots. Specifically, the total ginsenoside content in ginseng adventitious roots decreased by 19.98 % and 63.71 % following treatments with 1 muM and 10 muM PgRGF1, respectively, compared to the control. The results revealed that PgRGF1 affects the accumulation of ginsenosides by regulating the expression of genes associated with auxin transportation and ginsenoside biosynthesis. These findings suggest that PgRGF1, as a peptide hormone regulator in ginseng, can modulate adventitious root growth and ginsenoside accumulation.
PMID: 38945337
J Environ Manage , IF:6.789 , 2024 Jul , V367 : P121950 doi: 10.1016/j.jenvman.2024.121950
Resource recovery and contaminants of emerging concern mitigation by microalgae treating wastewater.
GEMMA - Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politecnica de Catalunya - BarcelonaTech, c/ Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain.; UAL - Chemical Engineering Department, Universidad de Almeria, Carretera Sacramento s/n, E-04120, Almeria, Spain.; Department of Environmental Chemistry, IDAEA-CSIC, c/Jordi Girona, 18-26, E-08034 Barcelona, Spain.; GEMMA - Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politecnica de Catalunya - BarcelonaTech, c/ Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain. Electronic address: ivet.ferrer@upc.edu.
This study aimed to investigate the recovery of agricultural biostimulants and biogas from microalgae treating wastewater, in the framework of a circular bioeconomy. To this end, municipal wastewater was treated in demonstrative raceway ponds, and microalgal biomass (Scenedesmus sp.) was then harvested and downstream processed to recover biostimulants and biogas in a biorefinery approach. The effect of microalgal biostimulants on plants was evaluated by means of bioassays, while the biogas produced was quantified in biochemical methane potential (BMP) tests. Furthermore, the fate of contaminants of emerging concern (CECs) over the process was also assessed. Bioassays confirmed the biostimulant effect of microalgae, which showed gibberellin-, auxin- and cytokinin-like activity in watercress seed germination, mung bean rooting, and wheat leaf chlorophyll retention. In addition, the downstream process applied to raw biomass acted as a pre-treatment to enhance anaerobic digestion performance. After biostimulant extraction, the residual biomass represented 91% of the methane yield from the raw biomass (276 mLCH(4).g(-1)VS). The kinetic profile of the residual biomass was 43% higher than that of the unprocessed biomass. Co-digestion with primary sludge further increased biogas production by 24%. Finally, the concentration of CECs in wastewater was reduced by more than 80%, and only 6 out of 22 CECs analyzed were present in the biostimulant obtained. Most importantly, the concentration of those contaminants was lower than in biosolids that are commonly used in agriculture, ensuring environmental safety.
PMID: 39068780
mSystems , IF:6.496 , 2024 Jul , V9 (7) : Pe0016524 doi: 10.1128/msystems.00165-24
Auxin-mediated regulation of susceptibility to toxic metabolites, c-di-GMP levels, and phage infection in the rhizobacterium Serratia plymuthica.
Department of Biotechnology and Environmental Protection, Estacion Experimental del Zaidin, Consejo Superior de Investigaciones Cientificas, Granada, Spain.; Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, Spain.
The communication between plants and their microbiota is highly dynamic and involves a complex network of signal molecules. Among them, the auxin indole-3-acetic acid (IAA) is a critical phytohormone that not only regulates plant growth and development, but is emerging as an important inter- and intra-kingdom signal that modulates many bacterial processes that are important during interaction with their plant hosts. However, the corresponding signaling cascades remain largely unknown. Here, we advance our understanding of the largely unknown mechanisms by which IAA carries out its regulatory functions in plant-associated bacteria. We showed that IAA caused important changes in the global transcriptome of the rhizobacterium Serratia plymuthica and multidisciplinary approaches revealed that IAA sensing interferes with the signaling mediated by other pivotal plant-derived signals such as amino acids and 4-hydroxybenzoic acid. Exposure to IAA caused large alterations in the transcript levels of genes involved in amino acid metabolism, resulting in significant metabolic alterations. IAA treatment also increased resistance to toxic aromatic compounds through the induction of the AaeXAB pump, which also confers resistance to IAA. Furthermore, IAA promoted motility and severely inhibited biofilm formation; phenotypes that were associated with decreased c-di-GMP levels and capsule production. IAA increased capsule gene expression and enhanced bacterial sensitivity to a capsule-dependent phage. Additionally, IAA induced the expression of several genes involved in antibiotic resistance and led to changes in the susceptibility and responses to antibiotics with different mechanisms of action. Collectively, our study illustrates the complexity of IAA-mediated signaling in plant-associated bacteria. IMPORTANCE: Signal sensing plays an important role in bacterial adaptation to ecological niches and hosts. This communication appears to be particularly important in plant-associated bacteria since they possess a large number of signal transduction systems that respond to a wide diversity of chemical, physical, and biological stimuli. IAA is emerging as a key inter- and intra-kingdom signal molecule that regulates a variety of bacterial processes. However, despite the extensive knowledge of the IAA-mediated regulatory mechanisms in plants, IAA signaling in bacteria remains largely unknown. Here, we provide insight into the diversity of mechanisms by which IAA regulates primary and secondary metabolism, biofilm formation, motility, antibiotic susceptibility, and phage sensitivity in a biocontrol rhizobacterium. This work has important implications for our understanding of bacterial ecology in plant environments and for the biotechnological and clinical applications of IAA, as well as related molecules.
PMID: 38837409
Plant J , IF:6.417 , 2024 Jul doi: 10.1111/tpj.16948
LATA1, a RING E3 ligase, modulates the tiller angle by affecting auxin asymmetric distribution and content in rice.
Frontiers Science Center for Molecular Design Breeding (MOE), Department of Plant Genetics and Breeding, China Agricultural University, Beijing, 100193, China.
The tiller angle is an important agronomic trait that determines plant architecture and grain yield in rice (Oryza sativa L.). However, the molecular regulation mechanism of the rice tiller angle remains unclear. Here, we identified a rice tiller angle gene, LARGE TILLER ANGLE 1 (LATA1), using the MutMap approach. LATA1 encodes a C3H2C3-type RING zinc finger E3 ligase and the conserved region of the RING zinc finger is essential for its E3 activity. LATA1 was highly expressed in the root and tiller base and LATA1-GFP fusion protein was specifically localized to the nucleus. The mutation of LATA1 significantly reduced indole-3-acetic acid content and attenuated lateral auxin transport, thereby resulting in defective shoot gravitropism and spreading plant architecture in rice. Further investigations found that LATA1 may indirectly affect gravity perception by modulating the sedimentation rate of gravity-sensing amyloplasts upon gravistimulation. Our findings provide new insights into the molecular mechanism underlying the rice tiller angle and new genetic resource for the improvement of plant architecture in rice.
PMID: 39052425
Plant J , IF:6.417 , 2024 Jul doi: 10.1111/tpj.16916
The auxin-responsive CsSPL9-CsGH3.4 module finely regulates auxin levels to suppress the development of adventitious roots in tea (Camellia sinensis).
College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China.
The cutting technique is extensively used in tea breeding, with key emphasis on promoting the growth of adventitious roots (ARs). Despite its importance in tea cultivation, the mechanisms underlying AR development in tea remain unclear. In this study, we demonstrated the essential role of auxins in the initiation and progression of AR and established that the application of exogenous 1-naphthaleneacetic acid-enhanced AR formation in tissue-cultured seedlings and cuttings. Then, we found that the auxin-responsive transcription factor CsSPL9 acted as a negative regulator of AR development by reducing the levels of free indole-3-acetic acid (IAA) in tea plants. Furthermore, we identified CsGH3.4 as a downstream target of CsSPL9, which was activated by direct binding to its promoter. CsGH3.4 also inhibited AR development and maintained low levels of free IAA. Thus, these results revealed the inhibitory effect of the auxin-responsive CsSPL9-CsGH3.4 module on AR development by reducing free IAA levels in tea. These findings have significant theoretical and practical value for enhancing tea breeding practices.
PMID: 39012276
Plant J , IF:6.417 , 2024 Aug , V119 (3) : P1327-1335 doi: 10.1111/tpj.16851
The additive function of YIGE2 and YIGE1 in regulating maize ear length.
National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China.; Hubei Hongshan Laboratory, Wuhan, 430070, China.; Yazhouwan National Laboratory, Sanya, 572024, China.; Department of Molecular Physiology, Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, 14476, Germany.; Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, 11724, USA.
Ear length (EL) is a key trait that greatly contributes to yield in maize. Although dozens of EL quantitative trait loci have been mapped, very few causal genes have been cloned, and the molecular mechanisms remain largely unknown. Our previous study showed that YIGE1 is involved in sugar and auxin pathways to regulate ear inflorescence meristem (IM) development and thus affects EL in maize. Here, we reveal that YIGE2, the paralog of YIGE1, regulates maize ear development and EL through auxin pathway. Knockout of YIGE2 causes a significant decrease of auxin level, IM length, floret number, EL, and grain yield. yige1 yige2 double mutants had even shorter IM and ears implying that these two genes redundantly regulate IM development and EL. The genes controlling auxin levels are differential expressed in yige1 yige2 double mutants, leading to lower auxin level. These results elucidated the critical role of YIGE2 and the redundancy between YIGE2 and YIGE1 in maize ear development, providing a new genetic resource for maize yield improvement.
PMID: 38804053
Plant J , IF:6.417 , 2024 Jul , V119 (2) : P1073-1090 doi: 10.1111/tpj.16818
SlPP2C2 interacts with FZY/SAUR and regulates tomato development via signaling crosstalk of ABA and auxin.
College of Horticulture, China Agricultural University, Beijing, 100193, P. R. China.; Yunnan Key Laboratory of Potato Biology, The AGISCAAS-YNNU Joint Academy of Potato Sciences, Yunnan Normal University, Kunming, 650000, P. R. China.
Abscisic acid (ABA) signaling interacts frequently with auxin signaling when it regulates plant development, affecting multiple physiological processes; however, to the best of our knowledge, their interaction during tomato development has not yet been reported. Here, we found that type 2C protein phosphatase (SlPP2C2) interacts with both flavin monooxygenase FZY, an indole-3-acetic acid (IAA) biosynthetic enzyme, and small auxin upregulated RNA (SAUR) of an IAA signaling protein and regulates their activity, thereby affecting the expression of IAA-responsive genes. The expression level of SlPP2C2 was increased by exogenous ABA, IAA, NaCl, or dehydration treatment of fruits, leaves, and seeds, and it decreased in imbibed seeds. Manipulating SlPP2C2 with overexpression, RNA interference, and CRISPR/Cas9-mediated genome editing resulted in pleiotropic changes, such as morphological changes in leaves, stem trichomes, floral organs and fruits, accompanied by alterations in IAA and ABA levels. Furthermore, the RNA-seq analysis indicated that SlPP2C2 regulates the expression of auxin-/IAA-responsive genes in different tissues of tomato. The results demonstrate that SlPP2C2-mediated ABA signaling regulates the development of both vegetative and reproductive organs via interaction with FZY/SAUR, which integrates the cross-talk of ABA and auxin signals during development and affects the expressions of development-related genes in tomato.
PMID: 38795008
Plant J , IF:6.417 , 2024 Jul , V119 (2) : P960-981 doi: 10.1111/tpj.16809
A Solanum lycopersicum polyamine oxidase contributes to the control of plant growth, xylem differentiation, and drought stress tolerance.
Department of Science, University Roma Tre, 00146, Rome, Italy.; Dipartimento di Scienze della Vita, Universita di Trieste, Trieste, Italy.; Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), BIOAG-BIOTEC C.R. Casaccia, Rome, Italy.; Department of Biochemical Sciences 'A. Rossi Fanelli', Sapienza University of Rome, Rome, Italy.; Department of Biosciences, University of Milano, Milan, Italy.; National Institute of Nuclear Physics, Roma Tre Section, 00146, Rome, Italy.; Istituto Nazionale Biostrutture e Biosistemi (INBB), Rome, Italy.; NBFC, National Biodiversity Future Center, Palermo, Italy.
Polyamines are involved in several plant physiological processes. In Arabidopsis thaliana, five FAD-dependent polyamine oxidases (AtPAO1 to AtPAO5) contribute to polyamine homeostasis. AtPAO5 catalyzes the back-conversion of thermospermine (T-Spm) to spermidine and plays a role in plant development, xylem differentiation, and abiotic stress tolerance. In the present study, to verify whether T-Spm metabolism can be exploited as a new route to improve stress tolerance in crops and to investigate the underlying mechanisms, tomato (Solanum lycopersicum) AtPAO5 homologs were identified (SlPAO2, SlPAO3, and SlPAO4) and CRISPR/Cas9-mediated loss-of-function slpao3 mutants were obtained. Morphological, molecular, and physiological analyses showed that slpao3 mutants display increased T-Spm levels and exhibit changes in growth parameters, number and size of xylem elements, and expression levels of auxin- and gibberellin-related genes compared to wild-type plants. The slpao3 mutants are also characterized by improved tolerance to drought stress, which can be attributed to a diminished xylem hydraulic conductivity that limits water loss, as well as to a reduced vulnerability to embolism. Altogether, this study evidences conservation, though with some significant variations, of the T-Spm-mediated regulatory mechanisms controlling plant growth and differentiation across different plant species and highlights the T-Spm role in improving stress tolerance while not constraining growth.
PMID: 38761363
Plant J , IF:6.417 , 2024 Jul , V119 (2) : P689-704 doi: 10.1111/tpj.16787
MtPIN4 plays critical roles in amino acid biosynthesis and metabolism of seed in Medicago truncatula.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, P.R. China.
The regulation of seed development is critical for determining crop yield. Auxins are vital phytohormones that play roles in various aspects of plant growth and development. However, its role in amino acid biosynthesis and metabolism in seeds is not fully understood. In this study, we identified a mutant with small seeds through forward genetic screening in Medicago truncatula. The mutated gene encodes MtPIN4, an ortholog of PIN1. Using molecular approaches and integrative omics analyses, we discovered that auxin and amino acid content significantly decreased in mtpin4 seeds, highlighting the role of MtPIN4-mediated auxin distribution in amino acid biosynthesis and metabolism. Furthermore, genetic analysis revealed that the three orthologs of PIN1 have specific and overlapping functions in various developmental processes in M. truncatula. Our findings emphasize the significance of MtPIN4 in seed development and offer insights into the molecular mechanisms governing the regulation of seed size in crops. This knowledge could be applied to enhance crop quality by targeted manipulation of seed protein regulatory pathways.
PMID: 38701004
Plant J , IF:6.417 , 2024 Jul , V119 (1) : P176-196 doi: 10.1111/tpj.16752
Ocimum kilimandscharicum 4CL11 negatively regulates adventitious root development via accumulation of flavonoid glycosides.
Plant Molecular Biology Unit, Biochemical Sciences Division, CSIR-National Chemical Laboratory, Pune, Maharashtra, 411008, India.; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, 201002, India.; Department of Botany, Savitribai Phule Pune University, Pune, Maharashtra, 411007, India.
4-Coumarate-CoA Ligase (4CL) is an important enzyme in the phenylpropanoid biosynthesis pathway. Multiple 4CLs are identified in Ocimum species; however, their in planta functions remain enigmatic. In this study, we independently overexpressed three Ok4CL isoforms from Ocimum kilimandscharicum (Ok4CL7, -11, and -15) in Nicotiana benthamiana. Interestingly, Ok4CL11 overexpression (OE) caused a rootless or reduced root growth phenotype, whereas overexpression of Ok4CL15 produced normal adventitious root (AR) growth. Ok4CL11 overexpression in N. benthamiana resulted in upregulation of genes involved in flavonoid biosynthesis and associated glycosyltransferases accompanied by accumulation of specific flavonoid-glycosides (kaempferol-3-rhamnoside, kaempferol-3,7-O-bis-alpha-l-rhamnoside [K3,7R], and quercetin-3-O-rutinoside) that possibly reduced auxin levels in plants, and such effects were not seen for Ok4CL7 and -15. Docking analysis suggested that auxin transporters (PINs/LAXs) have higher binding affinity to these specific flavonoid-glycosides, and thus could disrupt auxin transport/signaling, which cumulatively resulted in a rootless phenotype. Reduced auxin levels, increased K3,7R in the middle and basal stem sections, and grafting experiments (intra and inter-species) indicated a disruption of auxin transport by K3,7R and its negative effect on AR development. Supplementation of flavonoids and the specific glycosides accumulated by Ok4CL11-OE to the wild-type N. benthamiana explants delayed the AR emergence and also inhibited AR growth. While overexpression of all three Ok4CLs increased lignin accumulation, flavonoids, and their specific glycosides were accumulated only in Ok4CL11-OE lines. In summary, our study reveals unique indirect function of Ok4CL11 to increase specific flavonoids and their glycosides, which are negative regulators of root growth, likely involved in inhibition of auxin transport and signaling.
PMID: 38575203
Plant J , IF:6.417 , 2024 Jul , V119 (1) : P218-236 doi: 10.1111/tpj.16754
Knockout of endoplasmic reticulum-localized molecular chaperone HSP90.7 impairs seedling development and cellular auxin homeostasis in Arabidopsis.
Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.; Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada.
The Arabidopsis endoplasmic reticulum-localized heat shock protein HSP90.7 modulates tissue differentiation and stress responses; however, complete knockout lines have not been previously reported. In this study, we identified and analyzed a mutant allele, hsp90.7-1, which was unable to accumulate the HSP90.7 full-length protein and showed seedling lethality. Microscopic analyses revealed its essential role in male and female fertility, trichomes and root hair development, proper chloroplast function, and apical meristem maintenance and differentiation. Comparative transcriptome and proteome analyses also revealed the role of the protein in a multitude of cellular processes. Particularly, the auxin-responsive pathway was specifically downregulated in the hsp90.7-1 mutant seedlings. We measured a much-reduced auxin content in both root and shoot tissues. Through comprehensive histological and molecular analyses, we confirmed PIN1 and PIN5 accumulations were dependent on the HSP90 function, and the TAA-YUCCA primary auxin biosynthesis pathway was also downregulated in the mutant seedlings. This study therefore not only fulfilled a gap in understanding the essential role of HSP90 paralogs in eukaryotes but also provided a mechanistic insight on the ER-localized chaperone in regulating plant growth and development via modulating cellular auxin homeostasis.
PMID: 38565312
Int J Mol Sci , IF:5.923 , 2024 Jul , V25 (14) doi: 10.3390/ijms25147812
Plant Hormone Pathway Is Involved in Regulating the Embryo Development Mechanism of the Hydrangea macrophylla Hybrid.
College of Horticulture, Hunan Agricultural University, Changsha 410128, China.
The research is aimed to elucidate the role of plant hormones in regulating the development of hybrid embryos in Hydrangea macrophylla. Fruits from the intraspecific cross of H. macrophylla 'Otaksa' x 'Coerulea' were selected at the globular, heart, and torpedo stages of embryo development. Transcriptome sequencing and differential gene expression analysis were conducted. The results showed that fruit growth followed a single "S-shaped growth curve, with globular, heart, and torpedo embryos appearing at 30, 40, and 50 d post-pollination, respectively, and the embryo maintaining the torpedo shape from 60 to 90 d. A total of 12,933 genes was quantified across the three developmental stages, with 3359, 3803, and 3106 DEGs in the S1_vs_S2, S1_vs_S3, and S2_vs_S3 comparisons, respectively. Among these, 133 genes related to plant hormone biosynthesis and metabolism were differentially expressed, regulating the synthesis and metabolism of eight types of plant hormones, including cytokinin, auxin, gibberellin, abscisic acid, and jasmonic acid. The pathways with the most differentially expressed genes were cytokinin, auxin, and gibberellin, suggesting these hormones may play crucial roles in embryo development. In the cytokinin pathway, CKX (Hma1.2p1_0579F.1_g182670.gene, Hma1.2p1_1194F.1_g265700.gene, and NewGene_12164) genes were highly expressed during the globular embryo stage, promoting rapid cell division in the embryo. In the auxin pathway, YUC (Hma1.2p1_0271F.1_g109005.gene and Hma1.2p1_0271F.1_g109020.gene) genes were progressively up-regulated during embryo growth; the early response factor AUX/IAA (Hma1.2p1_0760F.1_g214260.gene) was down-regulated, while the later transcriptional activator ARF (NewGene_21460, NewGene_21461, and Hma1.2p1_0209F.1_g089090.gene) was up-regulated, sustaining auxin synthesis and possibly preventing the embryo from transitioning to maturity. In the gibberellin pathway, GA3ox (Hma1.2p1_0129F.1_g060100.gene) expression peaked during the heart embryo stage and then declined, while the negative regulator GA2ox (Hma1.2p1_0020F.1_g013915.gene) showed the opposite trend; and the gibberellin signaling repressor DELLA (Hma1.2p1_1054F.1_g252590.gene) increased over time, potentially inhibiting embryo development and maintaining the torpedo shape until fruit maturity. These findings preliminarily uncover the factors affecting the development of hybrid H. macrophylla embryos, laying a foundation for further research into the regulatory mechanisms of H. macrophylla hybrid embryo development.
PMID: 39063054
Int J Mol Sci , IF:5.923 , 2024 Jul , V25 (14) doi: 10.3390/ijms25147692
Transcriptomics Provide Insights into Early Responses to Sucrose Signaling in Lupinus albus, a Model Plant for Adaptations to Phosphorus and Iron Deficiency.
Department of Biological Sciences, California State University, East Bay, Hayward, CA 94542, USA.
Phosphorus (P) and iron (Fe) deficiency are major limiting factors for plant productivity worldwide. White lupin (Lupinus albus L.) has become a model plant for understanding plant adaptations to P and Fe deficiency, because of its ability to form cluster roots, bottle-brush-like root structures play an important role in the uptake of P and Fe from soil. However, little is known about the signaling pathways involved in sensing and responding to P and Fe deficiency. Sucrose, sent in increased concentrations from the shoot to the root, has been identified as a long-distance signal of both P and Fe deficiency. To unravel the responses to sucrose as a signal, we performed Oxford Nanopore cDNA sequencing of white lupin roots treated with sucrose for 10, 15, or 20 min compared to untreated controls. We identified a set of 17 genes, including 2 bHLH transcription factors, that were up-regulated at all three time points of sucrose treatment. GO (gene ontology) analysis revealed enrichment of auxin and gibberellin responses as early as 10 min after sucrose addition, as well as the emerging of ethylene responses at 20 min of sucrose treatment, indicating a sequential involvement of these hormones in plant responses to sucrose.
