Mol Plant , IF:13.164 , 2021 Dec doi: 10.1016/j.molp.2021.12.002
Molecular basis underlying rice tiller angle: Current progress and future perspectives.
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China.; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.; State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address: yhwang@genetics.ac.cn.
Crop plant architecture is an important agronomic trait that contributes greatly to crop yield. Tiller angle is one of the most critical components that determine crop plant architecture, which in turn substantially affects grain yield mainly owing to its large influence on plant density. Gravity is a fundamental physical force that acts on all organisms on earth. Plant organs sense gravity to control their growth orientation, including tiller angle in rice (Oryza sativa). This review summarizes recent research advances made using rice tiller angle as a research model, providing insights into domestication of rice tiller angle, genetic regulation of rice tiller angle, and shoot gravitropism. Finally, we propose that current discoveries in rice can shed light on shoot gravitropism and improvement of plant tiller/branch angle in other species, thereby contributing to agricultural production in the future.
PMID: 34896639
New Phytol , IF:10.151 , 2022 Jan , V233 (2) : P624-630 doi: 10.1111/nph.17867
Recent developments in the understanding of PIN polarity.
Department of Forest Genetics and Plant Physiology, Umea Plant Science Centre (UPSC), University of Agricultural Sciences (SLU), 90183, Umea, Sweden.
Polar localization of PIN-FORMED proteins (PINs) at the plasma membrane is essential for plant development as they direct the transport of phytohormone auxin between cells. PIN polar localization to certain sides of a given cell is dynamic, strictly regulated and provides directionality to auxin flow. Signals that act upstream to control subcellular PIN localization modulate auxin distribution, thereby regulating diverse aspects of plant development. Here I summarize the current understanding of mechanisms by which PIN polarity is established, maintained and rearranged to provide a glimpse into the complexity of PIN polarity.
PMID: 34882802
New Phytol , IF:10.151 , 2021 Dec doi: 10.1111/nph.17890
A plastidial retrograde signal potentiates biosynthesis of systemic stress response activators.
Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, CA, 92521, USA.; Laboratory of Allergy and Inflammation, Chengdu Third People's Hospital Branch of National Clinical Research Center for Respiratory Disease, Chengdu, 610031, China.; Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, 55108, USA.
Plants employ an array of intricate and hierarchical signaling cascades to perceive and transduce informational cues to synchronize and tailor adaptive responses. Systemic stress response (SSR) is a recognized complex signaling and response network quintessential to plant's local and distal responses to environmental triggers; however, the identity of the initiating signals has remained fragmented. Here, we show that both biotic (aphids and viral pathogens) and abiotic (high light and wounding) stresses induce accumulation of the plastidial-retrograde-signaling metabolite methylerythritol cyclodiphosphate (MEcPP), leading to reduction of the phytohormone auxin and the subsequent decreased expression of the phosphatase PP2C.D1. This enables phosphorylation of mitogen-activated protein kinases 3/6 and the consequential induction of the downstream events ultimately, resulting in biosynthesis of the two SSR priming metabolites pipecolic acid and N-hydroxy-pipecolic acid. This work identifies plastids as a major initiation site, and the plastidial retrograde signal MEcPP as an initiator of a multicomponent signaling cascade potentiating the biosynthesis of SSR activators, in response to biotic and abiotic triggers.
PMID: 34859454
Plant Biotechnol J , IF:9.803 , 2021 Dec doi: 10.1111/pbi.13765
TaMOR is essential for root initiation and improvement of root system architecture in wheat.
National Key Facility for Crop Gene Resources and Genetic Improvement/Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.
Optimal root system architecture is beneficial for water-fertilizer use efficiency, stress tolerance and yield improvement of crops. However, because of the complexity of root traits and difficulty in phenotyping deep roots, the study on mechanisms of root development is rarely reported in wheat (Triticum aestivum L.). In this study, we identified that the LBD (LATERAL ORGAN BOUNDARIES DOMAIN) gene TaMOR (MORE ROOT in wheat) determines wheat crown root initiation. The mor mutants exhibited less or even no crown root, dwarfism, less grain number and lodging caused by few roots. The observation of cross sections showed that crown root initiation is inhibited in the mor mutants. Molecular assays revealed that TaMOR interacts with the auxin response factor ARF5 to directly induce the expression of the auxin transporter gene PIN2 (PIN-FORMED 2) in the root base to regulate crown root initiation. In addition, a 159-bp MITE (miniature inverted-repeat transposable element) insertion causing DNA methylation and lower expression of TaMOR-B was identified in TaMOR-B promoter, which is associated with lower root dry weight and shorter plant height. The results bring new light into regulation mechanisms of crown root initiation and offer a new target for the improvement of root system architecture in wheat.
PMID: 34890129
Plant Physiol , IF:8.34 , 2021 Dec doi: 10.1093/plphys/kiab589
TARGET OF RAPAMYCIN is essential for asexual vegetative reproduction in Kalanchoe.
School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, M13 9PT, United Kingdom.
The unique mechanism by which leaf margin cells regain potency and then form a plantlet in Kalanchoe spp. remains elusive but involves organogenesis and embryogenesis in response to age, day length, nutrient availability and drought stress. In light of this, we investigated whether TARGET OF RAPAMYCIN (TOR), a conserved protein kinase in eukaryotes that controls cell growth and metabolism in response to nutrient and energy availability, may regulate plantlet formation. KdTOR was expressed in the leaf margin at the site of plantlet initiation, in the early plantlet cotyledons, and in the root tip of the developed plantlet. Both chemical and genetic inhibition of TOR Kinase activity in Kalanchoe daigremontiana leaves disrupted plantlet formation. Furthermore, downregulation of KdTOR in transgenic plants led to wide-ranging transcriptional changes, including decreased K. daigremontiana SHOOTMERISTEMLESS and K. daigremontiana LEAFYCOTYLEDON1 expression, whereas auxin treatments induced KdTOR expression in the plantlet roots. These results suggest that the KdTOR pathway controls plantlet development in cooperation with auxin, organogenesis, and embryogenesis pathways. The ancient and highly conserved TOR Kinase therefore controls diverse and unique developmental pathways, such as asexual reproduction within the land plant lineage.
PMID: 34935983
Plant Physiol , IF:8.34 , 2021 Dec doi: 10.1093/plphys/kiab568
Toward synthetic plant development.
Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA.
The ability to engineer plant form will enable the production of novel agricultural products designed to tolerate extreme stresses, boost yield, reduce waste, and improve manufacturing practices. While historically, plants were altered through breeding to change their size or shape, advances in our understanding of plant development and our ability to genetically engineer complex eukaryotes are leading to the direct engineering of plant structure. In this review, I highlight the central role of auxin in plant development and the synthetic biology approaches that could be used to turn auxin-response regulators into powerful tools for modifying plant form. I hypothesize that recoded, gain-of-function auxin response proteins combined with synthetic regulation could be used to override endogenous auxin signaling and control plant structure. I also argue that auxin-response regulators are key to engineering development in non-model plants and that single cell-omics techniques will be essential for characterizing and modifying auxin response in these plants. Collectively, advances in synthetic biology, single cell -omics, and our understanding of the molecular mechanisms underpinning development have set the stage for a new era in the engineering of plant structure.
PMID: 34904660
Plant Physiol , IF:8.34 , 2021 Dec doi: 10.1093/plphys/kiab571
Type 2C protein phosphatase clade D family members dephosphorylate guard cell plasma membrane H+-ATPase.
Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.; Department of Plant and Microbial Biology, University of Minnesota; St. Paul, MN 55108.; Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8602, Japan.
Plasma membrane (PM) H+-ATPase in guard cells is activated by phosphorylation of the penultimate residue, threonine (Thr), in response to blue and red light, promoting stomatal opening. Previous in vitro biochemical investigation suggested that Mg2+- and Mn2+-dependent membrane-localized type 2C protein phosphatase (PP2C)-like activity mediates dephosphorylation of PM H+-ATPase in guard cells. PP2C clade D (PP2C.D) was later demonstrated to be involved in PM H+-ATPase dephosphorylation during auxin-induced cell expansion in Arabidopsis (Arabidopsis thaliana). However, it is unclear whether PP2C.D phosphatases are involved in PM H+-ATPase dephosphorylation in guard cells. Transient expression experiments using Arabidopsis mesophyll cell protoplasts revealed that all PP2C.D isoforms dephosphorylate the endogenous PM H+-ATPase. We further analyzed PP2C.D6/8/9, which display higher expression levels than other isoforms in guard cells, observing that pp2c.d6, pp2c.d8 and pp2c.d9 single mutants showed similar light-induced stomatal opening and phosphorylation status of PM H+-ATPase in guard cells as Col-0. By contrast, the pp2c.d6/9 double mutant displayed wider stomatal apertures and greater PM H+-ATPase phosphorylation in response to blue light, but delayed dephosphorylation of PM H+-ATPase in guard cells; the pp2c.d6/8/9 triple mutant showed similar phenotypes to those of the pp2c.d6/9 double mutant. Taken together, these results indicate that PP2C.D6 and PP2C.D9 redundantly mediate PM H+-ATPase dephosphorylation in guard cells. Curiously, unlike auxin-induced cell expansion in seedlings, auxin had no effect on the phosphorylation status of PM H+-ATPase in guard cells.
PMID: 34894269
Plant Physiol , IF:8.34 , 2021 Dec doi: 10.1093/plphys/kiab587
Root electrotropism in Arabidopsis does not depend on auxin distribution but requires cytokinin biosynthesis.
Department of Life Sciences, Imperial College London, UK.
Efficient foraging by plant roots relies on the ability to sense multiple physical and chemical cues in soil and to reorient growth accordingly (tropism). Root tropisms range from sensing gravity (gravitropism), light (phototropism), water (hydrotropism), touch (thigmotropism), and more. Electrotropism, also known as galvanotropism, is the phenomenon of aligning growth with external electric fields and currents. Although root electrotropism has been observed in a few species since the end of the 19th century, its molecular and physical mechanisms remain elusive, limiting its comparison with the more well-defined sensing pathways in plants. Here we provide a quantitative and molecular characterization of root electrotropism in the model system Arabidopsis (Arabidopsis thaliana), showing that it does not depend on an asymmetric distribution of the plant hormone auxin, but instead requires the biosynthesis of a second hormone, cytokinin. We also show that the dose-response kinetics of the early steps of root electrotropism follows a power law analogous to the one observed in some physiological reactions in animals. Future studies involving more extensive molecular and quantitative characterization of root electrotropism would represent a step towards a better understanding of signal integration in plants and would also serve as an independent outgroup for comparative analysis of electroreception in animals and fungi.
PMID: 34893912
Plant Physiol , IF:8.34 , 2021 Dec doi: 10.1093/plphys/kiab565
The positive feedback regulatory loop of miR160-Auxin Response Factor 17- HYPONASTIC LEAVES 1 mediates drought tolerance in apple trees.
State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, Shaanxi 712100, China.; State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Life Science, Northwest A&F University, Yangling, Shaanxi 712100, China.
Drought stress tolerance is a complex trait regulated by multiple factors. Here, we demonstrate that the miRNA160 - Auxin Response Factor 17 - HYPONASTIC LEAVES 1 (miR160 - ARF17 - HYL1) module is crucial for apple (Malus domestica) drought tolerance. Using stable transgenic plants, we found that drought tolerance was improved by higher levels of Mdm-miR160 or MdHYL1 and by decreased levels of MdARF17, whereas reductions in MdHYL1 or increases in MdARF17 led to greater drought sensitivity. Further study revealed that modulation of drought tolerance was achieved through regulation of drought-responsive miRNA levels by MdARF17 and MdHYL1; MdARF17 interacted with MdHYL1 and bound to the promoter of MdHYL1. Genetic analysis further suggested that MdHYL1 is a direct downstream target of MdARF17. Importantly, MdARF17 and MdHYL1 regulated the abundance of Mdm-miR160. In addition, the Mdm-miR160-MdARF17-MdHYL1 module regulated adventitious root development. We also found that Mdm-miR160 can move from the scion to the rootstock in apple and tomato (Solanum lycopersicum), thereby improving root development and drought tolerance of the rootstock. Our study revealed the mechanisms by which the positive feedback loop of Mdm-miR160-MdARF17-MdHYL1 influences apple drought tolerance.
PMID: 34893896
Plant Physiol , IF:8.34 , 2021 Dec , V187 (4) : P2656-2673 doi: 10.1093/plphys/kiab441
Diverse phosphate and auxin transport loci distinguish phosphate tolerant from sensitive Arabidopsis accessions.
Department of Animal, Plant and Soil Sciences and La Trobe Institute for Agriculture and Food (LIAF), ARC Centre of Excellence in Plant Energy Biology, School of Life Sciences, La Trobe University, Bundoora VIC 3086, Australia.; Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture and Rural Affairs, Tea Research Institute, Chinese Academy of Agricultural Sciences, Zhejiang 31008, China.; Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University (Burwood Campus), Burwood VIC 3125, Australia.; School of BioSciences, The University of Melbourne, Melbourne VIC 3010, Australia.
Phosphorus (P) is an essential element for plant growth often limiting agroecosystems. To identify genetic determinants of performance under variable phosphate (Pi) supply, we conducted genome-wide association studies on five highly predictive Pi starvation response traits in 200 Arabidopsis (Arabidopsis thaliana) accessions. Pi concentration in Pi-limited organs had the strongest, and primary root length had the weakest genetic component. Of 70 trait-associated candidate genes, 17 responded to Pi withdrawal. The PHOSPHATE TRANSPORTER1 gene cluster on chromosome 5 comprises PHT1;1, PHT1;2, and PHT1;3 with known impact on P status. A second locus featured uncharacterized endomembrane-associated auxin efflux carrier encoding PIN-LIKES7 (PILS7) which was more strongly suppressed in Pi-limited roots of Pi-starvation sensitive accessions. In the Col-0 background, Pi uptake and organ growth were impaired in both Pi-limited pht1;1 and two pils7 T-DNA insertion mutants, while Pi -limited pht1;2 had higher biomass and pht1;3 was indistinguishable from wild-type. Copy number variation at the PHT1 locus with loss of the PHT1;3 gene and smaller scale deletions in PHT1;1 and PHT1;2 predicted to alter both protein structure and function suggest diversification of PHT1 is a key driver for adaptation to P limitation. Haplogroup analysis revealed a phosphorylation site in the protein encoded by the PILS7 allele from stress-sensitive accessions as well as additional auxin-responsive elements in the promoter of the "stress tolerant" allele. The former allele's inability to complement the pils7-1 mutant in the Col-0 background implies the presence of a kinase signaling loop controlling PILS7 activity in accessions from P-rich environments, while survival in P-poor environments requires fine-tuning of stress-responsive root auxin signaling.
PMID: 34636851
Plant Physiol , IF:8.34 , 2021 Dec , V187 (4) : P2356-2360 doi: 10.1093/plphys/kiab455
HYPONASTIC LEAVES 1 is required for proper establishment of auxin gradient in apical hooks.
Instituto de Biologia Molecular y Celular de Rosario, CONICET, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Rosario, Argentina.
PMID: 34601613
Sci Total Environ , IF:7.963 , 2021 Dec , V810 : P152260 doi: 10.1016/j.scitotenv.2021.152260
Copper oxide (CuO) nanoparticles affect yield, nutritional quality, and auxin associated gene expression in weedy and cultivated rice (Oryza sativa L.) grains.
Environmental Science and Engineering Ph.D. Program, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968, USA; University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968, USA.; The Connecticut Agricultural Experiment Station, 123 Huntington St., New Haven, CT 06504, USA; Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968, USA.; Department of Physics, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968, USA.; Department of Plants, Soil, and Climate, Utah State University, 4820 Old Main Hill, Logan, UT 84322, USA.; MSU-DOE - Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.; University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968, USA; Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968, USA.; Texas A&M Agrilife Research and Extension Centre at Dallas, 17360 Coit Road, TX 75252, USA.; The Connecticut Agricultural Experiment Station, 123 Huntington St., New Haven, CT 06504, USA.; Environmental Science and Engineering Ph.D. Program, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968, USA; University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968, USA; Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Ave., El Paso, TX 79968, USA. Electronic address: jgardea@utep.edu.
Weedy rice grows competitively with cultivated rice and significantly diminishes rice grain production worldwide. The different effects of Cu-based nanomaterials on the production of weedy and cultivated rice, especially the grain qualities are not known. Grains were collected from weedy and cultivated rice grown for four months in field soil amended with nanoscale CuO (nCuO), bulk CuO (bCuO), and copper sulfate (CuSO4) at 0, 75, 150, 300, and 600 mg Cu/kg soil. Cu translocation, essential element accumulation, yield, sugar, starch, protein content, and the expression of auxin associated genes in grains were determined. The grains of weedy and cultivated rice were differentially impacted by CuO-based compounds. At >/=300 mg/kg, nCuO and bCuO treated rice had no grain production. Treatment at 75 mg/kg significantly decreased grain yield as compared to control with the order: bCuO (by 88.7%) > CuSO4 (by 47.2%) ~ nCuO (by 38.3% only in cultivated rice); at the same dose, the Cu grain content was: nCuO ~ CuSO4 > bCuO > control. In weedy grains, K, Mg, Zn, and Ca contents were decreased by 75 and 150 mg/kg nCuO by up to 47.4%, 34.3%, 37.6%, and 60.0%, but no such decreases were noted in cultivated rice, and Fe content was increased by up to 88.6%, and 53.2%. In rice spikes, nCuO increased Mg, Ca, Fe, and Zn levels by up to 118.1%, 202.6%, 133.8%, and 103.9%, respectively. Nanoscale CuO at 75 and 150 mg/kg upregulated the transcription of an auxin associated gene by 5.22- and 1.38-fold, respectively, in grains of weedy and cultivated rice. The biodistribution of Cu-based compounds in harvested grain was determined by two-photon microscopy. These findings demonstrate a cultivar-specific and concentration-dependent response of rice to nCuO. A potential use of nCuO at 75 and 150 mg/kg in cultivar-dependent delivery system was suggested based on enhanced grain nutritional quality, although the yield was compromised. This knowledge, at the physiological and molecular level, provides valuable information for the future use of Cu-based nanomaterials in sustainable agriculture.
PMID: 34896498
Sci Total Environ , IF:7.963 , 2021 Dec , V801 : P149732 doi: 10.1016/j.scitotenv.2021.149732
Damage and recovery from drift of synthetic-auxin herbicide dicamba depends on concentration and varies among floral, vegetative, and lifetime traits in rapid cycling Brassica rapa.
Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA. Electronic address: s.ramos.castro@gmail.com.; Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Herbicides can drift from intended plants onto non-target species. It remains unclear how drift impacts plant functional traits that are important for fitness. To address this gap, we conducted an experiment where fast cycling Brassica rapa plants were exposed to one of three drift concentrations (0.5%, 1%, 10%) of synthetic-auxin dicamba. We evaluated damage to and capacity of floral and vegetative traits to recover as well as lifetime fitness by comparing treated plants to controls. Response to dicamba exposure was concentration-dependent across all traits but varied with trait type. At 0.5% dicamba, three out of five floral traits were affected, while at 1% dicamba, four floral traits and one out of two vegetative traits were negatively impacted. At 10% dicamba all floral and vegetative traits were stunted. Overall, floral traits were more responsive to all dicamba drift concentrations than vegetative traits and displayed a wide range of variation ranging from no response (e.g., pistil length) to up to 84% reduction (ovule number). However, despite floral traits were more affected across the dicamba drift concentrations they were also more likely to recover than the vegetative traits. There was also variation among lifetime traits; the onset of flowering was delayed, and reproductive fitness was negatively affected in a concentration-dependent manner, but the final biomass and total flower production were not affected. Altogether, we show substantial variation across plant traits in their response to dicamba and conclude that accounting for this variation is essential to understand the full impact of herbicide drift on plants and the ecological interactions these traits mediate.
PMID: 34438156
J Exp Bot , IF:6.992 , 2021 Dec doi: 10.1093/jxb/erab556
The role of AUX1 during lateral root development in the domestication of the model C4 grass Setaria italica.
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Institute of Biology II, University of Freiburg, Schanzlestrasse 1, 79104 Freiburg, Germany.; Academy of Agricultural Sciences/ Key Laboratory of Regional Ecological Protection & Agricultural and Animal Husbandry Development, Chifeng University, Chifeng, 024000, Inner Mongolia, China.; Department of Computational Biology, Center for Advanced Studies, St. Petersburg State Polytechnic University, St. Petersburg, 195259, Russia.; Faculty of Agriculture, Shahid Bahonar University of Kerman, Iran.; Institute of Biology III, University of Freiburg, Schanzlestrasse 1, 79104 Freiburg, Germany.; State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Daizong Street 61, Tai'an, 271018, China.; entre of Biological Systems Analysis and BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
C4 photosynthesis increases the efficiency of carbon fixation by spatially separating high concentrations of molecular oxygen from rubisco. The specialized leaf anatomy required for this separation evolved independently many times. The morphology of C4 root systems is also distinctive and adapted to support high rates of photosynthesis; however, little is known about the molecular mechanisms that have driven the evolution of C4 root system architecture (RSA). Using a mutant screen in the C4 model plant Setaria italica, we identify Siaux1-1 and Siaux1-2 and identify them as RSA mutants. Unlike in S. viridis, AUX1 is promotes lateral root development in S. italica. A cell-by-cell analysis of the Siaux1-1 root apical meristem revealed changes in the distribution of cell volumes in all cell layers and a dependence in the frequency of protophloem and protoxylem strands on SiAUX1. We explore the molecular basis of SiAUX1's role in seedling development using an RNAseq analysis of wild type and Siaux1-1 plants and present novel targets for SiAUX1-dependent gene regulation. Using a selection sweep and haplotype analysis of SiAUX1, we show that Hap-2412TT in the promoter region of SiAUX1 is an allele which is associated with lateral root number and has been strongly selected for during Setaria domestication.
PMID: 34940828
J Exp Bot , IF:6.992 , 2021 Dec doi: 10.1093/jxb/erab542
INTERMEDIUM-C mediates the shade-induced bud growth arrest in barley.
Department of Physiology and Cell Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse, Germany.; Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse, Germany.; International Rice Research Institute (IRRI), Grain Quality and Nutrition Center, Metro Manila, Philippines.