PMID: 39062943
Int J Mol Sci , IF:5.923 , 2024 Jul , V25 (13) doi: 10.3390/ijms25137473
Genome-Wide Analysis of the Auxin/Indoleacetic Acid (Aux/IAA) Gene Family in Autopolyploid Sugarcane (Saccharum spontaneum).
State Key Laboratory of Conservation and Utilization of Subtropical Agricultural Biological Resources, Guangxi University, Nanning 530004, China.; Guangxi Key Laboratory of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning 530004, China.; National Experimental Plant Science Education Demonstration Center, College of Agriculture, Guangxi University, Nanning 530004, China.
The auxin/indoleacetic acid (Aux/IAA) family plays a central role in regulating gene expression during auxin signal transduction. Nonetheless, there is limited knowledge regarding this gene family in sugarcane. In this study, 92 members of the IAA family were identified in Saccharum spontaneum, distributed on 32 chromosomes, and classified into three clusters based on phylogeny and motif compositions. Segmental duplication and recombination events contributed largely to the expansion of this superfamily. Additionally, cis-acting elements in the promoters of SsIAAs involved in plant hormone regulation and stress responsiveness were predicted. Transcriptomics data revealed that most SsIAA expressions were significantly higher in stems and basal parts of leaves, and at nighttime, suggesting that these genes might be involved in sugar transport. QRT-PCR assays confirmed that cold and salt stress significantly induced four and five SsIAAs, respectively. GFP-subcellular localization showed that SsIAA23 and SsIAA12a were localized in the nucleus, consistent with the results of bioinformatics analysis. In conclusion, to a certain extent, the functional redundancy of family members caused by the expansion of the sugarcane IAA gene family is related to stress resistance and regeneration of sugarcane as a perennial crop. This study reveals the gene evolution and function of the SsIAA gene family in sugarcane, laying the foundation for further research on its mode of action.
PMID: 39000581
Int J Mol Sci , IF:5.923 , 2024 Jul , V25 (13) doi: 10.3390/ijms25137402
PpGATA21 Enhances the Expression of PpGA2ox7 to Regulate the Mechanism of Cerasus humilis Rootstock-Mediated Dwarf in Peach Trees.
College of Horticulture and Plant Protection, Henan University of Science and Technology, Luoyang 471023, China.; Henan Provincial Engineering Research Center on Characteristic Berry Germplasm Innovation & Utilization, Luoyang 471023, China.
Dwarfing rootstocks enhance planting density, lower tree height, and reduce both labor in peach production. Cerasus humilis is distinguished by its dwarf stature, rapid growth, and robust fruiting capabilities, presenting substantial potential for further development. In this study, Ruipan 4 was used as the scion and grafted onto Amygdalus persica and Cerasus humilis, respectively. The results indicate that compared to grafting combination R/M (Ruipan 4/Amygdalus persica), grafting combination R/O (Ruipan 4/Cerasus humilis) plants show a significant reduction in height and a significant increase in flower buds. RNA-seq indicates that genes related to gibberellin (GA) and auxin metabolism are involved in the dwarfing process of scions mediated by C. humilis. The expression levels of the GA metabolism-related gene PpGA2ox7 significantly increased in R/O and are strongly correlated with plant height, branch length, and internode length. Furthermore, GA levels were significantly reduced in R/O. The transcription factor PpGATA21 was identified through yeast one-hybrid screening of the PpGA2ox7 promoter. Yeast one-hybrid (Y1H) and dual-luciferase reporter (DLR) demonstrate that PpGATA21 can bind to the promoter of PpGA2ox7 and activate its expression. Overall, PpGATA21 activates the expression of the GA-related gene PpGA2ox7, resulting in reduced GA levels and consequent dwarfing of plants mediated by C. humilis. This study provides new insights into the mechanisms of C. humilis and offers a scientific foundation for the dwarfing and high-density cultivation of peach trees.
PMID: 39000509
Front Plant Sci , IF:5.753 , 2024 , V15 : P1418319 doi: 10.3389/fpls.2024.1418319
Transcriptome profiling reveals key regulatory factors and metabolic pathways associated with curd formation and development in broccoli.
College of Life Sciences, Nankai University, Tianjin, China.; Cucumber Research Institute, Tianjin Academy of Agricultural Sciences, Tianjin, China.; State Key Laboratory of Vegetable Biobreeding, Tianjin, China.
Broccoli, a cruciferous vegetable, has a unique indeterminate inflorescence structure known as curds. It is the main edible organ of broccoli and has a rich nutritional value and health benefits. However, the formation and development mechanism of the curd is still not well understood. In the present study, the shoot apical meristem (SAM) stage and three different development stages of curd (formation stage (FS), expansion stage (ES), and maturation stage (MS)) were identified and subjected to transcriptome sequencing to uncover the potential genes and regulatory networks involved in curd formation and development. The results indicated that the genes associated with the development of SAM such as BolAP1A, BolAP1C, BolCAL, and BolAGL6 play an important role in the abnormal differentiation of the curd apical buds. The genes, BolFRI, BolbHLH89, BolKAN4, BolAGL12, and BolAGL24, displayed significantly differential expression patterns in curd development may function in the regulation of the transition from inflorescence meristem (IM) to floral meristem (FM). Moreover, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the differentially expressed genes (DEGs) indicate that phytohormones, such as auxin (AUX), gibberellins (GA), and abscisic acid (ABA) also play an important role in SAM proliferation and the transition from SAM to IM. In addition, the genes regulating photosynthetic reaction (BolLHCA1, BolLHCB1, BolPsbO, etc.) have a key involvement in the differentiation of secondary IMs during curd expansion. The genes associated with the metabolism of starch and sucrose (e.g., BolSPS4, BolBAM4) were significantly upregulated at the MS should contribute to the maturation of the curd. These findings provide new insights into the potential key regulatory factors and metabolic pathways involved in the formation and development of broccoli curds.
PMID: 39070909
Front Plant Sci , IF:5.753 , 2024 , V15 : P1422504 doi: 10.3389/fpls.2024.1422504
Drought and salt stress mitigation in crop plants using stress-tolerant auxin-producing endophytic bacteria: a futuristic approach towards sustainable agriculture.
School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India.
Abiotic stresses, especially drought stress and salt stress in crop plants are accelerating due to climate change. The combined impact of drought and salt is anticipated to lead to the loss of up to 50% of arable land globally, resulting in diminished growth and substantial yield losses threatening food security. Addressing the challenges, agriculture through sustainable practices emerges as a potential solution to achieve Zero Hunger, one of the sustainable development goals set by the IUCN. Plants deploy a myriad of mechanisms to effectively address drought and salt stress with phytohormones playing pivotal roles as crucial signaling molecules for stress tolerance. The phytohormone auxin, particularly indole acetic acid (IAA) emerges as a paramount regulator integral to numerous aspects of plant growth and development. During both drought and salt stress conditions, auxin plays crucial roles for tolerance, but stress-induced processes lead to decreased levels of endogenous free auxin in the plant, leading to an urgent need for auxin production. With an aim to augment this auxin deficiency, several researchers have extensively investigated auxin production, particularly IAA by plant-associated microorganisms, including endophytic bacteria. These endophytic bacteria have been introduced into various crop plants subjected to drought or salt stress and potential isolates promoting plant growth have been identified. However, post-identification, essential studies on translational research to advance these potential isolates from the laboratory to the field are lacking. This review aims to offer an overview of stress tolerant auxin-producing endophytic bacterial isolates while identifying research gaps that need to be fulfilled to utilize this knowledge for the formulation of crop-specific and stress-specific endophyte bioinoculants for the plant to cope with auxin imbalance occurring during these stress conditions.
PMID: 39015292
Front Microbiol , IF:5.64 , 2024 , V15 : P1440341 doi: 10.3389/fmicb.2024.1440341
Expanding the Pseudomonas diversity of the wheat rhizosphere: four novel species antagonizing fungal phytopathogens and with plant-beneficial properties.
Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland.
Plant-beneficial Pseudomonas bacteria hold the potential to be used as inoculants in agriculture to promote plant growth and health through various mechanisms. The discovery of new strains tailored to specific agricultural needs remains an open area of research. In this study, we report the isolation and characterization of four novel Pseudomonas species associated with the wheat rhizosphere. Comparative genomic analysis with all available Pseudomonas type strains revealed species-level differences, substantiated by both digital DNA-DNA hybridization and average nucleotide identity, underscoring their status as novel species. This was further validated by the phenotypic differences observed when compared to their closest relatives. Three of the novel species belong to the P. fluorescens species complex, with two representing a novel lineage in the Pseudomonas phylogeny. Functional genome annotation revealed the presence of specific features contributing to rhizosphere colonization, including flagella and components for biofilm formation. The novel species have the genetic potential to solubilize nutrients by acidifying the environment, releasing alkaline phosphatases and their metabolism of nitrogen species, indicating potential as biofertilizers. Additionally, the novel species possess traits that may facilitate direct promotion of plant growth through the modulation of the plant hormone balance, including the ACC deaminase enzyme and auxin metabolism. The presence of biosynthetic clusters for toxins such as hydrogen cyanide and non-ribosomal peptides suggests their ability to compete with other microorganisms, including plant pathogens. Direct inoculation of wheat roots significantly enhanced plant growth, with two strains doubling shoot biomass. Three of the strains effectively antagonized fungal phytopathogens (Thielaviopsis basicola, Fusarium oxysporum, and Botrytis cinerea), demonstrating their potential as biocontrol agents. Based on the observed genetic and phenotypic differences from closely related species, we propose the following names for the four novel species: Pseudomonas grandcourensis sp. nov., type strain DGS24(T) ( = DSM 117501(T) = CECT 31011(T)), Pseudomonas purpurea sp. nov., type strain DGS26(T) ( = DSM 117502(T) = CECT 31012(T)), Pseudomonas helvetica sp. nov., type strain DGS28(T) ( = DSM 117503(T) = CECT 31013(T)) and Pseudomonas aestiva sp. nov., type strain DGS32(T) ( = DSM 117504(T) = CECT 31014(T)).
PMID: 39077740
iScience , IF:5.458 , 2024 Jul , V27 (7) : P110363 doi: 10.1016/j.isci.2024.110363
Indole-3-propionic acid regulates lateral root development by targeting auxin signaling in Arabidopsis.
MOE Key Laboratory for Cellular Dynamics, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Molecular & Cell Biophysics, Hefei National Science Center for Physical Sciences at the Microscale, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China.
Indole-3-propionic acid (IPA) is known to be a microbe-derived compound with a similar structure to the phytohormone auxin (indole-3-acetic acid, IAA). Previous studies reported that IPA exhibited auxin-like bioactivities in plants. However, the underlying molecular mechanism is not totally understood. Here, we revealed that IPA modulated lateral root (LR) development via auxin signaling in the model plant Arabidopsis thaliana. Genetic analysis indicated that deficiency of the TIR1/AFB-Aux/IAA-ARF auxin signaling pathway abolished the effects of IPA on regulating LR development. Further biochemical, transcriptomic profiling and cell biological analyses revealed that IPA directly bound to the TIR1/AFB-Aux/IAA coreceptor complex and thus activated downstream gene expression. Therefore, our work revealed that IPA is a potential signaling molecule that modulates plant growth and development by targeting the TIR1/AFB-Aux/IAA-mediated auxin signaling pathway, providing potential insights into root growth regulation in plants.
PMID: 39071891
Microbiol Res , IF:5.415 , 2024 Sep , V286 : P127823 doi: 10.1016/j.micres.2024.127823
Aerial signaling by plant-associated Streptomyces setonii WY228 regulates plant growth and enhances salt stress tolerance.
The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, PR China.; The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, PR China. Electronic address: shengqin@jsnu.edu.cn.
Plant-associated streptomycetes play important roles in plant growth and development. However, knowledge of volatile-mediated crosstalk between Streptomyces spp. and plants remains limited. In this study, we investigated the impact of volatiles from nine endophytic Streptomyces strains on the growth and development of plants. One versatile strain, Streptomyces setonii WY228, was found to significantly promote the growth of Arabidopsis thaliana and tomato seedlings, confer salt tolerance, and induce early flowering and increased fruit yield following volatile treatment. Analysis of plant growth-promoting traits revealed that S. setonii WY228 could produce indole-3-acetic acid, siderophores, ACC deaminase, fix nitrogen, and solubilize inorganic phosphate. These capabilities were further confirmed through genome sequencing and analysis. Volatilome analysis indicated that the volatile organic compounds emitted from ISP-2 medium predominantly comprised sesquiterpenes and 2-ethyl-5-methylpyrazine. Further investigations showed that 2-ethyl-5-methylpyrazine and sesquiterpenoid volatiles were the primary regulators promoting growth, as confirmed by experiments using the terpene synthesis inhibitor phosphomycin, pure compounds, and comparisons of volatile components. Transcriptome analysis, combined with mutant and inhibitor studies, demonstrated that WY228 volatiles promoted root growth by activating Arabidopsis auxin signaling and polar transport, and enhanced root hair development through ethylene signaling activation. Additionally, it was confirmed that volatiles can stimulate plant abscisic acid signaling and activate the MYB75 transcription factor, thereby promoting anthocyanin synthesis and enhancing plant salt stress tolerance. Our findings suggest that aerial signaling-mediated plant growth promotion and abiotic stress tolerance represent potentially overlooked mechanisms of Streptomyces-plant interactions. This study also provides an exciting strategy for the regulation of plant growth and the improvement of horticultural crop yields within sustainable agricultural practices.
PMID: 38959523
Microbiol Res , IF:5.415 , 2024 Jul , V284 : P127726 doi: 10.1016/j.micres.2024.127726
Plant communication with rhizosphere microbes can be revealed by understanding microbial functional gene composition.
CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan 666303, China. Electronic address: sandhya@xtbg.ac.cn.; CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan 666303, China; University of Chinese Academy of Sciences, Beijing 100049, China.; CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan 666303, China. Electronic address: yangxd@xtbg.ac.cn.
Understanding rhizosphere microbial ecology is necessary to reveal the interplay between plants and associated microbial communities. The significance of rhizosphere-microbial interactions in plant growth promotion, mediated by several key processes such as auxin synthesis, enhanced nutrient uptake, stress alleviation, disease resistance, etc., is unquestionable and well reported in numerous literature. Moreover, rhizosphere research has witnessed tremendous progress due to the integration of the metagenomics approach and further shift in our viewpoint from taxonomic to functional diversity over the past decades. The microbial functional genes corresponding to the beneficial functions provide a solid foundation for the successful establishment of positive plant-microbe interactions. The microbial functional gene composition in the rhizosphere can be regulated by several factors, e.g., the nutritional requirements of plants, soil chemistry, soil nutrient status, pathogen attack, abiotic stresses, etc. Knowing the pattern of functional gene composition in the rhizosphere can shed light on the dynamics of rhizosphere microbial ecology and the strength of cooperation between plants and associated microbes. This knowledge is crucial to realizing how microbial functions respond to unprecedented challenges which are obvious in the Anthropocene. Unraveling how microbes-mediated beneficial functions will change under the influence of several challenges, requires knowledge of the pattern and composition of functional genes corresponding to beneficial functions such as biogeochemical functions (nutrient cycle), plant growth promotion, stress mitigation, etc. Here, we focus on the molecular traits of plant growth-promoting functions delivered by a set of microbial functional genes that can be useful to the emerging field of rhizosphere functional ecology.
PMID: 38643524
Biochem Soc Trans , IF:5.407 , 2024 Jul doi: 10.1042/BST20231558
Amino acids biosynthesis in root hair development: a mini-review.
Departamento de Genomica Funcional de Eucariotas, Centro de Ciencias Genomicas, Universidad Nacional Autonoma de Mexico, Cuernavaca 62210, Mexico.; Departamento de Biologia Molecular de Plantas, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico, Cuernavaca 62210, Mexico.
Metabolic factors are essential for developmental biology of an organism. In plants, roots fulfill important functions, in part due to the development of specific epidermal cells, called hair cells that form root hairs (RHs) responsible for water and mineral uptake. RH development consists in (a) patterning processes involved in formation of hair and non-hair cells developed from trichoblasts and atrichoblasts; (b) RH initiation; and (c) apical (tip) growth of the RH. Here we review how these processes depend on pools of different amino acids and what is known about RH phenotypes of mutants disrupted in amino acid biosynthesis. This analysis shows that some amino acids, particularly aromatic ones, are required for RH apical (tip) growth, and that not much is known about the role of amino acids at earlier stages of RH formation. We also address the role of amino acids in rhizosphere, inhibitory and stimulating effects of amino acids on RH growth, amino acids as N source in plant nutrition, and amino acid transporters and their expression in the RHs. Amino acids form conjugates with auxin, a hormone essential for RH growth, and respective genes are overviewed. Finally, we outline missing links and envision some perspectives in the field.
PMID: 38984866
Biochem Soc Trans , IF:5.407 , 2024 Jul doi: 10.1042/BST20231537
AZGs: a new family of cytokinin transporters.
Centre for Organismal Studies (COS), University of Heidelberg, Heidelberg 69120, Germany.; Molecular Plant Physiology, Institute of Cellular Molecular Botany (IZMB), University of Bonn, Kirschallee 1, 53115 Bonn, Germany.
Cytokinins (CKs) are phytohormones structurally similar to purines that play important roles in various aspects of plant physiology and development. The local and long-distance distribution of CKs is very important to control their action throughout the plant body. Over the past decade, several novel CK transporters have been described, many of which have been linked to a physiological function rather than simply their ability to transport the hormone in vitro. Purine permeases, equilibrative nucleotide transporters and ATP-binding cassette transporters are involved in the local and long-range distribution of CK. In addition, members of the Arabidopsis AZA-GUANINE RESISTANT (AZG) protein family, AZG1 and AZG2, have recently been shown to mediate CK uptake at the plasma membrane and endoplasmic reticulum. Despite sharing approximately 50% homology, AZG1 and AZG2 have unique transport mechanisms, tissue-specific expression patterns, and subcellular localizations that underlie their distinct physiological functions. AZG2 is expressed in a small group of cells in the overlying tissue around the lateral root primordia, where its expression is induced by auxins and it is involved in the regulation of lateral root growth. AZG1 is ubiquitously expressed, with high levels in the division zone of the root apical meristem. Here, it binds and stabilises the auxin efflux carrier PIN1, thereby shaping root architecture, particularly under salt stress. This review highlights the latest findings on the protein properties, transport mechanisms and cellular functions of this new family of CK transporters and discusses perspectives for future research in this field.
PMID: 38979638
Food Chem X , IF:5.182 , 2024 Jun , V22 : P101306 doi: 10.1016/j.fochx.2024.101306
Exogenous silicon applied at appropriate concentrations is effective at improving tomato nutritional and flavor qualities.
College of Horticulture, Gansu Agricultural University, Lanzhou 730070, China.; State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou 730070, China.
Silicon can mitigate biotic and abiotic stresses in various plants; however, its effects on tomato quality under normal growth conditions are remain unclear. We used a randomized design with four Si treatments, CON (0 mmol/L), T1 (0.6 mmol/L), T2 (1.2 mmol/L), and T3 (1.8 mmol/L) on tomato fruit components Chlorogenic acid and rutin, among polyphenolic components, were increased by 56.99% and 20.31%, respectively, with T2 treatment compared to CON concentrations. T2 increased the sugar-acid ratio by 19.21%, compared to that with the CON treatment, and increased fruit Ca and Mg contents, compared to those with other treatments, improving the characteristic aroma. Furthermore, silicon application reduced the abscisic acid content by 112%, promoting ripening. Endogenous gibberellin, auxin, and salicylic acid, which retard fruit ripening and softening, were increased by 34.96%, 14.56%, and 35.21%, respectively. These findings have far-reaching implications for exogenous Si applications to enrich tomato nutritional and flavor qualities.
PMID: 38550882
J Biol Chem , IF:5.157 , 2024 Jul , V300 (7) : P107421 doi: 10.1016/j.jbc.2024.107421
Fidelity in plant hormone modifications catalyzed by Arabidopsis GH3 acyl acid amido synthetases.
Department of Biology, Williams College, Williamstown, Massachusetts; Department of Biology, Washington University in St Louis, St Louis, Missouri.; Department of Biology, Washington University in St Louis, St Louis, Missouri. Electronic address: jjez@wustl.edu.
GRETCHEN HAGEN 3 (GH3) acyl acid amido synthetases conjugate amino acids to acyl acid hormones to either activate or inactivate the hormone molecule. The largest subgroup of GH3 proteins modify the growth-promoting hormone auxin (indole-3-acetic acid; IAA) with the second largest class activating the defense hormone jasmonic acid (JA). The two-step reaction mechanism of GH3 proteins provides a potential proofreading mechanism to ensure fidelity of hormone modification. Examining pyrophosphate release in the first-half reaction of Arabidopsis GH3 proteins that modify IAA (AtGH3.2/YDK2, AtGH3.5/WES1, AtGH3.17/VAS2), JA (AtGH3.11/JAR1), and other acyl acids (AtGH3.7, AtGH3.12/PBS3) indicates that acyl acid-AMP intermediates are hydrolyzed into acyl acid and AMP in the absence of the amino acid, a typical feature of pre-transfer editing mechanisms. Single-turnover kinetic analysis of AtGH3.2/YDK2 and AtGH3.5/WES1 shows that non-cognate acyl acid-adenylate intermediates are more rapidly hydrolyzed than the cognate IAA-adenylate. In contrast, AtGH3.11/JAR1 only adenylates JA, not IAA. While some of the auxin-conjugating GH3 proteins in Arabidopsis (i.e., AtGH3.5/WES1) accept multiple acyl acid substrates, others, like AtGH3.2/YDK2, are specific for IAA; however, both these proteins share similar active site residues. Biochemical analysis of chimeric variants of AtGH3.2/YDK2 and AtGH3.5/WES1 indicates that the C-terminal domain contributes to selection of cognate acyl acid substrates. These findings suggest that the hydrolysis of non-cognate acyl acid-adenylate intermediates, or proofreading, proceeds via a slowed structural switch that provides a checkpoint for fidelity before the full reaction proceeds.
PMID: 38815865
Mol Cells , IF:5.034 , 2024 Jul : P100093 doi: 10.1016/j.mocell.2024.100093
OsMYB14, an R2R3-MYB Transcription Factor, Regulates Plant Height through the Control of Hormone Metabolism in Rice.
Department of Biosciences and Bioinformatics, Myongji University, Yongin, Gyeonggi-do 17058, Republic of Korea.; Genomics Genetics Institute, GreenGene Biotech Inc., Yongin, Gyeonggi-do 17058, Republic of Korea.; Graduate School of Green-Bio Science and Crop Biotech Institute, Kyung Hee University, Yongin, Gyeonggi-do 17104, Republic of Korea.; Department of Agricultural Biotechnology, National Institute of Agricultural Sciences, Jeonju, Jeollabuk-do, 54875, Republic of Korea.; Department of Biosciences and Bioinformatics, Myongji University, Yongin, Gyeonggi-do 17058, Republic of Korea. Electronic address: kim750a11@gmail.com.
Plant growth must be regulated throughout the plant life cycle. The MYB TF family is one of the largest TF families and is involved in metabolism, lignin biosynthesis and developmental processes. Here, we showed that OsMYB14, a rice R2R3-MYB TF, was expressed in leaves and roots, especially in rice culm and panicles, and that it localized to the nucleus. Overexpression of OsMYB14 (OsMYB14-ox) in rice resulted in a 30% reduction in plant height compared to that of the wild type (WT), while the height of the osmyb14-ko mutant generated using the CRISPR/Cas9 system was not significantly different. Microscopic observations of the first internode revealed that the cell size did not differ significantly among the lines. RNA-seq analysis revealed that genes associated with plant development, regulation, lipid metabolism, carbohydrate metabolism, and gibberellin and auxin metabolic processes were downregulated in the OsMYB14-ox line. Hormone quantitation revealed that inactive GA19 accumulated in OsMYB14-ox but not in the WT or knockout plants, suggesting that GA20 generation was repressed. IAA and IAA-Asp accumulated in OsMYB14-ox and osmyb14-ko, respectively. Indeed, real-time PCR analysis revealed that the expression of OsGA20ox1, encoding Gibberellin20 oxidase 1, and OsGH3-2, encoding IAA-amido synthetase, was downregulated in OsMYB14-ox and upregulated in osmyb14-ko. A protein binding microarray (PBM) revealed the presence of a consensus DNA-binding sequence, the ACCTACC-like motif, in the promoters of the OsGA20ox1 and GA20ox2 genes. These results suggest that OsMYB14 may act as a negative regulator of biological processes affecting plant height in rice by regulating GA biosynthesis and auxin metabolism.
PMID: 39004308
Plant Cell Physiol , IF:4.927 , 2024 Jul , V65 (7) : P1115-1134 doi: 10.1093/pcp/pcae029
Dual Regulation of Cytochrome P450 Gene Expression by Two Distinct Small RNAs, a Novel tasiRNA and miRNA, in Marchantia polymorpha.
Institute of Biotechnology, National Taiwan University, No.1, Sec. 4, Roosevelt Rd., Taipei 106319, Taiwan, R.O.C.; Institute of Plant Biology, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106319, Taiwan, R.O.C.; Graduate School of Biostudies, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto 606-8502, Japan.; Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.; School of Biological Sciences, Monash University, Clayton Campus, Melbourne, VIC 3800, Australia.; Department of Biochemical Science and Technology, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106319, Taiwan, R.O.C.; Seed Improvement and Propagation Station, Council of Agriculture, No.46, Xingzhong St., Xinshe Dist., Taichung City 426015, Taiwan, R.O.C.; Biodiversity Research Center, Academia Sinica, 128 Academia Road, Sec. 2, Nankang, Taipei 11529, Taiwan, R.O.C.; Institute of Ecology and Evolutionary Biology, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106319, Taiwan, R.O.C.; Department of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei, 106319, Taiwan, R.O.C.; Agricultural Biotechnology Research Center, Academia Sinica, 128 Academia Road, Sec. 2, Nankang, Taipei 11529, Taiwan.; Center of Biotechnology, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106319, Taiwan, R.O.C.
The miR390-derived TAS3 trans-acting short-interfering RNAs (tasiRNAs) module represents a conserved RNA silencing pathway in the plant kingdom; however, its characterization in the bryophyte Marchantia polymorpha is limited. This study elucidated that MpDCL4 processes MpTAS3 double-stranded RNA (dsRNA) to generate tasiRNAs, primarily from the 5'- and 3'-ends of dsRNA. Notably, we discovered a novel tasiRNA, tasi78A, which can negatively regulate a cytochrome P450 gene, MpCYP78A101. Additionally, tasi78A was abundant in MpAGO1, and transient expression assays underscored the role of tasi78A in repressing MpCYP78A101. A microRNA, miR11700, also regulates MpCYP78A101 expression. This coordinate regulation suggests a role in modulating auxin signaling at apical notches of gemma, influencing the growth and sexual organ development of M. polymorpha and emphasizing the significance of RNA silencing in MpCYP78A101 regulation. However, phylogenetic analysis identified another paralog of the CYP78 family, Mp1g14150, which may have a redundant role with MpCYP78A101, explaining the absence of noticeable morphological changes in loss-of-function plants. Taken together, our findings provide new insights into the combined regulatory roles of miR390/MpTAS3/miR11700 in controlling MpCYP78A101 and expand our knowledge about the biogenesis and regulation of tasiRNAs in M. polymorpha.
PMID: 38545690
Biomolecules , IF:4.879 , 2024 Jul , V14 (7) doi: 10.3390/biom14070859
Comprehensive Review on Bimolecular Fluorescence Complementation and Its Application in Deciphering Protein-Protein Interactions in Cell Signaling Pathways.
State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China.
Signaling pathways are responsible for transmitting information between cells and regulating cell growth, differentiation, and death. Proteins in cells form complexes by interacting with each other through specific structural domains, playing a crucial role in various biological functions and cell signaling pathways. Protein-protein interactions (PPIs) within cell signaling pathways are essential for signal transmission and regulation. The spatiotemporal features of PPIs in signaling pathways are crucial for comprehending the regulatory mechanisms of signal transduction. Bimolecular fluorescence complementation (BiFC) is one kind of imaging tool for the direct visualization of PPIs in living cells and has been widely utilized to uncover novel PPIs in various organisms. BiFC demonstrates significant potential for application in various areas of biological research, drug development, disease diagnosis and treatment, and other related fields. This review systematically summarizes and analyzes the technical advancement of BiFC and its utilization in elucidating PPIs within established cell signaling pathways, including TOR, PI3K/Akt, Wnt/beta-catenin, NF-kappaB, and MAPK. Additionally, it explores the application of this technology in revealing PPIs within the plant hormone signaling pathways of ethylene, auxin, Gibberellin, and abscisic acid. Using BiFC in conjunction with CRISPR-Cas9, live-cell imaging, and ultra-high-resolution microscopy will enhance our comprehension of PPIs in cell signaling pathways.
PMID: 39062573
Pest Manag Sci , IF:4.845 , 2024 Jul doi: 10.1002/ps.8310
Cytochrome P450 CYP81A104 in Eleusine indica confers resistance to multiherbicide with different modes of action.
College of Plant Protection, Yangzhou University, Yangzhou, China.; Jiangsu Lixiahe District Institute of Agricultural Sciences, Yangzhou, China.
BACKGROUND: Developing herbicide-resistant (HR) crop cultivars is an efficient way to control weeds and minimize crop yield losses. However, widespread and long-term herbicide application has led to the evolution of resistant weeds. Here, we established a resistant (R) E. indica population, collected from imidazolinone-resistant rice cultivar fields. RESULTS: The R population evolved 4.5-fold resistance to imazamox. Acetolactate synthase (ALS) gene sequencing and ALS activity assays excluded the effect of target-site resistance in this population. P450 inhibitor malathion pretreatment significantly reversed resistance to imazamox. RNA sequencing showed that a P450 gene CYP81A104 was expressed higher in R versus susceptible (S) plants. Arabidopsis overexpressing CYP81A104 showed resistance to ALS inhibitors (imazamox, tribenuron-methyl, penoxsulam and flucarbazone-sodium), PSII inhibitor (bentazone), hydroxyphenyl pyruvate dioxygenase inhibitor (mesotrione) and auxin mimics (MCPA), which was generally consistent with the results presented in the R population. CONCLUSION: This study confirmed that the CYP81A104 gene endowed resistance to multiherbicides with different modes-of-action. Our findings provide an insight into the molecular characteristics of resistance and contribute to formulating an appropriate strategy for weed management in HR crops. (c) 2024 Society of Chemical Industry.
PMID: 39003629
Pest Manag Sci , IF:4.845 , 2024 Jul , V80 (7) : P3675-3683 doi: 10.1002/ps.8071
A novel mutation in IAA16 is associated with dicamba resistance in Chenopodium album.
School of Agriculture and Environment, Massey University, Palmerston North, New Zealand.; AgResearch Grasslands Research Center, Palmerston North, New Zealand.; Department of Agronomy and Seed Industry, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.; Department of Grassland Science, Animal Science and Technology College, Sichuan Agricultural University, Chengdu, China.; Faculty of Animal Science and Technology, Yunnan Agricultural University, Kunming, China.
BACKGROUND: Resistance to dicamba in Chenopodium album was first documented over a decade ago, however, the molecular basis of dicamba resistance in this species has not been elucidated. In this research, the resistance mechanism in a dicamba-resistant C. album phenotype was investigated using a transcriptomics (RNA-sequence) approach. RESULTS: The dose-response assay showed that the resistant (R) phenotype was nearly 25-fold more resistant to dicamba than a susceptible (S) phenotype of C. album. Also, dicamba treatment significantly induced transcription of the known auxin-responsive genes, Gretchen Hagen 3 (GH3), small auxin-up RNAs (SAURs), and 1-aminocyclopropane-1-carboxylate synthase (ACS) genes in the susceptible phenotype. Comparing the transcripts of auxin TIR/AFB receptors and auxin/indole-3-acetic acid (AUX/IAA) proteins identified from C. album transcriptomic analysis revealed that the R phenotype contained a novel mutation at the first codon of the GWPPV degron motif of IAA16, resulting in an amino acid substitution of glycine (G) with aspartic acid (D). Sequencing the IAA16 gene in other R and S individuals further confirmed that all the R individuals contained the mutation. CONCLUSION: In this research, we describe the dicamba resistance mechanism in the only case of dicamba-resistant C. album reported to date. Prior work has shown that the dicamba resistance allele confers significant growth defects to the R phenotype investigated here, suggesting that dicamba-resistant C. album carrying this novel mutation in the IAA16 gene may not persist at high frequencies upon removal of dicamba application. (c) 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
PMID: 38459963
Plant Sci , IF:4.729 , 2024 Jul , V347 : P112204 doi: 10.1016/j.plantsci.2024.112204
PoARRO-1 regulates adventitious rooting through interaction with PoIAA27b in Paeonia ostii.
College of Landscape Architecture and Art, Henan Agricultural University, Zhengzhou 450002, China.; College of Horticulture, Henan Agricultural University, Zhengzhou 450002, China.; School of Horticulture Landscape Architecture, Henan Institute of Science and Technology, Xinxiang 453003, China.; College of Landscape Architecture, Central South University of Forestry and Technology, Changsha 410004, China.; College of Landscape Architecture and Art, Henan Agricultural University, Zhengzhou 450002, China. Electronic address: wenqianshang@henau.edu.cn.; College of Landscape Architecture and Art, Henan Agricultural University, Zhengzhou 450002, China. Electronic address: hsl213@yeah.net.; College of Landscape Architecture and Art, Henan Agricultural University, Zhengzhou 450002, China. Electronic address: wzhengt@163.com.
Adventitious root (AR) formation is a limiting factor in the vegetative propagation of tree peony (Paeonia suffruticosa Andr.). PoARRO-1, which encodes an auxin oxidase involved in AR formation, plays a role in the root development of P. ostii, but its associated molecular regulatory mechanisms are not yet understood. In this study, we examined the role of PoARRO-1 in AR formation in P. ostii. The overexpression of PoARRO-1 in P. ostii test-tube plantlets led to a notable enhancement in both the rooting rate and the average number of ARs in vitro, as well as increased activities of peroxidase (POD), superoxide dismutase (SOD), and indoleacetic acid oxidase (IAAO). PoARRO-1 was involved in the conversion of IAA-Asp and IAA-Glu to OxIAA and promoted IAA oxidation. RNA sequencing analysis revealed that PoARRO-1 overexpression led to upregulation of enzyme activity, auxin metabolism related genes. Further analyses showed that PoARRO-1 interacted with the 1-175 aa position of PoIAA27b to regulate the formation of ARs. We therefore propose that PoARRO-1 interacts with PoIAA27b to promote AR formation, and it may be useful targets for enhancing the in vitro propagation of P. ostii.
PMID: 39059631
Plant Sci , IF:4.729 , 2024 Sep , V346 : P112177 doi: 10.1016/j.plantsci.2024.112177
The mutation of CsSUN, an IQD family protein, is responsible for the short and fat fruit (sff) in cucumber (Cucumis sativus L.).
College of Horticulture, Northwest A&F University, Yangling, Shaanxi 712100, China.; College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China.; College of Horticulture, Gansu Agricultural University, Lanzhou, Gansu 730070, China.; College of Horticulture, Shanxi Agricultural University, Taigu, Shanxi 030801, China.; Vegetable Research Institute, Gansu Academy of Agricultural Sciences, Lanzhou, Gansu 730070, China.; USDA-ARS Vegetable Crops Research Unit, University of Wisconsin, Madison, WI 53706, USA.; College of Horticulture, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: liyuhong73@nwsuaf.edu.cn.; College of Life Science, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: pengchen@nwsuaf.edu.cn.
The fruit shape of cucumber is an important agronomic trait, and mining regulatory genes, especially dominant ones, is vital for cucumber breeding. In this study, we identified a short and fat fruit mutant, named sff, from an EMS mutagenized population. Compared to the CCMC (WT), sff (MT) exhibited reduced fruit length and increased dimeter. Segregation analysis revealed that the sff phenotype is controlled by a semi-dominant single gene with dosage effects. Through map-based cloning, the SFF locus was narrowed down to a 52.6 kb interval with two SNPs (G651A and C1072T) in the second and third exons of CsaV3_1G039870, which encodes an IQD family protein, CsSUN. The G651A within the IQ domain of CsSUN was identified as the unique SNP among 114 cucumber accessions, and it was the primary cause of the functional alteration in CsSUN. By generating CsSUN knockout lines in cucumber, we confirmed that CsSUN was responsible for sff mutant phenotype. The CsSUN is localized to the plasma membrane. CsSUN exhibited the highest expression in the fruit with lower expression in sff compared to WT. Histological observations suggest that the sff mutant phenotype is due to increased transverse cell division and inhibited longitudinal cell division. Transcriptome analysis revealed that CsSUN significantly affected the expression of genes related to cell division, expansion, and auxin signal transduction. This study unveils CsSUN's crucial role in shaping cucumber fruit and offers novel insights for cucumber breeding.
PMID: 38964612
Plant Sci , IF:4.729 , 2024 Sep , V346 : P112160 doi: 10.1016/j.plantsci.2024.112160
Integrating histology and phytohormone/metabolite profiling to understand rooting in yellow camellia cuttings.
Department of Biochemistry and Genetics, Clemson University, Clemson, SC 29634, United States.; D.W. Daniel High School, Central, SC 29630, United States.; Department of Biochemistry and Genetics, Clemson University, Clemson, SC 29634, United States. Electronic address: hliang@clemson.edu.
Vegetative propagation through cutting is a widely used clonal approach for maintaining desired genotypes. However, some woody species have difficulty forming adventitious roots (ARs) with this approach, including yellow camellia (YC) C. nitidissima. Yellow camellias, prized for their ornamental value and potential health benefits in tea, remain difficult to propagate clonally due to this rooting recalcitrance. As part of the efforts to understand YC cuttings' recalcitrance, we conducted a detailed investigation into AR formation in yellow camellia cuttings via histology and endogenous phytohormone dynamics during this process. We also compared YC endogenous phytohormone and metabolite phytohormone profiles with those of easy-to-root poplar and willow cuttings. Our results indicate that the induction of ARs in YC cuttings is achievable through auxin treatment, and YC ARs are initiated from cambial derivatives and develop a vascular system connected with that of the stem. During AR induction, endogenous hormones showed a dynamic profile, with IAA continuing to increase starting 9 days after auxin induction. JA, JA-Ile, and OPDA showed a similar trend as IAA but decreased by the 45th day. Cytokinin first decreased to its lowest level by the 18th day and then increased. SA largely exhibited an increasing trend with a drop on the 36th day, while ABA first increased to its peak level by the 18th day and then decreased. Compared to poplar, YC cuttings had a low level of IAA, IAA-Asp, and OPDA, and a high level of cytokinin and SA. Metabolite profiling highlighted significant down-accumulation of compounds associated with AR formation in yellow camellias, such as citric and ascorbic acid, fructose, sucrose, flavonoids, and phenolic acid derivatives. Our study reveals the unfavorable endogenous hormone and metabolite profiles underlying the rooting recalcitrance of YC cuttings, providing valuable knowledge for addressing this challenge in clonal propagation.
PMID: 38908800
Plant Sci , IF:4.729 , 2024 Sep , V346 : P112133 doi: 10.1016/j.plantsci.2024.112133
WUSCHEL RELATED HOMEOBOX5 and 7 maintain callus development by promoting cell division in Arabidopsis.
State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, 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: zhaining@cemps.ac.cn.; State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China. Electronic address: limin.pi@whu.edu.cn.
In tissue culture, a high concentration of auxin in the callus induction medium (CIM) stimulates cell division and subsequent callus formation, which acquires root primordium-like characteristics necessary for cell pluripotency. In Arabidopsis, WUSCHEL-RELATED HOMEOBOX5 (WOX5) and its closest homolog WOX7, which are abundant in the middle cell layer of mature callus, play a crucial role in maintaining pluripotency by promoting auxin accumulation and enhancing cytokinin sensitivity. However, the mechanism by which WOX5/7 regulate callus formation remains unclear. In this study, we found that mutations in WOX5/7 resulted in a significant down-regulation of genes involved in the G2M and S phases during callus induction. Loss-of-function mutants of WOX5/7 exhibited reduced callus formation, which was correlated with decreased expression of CYCB1;1 compared to the wild-type. Furthermore, we provided evidence that WOX5 physically interacts with PHYTOCHROME A SIGNAL TRANSDUCTION1 (PAT1), which spatio-temporally co-expresses with WOX5 in early-induced callus, and up-regulates a subset of cycle-regulating genes targeted by PAT1. Collectively, our findings suggest a critical role for the WOX5-PAT1 protein complex in regulating cell cycle progression, thereby promoting the continuous growth capacity of pluripotent callus.
PMID: 38795752
Plant Sci , IF:4.729 , 2024 Jul , V344 : P112103 doi: 10.1016/j.plantsci.2024.112103
PbARF19-mediated auxin signaling regulates lignification in pear fruit stone cells.
Sanya Institute, College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.; Sanya Institute, College of Horticulture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: taost@njau.edu.cn.
The stone cells in pear fruits cause rough flesh and low juice, seriously affecting the taste. Lignin has been demonstrated as the main component of stone cells. Auxin, one of the most important plant hormone, regulates most physiological processes in plants including lignification. However, the concentration effect and regulators of auxin on pear fruits stone cell formation remains unclear. Here, endogenous indole-3-acetic acid (IAA) and stone cells were found to be co-localized in lignified cells by immunofluorescence localization analysis. The exogenous treatment of different concentrations of IAA demonstrated that the application of 200 microM IAA significantly reduced stone cell content, while concentrations greater than 500 microM significantly increased stone cell content. Besides, 31 auxin response factors (ARFs) were identified in pear genome. Putative ARFs were predicted as critical regulators involved in the lignification of pear flesh cells by phylogenetic relationship and expression analysis. Furthermore, the negative regulation of PbARF19 on stone cell formation in pear fruit was demonstrated by overexpression in pear fruitlets and Arabidopsis. These results illustrated that the PbARF19-mediated auxin signal plays a critical role in the lignification of pear stone cell by regulating lignin biosynthetic genes. This study provides theoretical and practical guidance for improving fruit quality in pear production.
PMID: 38657909
Analyst , IF:4.616 , 2024 Jul doi: 10.1039/d4an00682h
Phenotyping of single plant cells on a microfluidic cytometry platform with fluorescent, mechanical, and electrical modules.
State Key Laboratory of Precision Measuring Technology and Instruments, College of Precision Instruments and Optoelectronics Engineering, Tianjin University, Weijin Rd. 92, Tianjin 300072, China. xduan@tju.edu.cn.; School of Environmental Science and Engineering, Tianjin University, Weijin Rd. 92, Tianjin 300072, China. jiehuawang@tju.edu.cn.
Compared to animal cells, phenotypic characterization of single plant cells on microfluidic platforms is still rare. In this work, we collated population statistics on the morphological, biochemical, physical and electrical properties of Arabidopsis protoplasts under different external and internal conditions, using progressively improved microfluidic platforms. First, we analyzed the different effects of three phytohormones (auxin, cytokinin and gibberellin) on the primary cell wall (PCW) regeneration process using a microfluidic flow cytometry platform equipped with a single-channel fluorescence sensor. Second, we correlated the intracellular reactive oxygen species (ROS) level induced by heavy metal stress with the concurrent PCW regeneration process by using a dual-channel fluorescence sensor. Third, by integrating contraction channels, we were able to effectively discriminate variations in cell size while monitoring the intensity of intracellular ROS signaling. Fourth, by combining an electrical impedance electrode with the contraction channel, we analyzed the differences in electrical and mechanical properties of wild-type and mutant plant cells before and after primary cell wall regeneration. Overall, our work demonstrates the feasibility and sensitivity of microfluidic flow cytometry in high-throughput phenotyping of plant cells and provides a reference for assessing metabolic and physiological indicators of individual plant cells in multiple dimensions.