Tiller formation is a key agronomic determinant for grain yield in cereal crops. The modulation of this trait is controlled by transcriptional regulators and plant hormones, tightly regulated by external environmental conditions. While endogenous (genetic) and exogenous (environmental factors) triggers for tiller formation have mostly been investigated separately, it has remained elusive how they are integrated into the developmental program of this trait. The transcription factor INTERMEDIUM-C (INT-C), which is the barley ortholog of the maize domestication gene TEOSINTE BRANCHED1 (TB1) has a prominent role in regulating tiller bud outgrowth. Here we show that INT-C is expressed in tiller buds, required for bud growth arrest in response to shade. In contrast to wild type plants, int-c mutant plants are impaired in their shade response and do not stop tiller production after shading. Gene expression levels of INT-C are up-regulated under light-limiting growth conditions, and down-regulated after decapitation. Transcriptome analysis of wild-type and int-c buds under control and shading conditions identified target genes of INT-C that belong to auxin and gibberellin biosynthesis and signaling pathways. Our study identifies INT-C as integrator of the shade response into tiller formation, which is prerequisite for implementing shading responses in the breeding of cereal crops.
PMID: 34894212
J Exp Bot , IF:6.992 , 2021 Dec , V72 (22) : P7645-7647 doi: 10.1093/jxb/erab493
Small molecules mediate cellular reprogramming across two kingdoms.
Institute of Biology II, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Schanzlestrasse 1, D-79104 Freiburg, Germany.; ScreenSYS GmbH, Engesserstr. 4, D-79108 Freiburg, Germany.; National Center for Knowledge and Innovation in Agriculture, Ministry of Agriculture of the Republic of Uzbekistan, Tashkent region, Universitetskaya str. 2, The Republic of Uzbekistan.; BIOSS Center for Biological Signaling Studies, Albert-Ludwigs-University of Freiburg, Schanzlestrasse 1, D-79104 Freiburg, Germany.; Sino-German Joint Research Center on Agricultural Biology, College of Life Sciences, Shandong Agricultural University, Daizong Street 61, Tai'an, 271018, China.
The fertilized egg is the single totipotent cell from which multicellular organisms arise through the processes of cell division and differentiation. While animals typically lose their capacity to redifferentiate cells that are already fully differentiated, plant cells are thought to remain totipotent (Su et al., 2020). Every gardener knows well that plants can regenerate a full array of plant tissues from already differentiated organs. This also seems to be true for single plant cells such as protoplasts, which, under proper in vitro culture conditions, served as the initial source for generation of transgenic plants (Skoog and Miller, 1957; Birnbaum and Sanchez Alvarado, 2008). However, the mechanisms behind the totipotency of plant cells remain elusive, with the exception of the knowledge that the developmental fate of regenerating tissues can be directed by the ratio of two plant hormones, auxin and cytokinin (Skoog and Miller, 1957).
PMID: 34865113
J Exp Bot , IF:6.992 , 2021 Dec , V72 (22) : P7769-7777 doi: 10.1093/jxb/erab359
Identification of a gene responsible for seedpod spine formation and other phenotypic alterations using whole-genome sequencing analysis in Medicago truncatula.
College of Agronomy, Hunan Agricultural University, Changsha, China.; Grassland Agri-Husbandry Research Center, College of Grassland Science, Qingdao Agricultural University, Qingdao, China.; Noble Research Institute, Ardmore, OK, USA.; Research Computing, Boston Children's Hospital, Boston, MA, USA.; Harvard Medical School, Boston, MA, USA.
In nature, some plant species produce seedpods with spines, which is an adaptive biological trait for protecting the seed and helping seed dispersal. However, the molecular mechanism of spine formation is still unclear. While conducting routine tissue culture and transformation in the model legume Medicago truncatula, we identified a smooth seedpod (ssp1) mutant with a suite of other phenotypic changes. Preliminary analysis showed that the mutation was derived from the tissue culture process. Genetic segregation analysis suggested that ssp1 is a recessive mutant. By combining whole-genome sequencing and bioinformatics analysis, we found that the mutant phenotype was caused by a single nucleotide polymorphism and a 30 bp deletion in the gene locus Medtr4g039430, named SSP1. Complementation of the M. truncatula ssp1 and Arabidopsis twd1 mutants showed complete restoration, indicating that SSP1 is an ortholog of Arabidopsis TWD1 which encodes an immunophilin-like FK506-binding protein 42. The formation of spines on seedpods is associated with auxin transport. The method used in this study offers an effective way for detecting genes responsible for somaclonal variations. The results demonstrate, for the first time, that SSP1 plays a crucial role in the determination of spine formation on seedpods.
PMID: 34329408
Int J Biol Macromol , IF:6.953 , 2022 Jan , V195 : P217-228 doi: 10.1016/j.ijbiomac.2021.11.205
GhAPC8 regulates leaf blade angle by modulating multiple hormones in cotton (Gossypium hirsutum L.).
Key Laboratory of Oasis Eco-Agriculture, College of Agriculture, Shihezi University, Shihezi, 832000 Xinjiang, China; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100081, China.; Key Laboratory of Oasis Eco-Agriculture, College of Agriculture, Shihezi University, Shihezi, 832000 Xinjiang, China.; CSIRO Agriculture and Food, Canberra, ACT, Australia.; State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling 712100, China.; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100081, China.; Key Laboratory of Oasis Eco-Agriculture, College of Agriculture, Shihezi University, Shihezi, 832000 Xinjiang, China. Electronic address: sunjie@shzu.edu.cn.; Key Laboratory of Oasis Eco-Agriculture, College of Agriculture, Shihezi University, Shihezi, 832000 Xinjiang, China. Electronic address: xuefei@shzu.edu.cn.
Leaf angle, including leaf petiole angle (LPA) and leaf blade angle (LBA), is an important trait affecting plant architecture. Anaphase-promoting complex/cyclosome (APC/C) genes play a vital role in plant growth and development, including regulation of leaf angle. Here, we identified and characterized the APC genes in Upland cotton (G. hirsutum L.) with a focus on GhAPC8, a homolog of soybean GmILPA1 involved in regulation of LPA. We showed that independently silencing the At or Dt sub-genome homoeolog of GhAPC8 using virus-induced gene silencing reduced plant height and LBA, and that reduction of LBA could be caused by uneven growth of cortex parenchyma cells on the adaxial and abaxial sides of the junction between leaf blade and leaf petiole. The junction between leaf blade and leaf petiole of the GhAPC8-silenced plants had an elevated level of brassinosteroid (BR) and a decreased levels of auxin and gibberellin. Consistently, comparative transcriptome analysis found that silencing GhAPC8 activated genes of the BR biosynthesis and signaling pathways as well as genes related to ubiquitin-mediated proteolysis. Weighted gene co-expression network analysis (WGCNA) identified gene modules significantly associated with plant height and LBA, and candidate genes bridging GhAPC8, the pathways of BR biosynthesis and signaling and ubiquitin-mediated proteolysis. These results demonstrated a role of GhAPC8 in regulating LBA, likely achieved by modulating the accumulation and signaling of multiple phytohormones.
PMID: 34896470
Plant J , IF:6.417 , 2021 Dec doi: 10.1111/tpj.15642
Synergistic interaction between ABA and IAA due to moderate soil drying promotes grain filling of inferior spikelets in rice.
College of Agriculture, Hunan Agricultural University, Changsha, 410128, China.; Hunan Provincial Key Laboratory of Rice Stress Biology, Hunan Agricultural University, Changsha, 410128, China.; Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong, China.; Key Laboratory of Crop Genetics and Physiology of Jiangsu Province, Yangzhou University, Yangzhou, Jiangsu, China.; School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
Poor grain filling of inferior spikelets is becoming a severe problem in some super rice varieties with large panicles. Moderate soil drying (MD) after pollination has been proven to be a practical strategy to promote grain filling. However, the molecular mechanisms underlying this phenomenon remain largely unexplored. Here, transcriptomic analysis of the most active grain filling stage revealed that both starch metabolism and phytohormone signaling were significantly promoted by MD treatment, accompanied by increased enzyme activities of starch synthesis and elevated abscisic acid (ABA) and indole-3-acetic acid (IAA) content in the inferior spikelet. Moreover, the IAA biosynthesis genes OsYUC11 and OsTAR2 were upregulated, while OsIAA29 and OsIAA24, which encode two repressors of auxin signaling, were downregulated by MD, implying a regulation of both IAA biosynthesis and auxin signal transduction in the inferior spikelet by MD. A notable improvement in grain filling of the inferior spikelet was found in the aba8ox2 mutant, which is mutated in an ABA catabolism gene. In contrast, overexpression of OsABA8ox2 significantly reduced grain filling. Interestingly, not only the IAA content, but also the expression of IAA biosynthesis and auxin-responsive genes displayed a similar trend to that in the inferior spikelet under MD. In addition, several OsTPP genes were downregulated in the inferior spikelets of both MD/ABA-treated wild-type plants and the aba8ox2 mutant, resulting in lower trehalose content and higher levels of -6-phosphate (T6P), thereby increasing the expression of OsTAR2, a target of T6P. Taken together, our results suggest that the synergistic interaction of ABA-mediated accumulation of IAA promotes grain filling of inferior spikelets under MD.
PMID: 34921476
Int J Mol Sci , IF:5.923 , 2021 Dec , V22 (24) doi: 10.3390/ijms222413664
Over-Expression of Rose RrLAZY1 Negatively Regulates the Branch Angle of Transgenic Arabidopsis Inflorescence.
College of Forestry, Shandong Agricultural University, Taian 271018, China.
Branch angle is a key shoot architecture trait that strongly influences the ornamental and economic value of garden plants. However, the mechanism underlying the control of branch angle, an important aspect of tree architecture, is far from clear in roses. In the present study, we isolated the RrLAZY1 gene from the stems of Rosa rugosa 'Zilong wochi'. Sequence analysis showed that the encoded RrLAZY1 protein contained a conserved GPhiL (A/T) IGT domain, which belongs to the IGT family. Quantitative real-time PCR (qRT-PCR) analyses revealed that RrLAZY1 was expressed in all tissues and that expression was highest in the stem. The RrLAZY1 protein was localized in the plasma membrane. Based on a yeast two-hybrid assay and bimolecular fluorescence complementation experiments, the RrLAZY1 protein was found to interact with auxin-related proteins RrIAA16. The over-expression of the RrLAZY1 gene displayed a smaller branch angle in transgenic Arabidopsis inflorescence and resulted in changes in the expression level of genes related to auxin polar transport and signal transduction pathways. This study represents the first systematic analysis of the LAZY1 gene family in R. rugosa. The results of this study will provide a theoretical basis for the improvement of rose plant types and molecular breeding and provide valuable information for studying the regulation mechanism of branch angle in other woody plants.
PMID: 34948467
Int J Mol Sci , IF:5.923 , 2021 Dec , V22 (24) doi: 10.3390/ijms222413229
Hydrogen Sulfide Improves the Cold Stress Resistance through the CsARF5-CsDREB3 Module in Cucumber.
State Key Laboratory of Crop Biology, Key Laboratory of Crop Biology and Genetic Improvement of Horticultural Crops in Huanghuai Region, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an 271018, China.