PMID: 39015957
Plant Cell Rep , IF:4.57 , 2024 Jul , V43 (7) : P188 doi: 10.1007/s00299-024-03274-z
BIG coordinates auxin and SHORT ROOT to promote asymmetric stem cell divisions in Arabidopsis roots.
State Key Laboratory of Hybrid Rice, Department of Plant Sciences, College of Life Sciences, Wuhan University, Wuhan, 430072, China.; Hubei Hongshan Laboratory, Wuhan, 430070, China.; State Key Laboratory of Hybrid Rice, The Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China.; State Key Laboratory of Hybrid Rice, Department of Plant Sciences, College of Life Sciences, Wuhan University, Wuhan, 430072, China. ykliang@whu.edu.cn.; Hubei Hongshan Laboratory, Wuhan, 430070, China. ykliang@whu.edu.cn.
BIG regulates ground tissue formative divisions by bridging the auxin gradient with SHR abundance in Arabidopsis roots. The formative divisions of cortex/endodermis initials (CEIs) and CEI daughter cells (CEIDs) in Arabidopsis roots are coordinately controlled by the longitudinal auxin gradient and the radial SHORT ROOT (SHR) abundance. However, the mechanism underlying this coordination remains poorly understood. In this study, we demonstrate that BIG regulates ground tissue formative divisions by bridging the auxin gradient with SHR abundance. Mutations in BIG gene repressed cell cycle progression, delaying the formative divisions within the ground tissues and impairing the establishment of endodermal and cortical identities. In addition, we uncovered auxin's suppressive effect on BIG expression, triggering CYCLIND6;1 (CYCD6;1) activation in an SHR-dependent fashion. Moreover, the degradation of RETINOBLASTOMA-RELATED (RBR) is jointly regulated by BIG and CYCD6;1. The loss of BIG function led to RBR protein accumulation, detrimentally impacting the SHR/SCARECROW (SCR) protein complex and the CEI/CEID formative divisions. Collectively, these findings shed light on a fundamental mechanism wherein BIG intricately coordinates the interplay between SHR/SCR and auxin, steering ground tissue patterning within Arabidopsis root tissue.
PMID: 38960994
Physiol Plant , IF:4.5 , 2024 Jul-Aug , V176 (4) : Pe14424 doi: 10.1111/ppl.14424
LncRNA cis- and trans-regulation provides new insight into drought stress responses in wild barley.
Research Center of Crop Stresses Resistance Technologies/ MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River, Yangtze University, Jingzhou, China.
Drought is one of the most common abiotic stresses that affect barley productivity. Long noncoding RNA (lncRNA) has been reported to be widely involved in abiotic stress, however, its function in the drought stress response in wild barley remains unclear. In this study, RNA sequencing was performed to identify differentially expressed lncRNAs (DElncRNA) among two wild barley and two cultivated barley genotypes. Then, the cis-regulatory networks were according to the chromosome position and the expression level correction. The GO annotation indicates that these cis-target genes are mainly involved in "ion transport transporter activity" and "metal ion transport transporter activity". Through weighted gene co-expression network analysis (WGCNA), 10 drought-related modules were identified to contract trans-regulatory networks. The KEGG annotation demonstrated that these trans-target genes were enriched for photosynthetic physiology, brassinosteroid biosynthesis, and flavonoid metabolism. In addition, we constructed the lncRNA-mediated ceRNA regulatory network by predicting the microRNA response elements (MREs). Furthermore, the expressions of lncRNAs were verified by RT-qPCR. Functional verification of a candidate lncRNA, MSTRG.32128, demonstrated its positive role in drought response and root growth and development regulation. Hormone content analysis provided insights into the regulatory mechanisms of MSTRG.32128 in root development, revealing its involvement in auxin and ethylene signal transduction pathways. These findings advance our understanding of lncRNA-mediated regulatory mechanisms in barley under drought stress. Our results will provide new insights into the functions of lncRNAs in barley responding to drought stress.
PMID: 38973627
Physiol Plant , IF:4.5 , 2024 Jul-Aug , V176 (4) : Pe14419 doi: 10.1111/ppl.14419
The role of strigolactones in resistance to environmental stress in plants.
College of Agriculture, Guangxi University, Nanning, China.
Abiotic stress impairs plant growth and development, thereby causing low yield and inferior quality of crops. Increasing studies reported that strigolactones (SL) are plant hormones that enhance plant stress resistance by regulating plant physiological processes and gene expressions. In this review, we introduce the response and regulatory role of SL in salt, drought, light, heat, cold and cadmium stresses in plants. This review also discusses how SL alleviate the damage of abiotic stress in plants, furthermore, introducing the mechanisms of SL enhancing plant stress resistance at the genetic level. Under abiotic stress, the exogenous SL analog GR24 can induce the biosynthesis of SL in plants, and endogenous SL can alleviate the damage caused by abiotic stress. SL enhanced the stress resistance of plants by protecting photosynthesis, enhancing the antioxidant capacity of plants and promoting the symbiosis between plants and arbuscular mycorrhiza (AM). SL interact with abscisic acid (ABA), salicylic acid (SA), auxin, cytokinin (CK), jasmonic acid (JA), hydrogen peroxide (H(2)O(2)) and other signal molecules to jointly regulate plant stress resistance. Lastly, both the importance of SL and their challenges for future work are outlined in order to further elucidate the specific mechanisms underlying the roles of SL in plant responses to abiotic stress.
PMID: 38973451
Sci Rep , IF:4.379 , 2024 Jul , V14 (1) : P15830 doi: 10.1038/s41598-024-66202-x
Demequina capsici sp. nov., a novel plant growth-promoting actinomycete isolated from the rhizosphere of bell pepper (Capsicum annuum).
Korean Collection for Type Cultures (KCTC), Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeollabuk-do, 56212, Republic of Korea.; Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Yuseong, Daejeon, 34113, Republic of Korea.; Animal Model Research Group, Jeonbuk Branch Institute, Korea Institute of Toxicology, Jeongeup, Jeollabuk-do, 56212, Republic of Korea.; Human and Environmental Toxicology, University of Science and Technology (UST), Yuseong, Daejeon, 34113, Republic of Korea.; Korean Collection for Type Cultures (KCTC), Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeollabuk-do, 56212, Republic of Korea. jiyoung1@kribb.re.kr.; Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology (UST), Yuseong, Daejeon, 34113, Republic of Korea. jiyoung1@kribb.re.kr.
Demequina, commonly found in coastal and marine environments, represents a genus of Actinomycetes. In this study, strains Demequina PMTSA13(T) and OYTSA14 were isolated from the rhizosphere of Capsicum annuum, leading to the discovery of a novel species, Demequina capsici. Bacteria play a significant role in plant growth, yet there have been no reports of the genus Demequina acting as plant growth-promoting bacteria (PGPB). Comparative genomics analysis revealed ANI similarity values of 74.05-80.63% for PMTSA13(T) and 74.02-80.54% for OYTSA14, in comparison to various Demequina species. The digital DNA-DNA hybridization (dDDH) values for PMTSA13(T) ranged from 19 to 39%, and 19.1-38.6% for OYTSA14. Genome annotation revealed the presence of genes associated with carbohydrate metabolism and transport, suggesting a potential role in nutrient cycling and availability for plants. These strains were notably rich in genes related to 'carbohydrate metabolism and transport (G)', according to their Cluster of Orthologous Groups (COG) classification. Additionally, both strains were capable of producing auxin (IAA) and exhibited enzymatic activities for cellulose degradation and catalase. Furthermore, PMTSA13(T) and OYTSA14 significantly induced the growth of Arabidopsis thaliana seedlings primarily attributed to their capacity to produce IAA, which plays a crucial role in stimulating plant growth and development. These findings shed light on the potential roles of Demequina strains in plant-microbe interactions and agricultural applications. The type strain is Demequina capsici PMTSA13(T) (= KCTC 59028(T) = GDMCC 1.4451(T)), meanwhile OYTSA14 is identified as different strains of Demequina capsici.
PMID: 38982145
Ann Bot , IF:4.357 , 2024 Jul , V134 (2) : P219-232 doi: 10.1093/aob/mcae059
Hormonal profiles in dormant turions of 22 aquatic plant species: do they reflect functional or taxonomic traits?
Institute of Botany of the Czech Academy of Sciences, CZ-379 01 Trebon, Czech Republic.; Laboratory of Growth Regulators, Faculty of Science, Palacky University & Institute of Experimental Botany AS CR, CZ-783 71 Olomouc, Czech Republic.; Department of Chemical Biology, Faculty of Science, Palacky University, CZ-783 71 Olomouc, Czech Republic.
BACKGROUND AND AIMS: Turions are vegetative, dormant overwintering organs formed in aquatic plants in response to unfavourable ecological conditions. Contents of cytokinin (CK), auxin metabolites and abscisic acid (ABA) as main growth and development regulators were compared in innately dormant autumnal turions of 22 aquatic plant species of different functional ecological or taxonomic groups with those in non-dormant winter apices in three aquatic species and with those in spring turions of four species after their overwintering. METHODS: The hormones were analysed in miniature turion samples using ultraperformance liquid chromatography coupled with triple quadrupole mass spectrometry. KEY RESULTS: In innately dormant turions, the total contents of each of the four main CK types, biologically active forms and total CKs differed by two to three orders of magnitude across 22 species; the proportion of active CK forms was 0.18-67 %. Similarly, the content of four auxin forms was extremely variable and the IAA proportion as the active form was 0.014-99 %. The ABA content varied from almost zero to 54 micromol kg-1 dry weight and after overwintering it usually significantly decreased. Of all functional traits studied, hormone profiles depended most on the place of turion sprouting (surface vs bottom) and we suggest that this trait is crucial for turion ecophysiology. CONCLUSIONS: The key role of ABA in regulating turion dormancy was confirmed. However, the highly variable pattern of the ABA content in innately dormant and in overwintered turions indicates that the hormonal mechanism regulating the innate dormancy and its breaking in turions is not uniform within aquatic plants.
PMID: 38650442
Plant Physiol Biochem , IF:4.27 , 2024 Jul , V214 : P108972 doi: 10.1016/j.plaphy.2024.108972
Overexpression of EgrZFP6 from Eucalyptus grandis increases ROS levels by downregulating photosynthesis in plants.
State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, Zhejiang, 311300, China. Electronic address: ljcheng@zju.edu.cn.; State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, Zhejiang, 311300, China.; State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, Zhejiang, 311300, China. Electronic address: xfwang@zafu.edu.cn.
In plants, abiotic stressors are frequently encountered during growth and development. To counteract these challenges, zinc finger proteins play a critical role as transcriptional regulators. The EgrZFP6 gene, which codes for a zinc finger protein of the C2H2 type, was shown to be considerably elevated in the leaves of Eucalyptus grandis seedlings in the current study when they were subjected to a variety of abiotic stimuli, including heat, salinity, cold, and drought. Analysis conducted later showed that in EgrZFP6 transgenic Arabidopsis thaliana, EgrZFP6 was essential for causing hyponastic leaves and controlling the stress response. Furthermore, the transgenic plants showed elevated levels of reactive oxygen species (ROS), such as superoxide and hydrogen peroxide (H(2)O(2)). Additionally, in EgrZFP6-overexpressing plants, transcriptome sequencing analysis demonstrated a considerable downregulation of many genes involved in photosynthesis, decreasing electron transport efficiency and perhaps promoting the buildup of ROS. Auxin levels were higher and auxin signal transduction was compromised in the transgenic plants. Stress-related genes were also upregulated in Arabidopsis as a result of EgrZFP6 overexpression. It is hypothesized that EgrZFP6 can downregulate photosynthesis, which would cause the production of ROS in chloroplasts. As a result, this protein may alter plant stress responses and leaf morphology via a retrograde mechanism driven by ROS. These results highlight the significance of zinc finger proteins in this sophisticated process and advance our understanding of the complex link between gene regulation, ROS signaling, and plant stress responses.
PMID: 39067106
Plant Physiol Biochem , IF:4.27 , 2024 Jul , V214 : P108930 doi: 10.1016/j.plaphy.2024.108930
Selenite improves growth by modulating phytohormone pathways and reprogramming primary and secondary metabolism in tomato plants.
College of Horticulture, Shanxi Agricultural University, Taigu, 030801, China; Shanxi Key Laboratory of Germplasm Resources Innovation and Utilization of Vegetable and Flower, Taiyuan, 030031, China.; College of Horticulture, Shanxi Agricultural University, Taigu, 030801, China; Shanxi Key Laboratory of Germplasm Resources Innovation and Utilization of Vegetable and Flower, Taiyuan, 030031, China. Electronic address: xujin@sxau.edu.cn.
Selenium (Se) is an essential micronutrient in organisms that has a significant impact on physiological activity and gene expression in plants, thereby affecting growth and development. Humans and animals acquire Se from plants. Tomato (Solanum lycopersicum L.) is an important vegetable crop worldwide. Improving the Se nutrient level not only is beneficial for growth, development and stress resistance in tomato plants but also contributes to improving human health. However, the molecular basis of Se-mediated tomato plant growth has not been fully elucidated. In this study, using physiological and transcriptomic analyses, we investigated the effects of a low dosage of selenite [Se(â…£)] on tomato seedling growth. Se(IV) enhanced the photosynthetic efficiency and increased the accumulation of soluble sugars, dry matter and organic matter, thereby promoting tomato plant growth. Transcriptome analysis revealed that Se(IV) reprogrammed primary and secondary metabolic pathways, thus modulating plant growth. Se(IV) also increased the concentrations of auxin, jasmonic acid and salicylic acid in leaves and the concentration of cytokinin in roots, thus altering phytohormone signaling pathways and affecting plant growth and stress resistance in tomato plants. Furthermore, exogenous Se(IV) alters the expression of genes involved in flavonoid biosynthesis, thereby modulating plant growth and development in tomato plants. Taken together, these findings provide important insights into the regulatory mechanisms of low-dose Se(IV) on tomato growth and contribute to the breeding of Se-accumulating tomato cultivars.
PMID: 39013356
Plant Physiol Biochem , IF:4.27 , 2024 Aug , V213 : P108720 doi: 10.1016/j.plaphy.2024.108720
Synergy of plant growth promoting rhizobacteria and silicon in regulation of AgNPs induced stress of rice seedlings.
Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, UP, India.; Crop Nanobiology and Molecular Stress Physiology Lab, Amity Institute of Organic Agriculture, Amity University Uttar Pradesh, Sector-125, Noida, 201313, India.; Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004, UP, India. Electronic address: shiveshs@mnnit.ac.in.
Silver Nanoparticles (AgNPs), as an emerging pollutant, have been receiving significant attention as they deepen the concern regarding the issue of food security. Silicon (Si) and plant growth-promoting rhizobacteria (PGPR) are likely to serve as a sustainable approach to ameliorating abiotic stress and improving plant growth through various mechanisms. The present study aims to evaluate the synergistic effect of Si and PGPRs on growth, physiological, and molecular response in rice seedlings (Oryza sativa) under AgNPs stress. Data suggested that under AgNPs exposure, the root and shoot growth, photosynthetic pigments, antioxidant enzymes (CAT and APX), expression of antioxidant genes (OsAPX and OsGR), silicon transporter (OsLsi2), and auxin hormone-related genes (OsPIN10 and OsYUCCA1) were significantly decreased which accompanied with the overproduction of reactive oxygen species (ROS), nitric oxide (NO) and might be due to higher accumulation of Ag in plant cells. Interestingly, the addition of Si along with the AgNPs enhances the level of ROS generation, thus oxidative stress, which causes severe damage in all the above-tested parameters. On the other hand, application of PGPR alone and along with Si reduced the toxic effect of AgNPs through the improvement of growth, biochemical, and gene regulation (OsAPX and OsGR, OsPIN10 and OsYUCCA1). However, the addition of L-NAME along with PGPR and silicon drastically lowered the AgNPs induced toxicity through lowering the oxidative stress and maintained the overall growth of rice seedlings, which suggests the role of endogenous NO in Si and PGPRs mediated management of AgNPs toxicity in rice seedlings.
PMID: 38901227
Plant Physiol Biochem , IF:4.27 , 2024 Aug , V213 : P108827 doi: 10.1016/j.plaphy.2024.108827
Genomic analysis of PIN-FORMED genes reveals the roles of SmPIN3 in root architecture development in Salvia miltiorrhiza.
College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, Jiangsu, 225009, China.; College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, Jiangsu, 225009, China; Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.; Key Laboratory of Plant Secondary Metabolism and Regulation of Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, 310018, China.; College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, Jiangsu, 225009, China. Electronic address: zhangsc@yzu.edu.cn.
Salvia miltiorrhiza is a widely utilized medicinal herb in China. Its roots serve as crucial raw materials for multiple drugs. The root morphology is essential for the quality of this herb, but little is known about the molecular mechanism underlying the root development in S. miltiorrhiza. Previous study reveals that the polar auxin transport is critical for lateral root development in S. miltiorrhiza. Whether the auxin efflux carriers PIN-FORMEDs (PINs) are involved in this process is worthy investigation. In this study, we identified nine SmPIN genes in S. miltiorrhiza, and their chromosome localization, physico-chemical properties, and phylogenetic relationship were analyzed. SmPINs were unevenly distributed across four chromosomes, and a variety of hormone responsive elements were detected in their promoter regions. The SmPIN proteins were divided into three branches according to the phylogenetic relationship. SmPINs with close evolutionary distance showed similar conserved motif features. The nine SmPINs showed distinct tissue-specific expression patterns and most of them were auxin-inducible genes. We generated SmPIN3 overexpression S. miltiorrhiza seedlings to investigate the function of SmPIN3 in the root development in this species. The results demonstrated that SmPIN3 regulated the root morphogenesis of S. miltiorrhiza by simultaneously affecting the lateral root development and the root anatomical structure. The root morphology, patterns of root xylem and phloem as well as the expressions of genes in the auxin signaling pathway all altered in the SmPIN3 overexpression lines. Our findings provide new insights for elucidating the regulatory roles of SmPINs in the auxin-mediated root development in S. miltiorrhiza.
PMID: 38875779
Plant Physiol Biochem , IF:4.27 , 2024 Aug , V213 : P108813 doi: 10.1016/j.plaphy.2024.108813
Plastid dynamism integrates development and environment.
Department of Environmental Biology, Sapienza University of Rome, Italy. Electronic address: mariamaddalena.altamura@uniroma1.it.; Department of Environmental Biology, Sapienza University of Rome, Italy.
In land plants plastid type differentiation occurs concomitantly with cellular differentiation and the transition from one type to another is under developmental and environmental control. Plastid dynamism is based on a bilateral communication between plastids and nucleus through anterograde and retrograde signaling. Signaling occurs through the interaction with specific phytohormones (abscisic acid, strigolactones, jasmonates, gibberellins, brassinosteroids, ethylene, salicylic acid, cytokinin and auxin). The review is focused on the modulation of plastid capabilities at both transcriptional and post-translational levels at the crossroad between development and stress, with a particular attention to the chloroplast, because the most studied plastid type. The role of plastid-encoded and nuclear-encoded proteins for plastid development and stress responses, and the changes of plastid fate through the activity of stromules and plastoglobules, are discussed. Examples of plastid dynamism in response to soil stress agents (salinity, lead, cadmium, arsenic, and chromium) are described. Albinism and root greening are described based on the modulation activities of auxin and cytokinin. The physiological and functional responses of the sensory epidermal and vascular plastids to abiotic and biotic stresses along with their specific roles in stress sensing are described together with their potential modulation of retrograde signaling pathways. Future research perspectives include an in-depth study of sensory plastids to explore their potential for establishing a transgenerational memory to stress. Suggestions about anterograde and retrograde pathways acting at interspecific level and on the lipids of plastoglobules as a novel class of plastid morphogenic agents are provided.
PMID: 38861821
Plant Physiol Biochem , IF:4.27 , 2024 Jul , V212 : P108761 doi: 10.1016/j.plaphy.2024.108761
Abscisic acid induces PpeKIL1 to terminate fruit growth and promote fruit abortion in peach (Prunus persica).
Key Laboratory of Horticultural Crop Germplasm Innovation and Utilization (Co-construction by Ministry and Province), Key Laboratory of Horticultural Crop Genetic Improvement and Eco-Physiology of Anhui Province, Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei, 230031, China. Electronic address: huichou1987@126.com.; Soil and Fertilizer Research Institute, Anhui Academy of Agricultural Sciences, Hefei, 230031, China. Electronic address: wangxiao@aaas.org.cn.; Egyptian Deserts Genbank, Desert Research Center, Cairo, Egypt. Electronic address: mohamed.amar@wbgcas.cn.; Key Laboratory of Horticultural Crop Germplasm Innovation and Utilization (Co-construction by Ministry and Province), Key Laboratory of Horticultural Crop Genetic Improvement and Eco-Physiology of Anhui Province, Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei, 230031, China. Electronic address: shengyu@aaas.org.cn.; Key Laboratory of Horticultural Crop Germplasm Innovation and Utilization (Co-construction by Ministry and Province), Key Laboratory of Horticultural Crop Genetic Improvement and Eco-Physiology of Anhui Province, Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei, 230031, China. Electronic address: spei2491@gmail.com.; School of Life Science, Anhui Agricultural University, No. 130, Changjiangxi Road, Hefei, 230036, China. Electronic address: 978221324@qq.com.; School of Life Science, Anhui Agricultural University, No. 130, Changjiangxi Road, Hefei, 230036, China. Electronic address: wangyunyun@stu.ahau.edu.cn.; Key Laboratory of Horticultural Crop Germplasm Innovation and Utilization (Co-construction by Ministry and Province), Key Laboratory of Horticultural Crop Genetic Improvement and Eco-Physiology of Anhui Province, Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei, 230031, China. Electronic address: xieqingmei@aaas.org.cn.; Key Laboratory of Horticultural Crop Germplasm Innovation and Utilization (Co-construction by Ministry and Province), Key Laboratory of Horticultural Crop Genetic Improvement and Eco-Physiology of Anhui Province, Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei, 230031, China. Electronic address: 543613921@qq.com.; Key Laboratory of Horticultural Crop Germplasm Innovation and Utilization (Co-construction by Ministry and Province), Key Laboratory of Horticultural Crop Genetic Improvement and Eco-Physiology of Anhui Province, Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei, 230031, China. Electronic address: panhaifa@aaas.org.cn.; Key Laboratory of Horticultural Crop Germplasm Innovation and Utilization (Co-construction by Ministry and Province), Key Laboratory of Horticultural Crop Genetic Improvement and Eco-Physiology of Anhui Province, Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei, 230031, China. Electronic address: jinyunzhang600@163.com.