As an important gas signaling molecule, hydrogen sulfide (H2S) plays a crucial role in regulating cold tolerance. H2S cooperates with phytohormones such as abscisic acid, ethylene, and salicylic acid to regulate the plant stress response. However, the synergistic regulation of H2S and auxin in the plant response to cold stress has not been reported. This study showed that sodium hydrosulfide (NaHS, an H2S donor) treatment enhanced the cold stress tolerance of cucumber seedlings and increased the level of auxin. CsARF5, a cucumber auxin response factor (ARF) gene, was isolated, and its role in regulating H2S-mediated cold stress tolerance was described. Transgenic cucumber leaves overexpressing CsARF5 were obtained. Physiological analysis indicated that overexpression of CsARF5 enhanced the cold stress tolerance of cucumber and the regulation of the cold stress response by CsARF5 depends on H2S. In addition, molecular assays showed that CsARF5 modulated cold stress response by directly activating the expression of the dehydration-responsive element-binding (DREB)/C-repeat binding factor (CBF) gene CsDREB3, which was identified as a positive regulator of cold stress. Taken together, the above results suggest that CsARF5 plays an important role in H2S-mediated cold stress in cucumber. These results shed light on the molecular mechanism by which H2S regulates cold stress response by mediating auxin signaling; this will provide insights for further studies on the molecular mechanism by which H2S regulates cold stress. The aim of this study was to explore the molecular mechanism of H2S regulating cold tolerance of cucumber seedlings and provide a theoretical basis for the further study of cucumber cultivation and environmental adaptability technology in winter.
PMID: 34948028
J Fungi (Basel) , IF:5.816 , 2021 Dec , V7 (12) doi: 10.3390/jof7121050
The Endophytic Strain Trichoderma asperellum 6S-2: An Efficient Biocontrol Agent against Apple Replant Disease in China and a Potential Plant-Growth-Promoting Fungus.
State Key Laboratory of Crop Biology, College of Horticultural Science and Engineering, Shandong Agricultural University, Tai'an 271018, China.
A study was conducted for endophytic antagonistic fungi obtained from the roots of healthy apple trees growing in nine replanted orchards in Shandong Province, China. The fungi were assessed for their ability to inhibit Fusarium proliferatum f. sp. malus domestica MR5, a fungal strain associated with apple replant disease (ARD). An effective endophyte, designated as strain 6S-2, was isolated and identified as Trichoderma asperellum. Strain 6S-2 demonstrated protease, amylase, cellulase, and laccase activities, which are important for the parasitic and antagonistic functions of pathogenic fungi. The inhibition rate of 6S-2 against Fusarium proliferatum f. sp. malus domestica MR5 was 52.41%. Strain 6S-2 also secreted iron carriers, auxin, ammonia and was able to solubilize phosphorus. Its fermentation extract and volatile substances inhibited the growth of MR5, causing its hyphae to twist, shrink, swell, and rupture. The antifungal activity of the 6S-2 fermentation extract increased with increasing concentrations. It promoted the production and elongation of Arabidopsis thaliana lateral roots, and the strongest effects were seen at a concentration of 50 mg/mL. A GC-MS analysis of the 6S-2 fermentation extract and volatile substances showed that they comprised mainly alkanes, alcohols, and furanones, as well as the specific volatile substance 6-PP. The application of 6S-2 spore suspension to replanted apple orchard soils reduced plant oxidative damage and promoted plant growth in a pot experiment. Therefore, the endophytic strain T. asperellum 6S-2 has the potential to serve as an effective biocontrol fungus for the prevention of ARD in China, and appears to promote plant growth.
PMID: 34947033
Front Plant Sci , IF:5.753 , 2021 , V12 : P765897 doi: 10.3389/fpls.2021.765897
Ethylene and Auxin: Hormonal Regulation of Volatile Compound Production During Tomato (Solanum lycopersicum L.) Fruit Ripening.
Department of Food and Experimental Nutrition, School of Pharmaceutical Sciences, University of Sao Paulo (USP), Sao Paulo, Brazil.; Food Research Center (FoRC), Sao Paulo, Brazil.; Department of Botany, Institute of Bioscience, University of Sao Paulo (USP), Sao Paulo, Brazil.
As the auxin-ethylene interaction in climacteric fruit ripening has been highlighted, the hormonal regulation of aroma changes in climacteric fruits requires clarification. The influence of both phytohormones on the volatile organic compound (VOC) metabolism was evaluated during tomato (Solanum lycopersicum L.) fruit ripening. Tomato fruits cv. Micro-Tom and Sweet Grape at the mature green stage were randomly grouped according to treatment with ethylene (ETHY), auxin (IAA), or both (ETHY + IAA). At middle ripening, Micro-Tom ETHY + IAA fruits present VOC profiles similar to those of ETHY fruits, while Sweet Grape presents VOC profiles closer to those of IAA fruits. At full ripeness, Micro-Tom and Sweet Grape ETHY + IAA fruits show profiles closer to those of IAA fruits, suggesting that the auxin overlaps the ethylene effects. Aroma compounds positively correlated with consumer preferences (2-isobutylthiazole, 6-methyl-5-hepten-2-one, and others) are identified in both cultivars and have their contents affected by both hormone treatments. The transcription of genes related to the biosynthesis of important tomato VOCs that have fatty-acid and carotenoid precursors evidences their regulation by both plant hormones. Additionally, the results indicate that the observed effects on the VOC metabolism are not restricted to the Micro-Tom cultivar, as these are also observed in the Sweet Grape cultivar. In conclusion, ethylene and auxin directly regulate the metabolic pathways related to VOC formation, impacting tomato aroma formation during ripening since Micro-Tom fruits apparently at the same maturation stage have different aromas.
PMID: 34956263
Front Plant Sci , IF:5.753 , 2021 , V12 : P794349 doi: 10.3389/fpls.2021.794349
Plant Growth Promotion by Two Volatile Organic Compounds Emitted From the Fungus Cladosporium halotolerans NGPF1.
Biological Resource Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup, South Korea.; Wheat Research team, National Institute of Crop Science, Rural Development Administration, Wanju, South Korea.; Center for Industrialization of Agricultural and Livestock Microorganisms (CIALM), Jeongeup, South Korea.; Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea.
Microbial volatiles have beneficial roles in the agricultural ecological system, enhancing plant growth and inducing systemic resistance against plant pathogens without being hazardous to the environment. The interactions of plant and fungal volatiles have been extensively studied, but there is limited research specifically elucidating the effects of distinct volatile organic compounds (VOCs) on plant growth promotion. The current study was conducted to investigate the impact of VOCs from Cladosporium halotolerans NGPF1 on plant growth, and to elucidate the mechanisms for the plant growth-promoting (PGP) activity of these VOCs. The VOCs from C. halotolerans NGPF1 significantly promoted plant growth compared with the control, and this PGP activity of the VOCs was culture medium-dependent. Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) identified two VOC structures with profiles that differed depending on the culture medium. The two compounds that were only produced in potato dextrose (PD) medium were identified as 2-methyl-butanal and 3-methyl-butanal, and both modulated plant growth promotion and root system development. The PGP effects of the identified synthetic compounds were analyzed individually and in blends using N. benthamiana plants. A blend of the two VOCs enhanced growth promotion and root system development compared with the individual compounds. Furthermore, real-time PCR revealed markedly increased expression of genes involved in auxin, expansin, and gibberellin biosynthesis and metabolism in plant leaves exposed to the two volatile blends, while cytokinin and ethylene expression levels were decreased or similar in comparison with the control. These findings demonstrate that naturally occurring fungal VOCs can induce plant growth promotion and provide new insights into the mechanism of PGP activity. The application of stimulatory volatiles for growth enhancement could be used in the agricultural industry to increase crop yield.
PMID: 34925431
Front Plant Sci , IF:5.753 , 2021 , V12 : P765302 doi: 10.3389/fpls.2021.765302
CmRCC1 Gene From Pumpkin Confers Cold Tolerance in Tobacco by Modulating Root Architecture and Photosynthetic Activity.
Key Laboratory of Horticultural Plant Biology, Ministry of Education/College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China.
Low-temperature stress is the main limiting factor of cucurbit crop cultivation as it affects crop yield and quality. The identification of genes involved in cold tolerance is a crucial aspect of pumpkin rootstock breeding. Here, we examined the function of a pumpkin Regulator of Chromosome Condensation 1 (CmRCC1) gene in the root development and cold stress responses of tobacco (Nicotiana benthamiana). CmRCC1 expression was differentially induced in pumpkin root, stem, and leaf under cold stress. Transient transformation showed that CmRCC1 is located in the nucleus. CmRCC1 overexpression in tobacco increased the gravitropic set-point angle in lateral roots, as well as root diameter and volume. The expression of auxin polar transport factors, PIN1 and PIN3, decreased and increased in CmRCC1-overexpressed plants, respectively. Yeast two-hybrid verification and luciferase complementation imaging assay showed that CmRCC1 interacts with CmLAZY1. Furthermore, the decreases in maximum quantum yield of PS II, the effective quantum yield of PS II, and electron transfer rate and the increases in quantum yield of nonregulated energy dissipation and malondialdehyde content were compromised in transgenic plants compared with wild-type plants under cold stress. The results suggest that CmRCC1 plays an important role in the regulation of root architecture and positively modulates cold tolerance.
PMID: 34925414
Front Plant Sci , IF:5.753 , 2021 , V12 : P739101 doi: 10.3389/fpls.2021.739101
Network Analysis of Different Exogenous Hormones on the Regulation of Deep Sowing Tolerance in Maize Seedlings.
Gansu Provincial Key Laboratory of Aridland Crop Science, Gansu Agricultural University, College of Agronomy, Gansu Agricultural University, Gansu Key Lab of Crop Improvement & Germplasm Enhancement, Lanzhou, China.
The planting method of deep sowing can make the seeds make full use of water in deep soil, which is considered to be an effective way to respond to drought stress. However, deep sowing will affect the growth and development of maize (Zea mays L.) at seedling stage. To better understand the response of maize to deep sowing stress and the mechanism of exogenous hormones [Gibberellin (GA3), Brassinolide (BR), Strigolactone (SL)] alleviates the damaging effects of deep-sowing stress, the physiological and transcriptome expression profiles of seedlings of deep sowing sensitive inbred line Zi330 and the deep-tolerant inbred line Qi319 were compared under deep sowing stress and the conditions of exogenous hormones alleviates stress. The results showed that mesocotyl elongated significantly after both deep sowing stress and application of exogenous hormones, and its elongation was mainly through elongation and expansion of cell volume. Hormone assays revealed no significant changes in zeatin (ZT) content of the mesocotyl after deep sowing and exogenous hormone application. The endogenous GA3 and auxin (IAA) contents in the mesocotyl of the two inbred lines increased significantly after the addition of exogenous GA3, BR, and SL under deep sowing stress compared to deep sowing stress, while BR and SL decreased significantly. Transcriptome analysis showed that the deep seeding stress was alleviated by GA3, BR, and SLs, the differentially expressed genes (DEGs) mainly included cellulose synthase, expansin and glucanase, oxidase, lignin biosynthesis genes and so on. We also found that protein phosphatase 2C and GA receptor GID1 enhanced the ability of resist deep seeding stress in maize by participating in the abscisic acid (ABA) and the GA signaling pathway, respectively. In addition, we identified two gene modules that were significantly related to mesocotyl elongation, and identified some hub genes that were significantly related to mesocotyl elongation by WGCNA analysis. These genes were mainly involved in transcription regulation, hydrolase activity, protein binding and plasma membrane. Our results from this study may provide theoretical basis for determining the maize deep seeding tolerance and the mechanism by which exogenous hormones regulates deep seeding tolerance.
PMID: 34925395
Genomics , IF:5.736 , 2021 Dec , V114 (1) : P171-184 doi: 10.1016/j.ygeno.2021.12.015
Genome-wide identification of auxin response factor (ARF) gene family and the miR160-ARF18-mediated response to salt stress in peanut (Arachis hypogaea L.).
College of Agronomy, Qingdao Agricultural University, Dry-land Farming Technology Laboratory of Shandong Province, Key Laboratory of Qingdao Major Crop Germplasm Resource Innovation and Application, Qingdao 266109, China.; College of Life Sciences, Qingdao Agricultural University, Qingdao 266109, China.; College of Agronomy, Qingdao Agricultural University, Dry-land Farming Technology Laboratory of Shandong Province, Key Laboratory of Qingdao Major Crop Germplasm Resource Innovation and Application, Qingdao 266109, China.. Electronic address: suijiongming@163.com.
Auxin response factors (ARFs) are transcription factors that regulate the transcription of auxin-responsive genes during plant growth and development. In this study, 29 and 30 ARF members were identified from the two wild peanut species, A. duranensis and A. ipaensis, respectively. The ARFs, including their classifications, conserved domains and evolutionary relationships were characterized. RNA-seq analyses revealed that some of the ARF genes were responsive to abiotic stress, particularly high salinity. In addition to abiotic stress, the expression of 2 ARF members was also regulated by biotic stress, specifically Bradyrhizobium infection in A. duranensis. The ARF gene Arahy.7DXUOK was predicted to be a potential target of miR160. Overexpression of miR160 could cause degradation of the Arahy.7DXUOK target gene transcript and increased salt tolerance in miR160OX transgenic plants. Therefore, these molecular characterization and expression profile analyses provide comprehensive information on ARF family members and will help to elucidate their functions to facilitate further research on peanuts.
PMID: 34933069
J Agric Food Chem , IF:5.279 , 2021 Dec , V69 (49) : P14792-14801 doi: 10.1021/acs.jafc.1c04279
Non-Target-Site Resistance Mechanisms Endow Multiple Herbicide Resistance to Five Mechanisms of Action in Conyza bonariensis.
Department of Agricultural Chemistry, Edaphology and Microbiology, University of Cordoba, 14014 Cordoba, Spain.; Departamento de Parasitologia Agricola, Universidad Autonoma Chapingo, 56230 Texcoco, Mexico.; Departamento de Agronomia, Universidade Federal de Vicosa, Vicosa 36570-900, Minas Gerais, Brazil.; Centro de Ciencias da Natureza, Universidade Federal de Sao Carlos horizontal line Campus Lagoa do Sino, 18290-000 Buri, Brazil.; Department d'Hortofruticultura, Botanica i Jardineria, Agrotecnio, Universitat de Lleida, 25198 Lleida, Spain.
The repeated use of herbicides can lead to the selection of multiple resistance weeds. Some populations of Conyza bonariensis occurring in olive groves from southern Spain have developed resistance to various herbicides. This study determined the resistance levels to 2,4-D, glyphosate, diflufenican, paraquat, and tribenuron-methyl in a putative resistant (R) C. bonariensis population, and the possible non-target-site resistance (NTSR) mechanisms involved were characterized. Resistance factors varied as follows: glyphosate (8.9), 2,4-D (4.8), diflufenican (5.0), tribenuron-methyl (19.6), and paraquat (85.5). Absorption of (14)C-glyphosate was up to 25% higher in the susceptible (S) population compared to the R one, but (14)C-paraquat absorption was similar (up to 70%) in both populations. S plants translocated more than 60% of both (14)C-glyphosate and (14)C-paraquat toward shoots and roots, while R plants translocated less than 10%. The R population was able to metabolize 57% of the 2,4-D into nontoxic metabolites and 68% of the tribenuron-methyl into metsulfuron-methyl (10%), metsulfuron-methyl-hydroxylate (18%), and conjugate-metsulfuron-methyl (40%). Among the NTSR mechanisms investigated, absorption and translocation could be involved in glyphosate resistance, but only translocation for paraquat. Proofs of the presence of enhanced metabolism as a resistance mechanism were found for tribenuron-methyl and 2,4-D, but not for diflufenican. This research informs the first occurrence of multiple resistance to five herbicide classes (acetolactate synthase inhibitors, 5-enolpyruvylshikimate-3-phosphate synthase inhibitors, photosystem I electron diverters, photosystem II inhibitors, and synthetic auxin herbicides) in C. bonariensis.
PMID: 34852464
Plant Methods , IF:4.993 , 2021 Dec , V17 (1) : P128 doi: 10.1186/s13007-021-00828-0
A simple method for the application of exogenous phytohormones to the grass leaf base protodermal zone to improve grass leaf epidermis development research.
College of Agriculture, School of Life Science, State Key Laboratory of Cotton Biology/State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng, 475004, China. ljp905@126.com.; College of Agriculture, School of Life Science, State Key Laboratory of Cotton Biology/State Key Laboratory of Crop Stress Adaptation and Improvement, Henan University, Kaifeng, 475004, China.
BACKGROUND: The leaf epidermis functions to prevent the loss of water and reduce gas exchange. As an interface between the plant and its external environment, it helps prevent damage, making it an attractive system for studying cell fate and development. In monocotyledons, the leaf epidermis grows from the basal meristem that contains protodermal cells. Leaf protoderm zone is covered by the leaf sheath or coleoptile in maize and wheat, preventing traditional exogenous phytohormone application methods, such as directly spraying on the leaf surface or indirectly via culture media, from reaching the protoderm areas directly. The lack of a suitable application method limits research on the effect of phytohormone on the development of grass epidermis. RESULTS: Here, we describe a direct and straightforward method to apply exogenous phytohormones to the leaf protoderms of maize and wheat. We used the auxin analogs 2,4-D and cytokinin analogs 6-BA to test the system. After 2,4-D treatment, the asymmetrical division events and initial stomata development were decreased, and the subsidiary cells were induced in maize, the number of GMC (guard mother cell), SMC (subsidiary mother cell) and young stomata were increased in wheat, and the size of the epidermal cells increased after 6-BA treatment in maize. Thus, the method is suitable for the application of phytohormone to the grass leaf protodermal areas. CONCLUSIONS: The method to apply hormones to the mesocotyls of maize and wheat seedlings is simple and direct. Only a small amount of externally applied substances are needed to complete the procedure in this method. The entire experimental process lasts for ten days generally, and it is easy to evaluate the phytohormones' effect on the epidermis development.
PMID: 34903247
Plant Cell Physiol , IF:4.927 , 2021 Dec doi: 10.1093/pcp/pcab172
Auxin Efflux Transporters OsPIN1c and OsPIN1d Function Redundantly in Regulating Rice (Oryza sativa L.) Panicle Development.
College of Agriculture, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.; Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing 210095, People's Republic of China.; Collaborative Innovation Center for Modern Crop Production co-sponsored by Province and Ministry, Nanjing 210095, People's Republic of China.
The essential role of auxin in plant growth and development is well known. Pathways related to auxin synthesis, transport, and signaling have been extensively studied in recent years, and the PIN-FORMED (PIN) protein family has been identified to be pivotal for polar auxin transport (PAT) and distribution. However, research focused on the functional characterization of PIN proteins in rice is still lacking. In this study, we investigated the expression and function of OsPIN1c and OsPIN1d in the japonica rice variety (Nipponbare) using gene knockout and high-throughput RNA sequencing (RNA-Seq) analysis. Results showed that OsPIN1c and OsPIN1d were mainly expressed in young panicles and exhibited a redundant function. Furthermore, OsPIN1c or OsPIN1d loss-of-function mutants presented a mild phenotype compared with the wild type. In addition to significantly decreased plant height and tiller number, panicle development was severely disrupted in double mutant lines of OsPIN1c and OsPIN1d. Severe defects included smaller inflorescence meristem (IM) and panicle sizes, fewer primary branches, elongated bract leaves, non-degraded hair, and no spikelet growth. Interestingly, ospin1cd-3, a double mutant line with functional retention of OsPIN1d, showed milder defects than those observed in other mutants. Additionally, several critical regulators of reproductive development, such as OsPID, LAX1, OsMADS1, and OsSPL14/IPA1, were differentially expressed in ospin1c-1 ospin1d-1, supporting the hypothesis that OsPIN1c and OsPIN1d are involved in regulating panicle development. Therefore, this study provides novel insights into the auxin pathways that regulate plant reproductive development in monocots.
PMID: 34888695
Plant Cell Physiol , IF:4.927 , 2021 Dec doi: 10.1093/pcp/pcab169
NARROW AND DWARF LEAF 1, the Orthologue of Arabidopsis ENHANCER OF SHOOT REGENERATION1/DORNROSCHEN, Mediates Leaf Development and Maintenance of the Shoot Apical Meristem in Oryza sativa L.
Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan.; Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.; National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan.; Graduate School of Agricultural Regional Vitalization, Kibi International University, Minamiawaji, Hyogo 656-0484, Japan.; Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.
The molecular basis for leaf development, a major focus in developmental biology, remains unclear in the monocotyledonous grass, rice (Oryza sativa). Here, we performed a mutant screen in rice and identified an AP2-type transcription factor family protein, NARROW AND DWARF LEAF1 (NDL1). NDL1 is the orthologue of Arabidopsis thaliana (subsequently called Arabidopsis) ENHANCER OF SHOOT REGENERATION1 (ESR1)/DORNROSCHEN (DRN) and mediates leaf development and maintenance of the shoot apical meristem (SAM). Loss of function of NDL1 results in bladeless leaves and SAMs that are flat, rather than dome-shaped, and lack cell proliferation activity. This loss of function also causes reduced auxin signaling. Moreover, as is the case with Arabidopsis ESR1/DRN, NDL1 plays crucial roles in shoot regeneration. Importantly, we found that NDL1 is not expressed in the SAM but is expressed in leaf primordia. We propose that NDL1 cell autonomously regulates leaf development, but non-cell autonomously regulates SAM maintenance in rice.
PMID: 34865135
Plant Cell Physiol , IF:4.927 , 2021 Dec , V62 (10) : P1542-1555 doi: 10.1093/pcp/pcab107
Components and Functional Diversification of Florigen Activation Complexes in Cotton.
College of Life Sciences, Shihezi University, Shihezi 832003, China.; Center for Crop Biotechnology, College of Agriculture, Anhui Science and Technology University, Fengyang 233100, China.; Plant Genomics Laboratory, College of Life Sciences, Shihezi University, Shihezi 832003, China.