Abnormal pollination from chance events or hybridization between species leads to unusual embryo development, resulting in fruit abortion. To elucidate the mechanism underlying fruit abortion, we conducted a comprehensive analysis of the transcriptome and hormone profiles in aborting fruits (AF) derived from an interspecific cross between the peach cultivar 'Huangjinmi 3' and the Prunus mume cultivar 'Jiangmei', as well as in normal-seeded fruits (NF) resulting from an intraspecific cross of 'Huangjinmi 3' with the 'Manyuanhong' peach cultivars. Growth of AF was inhibited during the exponential growth phase, with up-regulation of oxidative stress related genes and down-regulation of DNA replication and cell cycle genes. Accumulation of the tissue growth-related hormones auxin and cytokinin was reduced in AF, while levels of the growth inhibiting hormone abscisic acid (ABA) were higher compared to NF. The increased ABA concentration aligned with down-regulation of the ABA catabolism gene CYP707A2, which encodes abscisic acid 8'-hydroxylase. Correlation analysis showed ABA could explain the maximum proportion of differently expressed genes between NF and AF. We also showed that expression of KIRA1-LIKE1 (PpeKIL1), a peach ortholog of the Arabidopsis KIRA1 gene, was up-regulated in AF. PpeKIL1 promotes senescence or delays normal growth in tobacco and Arabidopsis, and its promoter activity increases with exogenous ABA treatment. Our study demonstrates a candidate mechanism where ABA induces expression of PpeKIL1, which further blocks normal fruit growth and triggers fruit abscission.
PMID: 38805756
Plant Physiol Biochem , IF:4.27 , 2024 Jul , V212 : P108731 doi: 10.1016/j.plaphy.2024.108731
Seed endophytic bacterium Lysinibacillus sp. (ZM1) from maize (Zea mays L.) shapes its root architecture through modulation of auxin biosynthesis and nitrogen metabolism.
Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India; Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 276957612, USA. Electronic address: gpal@ncsu.edu.; National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.; Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India.; Department of Plant Biology, Rutgers University, New Brunswick, NJ, USA.; Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, India. Electronic address: skverma.bot@bhu.ac.in.
Seed endophytic bacteria have been shown to promote the growth and development of numerous plants. However, the underlying mechanism still needs to be better understood. The present study aims to investigate the role of a seed endophytic bacterium Lysinibacillus sp. (ZM1) in promoting plant growth and shaping the root architecture of maize seedlings. The study explores how bacteria-mediated auxin biosynthesis and nitrogen metabolism affect plant growth promotion and shape the root architecture of maize seedlings. The results demonstrate that ZM1 inoculation significantly enhances root length, root biomass, and the number of seminal roots in maize seedlings. Additionally, the treated seedlings exhibit increased shoot biomass and higher levels of photosynthetic pigments. Confocal laser scanning microscopy (CLSM) analysis revealed extensive colonization of ZM1 on root hairs, as well as in the cortical and stellar regions of the root. Furthermore, LC-MS analysis demonstrated elevated auxin content in the roots of the ZM1 treated maize seedlings compared to the uninoculated control. Inoculation with ZM1 significantly increased the levels of endogenous ammonium content, GS, and GOGAT enzyme activities in the roots of treated maize seedlings compared to the control, indicating enhanced nitrogen metabolism. Furthermore, inoculation of bacteria under nitrogen-deficient conditions enhanced plant growth, as evidenced by increased root shoot length, fresh and dry weights, average number of seminal roots, and content of photosynthetic pigments. Transcript analysis indicated upregulation of auxin biosynthetic genes, along with genes involved in nitrogen metabolism at different time points in roots of ZM1-treated maize seedlings. Collectively, our findings highlight the positive impact of Lysinibacillus sp. ZM1 inoculation on maize seeds by improving root architecture through modulation of auxin biosynthesis and affecting various nitrogen metabolism related parameters. These findings provide valuable insights into the potential utilization of seed endophytic bacteria as biofertilizers to enhance plant growth and yield in nutrient deficient soils.
PMID: 38761545
Environ Sci Pollut Res Int , IF:4.223 , 2024 Jul , V31 (33) : P46002-46022 doi: 10.1007/s11356-024-34150-8
Potential of the plant growth-promoting rhizobacterium Rhodococcus qingshengii LMR356 in mitigating lead stress impact on Sulla spinosissima L.
Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 1014, 10000, Rabat, Morocco. malika.oubohssaine1@gmail.com.; Microbiology and Molecular Biology Team, Center of Plant and Microbial Biotechnology, Biodiversity and Environment, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 1014, 10000, Rabat, Morocco.
Mining-related lead (Pb) pollution of the soil poses serious hazards to ecosystems and living organisms, including humans. Improved heavy metal phytoremediation efficacy, achieved by using phytostabilizing plants assisted by plant-growth-promoting (PGP) microorganisms, has been presented as an effective strategy for remediating polluted soils. The objective of this research was to examine the response and potential of the plant-growth-promoting bacterium LMR356, a Rhodococcus qingshengii strain isolated from an abandoned mining soil, under lead stress conditions. Compared to non-contaminated culture media, the presence of lead induced a significant decrease in auxin production (from 21.17 to 2.65 mug mL(-1)) and phosphate solubilization (from 33.60 to 8.22 mg L(-1)), whereas other PGP traits increased drastically, such as 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity (from 38.17 to 71.37 nmol mg(-1) h(-1) alpha-ketobutyrate), siderophore production (from 69 to 83%), exopolysaccharide production (from 1952.28 to 3637.72 mg mL(-1)), biofilm formation, and motility. We, therefore, investigated the behavior of Sulla spinosissima L. in the presence or absence of this strain under a variety of experimental conditions. Under hydroponic conditions, Sulla plants showed endurance to varying lead concentrations (500-1000 muM). Inoculation of plants with Rhodococcus qingshengii strain LMR356 enhanced plant tolerance, as demonstrated by the increase in plant biomass (ranging from 14.41 to 79.12%) compared to non-inoculated Pb-stressed and non-stressed control plants. Antioxidant enzyme activities (increasing by -42.71 to 126.8%) and chlorophyll (383.33%) and carotenoid (613.04%) content were also augmented. In addition to its impact on plant lead tolerance, strain LMR356 showed a growth-promoting effect on Sulla plants when cultivated in sterilized non-contaminated sand. Parameters such as plant biomass (16.57%), chlorophyll (24.14%), and carotenoid (30%) contents, as well as ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT) activities, were all elevated compared to non-inoculated plants. Furthermore, when the same plant species was cultivated in highly polluted soil, inoculation increased plant biomass and improved its physiological properties. These findings demonstrate that LMR356 is a phytobeneficial bacterial strain capable of enhancing Sulla growth under normal conditions and improving its heavy metal tolerance in multi-polluted soils. Thus, it can be considered a promising biofertilizer candidate for growing Sulla spinosissima L. or other selected plants intended for application in restoration and stabilization initiatives aimed at reviving and safeguarding environmentally compromised and polluted soils after mining activities.
PMID: 38980484
BMC Plant Biol , IF:4.215 , 2024 Jul , V24 (1) : P721 doi: 10.1186/s12870-024-05394-w
Integrative phenotyping analyses reveal the relevance of the phyB-PIF4 pathway in Arabidopsis thaliana reproductive organs at high ambient temperature.
Hormonal Crosstalk in Plant Development, Mendel Center for Plant Genomics and Proteomics, CEITEC MU-Central European Institute of Technology, Masaryk University, Brno, 625 00, Czech Republic.; Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, 625 00, Czech Republic.; Mendel Center for Plant Genomics and Proteomics, CEITEC MU-Central European Institute of Technology, Masaryk University, Brno, 625 00, Czech Republic.; PSI - Photon Systems Instruments, Drasov, 66424, Czech Republic.; Labdeers s.r.o, Boskovice, 68001, Czech Republic.; Hormonal Crosstalk in Plant Development, Mendel Center for Plant Genomics and Proteomics, CEITEC MU-Central European Institute of Technology, Masaryk University, Brno, 625 00, Czech Republic. helene.robert.boisivon@ceitec.muni.cz.
BACKGROUND: The increasing ambient temperature significantly impacts plant growth, development, and reproduction. Uncovering the temperature-regulating mechanisms in plants is of high importance, for increasing our fundamental understanding of plant thermomorphogenesis, for its potential in applied science, and for aiding plant breeders in improving plant thermoresilience. Thermomorphogenesis, the developmental response to warm temperatures, has been primarily studied in seedlings and in the regulation of flowering time. PHYTOCHROME B and PHYTOCHROME-INTERACTING FACTORs (PIFs), particularly PIF4, are key components of this response. However, the thermoresponse of other adult vegetative tissues and reproductive structures has not been systematically evaluated, especially concerning the involvement of phyB and PIFs. RESULTS: We screened the temperature responses of the wild type and several phyB-PIF4 pathway Arabidopsis mutant lines in combined and integrative phenotyping platforms for root growth in soil, shoot, inflorescence, and seed. Our findings demonstrate that phyB-PIF4 is generally involved in the relay of temperature signals throughout plant development, including the reproductive stage. Furthermore, we identified correlative responses to high ambient temperature between shoot and root tissues. This integrative and automated phenotyping was complemented by monitoring the changes in transcript levels in reproductive organs. Transcriptomic profiling of the pistils from plants grown under high ambient temperature identified key elements that may provide insight into the molecular mechanisms behind temperature-induced reduced fertilization rate. These include a downregulation of auxin metabolism, upregulation of genes involved auxin signalling, miRNA156 and miRNA160 pathways, and pollen tube attractants. CONCLUSIONS: Our findings demonstrate that phyB-PIF4 involvement in the interpretation of temperature signals is pervasive throughout plant development, including processes directly linked to reproduction.
PMID: 39075366
BMC Plant Biol , IF:4.215 , 2024 Jul , V24 (1) : P704 doi: 10.1186/s12870-024-05413-w
Effect of seed priming with auxin on ROS detoxification and carbohydrate metabolism and their relationship with germination and early seedling establishment in salt stressed maize.
Laboratory of Extremophile Plants (LPE), Centre of Biotechnology of Borj-Cedria (CBBC), P.O. Box 901, Hammam‑Lif, 2050, Tunisia.; Laboratory of Bioactive Substances (LSBA), Centre of Biotechnology of Borj-Cedria (CBBC), P. O. Box 901, Hammam‑Lif, 2050, Tunisia.; Department of Plant Production, College of Agriculture and Food, Qassim University, Buraydah, Saudi Arabia.; Department of Zoology, College of Science, King Saud University, PO Box -2455, Riyadh, 11451, Saudi Arabia.; Laboratory of Extremophile Plants (LPE), Centre of Biotechnology of Borj-Cedria (CBBC), P.O. Box 901, Hammam‑Lif, 2050, Tunisia. zorrigwalid@gmail.com.
As crucial stages in the plant ontogeny, germination and seedling establishment under adverse conditions greatly determine staple crop growth and productivity. In the context of green technologies aiming to improve crop yield, seed priming is emerging as an effective approach to enhance seed vigor and germination performance under salt stress. In this study, we assess the efficiency of seed priming with indole-3-acetic acid (IAA) in mitigating the adverse effects of salt stress on maize (Zea mays L.) seedlings during germination and early seedling stages. In unprimed seeds, salt stress reduced germination indices, and seedling (both radicle and coleoptile) growth, together with decreased tissue hydration. However, seed priming using IAA significantly improved maize salt response, as reflected by the increased seed germination dynamics, early seedling establishment, and water status. Besides, seedlings from IAA-primed seeds showed a higher activity of alpha-amylase, resulting in increased sugar contents in roots and coleoptiles of salt-stressed plants. Further, IAA-seed priming stimulated the accumulation of endogenous IAA in salt-stressed seedlings, in concomitance with a significant effect on reactive oxygen species detoxification and lipid peroxidation prevention. Indeed, our data revealed increased antioxidant enzyme activities, differentially regulated in roots and coleoptiles, leading to increased activities of the antioxidant enzymes (SOD, CAT and GPX). In summary, data gained from this study further highlight the potential of IAA in modulating early interactions between multiple signaling pathways in the seed, endowing maize seedlings with enhanced potential and sustained tolerance to subsequent salt stress.
PMID: 39054427
Microorganisms , IF:4.128 , 2024 Jul , V12 (7) doi: 10.3390/microorganisms12071473
The Microbiome of Fertilization-Stage Maize Silks (Style) Encodes Genes and Expresses Traits That Potentially Promote Survival in Pollen/Style Niches and Host Reproduction.
Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada.
Within flowers, the style channel receives pollen and transmits male gametes inside elongating pollen tubes to ovules. The styles of maize/corn are called silks. Fertilization-stage silks possess complex microbiomes, which may partially derive from pollen. These microbiomes lack functional analysis. We hypothesize that fertilization-stage silk microbiomes promote host fertilization to ensure their own vertical transmission. We further hypothesize that these microbes encode traits to survive stresses within the silk (water/nitrogen limitation) and pollen (dehydration/aluminum) habitats. Here, bacteria cultured from fertilization-stage silks of 14 North American maize genotypes underwent genome mining and functional testing, which revealed osmoprotection, nitrogen-fixation, and aluminum-tolerance traits. Bacteria contained auxin biosynthesis genes, and testing confirmed indole compound secretion, which is relevant, since pollen delivers auxin to silks to stimulate egg cell maturation. Some isolates encoded biosynthetic/transport compounds known to regulate pollen tube guidance/growth. The isolates encoded ACC deaminase, which degrades the precursor for ethylene that otherwise accelerates silk senescence. The findings suggest that members of the microbiome of fertilization-stage silks encode adaptations to survive the stress conditions of silk/pollen and have the potential to express signaling compounds known to impact reproduction. Overall, whereas these microbial traits have traditionally been assumed to primarily promote vegetative plant growth, this study proposes they may also play selfish roles during host reproduction.
PMID: 39065240
Planta , IF:4.116 , 2024 Jul , V260 (2) : P54 doi: 10.1007/s00425-024-04482-3
Low-oxygen-induced root bending is altered by phytoglobin1 through mediation of ethylene response factors (ERFs) and auxin signaling.
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.
phytoglobin1 positively regulates root bending in hypoxic Arabidopsis roots through regulation of ethylene response factors and auxin transport. Hypoxia-induced root bending is known to be mediated by the redundant activity of the group VII ethylene response factors (ERFVII) RAP2.12 and HRE2, causing changes in polar auxin transport (PAT). Here, we show that phytoglobin1 (Pgb1), implicated in hypoxic adaptation through scavenging of nitric oxide (NO), can alter root direction under low oxygen. Hypoxia-induced bending is exaggerated in roots over-expressing Pgb1 and attenuated in those where the gene is suppressed. These effects were attributed to Pgb1 repressing both RAP2.12 and HRE2. Expression, immunological and genetic data place Pgb1 upstream of RAP2.12 and HRE2 in the regulation of root bending in oxygen-limiting environments. The attenuation of slanting in Pgb1-suppressing roots was associated with depletion of auxin activity at the root tip because of depression in PAT, while exaggeration of root bending in Pgb1-over-expressing roots with the retention of auxin activity. Changes in PIN2 distribution patterns, suggestive of redirection of auxin movement during hypoxia, might contribute to the differential root bending responses of the transgenic lines. In the end, Pgb1, by regulating NO levels, controls the expression of 2 ERFVIIs which, in a cascade, modulate PAT and, therefore, root bending.
PMID: 39012577
Planta , IF:4.116 , 2024 Jul , V260 (2) : P42 doi: 10.1007/s00425-024-04468-1
Atmospheric nitrogen dioxide suppresses the activity of phytochrome interacting factor 4 to suppress hypocotyl elongation.
Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi, Hiroshima, 739-8526, Japan. misat@hiroshima-u.ac.jp.; Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi, Hiroshima, 739-8526, Japan.; School of Science, Hiroshima University, Higashi, Hiroshima, 739-8526, Japan.
Ambient concentrations of atmospheric nitrogen dioxide (NO(2)) inhibit the binding of PIF4 to promoter regions of auxin pathway genes to suppress hypocotyl elongation in Arabidopsis. Ambient concentrations (10-50 ppb) of atmospheric nitrogen dioxide (NO(2)) positively regulate plant growth to the extent that organ size and shoot biomass can nearly double in various species, including Arabidopsis thaliana (Arabidopsis). However, the precise molecular mechanism underlying NO(2)-mediated processes in plants, and the involvement of specific molecules in these processes, remain unknown. We measured hypocotyl elongation and the transcript levels of PIF4, encoding a bHLH transcription factor, and its target genes in wild-type (WT) and various pif mutants grown in the presence or absence of 50 ppb NO(2). Chromatin immunoprecipitation assays were performed to quantify binding of PIF4 to the promoter regions of its target genes. NO(2) suppressed hypocotyl elongation in WT plants, but not in the pifq or pif4 mutants. NO(2) suppressed the expression of target genes of PIF4, but did not affect the transcript level of the PIF4 gene itself or the level of PIF4 protein. NO(2) inhibited the binding of PIF4 to the promoter regions of two of its target genes, SAUR46 and SAUR67. In conclusion, NO(2) inhibits the binding of PIF4 to the promoter regions of genes involved in the auxin pathway to suppress hypocotyl elongation in Arabidopsis. Consequently, PIF4 emerges as a pivotal participant in this regulatory process. This study has further clarified the intricate regulatory mechanisms governing plant responses to environmental pollutants, thereby advancing our understanding of how plants adapt to changing atmospheric conditions.
PMID: 38958765
Genes (Basel) , IF:4.096 , 2024 Jul , V15 (7) doi: 10.3390/genes15070919
Molecular Mapping and Transfer of Quantitative Trait Loci (QTL) for Sheath Blight Resistance from Wild Rice Oryza nivara to Cultivated Rice (Oryza sativa L.).
School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana 141004, India.; Department of Plant Pathology, Punjab Agricultural University, Ludhiana 141004, India.; ICAR-Indian Institute of Maize Research, PAU Campus, Ludhiana 141004, India.; Division of Agricultural Biotechnology, Ramakrishna Mission Vivekananda Educational and Research Institute, Narendrapur Campus, Kolkata 700103, India.; Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana 141004, India.; International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru 502324, India.
Sheath blight (ShB) is the most serious disease of rice (Oryza sativa L.), caused by the soil-borne fungus Rhizoctonia solani Kuhn (R. solani). It poses a significant threat to global rice productivity, resulting in approximately 50% annual yield loss. Managing ShB is particularly challenging due to the broad host range of the pathogen, its necrotrophic nature, the emergence of new races, and the limited availability of highly resistant germplasm. In this study, we conducted QTL mapping using an F(2) population derived from a cross between a partially resistant accession (IRGC81941A) of Oryza nivara and the susceptible rice cultivar Punjab rice 121 (PR121). Our analysis identified 29 QTLs for ShB resistance, collectively explaining a phenotypic variance ranging from 4.70 to 48.05%. Notably, a cluster of four QTLs (qRLH1.1, qRLH1.2, qRLH1.5, and qRLH1.8) on chromosome 1 consistently exhibit a resistant response against R. solani. These QTLs span from 0.096 to 420.1 Kb on the rice reference genome and contain several important genes, including Ser/Thr protein kinase, auxin-responsive protein, protease inhibitor/seed storage/LTP family protein, MLO domain-containing protein, disease-responsive protein, thaumatin-like protein, Avr9/Cf9-eliciting protein, and various transcription factors. Additionally, simple sequence repeats (SSR) markers RM212 and RM246 linked to these QTLs effectively distinguish resistant and susceptible rice cultivars, showing great promise for marker-assisted selection programs. Furthermore, our study identified pre-breeding lines in the advanced backcrossed population that exhibited superior agronomic traits and sheath blight resistance compared to the recurrent parent. These promising lines hold significant potential for enhancing the sheath blight resistance in elite cultivars through targeted improvement efforts.
PMID: 39062698
Plant Mol Biol , IF:4.076 , 2024 Jul , V114 (4) : P82 doi: 10.1007/s11103-024-01476-3
OsNAC121 regulates root development, tillering, panicle morphology, and grain filling in rice plant.
Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India.; Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India. mrinalkmaiti@gmail.com.
Transcription factors in coordination with phytohormones form an intricate regulatory network modulating vital cellular mechanisms like development, growth and senescence in plants. In this study, we have functionally characterized the transcription factor OsNAC121 by developing gene silencing and overexpressing transgenic rice plants, followed by detailed analyses of the plant architecture. Transgenic lines exhibited remodelling in crown root development, lateral root structure and density, tiller height and number, panicle and grain morphologies, underpinning the imbalanced auxin: cytokinin ratio due to perturbed auxin transportation. Application of cytokinin, auxin and abscisic acid increased OsNAC121 gene expression nearly 17-, 6- and 91-folds, respectively. qRT-PCR results showed differential expressions of auxin and cytokinin pathway genes, implying their altered levels. A 47-fold higher expression level of OsNAC121 during milky stage in untransformed rice, compared to 14-day old shoot tissue, suggests its crucial role in grain filling; as evidenced by a large number of undeveloped grains produced by the gene silenced lines. Crippled gravitropic response by the transgenic plants indicates their impaired auxin transport. Bioinformatics revealed that OsNAC121 interacts with co-repressor (TOPLESS) proteins and forms a part of the inhibitor complex OsIAA10, an essential core component of auxin signalling pathway. Therefore, OsNAC121 emerges as an important regulator of various aspects of plant architecture through modulation of crosstalk between auxin and cytokinin, altering their concentration gradient in the meristematic zones, and consequently modifying different plant organogenesis processes.
PMID: 38954114
BMC Genomics , IF:3.969 , 2024 Jul , V25 (1) : P704 doi: 10.1186/s12864-024-10624-4
Transcriptome analysis suggested that lncRNAs regulate rapeseed seedlings in responding to drought stress by coordinating the phytohormone signal transduction pathways.
School of Agronomy and Horticulture, Jiangsu Vocational College of Agriculture and Forestry, Zhenjiang, China.; School of Rural Revitalization, Jiangsu Open University, Nanjing, China. longwh@jsou.edu.cn.; Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oilcrops Research Institute of the Chinese Academy of Agricultural, Wuhan, China.; College of Life Sciences, Henan Normal University, Xinxiang, China.
The growth, yield, and seed quality of rapeseed are negatively affected by drought stress. Therefore, it is of great value to understand the molecular mechanism behind this phenomenon. In a previous study, long non-coding RNAs (lncRNAs) were found to play a key role in the response of rapeseed seedlings to drought stress. However, many questions remained unanswered. This study was the first to investigate the expression profile of lncRNAs not only under control and drought treatment, but also under the rehydration treatment. A total of 381 differentially expressed lncRNA and 10,253 differentially expressed mRNAs were identified in the comparison between drought stress and control condition. In the transition from drought stress to rehydration, 477 differentially expressed lncRNAs and 12,543 differentially expressed mRNAs were detected. After identifying the differentially expressed (DE) lncRNAs, the comprehensive lncRNAs-engaged network with the co-expressed mRNAs in leaves under control, drought and rehydration was investigated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of co-expressed mRNAs identified the most significant pathways related with plant hormones (expecially abscisic acid, auxin, cytokinins, and gibberellins) in the signal transduction. The genes, co-expressed with the most-enriched DE-lncRNAs, were considered as the most effective candidates in the water-loss and water-recovery processes, including protein phosphatase 2 C (PP2C), ABRE-binding factors (ABFs), and SMALL AUXIN UP-REGULATED RNAs (SAURs). In summary, these analyses clearly demonstrated that DE-lncRNAs can act as a regulatory hub in plant-water interaction by controlling phytohormone signaling pathways and provided an alternative way to explore the complex mechanisms of drought tolerance in rapeseed.
PMID: 39030492
BMC Genomics , IF:3.969 , 2024 Jul , V25 (1) : P702 doi: 10.1186/s12864-024-10622-6
Genome-wide identification and molecular evolution of Dof gene family in Camellia oleifera.
Key Laboratory of Sichuan Province for Bamboo Pests Control and Resource Development, Leshan Normal University, No. 778 Binhe Road, Shizhong District, Leshan, Sichuan, 614000, China. fuchun421@aliyun.com.; College of Life Science, Leshan Normal University, No. 778 Binhe Road, Shizhong District, Leshan, Sichuan, 614000, China. fuchun421@aliyun.com.; Key Laboratory of Sichuan Province for Bamboo Pests Control and Resource Development, Leshan Normal University, No. 778 Binhe Road, Shizhong District, Leshan, Sichuan, 614000, China.; College of Life Science, Leshan Normal University, No. 778 Binhe Road, Shizhong District, Leshan, Sichuan, 614000, China.; College of Tourism and Geographical Science, Leshan Normal University, No. 778 Binhe Road, Shizhong District, Leshan, Sichuan, 614000, China.
DNA binding with one finger(Dof) gene family is a class of transcription factors which play an important role on plant growth and development. Genome-wide identification results indicated that there were 45 Dof genes(ColDof) in C.oleifera genome. All 45 ColDof proteins were non-transmembrane and non-secretory proteins. Phosphorylation site analysis showed that biological function of ColDof proteins were mainly realized by phosphorylation at serine (Ser) site. The secondary structure of 44 ColDof proteins was dominated by random coil, and only one ColDof protein was dominated by alpha-helix. ColDof genes' promoter region contained a variety of cis-acting elements, including light responsive regulators, gibberellin responsive regulators, abscisic acid responsive regulators, auxin responsive regulators and drought induction responsive regulators. The SSR sites analysis showed that the proportion of single nucleotide repeats and the frequency of A/T in ColDof genes were the largest. Non-coding RNA analysis showed that 45 ColDof genes contained 232 miRNAs. Transcription factor binding sites of ColDof genes showed that ColDof genes had 5793 ERF binding sites, 4381 Dof binding sites, 2206 MYB binding sites, 3702 BCR-BPC binding sites. ColDof9, ColDof39 and ColDof44 were expected to have the most TFBSs. The collinearity analysis showed that there were 40 colinear locis between ColDof proteins and AtDof proteins. Phylogenetic analysis showed that ColDof gene family was most closely related to that of Camellia sinensis var. sinensis cv.Biyun and Camellia lanceoleosa. Protein-protein interaction analysis showed that ColDof34, ColDof20, ColDof28, ColDof35, ColDof42 and ColDof26 had the most protein interactions. The transcriptome analysis of C. oleifera seeds showed that 21 ColDof genes were involved in the growth and development process of C. oleifera seeds, and were expressed in 221 C. oleifera varieties. The results of qRT-PCR experiments treated with different concentrations NaCl and PEG6000 solutions indicated that ColDof1, ColDof2, ColDof14 and ColDof36 not only had significant molecular mechanisms for salt stress tolerance, but also significant molecular functions for drought stress tolerance in C. oleifera. The results of this study provide a reference for further understanding of the function of ColDof genes in C.oleifera.
PMID: 39026173
BMC Genomics , IF:3.969 , 2024 Jul , V25 (1) : P682 doi: 10.1186/s12864-024-10579-6
Understanding the responses of tillering to 2,4-D isooctyl ester in Setaria viridis L.
Grassland Agri-Husbandry Research Center, College of Grassland Science, Qingdao Agricultural University, Qingdao, Shandong, China.; Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, Qingdao Agricultural University, Qingdao, 266109, China.; Qingdao Key Laboratory of Specialty Plant Germplasm Innovation and Utilization in Saline Soils of Coastal Beach, Qingdao Agricultural University, Qingdao, 266109, China.; Grassland Agri-Husbandry Research Center, College of Grassland Science, Qingdao Agricultural University, Qingdao, Shandong, China. sunjuan@qau.edu.cn.; Key Laboratory of National Forestry and Grassland Administration on Grassland Resources and Ecology in the Yellow River Delta, Qingdao Agricultural University, Qingdao, 266109, China. sunjuan@qau.edu.cn.
BACKGROUND: Green foxtail [Setaria viridis (L.)] is one of the most abundant and troublesome annual grass weeds in alfalfa fields in Northeast China. Synthetic auxin herbicide is widely used in agriculture, while how auxin herbicide affects tillering on perennial grass weeds is still unclear. A greenhouse experiment was conducted to examine the effects of auxin herbicide 2,4-D on green foxtail growth, especially on tillers. RESULTS: In the study, 2,4-D isooctyl ester was used. There was an inhibition of plant height and fresh weight on green foxtail after application. The photosynthetic rate of the leaves was dramatically reduced and there was an accumulation of malondialdehyde (MDA) content. Moreover, applying 2,4-D isooctyl ester significantly reduced the tillering buds at rates between 2100 and 8400 ga. i. /ha. Transcriptome results showed that applying 2,4-D isooctyl ester on leaves affected the phytohormone signal transduction pathways in plant tillers. Among them, there were significant effects on auxin, cytokinin, abscisic acid (ABA), gibberellin (GA), and brassinosteroid signaling. Indeed, external ABA and GA on leaves also limited tillering in green foxtail. CONCLUSIONS: These data will be helpful to further understand the responses of green foxtail to 2, 4-D isooctyl ester, which may provide a unique perspective for the development and identification of new target compounds that are effective against this weed species.
PMID: 38982341
BMC Genomics , IF:3.969 , 2024 Jul , V25 (1) : P666 doi: 10.1186/s12864-024-10549-y
Metabolomic and transcriptomic analyses of peach leaves and fruits in response to pruning.
College of Horticulture, Hebei Agricultural University, Baoding, Hebei, 071000, China.; National Engineering Research Center for Agriculture in Northern Mountainous Areas, Agricultural Technology Innovation Center in Mountainous Areas of Hebei Province, Hebei Agricultural University, Baoding, Hebei, 071000, China.; College of Horticulture, Hebei Agricultural University, Baoding, Hebei, 071000, China. yychj@hebau.edu.cn.; College of Horticulture, Hebei Agricultural University, Baoding, Hebei, 071000, China. tianyi@hebau.edu.cn.; National Engineering Research Center for Agriculture in Northern Mountainous Areas, Agricultural Technology Innovation Center in Mountainous Areas of Hebei Province, Hebei Agricultural University, Baoding, Hebei, 071000, China. tianyi@hebau.edu.cn.
BACKGROUND: Pruning is an important cultivation management option that has important effects on peach yield and quality. However, the effects of pruning on the overall genetic and metabolic changes in peach leaves and fruits are poorly understood. RESULTS: The transcriptomic and metabolomic profiles of leaves and fruits from trees subjected to pruning and unpruning treatments were measured. A total of 20,633 genes and 622 metabolites were detected. Compared with those in the control, 1,127 differentially expressed genes (DEGs) and 77 differentially expressed metabolites (DEMs) were identified in leaves from pruned and unpruned trees (pdLvsupdL), whereas 423 DEGs and 29 DEMs were identified in fruits from the pairwise comparison pdFvsupdF. The content of three auxin analogues was upregulated in the leaves of pruned trees, the content of all flavonoids detected in the leaves decreased, and the expression of almost all genes involved in the flavonoid biosynthesis pathway decreased. The phenolic acid and amino acid metabolites detected in fruits from pruned trees were downregulated, and all terpenoids were upregulated. The correlation analysis revealed that DEGs and DEMs in leaves were enriched in tryptophan metabolism, auxin signal transduction, and flavonoid biosynthesis. DEGs and DEMs in fruits were enriched in flavonoid and phenylpropanoid biosynthesis, as well as L-glutamic acid biosynthesis. CONCLUSIONS: Pruning has different effects on the leaves and fruits of peach trees, affecting mainly the secondary metabolism and hormone signalling pathways in leaves and amino acid biosynthesis in fruits.
PMID: 38961329
Plants (Basel) , IF:3.935 , 2024 Jul , V13 (14) doi: 10.3390/plants13141993
Sphingosine Promotes Fiber Early Elongation in Upland Cotton.
Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450001, China.; State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China.; Key Laboratory of Biotechnology and Crop Quality Improvement of Ministry of Agriculture, Biotechnology Research Center, Southwest University, Chongqing 400716, China.
Sphingolipids play an important role in cotton fiber development, but the regulatory mechanism is largely unclear. We found that serine palmitoyltransferase (SPT) enzyme inhibitors, myriocin and sphingosine (dihydrosphingosine (DHS) and phytosphingosine (PHS)), affected early fiber elongation in cotton, and we performed a sphingolipidomic and transcriptomic analysis of control and PHS-treated fibers. Myriocin inhibited fiber elongation, while DHS and PHS promoted it in a dose-effect manner. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we found that contents of 22 sphingolipids in the PHS-treated fibers for 10 days were changed, of which the contents of 4 sphingolipids increased and 18 sphingolipids decreased. The transcriptome analysis identified 432 differentially expressed genes (238 up-regulated and 194 down-regulated) in the PHS-treated fibers. Among them, the phenylpropanoid biosynthesis pathway is the most significant enrichment. The expression levels of transcription factors such as MYB, ERF, LBD, and bHLH in the fibers also changed, and most of MYB and ERF were up-regulated. Auxin-related genes IAA, GH3 and BIG GRAIN 1 were up-regulated, while ABPs were down-regulated, and the contents of 3 auxin metabolites were decreased. Our results provide important sphingolipid metabolites and regulatory pathways that influence fiber elongation.
PMID: 39065521
Plants (Basel) , IF:3.935 , 2024 Jul , V13 (14) doi: 10.3390/plants13141991
6-BA Reduced Yield Loss under Waterlogging Stress by Regulating the Phenylpropanoid Pathway in Wheat.
State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Ministry of Science and Technology, Chengdu 611130, China.; Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China.; Crop Ecophysiology and Cultivation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China.; Key Laboratory of Crop Ecophysiology & Farming System in Southwest China, Ministry of Agriculture and Rural Affairs, Chengdu 611130, China.
Waterlogging stress causes substantial destruction to plant growth and production under climatic fluctuations globally. Plants hormones have been widely explored in numerous crops, displaying an imperative role in crop defense and growth mechanism. However, there is a paucity of research on the subject of plant hormones regulating waterlogging stress responses in wheat crop. In this study, we clarified the role of 6-BA in waterlogging stress through inducing phenylpropanoid biosynthesis in wheat. The application of 6-BA (6-benzyladenine) enhanced the growth and development of wheat plants under waterlogging stress, which was accompanied by reduced electrolyte leakage, high chlorophyll, and soluble sugar content. ROS scavenging was also enhanced by 6-BA, resulting in reduced MDA and H(2)O(2) accumulation and amplified antioxidant enzyme activities. Additionally, under the effect of 6-BA, the acceleration of lignin content and accumulation in the cell walls of wheat tissues, along with the activation of PAL (phenylalanine ammonia lyase), TAL (tyrosine ammonia lyase), and 4CL (4-hydroxycinnamate CoA ligase) activities and the increase in the level of transcription of the TaPAL and Ta4CL genes, were observed under waterlogging stress. Also, 6-BA improved the root growth system under waterlogging stress conditions. Further qPCR analysis revealed increased auxin signaling (TaPR1) in 6-BA-treated plants under waterlogging stress that was consistent with the induction of endogenous IAA hormone content under waterlogging stress conditions. Here, 6-BA also reduced yield loss, as compared to control plants. Thus, the obtained data suggested that, under the application of 6-BA, phenylpropanoid metabolism (i.e., lignin) was stimulated, playing a significant role in reducing the negative effects of waterlogging stress on yield, as evinced by the improved plant growth parameters.
PMID: 39065518
Plants (Basel) , IF:3.935 , 2024 Jul , V13 (14) doi: 10.3390/plants13141960
Understanding Ameliorating Effects of Boron on Adaptation to Salt Stress in Arabidopsis.
International Research Center for Environmental Membrane Biology, Foshan University, Foshan 528000, China.; Tasmanian Institute of Agriculture, University of Tasmania, Hobart 7005, Australia.; Department of Plant and Environmental Sciences, University of Copenhagen, 1871 Copenhagen, Denmark.; School of Biological Sciences, University of Western Australia, Perth 6009, Australia.
When faced with salinity stress, plants typically exhibit a slowdown in their growth patterns. Boron (B) is an essential micronutrient for plants that are known to play a critical role in controlling cell wall properties. In this study, we used the model plant Arabidopsis thaliana Col-0 and relevant mutants to explore how the difference in B availability may modulate plant responses to salt stress. There was a visible root growth suppression of Col-0 with the increased salt levels in the absence of B while this growth reduction was remarkably alleviated by B supply. Pharmacological experiments revealed that orthovanadate (a known blocker of H(+)-ATPase) inhibited root growth at no B condition, but had no effect in the presence of 30 muM B. Salinity stress resulted in a massive K(+) loss from mature zones of A. thaliana roots; this efflux was attenuated in the presence of B. Supplemental B also increased the magnitude of net H(+) pumping by plant roots. Boron availability was also essential for root halotropism. Interestingly, the aha2Delta57 mutant with active H(+)-ATPase protein exhibited the same halotropism response as Col-0 while the aha2-4 mutant had a stronger halotropism response (larger bending angle) compared with that of Col-0. Overall, the ameliorative effect of B on the A. thaliana growth under salt stress is based on the H(+)-ATPase stimulation and a subsequent K(+) retention, involving auxin- and ROS-pathways.
PMID: 39065487
Plants (Basel) , IF:3.935 , 2024 Jul , V13 (14) doi: 10.3390/plants13141905
Computational Reconstruction of the Transcription Factor Regulatory Network Induced by Auxin in Arabidopsis thaliana L.
Department of Systems Biology, Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia.; Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia.
In plant hormone signaling, transcription factor regulatory networks (TFRNs), which link the master transcription factors to the biological processes under their control, remain insufficiently characterized despite their crucial function. Here, we identify a TFRN involved in the response to the key plant hormone auxin and define its impact on auxin-driven biological processes. To reconstruct the TFRN, we developed a three-step procedure, which is based on the integrated analysis of differentially expressed gene lists and a representative collection of transcription factor binding profiles. Its implementation is available as a part of the CisCross web server. With the new method, we distinguished two transcription factor subnetworks. The first operates before auxin treatment and is switched off upon hormone application, the second is switched on by the hormone. Moreover, we characterized the functioning of the auxin-regulated TFRN in control of chlorophyll and lignin biosynthesis, abscisic acid signaling, and ribosome biogenesis.
PMID: 39065433
Plants (Basel) , IF:3.935 , 2024 Jul , V13 (14) doi: 10.3390/plants13141904
High-Efficiency In Vitro Root Induction in Pear Microshoots (Pyrus spp.).
National Agrobiodiversity Center, National Institute of Agricultural Sciences, RDA, Suwon 16613, Republic of Korea.; Planning & Coordination Division, National Institute of Agricultural Sciences, RDA, Wanju 55365, Republic of Korea.; Fruit Research Division, National Institute of Horticultural & Herbal Science, Wanju 55365, Republic of Korea.
Extensive research has been conducted on the in vitro mass propagation of pear (Pyrus spp.) trees through vegetative propagation, demonstrating high efficiency in shoot multiplication across various pear species. However, the low in vitro rooting rates remain a significant barrier to the practical application and commercialization of mass propagation. This study aims to determine the favorable conditions for inducing root formation in the in vitro microshoots of Pyrus genotypes. The base of the microshoots was exposed to a high concentration (2 mg L(-1)) of auxins (a combination of IBA and NAA) for initial root induction at the moment when callus formation begins. The microshoots were then transferred to an R1 medium (1/2 MS with 30 g L(-1) sucrose without PGRs) to promote root development. This method successfully induced rooting in three European pear varieties, one Asian pear variety, and a European-Asian hybrid, resulting in rooting rates of 66.7%, 87.2%, and 100% for the European pear (P. communis), 60% for the Asian pear (P. pyrifolia), and 83.3% for the hybrid pear (P. pyrifolia x P. communis) with an average of 25 days. In contrast, the control group (MS medium) exhibited rooting rates of 0-13.3% after 60 days of culture. These findings will enhance in vitro root induction for various pear varieties and support the mass propagation and acclimatization of pear. The in vitro root induction method developed in this study has the potential for global commercial application in pear cultivation.
PMID: 39065431
J Appl Microbiol , IF:3.772 , 2024 Jul , V135 (7) doi: 10.1093/jambio/lxae166
Bacterial exopolysaccharide amendment improves the shelf life and functional efficacy of bioinoculant under salinity stress.
Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110016, India.
AIM: Bacterial exopolysaccharides (EPS) possess numerous properties beneficial for the growth of microbes and plants under hostile conditions. The study aimed to develop a bioformulation with bacterial EPS to enhance the bioinoculant's shelf life and functional efficacy under salinity stress. METHODS AND RESULTS: High EPS-producing and salt-tolerant bacterial strain (Bacillus haynessi SD2) exhibiting auxin-production, phosphate-solubilization, and biofilm-forming ability, was selected. EPS-based bioformulation of SD2 improved the growth of three legumes under salt stress, from which pigeonpea was selected for further experiments. SD2 improved the growth and lowered the accumulation of stress markers in plants under salt stress. Bioformulations with varying EPS concentrations (1% and 2%) were stored for 6 months at 4 degrees C, 30 degrees C, and 37 degrees C to assess their shelf life and functional efficacy. The shelf life and efficacy of EPS-based bioformulation were sustained even after 6 months of storage at high temperature, enhancing pigeonpea growth under stress in both control and natural conditions. However, the efficacy of non EPS-based bioformulation declined following four months of storage. The bioformulation (with 1% EPS) modulated bacterial abundance in the plant's rhizosphere under stress conditions. CONCLUSION: The study brings forth a new strategy for developing next-generation bioformulations with higher shelf life and efficacy for salinity stress management in pigeonpea.
PMID: 38960398
Gene , IF:3.688 , 2024 Oct , V926 : P148623 doi: 10.1016/j.gene.2024.148623
Transcriptome analysis reveals the key network of axillary bud outgrowth modulated by topping in citrus.
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops / College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, PR China.; National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops / College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, PR China. Electronic address: liuyongzhong@mail.hzau.edu.cn.
Topping, an important tree shaping and pruning technique, can promote the outgrowth of citrus axillary buds. However, the underlying molecular mechanism is still unclear. In this study, spring shoots of Citrus reticulata 'Huagan No.2' were topped and transcriptome was compared between axillary buds of topped and untopped shoots at 6 and 11 days after topping (DAT). 1944 and 2394 differentially expressed genes (DEGs) were found at 6 and 11 DAT, respectively. KEGG analysis revealed that many DEGs were related to starch and sucrose metabolism, signal transduction of auxin, cytokinin and abscisic acid. Specially, transcript levels of auxin synthesis, transport, and signaling-related genes (SAURs and ARF5), cytokinin signal transduction related genes (CRE1, AHP and Type-A ARRs), ABA signal responsive genes (PYL and ABF) were up-regulated by topping; while transcript levels of auxin receptor TIR1, auxin responsive genes AUX/IAAs, ABA signal transduction related gene PP2Cs and synthesis related genes NCED3 were down-regulated. On the other hand, the contents of sucrose and fructose in axillary buds of topped shoots were significantly higher than those in untopped shoots; transcript levels of 16 genes related to sucrose synthase, hexokinase, sucrose phosphate synthase, endoglucanase and glucosidase, were up-regulated in axillary buds after topping. In addition, transcript levels of genes related to trehalose 6-phosphate metabolism and glycolysis/tricarboxylic acid (TCA) cycle, as well to some transcription factors including Pkinase, Pkinase_Tyr, Kinesin, AP2/ERF, P450, MYB, NAC and Cyclin_c, significantly responded to topping. Taken together, the present results suggested that topping promoted citrus axillary bud outgrowth through comprehensively regulating plant hormone and carbohydrate metabolism, as well as signal transduction. These results deepened our understanding of citrus axillary bud outgrowth by topping and laid a foundation for further research on the molecular mechanisms of citrus axillary bud outgrowth.