In shoot apex cells of rice, a hexameric florigen activation complex (FAC), comprising flowering locus T (FT), 14-3-3 and the basic leucine zipper transcription factor FD, activates downstream target genes and regulates several developmental transitions, including flowering. The allotetraploid cotton (Gossypium hirsutum L.) contains only one FT locus in both of the A- and D-subgenomes. However, there is limited information regarding cotton FACs. Here, we identified a 14-3-3 protein that interacts strongly with GhFT in the cytoplasm and the nuclei, and five FD homoeologous gene pairs were characterized. In vivo, all five GhFD proteins interacted with Gh14-3-3 and GhFT in the nucleus. GhFT, 14-3-3 and all the GhFDs interacted in the nucleus as well, suggesting that they formed a ternary complex. Virus-induced silencing of GhFD1, -2 and -4 in cotton delayed flowering and inhibited the expression of floral meristem identity genes. Silencing GhFD3 strongly decreased lateral root formation, suggesting a function in lateral root development. GhFD overexpression in Arabidopsis and transcriptional activation assays suggested that FACs containing GhFD1 and GhFD2 function mainly in promoting flowering with partial functional redundancy. Moreover, GhFD3 was specifically expressed in lateral root meristems and dominantly activated the transcription of auxin response factor genes, such as ARF19. Thus, the diverse functions of FACs may depend on the recruited GhFD. Creating targeted genetic mutations in the florigen system using Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated proteins (Cas) genome editing may fine-tune flowering and improve plant architecture.
PMID: 34245289
BMC Plant Biol , IF:4.215 , 2021 Dec , V21 (1) : P602 doi: 10.1186/s12870-021-03385-9
Spatiotemporal auxin distribution in Arabidopsis tissues is regulated by anabolic and catabolic reactions under long-term ammonium stress.
Institute of Plant Bioenergetics, Faculty of Biology, University of Warsaw, I. Miecznikowa 01, 02-096, Warsaw, Poland.; Laboratory of Growth Regulators, Faculty of Science, Palacky University and Institute of Experimental Botany, The Czech Academy of Sciences, Slechtitelu 27, CZ-78371, Olomouc, Czech Republic.; Institute of Plant Bioenergetics, Faculty of Biology, University of Warsaw, I. Miecznikowa 01, 02-096, Warsaw, Poland. apodgorski@biol.uw.edu.pl.
BACKGROUND: The plant hormone auxin is a major coordinator of plant growth and development in response to diverse environmental signals, including nutritional conditions. Sole ammonium (NH4(+)) nutrition is one of the unique growth-suppressing conditions for plants. Therefore, the quest to understand NH4(+)-mediated developmental defects led us to analyze auxin metabolism. RESULTS: Indole-3-acetic acid (IAA), the most predominant natural auxin, accumulates in the leaves and roots of mature Arabidopsis thaliana plants grown on NH4(+), but not in the root tips. We found changes at the expressional level in reactions leading to IAA biosynthesis and deactivation in different tissues. Finally, NH4(+) nutrition would facilitate the formation of inactive oxidized IAA as the final product. CONCLUSIONS: NH4(+)-mediated accelerated auxin turnover rates implicate transient and local IAA peaks. A noticeable auxin pattern in tissues correlates with the developmental adaptations of the short and highly branched root system of NH4(+)-grown plants. Therefore, the spatiotemporal distribution of auxin might be a root-shaping signal specific to adjust to NH4(+)-stress conditions.
PMID: 34922457
Mol Plant Microbe Interact , IF:4.171 , 2021 Dec doi: 10.1094/MPMI-05-21-0118-R
Bradyrhizobium japonicum IRAT FA3 alters Arabidopsis thaliana root architecture via regulation of auxin efflux transporters PIN2, PIN3, PIN7 and ABCB19.
University of California Riverside, 8790, Riverside, California, United States; mercedes.schroeder@ucr.edu.; University of California Riverside, 8790, Microbiology and Plant Pathology, 900 University Ave, Riverside, California, United States, 92521; melissay.gomez@ucr.edu.; University of California Riverside, 8790, Microbiology and Plant Pathology, Riverside, California, United States; nmcla001@ucr.edu.; University of California Riverside, 8790, Microbiology and Plant Pathology, Riverside, California, United States; egachomo@ucr.edu.
Beneficial rhizobacteria can stimulate changes in plant root development. While root system growth is mediated by multiple factors, the regulated distribution of the phytohormone auxin within root tissues plays a principal role. Auxin transport facilitators help to generate the auxin gradients and maxima that determine root structure. Here, we show that the plant growth-promoting rhizobacterial strain Bradyrhizobium japonicum IRAT FA3 influences specific auxin efflux transporters to alter Arabidopsis thaliana root morphology. Gene expression profiling of host transcripts in control and B. japonicum-inoculated roots of the wild type A. thaliana accession Col-0 confirmed upregulation of PIN2, PIN3, PIN7 and ABCB19 with B. japonicum and identified genes potentially contributing to a diverse array of auxin-related responses. Co-cultivation of the bacterium with loss-of-function auxin efflux transport mutants revealed that B. japonicum requires PIN3, PIN7 and ABCB19 to increase lateral root development and utilizes PIN2 to reduce primary root length. Accelerated lateral root primordia production due to B. japonicum was not observed in single pin3, pin7 or abcb19 mutants, suggesting independent roles for PIN3, PIN7 and ABCB19 during the plant-microbe interaction. Our work demonstrates B. japonicum's influence over host transcriptional reprogramming during plant interaction with this beneficial microbe and the subsequent alterations to root system architecture.
PMID: 34941379
Plant Mol Biol , IF:4.076 , 2021 Dec doi: 10.1007/s11103-021-01233-w
Early gene expression response of barley root tip to toxic concentrations of cadmium.
Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dubravska cesta 9, 84523, Bratislava, Slovak Republic.; Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dubravska cesta 9, 84523, Bratislava, Slovak Republic. Ladislav.Tamas@savba.sk.
KEY MESSAGE: Already a short-term Cd treatment induces changes in gene expression in barley root tips via IAA and ROS signaling during mild and severe Cd stress, respectively. Even a short, 30 min, Cd treatment of roots induced a considerable alteration in gene expression in the barley root tips within an hour after the treatments. The very early activation of MYB1 transcription factor expression is partially regulated by auxin signaling in mildly stressed seedlings. An increase in allene oxide cyclase and NADPH oxidase expression was a distinguishing feature of root tips response to mild Cd stress and their expression is activated via IAA signaling. Meanwhile, early changes in the level of dehydrin transcripts were detected in moderately and severely stressed root tips, and their induction is related to altered ROS homeostasis in cells. The early activation of glutathione peroxidase expression by mild Cd stress indicates the involvement of IAA in the signaling process. In contrast, early ascorbate peroxidase expression was induced only with Cd treatment causing severe stress and ROS play central roles in its induction. The expression of cysteine protease was activated similarly in both mildly and severely Cd-stressed roots; consequently, both increased IAA and ROS levels take part in the regulation of cysteine protease expression. The Cd-evoked accumulation of BAX Inhibitor-1 mRNA was characteristic for moderately and severely stressed roots. Whereas decreased IAA level did not affect its expression, rotenone-mediated ROS depletion markedly reduced the Cd-induced expression of BAX Inhibitor-1. An early increase of alternative oxidase levels in the root tip cells indicated that the reduction of mitochondrial superoxide generation is an important component of barley root response to severe Cd stress.
PMID: 34928487
Plant Mol Biol , IF:4.076 , 2021 Dec doi: 10.1007/s11103-021-01224-x
Early sensing of phosphate deprivation triggers the formation of extra root cap cell layers via SOMBRERO through a process antagonized by auxin signaling.
Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B1, Ciudad Universitaria, C.P. 58030, Morelia, Michoacan, Mexico.; CONACYT-Instituto de Investigaciones Quimico-Biologicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio B1, Ciudad Universitaria, C.P. 58030, Morelia, Michoacan, Mexico. jlopezb@conacyt.mx.
KEY MESSAGE: The role of the root cap in the plant response to phosphate deprivation has been scarcely investigated. Here we describe early structural, physiological and molecular changes prior to the determinate growth program of the primary roots under low Pi and unveil a critical function of the transcription factor SOMBRERO in low Pi sensing. Mineral nutrient distribution in the soil is uneven and roots efficiently adapt to improve uptake and assimilation of sparingly available resources. Phosphate (Pi) accumulates in the upper layers and thus short and branched root systems proliferate to better exploit organic and inorganic Pi patches. Here we report an early adaptive response of the Arabidopsis primary root that precedes the entrance of the meristem into the determinate developmental program that is a hallmark of the low Pi sensing mechanism. In wild-type seedlings transferred to low Pi medium, the quiescent center domain in primary root tips increases as an early response, as revealed by WOX5:GFP expression and this correlates with a thicker root tip with extra root cap cell layers. The halted primary root growth in WT seedlings could be reversed upon transfer to medium supplemented with 250 microM Pi. Mutant and gene expression analysis indicates that auxin signaling negatively affects the cellular re-specification at the root tip and enabled identification of the transcription factor SOMBRERO as a critical element that orchestrates both the formation of extra root cap layers and primary root growth under Pi scarcity. Moreover, we provide evidence that low Pi-induced root thickening or the loss-of-function of SOMBRERO is associated with expression of phosphate transporters at the root tip. Our data uncover a developmental window where the root tip senses deprivation of a critical macronutrient to improve adaptation and surveillance.
PMID: 34855067
Plants (Basel) , IF:3.935 , 2021 Dec , V10 (12) doi: 10.3390/plants10122709
Involvement of Auxin Biosynthesis and Transport in the Antheridium and Prothalli Formation in Lygodium japonicum.
Graduate School of Science and Engineering, Teikyo University, 1-1 Toyosatodai, Utsunomiya 320-8551, Tochigi, Japan.; Department of Biosciences, Teikyo University, 1-1 Toyosatodai, Utsunomiya 320-8551, Tochigi, Japan.; Advanced Instrumental Analysis Center, Teikyo University, 1-1 Toyosatodai, Utsunomiya 320-8551, Tochigi, Japan.
The spores of Lygodium japonicum, cultured in the dark, form a filamentous structure called protonema. Earlier studies have shown that gibberellin (GA) induces protonema elongation, along with antheridium formation, on the protonema. In this study, we have performed detailed morphological analyses to investigate the roles of multiple phytohormones in antheridium formation, protonema elongation, and prothallus formation in L. japonicum. GA4 methyl ester is a potent GA that stimulates both protonema elongation and antheridium formation. We found that these effects were inhibited by simultaneous application of abscisic acid (ABA). On the other hand, IAA (indole-3-acetic acid) promoted protonema elongation but reduced antheridium formation, while these effects were partially recovered by transferring to an IAA-free medium. An auxin biosynthesis inhibitor, PPBo (4-phenoxyphenylboronic acid), and a transport inhibitor, TIBA (2,3,5-triiodobenzoic acid), both inhibited protonema elongation and antheridium formation. L. japonicum prothalli are induced from germinating spores under continuous white light. Such development was negatively affected by PPBo, which induced smaller-sized prothalli, and TIBA, which induced aberrantly shaped prothalli. The evidence suggests that the crosstalk between these plant hormones might regulate protonema elongation and antheridium formation in L. japonicum. Furthermore, the possible involvement of auxin in the prothalli development of L. japonicum is suggested.
PMID: 34961180
Life (Basel) , IF:3.817 , 2021 Dec , V11 (12) doi: 10.3390/life11121404
Diverse Effect of Two Cytokinins, Kinetin and Benzyladenine, on Plant Development, Biotic Stress Tolerance, and Gene Expression.
Centre for Agricultural Research, ELKH, Plant Protection Institute, Herman Otto Str. 15, H-1022 Budapest, Hungary.
The plant hormones cytokinins affect a various array of plant growth and development processes as well as responses to biotic and abiotic stresses. In this study, the opposite effect of two different cytokinins kinetin (N(6)-furfuryladenine) and benzyladenine (BA) on development and on the tolerance of Arabidopsis and tobacco plants to virus, bacteria, and fungi infection was reported. Treatments of Arabidopsis and tobacco seedlings with saturated solutions of BA inhibited plant progress, while treatments with saturated water solution of kinetin promoted plant development. Furthermore, BA pre-treatments strongly reduced the number of TMV (Tobacco mosaic virus) lesions on tobacco and the tissue damage caused by the incompatible Pseudomonas bacteria on Arabidopsis and tobacco leaves. Similarly, BA pre-treatment significantly reduced the necrotic disease symptoms of Botrytis cinerea infection. Kinetin pre-treatments had a much weaker or no protective effect on the damage caused by the above pathogens. Accordingly, Arabidopsis gene expression profiles after treatments also showed that the two cytokinins have different effects on several plant processes. The gene expression results supported the more robust effect of BA, which up and downregulated more than 2000 genes, while only 436 genes were influenced by kinetin treatment. It is noteworthy that BA and kinetin treatment changed gene expressions in the same direction only in a relatively few cases (73 upregulated and 70 downregulated genes), and even 28 genes were regulated into the opposite directions by BA and kinetin. Both treatments had a strong effect on auxin and gibberellin-related genes, but only BA had a significant effect on cytokinin-induced processes. While kinetin exclusively activated the flavonoid synthesis genes, BA affected more significantly protein synthesis, photosynthesis, and plant defence-related genes. In conclusion, BA solution had sometimes the opposite and generally a much stronger effect than kinetin solution not only on the development and on biotic stress tolerance of tobacco and Arabidopsis plants but also on the gene expressions. The stronger protective effect of BA to necrotic stresses is probably due to its stronger senescence inhibitory effect on plant tissues, as supported by the stronger chlorophyll retardation of the BA-treated leaves.
PMID: 34947935
Proteins , IF:3.756 , 2021 Dec doi: 10.1002/prot.26293
Identification, analysis, and modeling of the YUCCA protein family genome-wide in Coffea canephora.
Centro de Investigacion Cientifica de Yucatan, Unidad de Bioquimica y Biologia Molecular de Plantas, Merida, Mexico.
Auxin is involved in almost every aspect of plant growth and development, from embryogenesis to senescence. Indole-3-acetic acid (IAA) is the main known natural auxin that is synthesized by enzymes tryptophan aminotransferase of arabidopsis (TAA) and YUCCA (YUC) of the flavin-containing monooxygenases family (FMO) from one of the tryptophan-dependent pathways. Genome-wide identification and comprehensive analysis of the YUC-protein family have been conducted in Coffea canephora in the present study. A total of 10 members CcYUC gene family were identified in C. canephora. Phylogenetic analysis revealed that the CcYUC protein family is evolutionarily conserved, and they consist of four groups. In contrast, bioinformatic analysis predicted a hydrophobic transmembrane helix (TMH) for one CcYUC (YUC10) member only. Isoelectric point (pI), molecular mass (Ms), signal peptide, subcellular localization, and phosphorylation sites were predicted for CcYUC proteins. YUC enzymes require the prosthetic group flavin adenine dinucleotide (FAD) and the cofactor nicotinamide adenine dinucleotide phosphate (NADPH) for their enzymatic activity. Therefore, we include the molecular docking for CcYUC2-FAD-NADPH-IPyA and yucasin, which is a specific inhibitor for YUC activity. The docking results showed FAD and NADPH binding at the big and small domain sites, respectively, in CcYUC2. IPyA binds very close to FAD along the big domain, and yucasin competes for the same site as IPA, blocking IAA production. Furthermore, in silico point mutations affect the stability of the CcYUC2-4 proteins.
PMID: 34890079
Gene , IF:3.688 , 2021 Dec , V804 : P145905 doi: 10.1016/j.gene.2021.145905
Auxin drives tomato spotted wilt virus (TSWV) resistance through epigenetic regulation of auxin response factor ARF8 expression in tomato.
Laboratory of Molecular Genetics, Immunology and Biotechnology, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 2092, Tunisia.; Institute of Molecular and Cellular Biology of Plants (UPV-CSIC), Valencia 46022, Spain; Dept of Biotechnology, ETSIAMN, Universidad Politecnica de Valencia, 46002, Spain.; Laboratory of Molecular Genetics, Immunology and Biotechnology, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 2092, Tunisia; Faculty of Sciences of Bizerte, Zarzouna 702, University of Carthage, Tunisia.; Laboratory of Molecular Genetics, Immunology and Biotechnology, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 2092, Tunisia; Faculty of Sciences of Bizerte, Zarzouna 702, University of Carthage, Tunisia. Electronic address: faten.gorsane@fsb.u-carthage.tn.
Tomato spotted wilt virus (TSWV) causes severe losses of tomato crops worldwide. To cope dynamically with such a threat, plants deploy strategies acting at the molecular and the epigenetic levels. We found that tomato symptoms progress in a specific-genotype-manner upon TSWV infection. Susceptible genotypes showed within the Auxin Response Factor (ARF8) promoter coupled to enhanced expression of miRNA167a, reduced ARF8 gene and decreased levels of the hormone auxin. This constitutes a deliberate attempt of TSWV to disrupt plant growth to promote spread in sensitive cultivars. Epigenetic regulation through the level of cytosine methylation and the miR167a-ARF8 module are part of a complex network modulating auxin-triggered synthesis and shaping tomato responses to TSWV. Furthermore, modulation of miR167a-ARF8 regulatory module could be applied in tomato-resistance breeding programs.
PMID: 34411646
J Sci Food Agric , IF:3.638 , 2021 Dec doi: 10.1002/jsfa.11711
Controlled-release urea combined with fulvic acid enhanced carbon/nitrogen metabolic processes and maize growth.
National Engineering Laboratory for Efficient Use of Soil and Fertilizer Resources, College of Resources and the Environment, Shandong Agricultural University, Taian, China.; Shandong Pengbo Biotechnology Co., Ltd, Taian, China.; Shandong Wanhao Fertilizer Co. Ltd, Jinan, China.
BACKGROUND: Controlled-release urea (CRU) or fulvic acid (FA), when applied, have been shown to increase nitrogen (N) use efficiency (NUE) or to stimulate plant growth, yet their interactive effects are not well explored. The objective of this study was to investigate the synergistic mechanisms of CRU combined with FA (CRU + FA) on maize (Zea mays L.) growth. Through the experimental design with five treatments, the N metabolism through the transcriptomic analysis of maize leaf, endogenous hormones, photosynthesis enzymes in maize leaf and root, and maize yield and NUE were evaluated. RESULTS: Compared with CRU treatment, CRU + FA treatment significantly increased auxin, nitrate reductase, and glutamate dehydrogenase in leaf by 35.4%, 43.9%, 40.8% and 19.5%, respectively, as well as, the relative content of the leaf chlorophyll and photosynthetic rate by 14.8% and 45.6%, respectively, at 12-leaf collar stage; the carbon/nitrogen (C/N) metabolic process was significantly enriched in CRU + FA treatment by 312 and 418 genes, according to transcriptome profiles of C/N metabolic in leaves from various fertilizer treated maize; maize yield and NUE of CRU + FA treatment were increased by 6.3% and 38.4%, respectively. CONCLUSIONS: These results demonstrated that CRU + FA is a viable fertilization scheme that can enhance maize growth, yield and NUE through their synergies in improving N uptake, promoting photosynthesis, increasing C/N metabolic processes, and enhancing enzyme activities. (c) 2021 Society of Chemical Industry.
PMID: 34888887
Biochem Biophys Res Commun , IF:3.575 , 2021 Dec , V589 : P16-22 doi: 10.1016/j.bbrc.2021.11.109
Local conjugation of auxin by the GH3 amido synthetases is required for normal development of roots and flowers in Arabidopsis.
State Key Laboratory of Crop Genetics & Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China; Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA.; Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA.; Department of Bioregulation and Biointeraction, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, 183-8509, Japan.; Department of Applied Biological Science, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, 183-8509, Japan.; Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, 183-8509, Japan.; Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, 92093, USA. Electronic address: yundezhao@ucsd.edu.
Gretchen Hagen 3 (GH3) amido synthetases conjugate amino acids to a carboxyl group of small molecules including hormones auxin, jasmonate, and salicylic acid. The Arabidopsis genome harbors 19 GH3 genes, whose exact roles in plant development have been difficult to define because of genetic redundancy among the GH3 genes. Here we use CRISPR/Cas9 gene editing technology to delete the Arabidopsis group II GH3 genes, which are able to conjugate indole-3-acetic acid (IAA) to amino acids. We show that plants lacking the eight group II GH3 genes (gh3 octuple mutants) accumulate free IAA and fail to produce IAA-Asp and IAA-Glu conjugates. Consequently, gh3 octuple mutants have extremely short roots, long and dense root hairs, and long hypocotyls. Our characterization of gh3 septuple mutants, which provide sensitized backgrounds, reveals that GH3.17 and GH3.9 play prominent roles in root elongation and seed production, respectively. We show that GH3 functions correlate with their expression patterns, suggesting that local deactivation of auxin also contributes to maintaining auxin homeostasis. Moreover, this work provides a method for elucidating functions of individual members of a gene family, whose members have overlapping functions.
PMID: 34883285
J Plant Physiol , IF:3.549 , 2021 Dec , V269 : P153594 doi: 10.1016/j.jplph.2021.153594
Auxin transport in developing protophloem: A case study in canalization.
Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland.; Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015, Lausanne, Switzerland. Electronic address: christian.hardtke@unil.ch.
Spatiotemporal cues orchestrate the development of organs and cellular differentiation in multicellular organisms. For instance, in the root apical meristem an auxin gradient patterns the transition from stem cell maintenance to transit amplification and eventual differentiation. Among the proximal tissues generated by this growth apex, the early, so-called protophloem, is the first tissue to differentiate. This observation has been linked to increased auxin activity in the developing protophloem sieve element cell files as compared to the neighboring tissues. Here we review recent progress in the characterization of the unique mechanism by which auxin canalizes its activity in the developing protophloem and fine-tunes its own transport to guide proper timing of protophloem sieve element differentiation.
PMID: 34953411
J Plant Physiol , IF:3.549 , 2022 Jan , V268 : P153589 doi: 10.1016/j.jplph.2021.153589
The reliance of phytohormone biosynthesis on primary metabolite precursors.
Max-Planck-Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany. Electronic address: normafabregas@gmail.com.; Max-Planck-Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany. Electronic address: fernie@mpimp-golm.mpg.de.