PMID: 38821328
Gene , IF:3.688 , 2024 Aug , V921 : P148532 doi: 10.1016/j.gene.2024.148532
Identification of cotton PIP5K genes and role of GhPIP5K9a in primary root development.
National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research of Chinese Academy of Agricultural Sciences (CAAS), Anyang 455000, China; Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji 831100, China.; Anyang Academy of Agricultural Sciences, Anyang 455000, China.; National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research of Chinese Academy of Agricultural Sciences (CAAS), Anyang 455000, China.; National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya 572024, China; National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research of Chinese Academy of Agricultural Sciences (CAAS), Anyang 455000, China.; National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya 572024, China; National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research of Chinese Academy of Agricultural Sciences (CAAS), Anyang 455000, China; Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji 831100, China. Electronic address: fsl427@126.com.; National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research of Chinese Academy of Agricultural Sciences (CAAS), Anyang 455000, China; Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji 831100, China. Electronic address: 13837240176@163.com.
Phosphatidylinositol 4 phosphate 5-kinase (PIP5K) is crucial for the phosphatidylinositol (PI) signaling pathway. It plays a significant role in plant growth and development, as well as stress response. However, its effects on cotton are unknown. This study identified PIP5K genes from four cotton species and conducted bioinformatic analyses, with a particular emphasis on the functions of GhPIP5K9a in primary roots. The results showed that cotton PIP5Ks were classified into four subgroups. Analysis of gene structure and motif composition showed obvious conservation within each subgroup. Synteny analysis suggested that the PIP5K gene family experienced significant expansion due to both whole-genome duplication (WGD) and segmental duplication. Transcriptomic data analysis revealed that the majority of GhPIP5K genes had the either low or undetectable levels of expression. Moreover, GhPIP5K9a is highly expressed in the root and was located in plasmalemma. Suppression of GhPIP5K9a transcripts resulted in longer primary roots, longer primary root cells and increased auxin polar transport-related genes expression, and decreased abscisic acid (ABA) content, indicating that GhPIP5K9a negatively regulates cotton primary root growth. This study lays the foundation for further exploration of the role of the PIP5K genes in cotton.
PMID: 38705423
Gene , IF:3.688 , 2024 Jul , V915 : P148423 doi: 10.1016/j.gene.2024.148423
The vesicle trafficking gene, OsRab7, is critical for pollen development and male fertility in cytoplasmic male-sterility rice.
Key Laboratory of Molecular Biology and Gene Engineering of Jiangxi Province, College of Life Sciences, Nanchang University, Nanchang 330031, China.; Department of Chemistry, University of Kentucky, Lexington, United States.; Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China. Electronic address: liuwei@gdaas.cn.; Key Laboratory of Molecular Biology and Gene Engineering of Jiangxi Province, College of Life Sciences, Nanchang University, Nanchang 330031, China. Electronic address: xiaojuepeng@ncu.edu.cn.
Rice cytoplasmic male sterility (CMS) provides an exceptional model for studying genetic interaction within plant nuclei given its inheritable trait of non-functional male gametophyte. Gaining a comprehensive understanding of the genes and pathways associated with the CMS mechanism is imperative for improving the vigor of hybrid rice agronomically, such as its productivity. Here, we observed a significant decrease in the expression of a gene named OsRab7 in the anther of the CMS line (SJA) compared to the maintainer line (SJB). OsRab7 is responsible for vesicle trafficking and loss function of OsRab7 significantly reduced pollen fertility and setting rate relative to the wild type. Meanwhile, over-expression of OsRab7 enhanced pollen fertility in the SJA line while a decrease in its expression in the SJB line led to the reduced pollen fertility. Premature tapetum and abnormal development of microspores were observed in the rab7 mutant. The expression of critical genes involved in tapetum development (OsMYB103, OsPTC1, OsEAT1 and OsAP25) and pollen development (OsMSP1, OsDTM1 and OsC4) decreased significantly in the anther of rab7 mutant. Reduced activities of the pDR5::GUS marker in the young panicle and anther of the rab7 mutant were also observed. Furthermore, the mRNA levels of genes involved in auxin biosynthesis (YUCCAs), auxin transport (PINs), auxin response factors (ARFs), and members of the IAA family (IAAs) were all downregulated in the rab7 mutant, indicating its impact on auxin signaling and distribution. In summary, these findings underscore the importance of OsRab7 in rice pollen development and its potential link to cytoplasmic male sterility.
PMID: 38575100
J Plant Physiol , IF:3.549 , 2024 Jul , V302 : P154318 doi: 10.1016/j.jplph.2024.154318
NHX5/NHX6/SPY22 complex regulates BRI1 and brassinosteroid signaling in Arabidopsis.
Academy of Plateau Science and Sustainability, School of Life Sciences, Qinghai Normal University, Xining, Qinghai, 810000, China.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China; College of Life Science and Technology, Tarim University, Alar, 843300, China.; MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China. Electronic address: qiuqsh@lzu.edu.cn.
NHX5 and NHX6, Arabidopsis endosomal antiporters, play a vital role in facilitating ion and pH homeostasis in endosomal compartments. Studies have found that NHX5 and NHX6 are essential for protein trafficking, auxin homeostasis, and plant growth and development. Here, we report the role of NHX5 and NHX6 in brassinosteroid (BR) signaling. We found that hypocotyl growth was enhanced in nhx5 nhx6 under epibrassinolide (eBR) treatment. nhx5 nhx6 bri1 was insensitive to eBR treatment, indicating that NHX5 and NHX6 are downstream of the BRI1 receptor in BR signaling. Moreover, confocal observation with both hypocotyls and root tips showed that BRI1-YFP localization in the plasma membrane (PM) was reduced in nhx5 nhx6. Interestingly, brefeldin A (BFA) treatment showed that formation of the BFA bodies containing BRI1 and their disassembling were disrupted in nhx5 nhx6. Further genetic analysis showed that NHX5/NHX6 and SYP22 may act coordinately in BR signaling. NHX5 and NHX6 may regulate SYP22 function by modulating cellular K(+) and pH homeostasis. Importantly, NHX5 and NHX6 colocalize and interact with SYP22, but do not interact with BRI1. In summary, our findings indicate that NHX5/NHX6/SYP22 complex is essential for the regulation of BRI1 recycling and PM localization. The H(+)-leak facilitated by NHX5 and NHX6 offers a means of controlling BR signaling in plants.
PMID: 39059150
J Plant Physiol , IF:3.549 , 2024 Jul , V301 : P154313 doi: 10.1016/j.jplph.2024.154313
miRNAs: Primary modulators of plant drought tolerance.
State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China.; State Key Laboratory of Tree Genetics and Breeding, National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083, China. Electronic address: ywwang@bjfu.edu.cn.
Drought is a principal environmental factor that affects the growth and development of plants. Accordingly, plants have evolved adaptive mechanisms to cope with adverse environmental conditions. One of the mechanisms is gene regulation mediated by microRNAs (miRNAs). miRNAs are regarded as primary modulators of gene expression at the post-transcriptional level and have been shown to participate in drought stress response, including ABA response, auxin signaling, antioxidant defense, and osmotic regulation through downregulating the corresponding targets. miRNA-based genetic reconstructions have the potential to improve the tolerance of plants to drought. However, there are few precise classification and discussion of miRNAs in specific response behaviors to drought stress and their applications. This review summarized and discussed the specific response behaviors of miRNAs under drought stress and the role of miRNAs as regulators in the response of plants to drought and highlighted that the modification of miRNAs might effectively improve the tolerance of plants to drought.
PMID: 38991233
Phytochem Anal , IF:3.373 , 2024 Jul , V35 (5) : P1052-1062 doi: 10.1002/pca.3340
A rapid and robust colorimetric method for measuring relative abundance of auxins in plant tissues.
National Institute of Plant Genome Research, New Delhi, India.
INTRODUCTION: Auxin estimation in plant tissues is a crucial component of auxin signaling studies. Despite the availability of various high-throughput auxin quantification methods like LC-MS, GC-MS, HPLC, biosensors, and DR5-gus/gfp-based assays, auxin quantification remains troublesome because these techniques are very expensive and technology intensive and they mostly involve elaborate sample preparation or require the development of transgenic plants. OBJECTIVES: To find a solution to these problems, we made use of an old auxin detection system to quantify microbe derived auxins and modified it to effectively measure auxin levels in rice plants. MATERIALS AND METHODS: Auxins from different tissues of rice plants, including root samples of seedlings exposed to IAA/TIBA or subjected to different abiotic stresses, were extracted in ethanol. The total auxin level was measured by the presently described colorimetric assay and counterchecked by other auxin estimation methods like LC-MS or gus staining of DR5-gus overexpressing lines. RESULTS: The presented colorimetric method could measure (1) the auxin levels in different tissues of rice plants, thus identifying the regions of higher auxin abundance, (2) the differential accumulation of auxins in rice roots when auxin or its transport inhibitor was supplied exogenously, and (3) the levels of auxin in roots of rice seedlings subjected to various abiotic stresses. The thus obtained auxin levels correlated well with the auxin levels determined by other methods like LC-MS or gus staining and the expression pattern of auxin biosynthesis pathway genes. CONCLUSIONS: The auxin estimation method described here is simple, rapid, cost-effective, and sensitive and allows for the efficient detection of relative auxin abundances in plant tissues.
PMID: 38419380
Environ Technol , IF:3.247 , 2024 Aug , V45 (20) : P4003-4016 doi: 10.1080/09593330.2023.2238928
Isolation of bacteria with plant growth-promoting properties from microalgae-bacterial flocs produced in high-rate oxidation ponds.
Institute for Environmental Biotechnology, Rhodes University (EBRU), Makhanda, South Africa.
Exploring plant growth-promoting (PGP) bacterial activity of microbial components aggregated by wastewater treatment can reduce dependence on fossil fuel-derived fertilisers. This study describes the isolation and identification of bacteria from microalgae-bacteria flocs (MaB-flocs) generated in high-rate algal oxidation ponds (HRAOP) of an integrated algal pond system (IAPS) remediating municipal wastewater. Amplified 16S rRNA gene sequence analysis determined the molecular identity of the individual strains. Genetic relatedness to known PGP rhizobacteria in the NCBI GenBank database was by metagenomics. Isolated strains were screened for the production of indoles (measured as indole-3-acetic acid; IAA) and an ability to mineralise NH4+, PO43-, and K (+) . Of the twelve bacterial strains isolated from HRAOP MaB-flocs, four produced indoles, nine mineralised NH4+, seven solubilised P, and one K. Potential of isolated strains for PGP activity according to one-way ANOVA on ranks was: ECCN 7b > ECCN 4b > ECCN 6b > ECCN 3b = ECCN 10b > ECCN 1b = ECCN 5b > ECCN 8b > ECCN 2b > ECCN 12b > ECCN 9b = ECCN 11b. Further study revealed that cell-free filtrate from indole-producing cultures of Aeromonas strain ECCN 4b, Enterobacter strain ECCN 7b, and Arthrobacter strain ECCN 6b promoted mung bean adventitious root formation suggestive of the presence of auxin-like biological activity.
PMID: 37469005
3 Biotech , IF:2.406 , 2024 Jul , V14 (7) : P174 doi: 10.1007/s13205-024-04019-1
Transcriptomic and metabolomic profiling reveals molecular regulatory network involved in flower development and phenotypic changes in two Lonicera macranthoides varieties.
College of Pharmacy, Hunan University of Chinese Medicine, Changsha, 410208 Hunan Province China. GRID: grid.488482.a. ISNI: 0000 0004 1765 5169; Key Laboratory of Germplasm Resources and Standardized Planting of Hunan Large-Scale Genuine Medicinal Materials, Changsha, 410208 Hunan Province China.; Key Laboratory of Modern Research of TCM, Education Department of Hunan Province, Changsha, 410208 Hunan Province China. ROR: https://ror.org/05ckg3w11. GRID: grid.454772.7. ISNI: 0000 0004 5901 2284
Due to the medicinal importance of the flowers of Xianglei type (XL) Lonicera macranthoides, it is important to understand the molecular mechanisms that underlie their development. In this study, we elucidated the transcriptomic and metabolomic mechanisms that underlie the flower development mechanism of two L. macranthoides varieties. In this study, 3435 common differentially expressed unigenes (DEGs) and 1138 metabolites were identified. These common DEGs were mainly enriched in plant hormone signal transduction pathways. Metabolomic analysis showed that amino acids were the main metabolites of differential accumulation in wild-type (WT) L. macranthoides, whereas in XL, they were flavonoids and phenylalanine metabolites. Genes and transcription factors (TFs), such as MYB340, histone deacetylase 1 (HDT1), small auxin-up RNA 32 (SAUR32), auxin response factor 6 (ARF6), PIN-LIKES 7 (PILS7), and WRKY6, likely drive metabolite accumulation. Plant hormone signals, especially auxin signals, and various TFs induce downstream flower organ recognition genes, resulting in a differentiation of the two L. macranthoides varieties in terms of their developmental trajectories. In addition, photoperiodic, autonomous, and plant hormone pathways jointly regulated the L. macranthoides corolla opening. SAUR32, Arabidopsis response regulator 9 (ARR9), Gibberellin receptor (GID1B), and Constans-like 10 (COL10) were closely related to the unfolding of the L. macranthoides corolla. These findings offer valuable understanding of the flower growth process of L. macranthoides and the excellent XL phenotypes at the molecular level. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-024-04019-1.
PMID: 38855147
Antonie Van Leeuwenhoek , IF:2.271 , 2024 Jul , V117 (1) : P105 doi: 10.1007/s10482-024-01989-3
Genomics and taxonomy of the glyphosate-degrading, copper-tolerant rhizospheric bacterium Achromobacter insolitus LCu2.
Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, Russia, 410049. kryu-lena@yandex.ru.; Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 13 Prospekt Entuziastov, Saratov, Russia, 410049.; Institute for Cellular and Intracellular Symbiosis, Ural Branch of the Russian Academy of Sciences, 11 Pionerskaya Street, Orenburg, Russia, 460000.; Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlyovskaya Street, Kazan, Russia, 420111.; All-Russia Research Institute for Agricultural Microbiology, 3 Podbelsky Shausse, Pushkin 8, St. Petersburg, Russia, 196608.; Faculty of Agronomy, Saratov State University of Genetics, Biotechnology and Engineering named after N.I. Vavilov, 4 Pyotr Stolypin Avenue, Saratov, Russia, 410012.; Moscow Clinical Scientific Center named after Loginov MHD, 1 Novogireevskaya Street, Moscow, Russia, 111123.; Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 2/31 Lobachevsky Street, Kazan, Russia, 420111.; Institute of Chemistry, Chernyshevsky Saratov State University, 83 Astrakhanskaya Street, Saratov, Russia, 410012.
A rhizosphere strain, Achromobacter insolitus LCu2, was isolated from alfalfa (Medicago sativa L.) roots. It was able to degrade of 50% glyphosate as the sole phosphorus source, and was found resistant to 10 mM copper (II) chloride, and 5 mM glyphosate-copper complexes. Inoculation of alfalfa seedlings and potato microplants with strain LCu2 promoted plant growth by 30-50%. In inoculated plants, the toxicity of the glyphosate-copper complexes to alfalfa seedlings was decreased, as compared with the noninoculated controls. The genome of A. insolitus LCu2 consisted of one circular chromosome (6,428,890 bp) and encoded 5843 protein genes and 76 RNA genes. Polyphasic taxonomic analysis showed that A. insolitus LCu2 was closely related to A. insolitus DSM23807(T) on the basis of the average nucleotide identity of the genomes of 22 type strains and the multilocus sequence analysis. Genome analysis revealed genes putatively responsible for (1) plant growth promotion (osmolyte, siderophore, and 1-aminocyclopropane-1-carboxylate deaminase biosynthesis and auxin metabolism); (2) degradation of organophosphonates (glyphosate oxidoreductase and multiple phn clusters responsible for the transport, regulation and C-P lyase cleavage of phosphonates); and (3) tolerance to copper and other heavy metals, effected by the CopAB-CueO system, responsible for the oxidation of copper (I) in the periplasm, and by the efflux Cus system. The putative catabolic pathways involved in the breakdown of phosphonates are predicted. A. insolitus LCu2 is promising in the production of crops and the remediation of soils contaminated with organophosphonates and heavy metals.
PMID: 39043973
Plant Signal Behav , IF:2.247 , 2024 Dec , V19 (1) : P2383822 doi: 10.1080/15592324.2024.2383822
Highly efficient CRISPR/Cas9-RNP mediated CaPAD1 editing in protoplasts of three pepper (Capsicum annuum L.) cultivars.
Department of Biological Sciences, Kangwon National University, Chuncheon, Republic of Korea.; Interdisciplinary Program of Genomic Data Science, Pusan National University, Busan, Republic of Korea.; Graduate School of Medical AI, Pusan National University, Busan, Republic of Korea.; Interdisciplinary Graduate Program in BIT Medical Convergence, Kangwon National University, Chuncheon, Republic of Korea.
Parthenocarpy, characterized by seedless fruit development without pollination or fertilization, offers the advantage of consistent fruit formation, even under challenging conditions such as high temperatures. It can be induced by regulating auxin homeostasis; PAD1 (PARENTAL ADVICE-1) is an inducer of parthenocarpy in Solanaceae plants. However, precise editing of PAD1 is not well studied in peppers. Here, we report a highly efficient clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) ribonucleoprotein (RNP) for CaPAD1 editing in three valuable cultivars of pepper (Capsicum annuum L.): Dempsey, a gene-editable bell pepper; C15, a transformable commercial inbred line; and Younggo 4, a Korean landrace. To achieve the seedless pepper trait under high temperatures caused by unstable climate change, we designed five single guide RNAs (sgRNAs) targeting the CaPAD1 gene. We evaluated the in vitro on-target activity of the RNP complexes in three cultivars. Subsequently, we introduced five CRISPR/Cas9-RNP complexes into protoplasts isolated from three pepper leaves and compared indel frequencies and patterns through targeted deep sequencing analyses. We selected two sgRNAs, sgRNA2 and sgRNA5, which had high in vivo target efficiencies for the CaPAD1 gene across the three cultivars and were validated as potential off-targets in their genomes. These findings are expected to be valuable tools for developing new seedless pepper cultivars through precise molecular breeding of recalcitrant crops in response to climate change.
PMID: 39052485
Plant Signal Behav , IF:2.247 , 2024 Dec , V19 (1) : P2348917 doi: 10.1080/15592324.2024.2348917
Investigation of Arabidopsis root skototropism with different distance settings.
Institute of Cellular and Molecular Botany, University of Bonn, Bonn, Germany.
Plants can activate protective and defense mechanisms under biotic and abiotic stresses. Their roots naturally grow in the soil, but when they encounter sunlight in the top-soil layers, they may move away from the light source to seek darkness. Here we investigate the skototropic behavior of roots, which promotes their fitness and survival. Glutamate-like receptors (GLRs) of plants play roles in sensing and responding to signals, but their role in root skototropism is not yet understood. Light-induced tropisms are known to be affected by auxin distribution, mainly determined by auxin efflux proteins (PIN proteins) at the root tip. However, the role of PIN proteins in root skototropism has not been investigated yet. To better understand root skototropism and its connection to the distance between roots and light, we established five distance settings between seedlings and darkness to investigate the variations in root bending tendencies. We compared differences in root skototropic behavior across different expression lines of Arabidopsis thaliana seedlings (atglr3.7 ko, AtGLR3.7 OE, and pin2 knockout) to comprehend their functions. Our research shows that as the distance between roots and darkness increases, the root's positive skototropism noticeably weakens. Our findings highlight the involvement of GLR3.7 and PIN2 in root skototropism.
PMID: 38704856
Plant Signal Behav , IF:2.247 , 2024 Dec , V19 (1) : P2341506 doi: 10.1080/15592324.2024.2341506
Complex genetic interaction between glucose sensor HXK1 and E3 SUMO ligase SIZ1 in regulating plant morphogenesis.
National Institute of Plant Genome Research, New Delhi, India.
Sugar signaling forms the basis of metabolic activities crucial for an organism to perform essential life activities. In plants, sugars like glucose, mediate a wide range of physiological responses ranging from seed germination to cell senescence. This has led to the elucidation of cell signaling pathways involving glucose and its counterparts and the mechanism of how these sugars take control over major hormonal pathways such as auxin, ethylene, abscisic acid and cytokinin in Arabidopsis. Plants use HXK1(Hexokinase) as a glucose sensor to modulate changes in photosynthetic gene expression in response to high glucose levels. Other proteins such as SIZ1, a major SUMO E3 ligase have recently been implicated in controlling sugar responses via transcriptional and translational regulation of a wide array of sugar metabolic genes. Here, we show that these two genes work antagonistically and are epistatic in controlling responsiveness toward high glucose conditions.
PMID: 38607960
Plant Signal Behav , IF:2.247 , 2024 Dec , V19 (1) : P2331358 doi: 10.1080/15592324.2024.2331358
Plant hormone profiling of scion and rootstock incision sites and intra- and inter-family graft junctions in Nicotiana benthamiana.
Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.; RIKEN Center for Sustainable Resource Science, Plant Productivity Systems Research Group, Yokohama, Japan.