There is some debate as to whether phytohormone metabolites should be classified as primary or secondary metabolites. Phytohormones have profound effects on growth - a typical trait of primary metabolites - yet several of them are formed from secondary metabolite precursors. This is further exacerbated by the blurred distinction between primary and secondary metabolism. What is clearer, however, is that phytohormones display distinctive regulatory mechanisms from other metabolites. Moreover, by contrast to microbial and mammalian systems, the majority of plant metabolite receptors characterized to date are hormone receptors. Here, we provide an overview of the metabolic links between primary metabolism and phytohormone biosynthesis in an attempt to complement recent reviews covering the signaling crosstalk between elements of core metabolism and the phytohormones. In doing so, we cover the biosynthesis of both the classical metabolic phytohormones namely auxins, salicylic acid, jasmonate, ethylene, cytokinins, brassinosteroids, gibberellins and abscisic acid as well as recently described plant growth regulators which have been proposed as novel phytohormones namely strigolactones blumenols, zaxinone and beta-cyclocitral as well as melatonin. For each hormone, we describe the primary metabolite precursors which fuel its synthesis, act as conjugates or in the case of 2-oxoglutarate act more directly as a co-substrate in the biosynthesis of gibberellin, auxin and salicylic acid. Furthermore, several amino acids operate as hormone conjugates, such as jasmonate-conjugates. In reviewing the biosynthesis of all the phytohormones simultaneously, the exceptional intricacy of the biochemical interplay that underpins their interaction emerges.
PMID: 34896926
J Biotechnol , IF:3.307 , 2021 Dec , V342 : P36-44 doi: 10.1016/j.jbiotec.2021.09.013
Detoxification of phenanthrene in Arabidopsis thaliana involves a Dioxygenase For Auxin Oxidation 1 (AtDAO1).
Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA.; Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA. Electronic address: adan.colon-carmona@umb.edu.
Polycyclic aromatic hydrocarbon (PAH) contamination has a negative impact on ecosystems. PAHs are a large group of toxins with two or more benzene rings that are persistent in the environment. Some PAHs can be cytotoxic, teratogenic, and/or carcinogenic. In the bacterium Pseudomonas, PAHs can be modified by dioxygenases, which increase the reactivity of PAHs. We hypothesize that some plant dioxygenases are capable of PAH biodegradation. Herein, we investigate the involvement of Arabidopsis thaliana At1g14130 in the degradation of phenanthrene, our model PAH. The At1g14130 gene encodes Dioxygenase For Auxin Oxidation 1 (AtDAO1), an enzyme involved in the oxidative inactivation of the hormone auxin. Expression analysis using a beta-glucuronidase (GUS) reporter revealed that At1g14130 is prominently expressed in new leaves of plants exposed to media with phenanthrene. Analysis of the oxidative state of gain-of-function mutants showed elevated levels of H2O2 after phenanthrene treatments, probably due to an increase in the oxidation of phenanthrene by AtDAO1. Biochemical assays with purified AtDAO1 and phenanthrene suggest an enzymatic activity towards the PAH. Thus, data presented in this study support the hypothesis that an auxin dioxygenase, AtDAO1, from Arabidopsis thaliana contributes to the degradation of phenanthrene and that there is possible toxic metabolite accumulation after PAH exposure.
PMID: 34610365
Plant Biol (Stuttg) , IF:3.081 , 2021 Dec doi: 10.1111/plb.13376
Hydrogen sulphide: an emerging regulator of plant defence signalling.
Department of Botany, University of Delhi, New Delhi, India.; Department of Biotechnology, TERI School of Advanced Studies, Vasant Kunj, New Delhi, India.; Department of Botany, Dyal Singh College, New Delhi, India.; College of General Education, Kookmin University, Seoul, South Korea.
Hydrogen sulphide (H2 S), a gaseous signalling molecule in plants, has gained considerable attention in recent years because of its emerging roles in the regulation of plant growth and development and responses to abiotic stressors. Although the involvement of H2 S in biotic stress is not well documented in the literature, a growing body of evidence indicates its potential role in plant defence, particularly against bacterial and fungal pathogens. Recent reports have suggested that H2 S participates in plant defence signalling potentially by (1) regulating glutathione metabolism, (2) inducing expression of pathogenesis-related (PR) and other defence-related genes, (3) modulating enzyme activity through post-translational modifications, and (4) interacting with phytohormones such as jasmonic acid, ethylene and auxin. In this review, we discuss the biosynthesis, metabolism and interaction of H2 S with phytohormones, and highlight evidence gathered so far to support the emerging roles of H2 S in plant defence against invading pathogens.
PMID: 34904345
J Zhejiang Univ Sci B , IF:3.066 , 2021 Dec , V22 (12) : P1002-1021 doi: 10.1631/jzus.B2100174
Effects of gibberellin priming on seedling emergence and transcripts involved in mesocotyl elongation in rice under deep direct-seeding conditions.
Cereal Crops Research Institute, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China.; Crop Breeding and Cultivation Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.; Cereal Crops Research Institute, Henan Academy of Agricultural Sciences, Zhengzhou 450002, China. hnrice@163.com.
Mesocotyl elongation is a key trait influencing seedling emergence and establishment in direct-seeding rice cultivation. The phytohormone gibberellin (GA) has positive effects on mesocotyl elongation in rice. However, the physiological and molecular basis underlying the regulation of mesocotyl elongation mediated by GA priming under deep-sowing conditions remains largely unclear. In the present study, we performed a physiological and comprehensive transcriptomic analysis of the function of GA priming in mesocotyl elongation and seedling emergence using a direct-seeding japonica rice cultivar ZH10 at a 5-cm sowing depth. Physiological experiments indicated that GA priming significantly improved rice seedling emergence by increasing the activity of starch-metabolizing enzymes and compatible solute content to supply the energy essential for subsequent development. Transcriptomic analysis revealed 7074 differentially expressed genes (false discovery rate of <0.05, |log2(fold change)| of >/=1) after GA priming. Furthermore, gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses revealed that genes associated with transcriptional regulation, plant hormone biosynthesis or signaling, and starch and sucrose metabolism were critical for GA-mediated promotion of rice mesocotyl elongation. Further analyses showed that the expression of the transcription factor (TF) genes (v-myb avian myeloblastosis viral oncogene homolog (MYB) alternative splicing 1 (MYBAS1), phytochrome-interacting factors 1 (PIF1), Oryza sativa teosinte branched 1/cycloidea/proliferating cell factor 5 (OsTCP5), slender 1 (SLN1), and mini zinc finger 1 (MIF1)), plant hormone biosynthesis or signaling genes (brassinazole-resistant 1 (BZR1), ent-kaurenoic acid oxidase-like (KAO), GRETCHEN HAGEN 3.2 (GH3.2), and small auxin up RNA 36 (SAUR36)), and starch and sucrose metabolism genes (alpha-amylases (AMY2A and AMY1.4)) was highly correlated with the mesocotyl elongation and deep-sowing tolerance response. These results enhance our understanding of how nutrient metabolism-related substances and genes regulate rice mesocotyl elongation. This may facilitate future studies on related genes and the development of novel rice varieties tolerant to deep sowing.
PMID: 34904413
Bot Stud , IF:2.787 , 2021 Dec , V62 (1) : P23 doi: 10.1186/s40529-021-00330-9
Floral organ-specific proteome profiling of the floral ornamental orchid (Cymbidium goeringii) reveals candidate proteins related to floral organ development.
Institute of Horticulture, Zhejiang Academy of Agriculture Science, Hangzhou, Zhejiang, China.; College of Landscape and Architecture, Nanjing Forestry University, Nanjing, Jiangsu, China.; Plant Protection and Microbiology, Zhejiang Academy of Agricultural Science, Hangzhou, Zhejiang, China.; Institute of Horticulture, Zhejiang Academy of Agriculture Science, Hangzhou, Zhejiang, China. chongpo1230@163.com.
BACKGROUND: Cymbidium goeringii, belonging to the Orchidaceae family, is an important ornamental plant with striking petals and lips. Extremely diversified floral patterns and morphologies make C. goeringii good research material to examine floral development of orchids. However, no floral organ-specific protein has been identified yet. To screen floral development associated proteins, four proteomes from petal (PE), lip (LI), gynostemium (GY), and sepal (SE) were analyzed using Tandem Mass Tag-based proteomic analysis. RESULTS: A total of 6626 unique peptides encoding 2331 proteins were identified in our study. Proteins in several primary metabolic pathways, including amino acid metabolism, energy metabolism, and lipid metabolism, were identified as differentially expressed proteins. Interestingly, most of the energy metabolism-related proteins highly expressed in SE, indicating that SE is an important photosynthetic organ of C. goeringii flower. Furthermore, a number of phytohormone-related proteins and transcription factors (TFs) were identified in C. goeringii flowers. Expression analysis showed that 1-aminocyclopropane-1-carboxylate oxidase highly expressed in GY, IAA-amino acid hydrolase ILR1-like 4 and gibberellin receptor 1 C greatly expressed in LI, and auxin-binding protein ABP20 significantly expressed in SE, suggesting a significant role of hormones in the regulation of flower morphogenesis and development. For TFs, GY-highly expressed bHLH13, PE-highly expressed WRKY33, and GY-highly expressed VIP1, were identified. CONCLUSIONS: Mining of floral organ differential expressed enzymes and TFs helps us to excavate candidate proteins related to floral organ development and to accelerate the breeding of Cymbidium plants.
PMID: 34921643
J Genet Eng Biotechnol , 2021 Dec , V19 (1) : P179 doi: 10.1186/s43141-021-00252-w
A highly efficient auxin-producing bacterial strain and its effect on plant growth.
Research & Development Center, Cosmicgreen Inc., Daeryung Post Tower I, Digital-ro 288, Seoul, 08377, Republic of Korea.; Research & Development Center, Cosmicgreen Inc., Daeryung Post Tower I, Digital-ro 288, Seoul, 08377, Republic of Korea. joosehwan@gmail.com.
BACKGROUND: Various bacteria promote plant root growth in the rhizosphere, as a measure of securing and enlarging their ecological niche. These interactions are mediated by plant growth regulators (PGRs) such as auxin, and indole-3-acetic acid (IAA) is one of the physiologically active auxin. In this study, we isolated an unusual bacterial strain from food process waste with high efficiency and demonstrated its effects on plant rooting and early-stage growth. RESULTS: The efficiency of this bacterial strain in producing IAA was 16.6 mg/L/h in Luria-Bertani broth containing 0.05% L-tryptophan (Trp) at room temperature (24 +/- 2 degrees C). Its IAA production was highly dependent on the presence of precursor, Trp. This bacterium was identified as Ignatzschineria sp. by 16S rDNA sequencing. Its bacterial culture supernatant (BCS) enhanced plant root initiation, root growth, and plant growth in the early stages. The root mass formed BCS-treated in apple mint cuttings was twofold of that formed in the control. The root number and length were 46% and 18% higher, respectively, in BCS-treated chrysanthemum cuttings than in the control. CONCLUSIONS: These results show that the BCS of Ignatzschineria sp. CG20001 isolate obtained in this study can be used for agricultural applications. In addition, the novelty of this strain makes it a valuable genetic resource for biotechnological applications.
PMID: 34859356