Many previous studies have suggested that various plant hormones play essential roles in the grafting process. In this study, to understand the plant hormones that accumulate in the graft junctions, whether these are supplied from the scion or rootstock, and how these hormones play a role in the grafting process, we performed a hormonome analysis that accumulated in the incision site of the upper plants from the incision as "ungrafted scion" and lower plants from the incision as "ungrafted rootstock" in Nicotiana benthamiana. The results revealed that indole-3-acetic acid (IAA) and gibberellic acid (GA), which regulate cell division; abscisic acid (ABA) and jasmonic acid (JA), which regulate xylem formation; cytokinin (CK), which regulates callus formation, show different accumulation patterns in the incision sites of the ungrafted scion and rootstock. In addition, to try discussing the differences in the degree and speed of each event during the grafting process between intra- and inter-family grafting by determining the concentration and accumulation timing of plant hormones in the graft junctions, we performed hormonome analysis of graft junctions of intra-family grafted plants with N. benthamiana as scion and Solanum lycopersicum as rootstock (Nb/Sl) and inter-family grafted plants with N. benthamiana as scion and Arabidopsis thaliana as rootstock (Nb/At), using the ability of Nicotiana species to graft with many plant species. The results revealed that ABA and CK showed different accumulation timings; IAA, JA, and salicylic acid (SA) showed similar accumulation timings, while different accumulated concentrations in the graft junctions of Nb/Sl and Nb/At. This information is important for understanding the molecular mechanisms of plant hormones in the grafting process and the differences in molecular mechanisms between intra- and inter-family grafting.
PMID: 38513064
Plant Signal Behav , IF:2.247 , 2024 Dec , V19 (1) : P2305030 doi: 10.1080/15592324.2024.2305030
Cytokinin signaling is involved in root hair elongation in response to phosphate starvation.
School of Biological Science and Technology, College of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa, Japan.; Graduate School of Science and Technology, Nara Institute of Science and Technology, Takayama, Ikoma, Nara, Japan.
Root hair, single-celled tubular structures originating from the epidermis, plays a vital role in the uptake of nutrients from the soil by increasing the root surface area. Therefore, optimizing root hair growth is crucial for plants to survive in fluctuating environments. Root hair length is determined by the action of various plant hormones, among which the roles of auxin and ethylene have been extensively studied. However, evidence for the involvement of cytokinins has remained elusive. We recently reported that the cytokinin-activated B-type response regulators, ARABIDOPSIS RESPONSE REGULATOR 1 (ARR1) and ARR12 directly upregulate the expression of ROOT HAIR DEFECTIVE 6-LIKE 4 (RSL4), which encodes a key transcription factor that controls root hair elongation. However, depending on the nutrient availability, it is unknown whether the ARR1/12-RSL4 pathway controls root hair elongation. This study shows that phosphate deficiency induced the expression of RSL4 and increased the root hair length through ARR1/12, though the transcript and protein levels of ARR1/12 did not change. These results indicate that cytokinins, together with other hormones, regulate root hair growth under phosphate starvation conditions.
PMID: 38267225
BioTech (Basel) , 2024 Jul , V13 (3) doi: 10.3390/biotech13030025
An Efficient and Rapid Protocol for Somatic Shoot Organogenesis from Juvenile Hypocotyl-Derived Callus of Castor Bean cv. Zanzibar Green.
All-Russia Research Institute of Agricultural Biotechnology, Timiryazevskaya 42, 127434 Moscow, Russia.; Agrobiotechnology Institute, Russian State Agrarian University-Moscow Timiryazev Agricultural Academy, Timiryazevskaya 49, 127434 Moscow, Russia.
Aseptic seedlings of different ages derived from surface-sterilized mature seeds were applied as an explant source. Various explants such as 7- and 21-day-old hypocotyl fragments, 42-day-old nodal stem segments, and transverse nodal segments of stem, as well as leaf petioles, were cultured on the agar-solidified Murashige and Skoog (MS) basal medium supplemented with 0.1 mg/L IAA, 5 mg/L AgNO(3) and different types and concentrations of cytokinin (1 mg/L zeatin, 0.25 mg/L thidiazuron (TDZ), and 5 mg/L 6-benzylaminopurine (6-BAP)). Consequently, it was found that 7- and 21-day-old hypocotyl fragments, as well as nodal stem segments obtained from adult aseptic seedlings, are characterized by a high explant viability and callus formation capacity with a frequency of 79.7-100%. However, the success of in vitro somatic shoot organogenesis was significantly determined not only by the culture medium composition and explant type but also depending on its age, as well as on the size and explant preparation in cases of hypocotyl and age-matched nodal stem fragments, respectively. Multiple somatic shoot organogenesis (5.7 regenerants per explant) with a frequency of 67.5% was achieved during 3 subcultures of juvenile hypocotyl-derived callus tissue on MS culture medium containing 0.25 mg/L TDZ as cytokinin source. Castor bean regenerants were excised from the callus and successfully rooted on (1/2) MS basal medium without exogenous auxin (81%). In vitro plantlets with well-developed roots were adapted to ex vitro conditions with a frequency of 90%.
PMID: 39051340
BMC Genom Data , 2024 Jul , V25 (1) : P71 doi: 10.1186/s12863-024-01248-4
Genome-wide analysis and identification of Carotenoid Cleavage Oxygenase (CCO) gene family in coffee (coffee arabica) under abiotic stress.
School of Public Policy & Management, China University of Mining and Technology, Xuzhou, China.; Department of Plant Breeding and Genetics, Faculty of Agricultural Sciences, University of the Punjab, P.O BOX. 54590, Lahore, Pakistan.; School of Biological Sciences and Technology, Liupanshui Normal University, Liupanshui, 553004, China.; School of Public Policy & Management, China University of Mining and Technology, Xuzhou, China. hanshiliang888@163.com.; School of Biological Sciences and Technology, Liupanshui Normal University, Liupanshui, 553004, China. hanshiliang888@163.com.; Department of Horticulture, Faculty of Agricultural Sciences, University of the Punjab, P.O BOX. 54590, Lahore, Pakistan.; Department of Horticulture, Faculty of Agricultural Sciences, University of the Punjab, P.O BOX. 54590, Lahore, Pakistan. shafiq.iags@pu.edu.pk.; Department of Plant Breeding and Genetics, Faculty of Agricultural Sciences, University of the Punjab, P.O BOX. 54590, Lahore, Pakistan. saim1692@gmail.com.; Department of Entomology, Faculty of Agricultural Sciences, University of the Punjab, P.O BOX. 54590, Lahore, Pakistan.; College of Horticulture, South China Agricultural University, Guangzhou, 510642, China.; School of Environment and Surveying, China University of Mining and Technology, Xuzhou, Jiangsu, 221116, China.; Department of Biology, College of Science and Humanities, Prince Sattam Bin Abdulaziz University, Alkharj, 11942, Saudi Arabia.; Department of Plant Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China. aamirmanzoor1@hotmail.com.
The coffee industry holds importance, providing livelihoods for millions of farmers globally and playing a vital role in the economies of coffee-producing countries. Environmental conditions such as drought and temperature fluctuations can adversely affect the quality and yield of coffee crops.Carotenoid cleavage oxygenases (CCO) enzymes are essential for coffee plants as they help break down carotenoids contributing to growth and stress resistance. However, knowledge about the CCO gene family in Coffee arabica was limited. In this study identified 21 CCO genes in Coffee arabica (C. arabica) revealing two subfamilies carotenoid cleavage dioxygenases (CCDs) and 9-cis-epoxy carotenoid dioxygenases (NCED) through phylogenic analysis. These subfamilies exhibited distribution patterns in terms of gene structure, domains, and motifs. The 21 CaCCO genes, comprising 5 NCED and 16 CCD genes were found across chromosomes. Promoter sequencing analysis revealed cis-elements that likely interact with plant stress-responsive, growth-related, and phytohormones, like auxin and abscisic acid. A comprehensive genome-wide comparison, between C. arabica and A. thaliana was conducted to understand the characteristics of CCO genes. RTqPCR data indicated that CaNCED5, CaNCED6, CaNCED12, and CaNCED20 are target genes involved in the growth of drought coffee plants leading to increased crop yield, in a conditions, with limited water availability. This reveals the role of coffee CCOs in responding to abiotic stress and identifies potential genes useful for breeding stress-resistant coffee varieties.
PMID: 39030545
Biotechnol Biofuels Bioprod , 2024 Jul , V17 (1) : P105 doi: 10.1186/s13068-024-02551-z
An integrated QTL and RNA-seq analysis revealed new petal morphology loci in Brassica napus L.
College of Life Science and Technology, Key Laboratory of Molecular Biophysics of the Ministry of Education, Huazhong University of Science and Technology, Wuhan, 430074, China.; School of Agricultural Sciences, Zhengzhou University, Zhengzhou, 450001, China.; College of Life Science and Technology, Key Laboratory of Molecular Biophysics of the Ministry of Education, Huazhong University of Science and Technology, Wuhan, 430074, China. limaoteng426@hust.edu.cn.
BACKGROUND: Rapeseed (Brassica napus L.) is one of the most important oil crops and a wildly cultivated horticultural crop. The petals of B. napus serve to protect the reproductive organs and attract pollinators and tourists. Understanding the genetic basis of petal morphology regulation is necessary for B. napus breeding. RESULTS: In the present study, the quantitative trait locus (QTL) analysis for six B. napus petal morphology parameters in a double haploid (DH) population was conducted across six microenvironments. A total of 243 QTLs and five QTL hotspots were observed, including 232 novel QTLs and three novel QTL hotspots. The spatiotemporal transcriptomic analysis of the diversiform petals was also conducted, which indicated that the expression of plant hormone metabolic and cytoskeletal binding protein genes was variant among diversiform petals. CONCLUSIONS: The integration of QTL and RNA-seq analysis revealed that plant hormones (including cytokinin, auxin, and gibberellin) and cytoskeleton were key regulators of the petal morphology. Subsequently, 61 high-confidence candidate genes of petal morphology regulation were identified, including Bn.SAUR10, Bn.ARF18, Bn.KIR1, Bn.NGA2, Bn.PRF1, and Bn.VLN4. The current study provided novel QTLs and candidate genes for further breeding B. napus varieties with diversiform petals.
PMID: 39026359
Plant Commun , 2024 Jul : P101039 doi: 10.1016/j.xplc.2024.101039
Quantitative imaging reveals the role of MpARF proteasomal degradation during gemma germination.
Laboratory of Biochemistry, Wageningen University and Research, the Netherlands; Current address: Institute of Science and Technology, Austria.; Laboratory of Biochemistry, Wageningen University and Research, the Netherlands.; School of Mathematical Sciences, University of Nottingham, United Kingdom.; Laboratory of Molecular Biology, Wageningen University and Research, the Netherlands.; Laboratory of Biochemistry, Wageningen University and Research, the Netherlands. Electronic address: dolf.weijers@wur.nl.
The auxin signaling molecule controls a variety of growth and developmental processes in land plants. Auxin regulates gene expression through a nuclear auxin signaling pathway (NAP) consisting of a ubiquitin ligase auxin receptor TIR1/AFB, its Aux/IAA degradation substrate, and DNA-binding ARF transcription factors. While extensive qualitative understanding of the pathway and its interactions has been obtained, mostly by studying the flowering plant Arabidopsis thaliana, it is so far unknown how these translate to quantitative system behaviour in vivo, a problem that is confounded by large NAP gene families in most species. Here we used the minimal NAP of the liverwort Marchantia polymorpha to quantitatively map NAP protein accumulation and dynamics in vivo through the use of knock-in fluorescent fusion proteins. Beyond revealing the dynamic native accumulation profile of the entire NAP protein network, we discovered that the two central ARFs, MpARF1 and MpARF2, are proteasomally degraded. This auxin-independent degradation tunes ARF protein stoichiometry to favor gene activation, thereby reprogramming auxin response during developmental progression. Thus, quantitative analysis of the entire NAP allowed us to identify ARF degradation and stoichiometries of activator and repressor ARFs as a potential mechanism for controlling gemma germination.
PMID: 38988072
Braz J Biol , 2024 , V84 : Pe284946 doi: 10.1590/1519-6984.284946
Creation of rice doubled haploids with low amylose content using in vitro anther culture.
Institute of Plant Biology and Biotechnology - IPBB, Almaty, Kazakhstan.; Al-Farabi Kazakh National University, Almaty, Kazakhstan.; Almaty Technological University, Almaty, Kazakhstan.
In vitro androgenesis is a unique model for producing homozygous doubled haploid plants. The use of haploid biotechnology accelerates to obtain of doubled haploid plants, which is very important in rice breeding. The purpose of this work is to improve the production of doubled haploids in rice anther culture in vitro and selection of doubled haploid plants with valuable traits. The study the influence of nutrient media on the production of calli and plant regeneration processes in anther culture of 35 rice genotypes was revealed a significant influence of nutrient media on callus production. It was shown that the addition to culture medium phytohormones ratio with high level of cytokinin (5.0 mg/L BAP) and a low level of auxin (0.5 mg/L NAA), supplemented with amino acid composition promotes high production of green regenerated plants (68.75%) compared to albino plants (31.25%). As a result, doubled haploid lines of the glutinous variety Violetta were selected, which characterized by a low amylose content variation (from 1.86 to 2.80%). These doubled haploids are superior to the original variety in some yield traits and represent valuable breeding material.
PMID: 38985062
J Genet Genomics , 2024 Jul doi: 10.1016/j.jgg.2024.06.019
The interplay between extracellular and intracellular auxin signaling in plants.
Haixia Institute of Science and Technology, and College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.; Haixia Institute of Science and Technology, and College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China. Electronic address: tdxu@sibs.ac.cn.
The phytohormone auxin exerts control over remarkable developmental processes in plants. It moves from cell to cell, resulting in the creation of both extracellular auxin and intracellular auxin, which are recognized by distinct auxin receptors. These two auxin signaling systems govern different auxin responses while working together to regulate plant development. In this review, we outline the latest research advancements in unraveling these auxin signaling pathways, encompassing auxin perception and signaling transductions. We emphasize the interaction between extracellular auxin and intracellular auxin, which contributes to the intricate role of auxin in plant development.
PMID: 38969259
Mol Breed , 2024 Jul , V44 (7) : P47 doi: 10.1007/s11032-024-01484-7
A novel regulator of wheat tillering LT1 identified by using an upgraded BSA method, uni-BSA.
National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Tai'an, 271018 China. ROR: https://ror.org/02ke8fw32. GRID: grid.440622.6. ISNI: 0000 0000 9482 4676; Plant Sciences, Gembloux Agro-Bio Tech, University of Liege, Liege, Belgium. GRID: grid.4861.b. ISNI: 0000 0001 0805 7253
Branching/tillering is a critical process for plant architecture and grain yield. However, Branching is intricately controlled by both endogenous and environmental factors. The underlying mechanisms of tillering in wheat remain poorly understood. In this study, we identified Less Tiller 1 (LT1) as a novel regulator of wheat tillering using an enhanced bulked segregant analysis (BSA) method, uni-BSA. This method effectively reduces alignment noise caused by the high repetitive sequence content in the wheat genome. Loss-of-function of LT1 results in fewer tillers due to defects in axillary meristem initiation and bud outgrowth. We mapped LT1 to a 6 Mb region on the chromosome 2D short arm and validated a nucleotide-binding (NB) domain encoding gene as LT1 using CRISPR/Cas9. Furthermore, the lower sucrose concentration in the shoot bases of lt1 might result in inadequate bud outgrowth due to disturbances in the sucrose biosynthesis pathways. Co-expression analysis suggests that LT1 controls tillering by regulating TaROX/TaLAX1, the ortholog of the Arabidopsis tiller regulator REGULATOR OF AXILLARY MERISTEM FORMATION (ROX) or the rice axillary meristem regulator LAX PANICLE1 (LAX1). This study not only offers a novel genetic resource for cultivating optimal plant architecture but also underscores the importance of our innovative BSA method. This uni-BSA method enables the swift and precise identification of pivotal genes associated with significant agronomic traits, thereby hastening gene cloning and crop breeding processes in wheat. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11032-024-01484-7.
PMID: 38939116
Plant Commun , 2024 Jul , V5 (7) : P100892 doi: 10.1016/j.xplc.2024.100892
ESR2-HDA6 complex negatively regulates auxin biosynthesis to delay callus initiation in Arabidopsis leaf explants during tissue culture.
Department of Chemistry, Seoul National University, Seoul 08826, Korea; Research Institute of Basic Sciences, Seoul National University, Seoul 08826, Korea.; Interdisciplinary Program in Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea.; Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea.; Department of Biological Sciences, KAIST, Daejeon 34141, Korea.; Department of Chemistry, Seoul National University, Seoul 08826, Korea; Research Institute of Basic Sciences, Seoul National University, Seoul 08826, Korea; Interdisciplinary Program in Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea; Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, Korea. Electronic address: pjseo1@snu.ac.kr.
Plants exhibit an astonishing ability to regulate organ regeneration upon wounding. Excision of leaf explants promotes the biosynthesis of indole-3-acetic acid (IAA), which is polar-transported to excised regions, where cell fate transition leads to root founder cell specification to induce de novo root regeneration. The regeneration capacity of plants has been utilized to develop in vitro tissue culture technologies. Here, we report that IAA accumulation near the wounded site of leaf explants is essential for callus formation on 2,4-dichlorophenoxyacetic acid (2,4-D)-rich callus-inducing medium (CIM). Notably, a high concentration of 2,4-D does not compensate for the action of IAA because of its limited efflux; rather, it lowers IAA biosynthesis via a negative feedback mechanism at an early stage of in vitro tissue culture, delaying callus initiation. The auxin negative feedback loop in CIM-cultured leaf explants is mediated by an auxin-inducible APETALA2 transcription factor, ENHANCER OF SHOOT REGENERATION 2 (ESR2), along with its interacting partner HISTONE DEACETYLASE 6 (HDA6). The ESR2-HDA6 complex binds directly to, and removes the H3ac mark from, the YUCCA1 (YUC1), YUC7, and YUC9 loci, consequently repressing auxin biosynthesis and inhibiting cell fate transition on 2,4-D-rich CIM. These findings indicate that negative feedback regulation of auxin biosynthesis by ESR2 and HDA6 interferes with proper cell fate transition and callus initiation.
PMID: 38566417
Plant Commun , 2024 Jul , V5 (7) : P100886 doi: 10.1016/j.xplc.2024.100886
A predictive model for ethylene-mediated auxin and cytokinin patterning in the Arabidopsis root.
Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK; Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.; Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK.; Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei 430070, China.; Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK. Electronic address: junli.liu@durham.ac.uk.; Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK. Electronic address: keith.lindsey@durham.ac.uk.
The interaction between auxin and cytokinin is important in many aspects of plant development. Experimental measurements of both auxin and cytokinin concentration and reporter gene expression clearly show the coexistence of auxin and cytokinin concentration patterning in Arabidopsis root development. However, in the context of crosstalk among auxin, cytokinin, and ethylene, little is known about how auxin and cytokinin concentration patterns simultaneously emerge and how they regulate each other in the Arabidopsis root. This work utilizes a wide range of experimental observations to propose a mechanism for simultaneous patterning of auxin and cytokinin concentrations. In addition to revealing the regulatory relationships between auxin and cytokinin, this mechanism shows that ethylene signaling is an important factor in achieving simultaneous auxin and cytokinin patterning, while also predicting other experimental observations. Combining the mechanism with a realistic in silico root model reproduces experimental observations of both auxin and cytokinin patterning. Predictions made by the mechanism can be compared with a variety of experimental observations, including those obtained by our group and other independent experiments reported by other groups. Examples of these predictions include patterning of auxin biosynthesis rate, changes in PIN1 and PIN2 patterns in pin3,4,7 mutants, changes in cytokinin patterning in the pls mutant, PLS patterning, and various trends in different mutants. This research reveals a plausible mechanism for simultaneous patterning of auxin and cytokinin concentrations in Arabidopsis root development and suggests a key role for ethylene pattern integration.
PMID: 38504522
Plant Commun , 2024 Jul , V5 (7) : P100880 doi: 10.1016/j.xplc.2024.100880
CCaP1/CCaP2/CCaP3 interact with plasma membrane H(+)-ATPases and promote thermo-responsive growth by regulating cell wall modification in Arabidopsis.
State Key Laboratory of Plant Environmental Resilience, College of Life Sciences, Zhejiang University, Hangzhou 310027, China.; State Key Laboratory of Plant Environmental Resilience, College of Life Sciences, Zhejiang University, Hangzhou 310027, China; College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310027, China.; State Key Laboratory of Plant Environmental Resilience, College of Life Sciences, Zhejiang University, Hangzhou 310027, China. Electronic address: jianxiangliu@zju.edu.cn.
Arabidopsis plants adapt to warm temperatures by promoting hypocotyl growth primarily through the basic helix-loop-helix transcription factor PIF4 and its downstream genes involved in auxin responses, which enhance cell division. In the current study, we discovered that cell wall-related calcium-binding protein 2 (CCaP2) and its paralogs CCaP1 and CCaP3 function as positive regulators of thermo-responsive hypocotyl growth by promoting cell elongation in Arabidopsis. Interestingly, mutations in CCaP1/CCaP2/CCaP3 do not affect the expression of PIF4-regulated classic downstream genes. However, they do noticeably reduce the expression of xyloglucan endotransglucosylase/hydrolase genes, which are involved in cell wall modification. We also found that CCaP1/CCaP2/CCaP3 are predominantly localized to the plasma membrane, where they interact with the plasma membrane H(+)-ATPases AHA1/AHA2. Furthermore, we observed that vanadate-sensitive H(+)-ATPase activity and cell wall pectin and hemicellulose contents are significantly increased in wild-type plants grown at warm temperatures compared with those grown at normal growth temperatures, but these changes are not evident in the ccap1-1 ccap2-1 ccap3-1 triple mutant. Overall, our findings demonstrate that CCaP1/CCaP2/CCaP3 play an important role in controlling thermo-responsive hypocotyl growth and provide new insights into the alternative pathway regulating hypocotyl growth at warm temperatures through cell wall modification mediated by CCaP1/CCaP2/CCaP3.
PMID: 38486455