Science , IF:47.728 , 2023 Jun , V380 (6651) : P1275-1281 doi: 10.1126/science.adf0752
Brassinosteroid coordinates cell layer interactions in plants via cell wall and tissue mechanics.
Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK.; Department of Biochemistry and Metabolism, John Innes Centre, Norwich NR4 7UH, UK.; National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100039, China.; State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; Department of Computational and Systems Biology, John Innes Centre, Norwich NR4 7UH, UK.; Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK.
Growth coordination between cell layers is essential for development of most multicellular organisms. Coordination may be mediated by molecular signaling and/or mechanical connectivity between cells, but how genes modify mechanical interactions between layers is unknown. Here we show that genes driving brassinosteroid synthesis promote growth of internal tissue, at least in part, by reducing mechanical epidermal constraint. We identified a brassinosteroid-deficient dwarf mutant in the aquatic plant Utricularia gibba with twisted internal tissue, likely caused by mechanical constraint from a slow-growing epidermis. We tested this hypothesis by showing that a brassinosteroid mutant in Arabidopsis enhances epidermal crack formation, indicative of increased tissue stress. We propose that by remodeling cell walls, brassinosteroids reduce epidermal constraint, showing how genes can control growth coordination between layers by means of mechanics.
PMID: 37347863
Trends Plant Sci , IF:18.313 , 2023 Aug doi: 10.1016/j.tplants.2023.07.010
Single cell RNA-seq in phytohormone signaling: a promising future.
College of Agriculture, South China Agriculture University, Guangzhou, Guangdong 510642, China.; State Agricultural Biotechnology Centre, Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia.; State Agricultural Biotechnology Centre, Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia. Electronic address: rajeev.varshney@murdoch.edu.au.; Guangdong Provincial Key Laboratory of Crop Genetic Improvement, South China Peanut Sub-Center of National Center of Oilseed Crops Improvement, Crops Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong 510640, China. Electronic address: liuhao@gdaas.cn.
Phytohormone signaling regulates plant growth and development. Single cell RNA sequencing (scRNA-seq) provides unprecedented opportunities to decipher hormone-mediated spatiotemporal gene regulatory networks. In a recent study, Nolan et al. used time-series scRNA-seq to identify the cortex as a key site for brassinosteroid (BR)-mediated gene expression and revealed a signaling network during cell phase transition.
PMID: 37550122
Nat Chem Biol , IF:15.04 , 2023 Jun doi: 10.1038/s41589-023-01346-x
Plasmodesmata mediate cell-to-cell transport of brassinosteroid hormones.
Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.; Center for Plant Systems Biology, VIB, Ghent, Belgium.; Laboratoire de Biogenese Membranaire, Unite Mixte de Recherche 5200, Universite de Bordeaux, Centre National de la Recherche Scientifique, Villenave d'Ornon, France.; Plant Molecular and Cellular Biology Laboratory and Integrative Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA.; Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium.; Laboratory of Growth Regulators, Institute of Experimental Botany, The Czech Academy of Sciences and Palacky University, Olomouc, Czech Republic.; Faculty of Science, Hokkaido University, Sapporo, Japan.; Department of Biology, Duke University, Durham, NC, USA.; Howard Hughes Medical Institute, Duke University, Durham, NC, USA.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium. nemanja.vukasinovic@psb.vib-ugent.be.; Center for Plant Systems Biology, VIB, Ghent, Belgium. nemanja.vukasinovic@psb.vib-ugent.be.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium. eurus@psb.vib-ugent.be.; Center for Plant Systems Biology, VIB, Ghent, Belgium. eurus@psb.vib-ugent.be.
Brassinosteroids (BRs) are steroidal phytohormones that are essential for plant growth, development and adaptation to environmental stresses. BRs act in a dose-dependent manner and do not travel over long distances; hence, BR homeostasis maintenance is critical for their function. Biosynthesis of bioactive BRs relies on the cell-to-cell movement of hormone precursors. However, the mechanism of the short-distance BR transport is unknown, and its contribution to the control of endogenous BR levels remains unexplored. Here we demonstrate that plasmodesmata (PD) mediate the passage of BRs between neighboring cells. Intracellular BR content, in turn, is capable of modulating PD permeability to optimize its own mobility, thereby manipulating BR biosynthesis and signaling. Our work uncovers a thus far unknown mode of steroid transport in eukaryotes and exposes an additional layer of BR homeostasis regulation in plants.
PMID: 37365405
EMBO J , IF:11.598 , 2023 Jul , V42 (13) : Pe112998 doi: 10.15252/embj.2022112998
Salicylic acid attenuates brassinosteroid signaling via protein de-S-acylation.
Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou, China.
Brassinosteroids (BRs) are important plant hormones involved in many aspects of development. Here, we show that BRASSINOSTEROID SIGNALING KINASEs (BSKs), key components of the BR pathway, are precisely controlled via de-S-acylation mediated by the defense hormone salicylic acid (SA). Most Arabidopsis BSK members are substrates of S-acylation, a reversible protein lipidation that is essential for their membrane localization and physiological function. We establish that SA interferes with the plasma membrane localization and function of BSKs by decreasing their S-acylation levels, identifying ABAPT11 (ALPHA/BETA HYDROLASE DOMAIN-CONTAINING PROTEIN 17-LIKE ACYL PROTEIN THIOESTERASE 11) as an enzyme whose expression is quickly induced by SA. ABAPT11 de-S-acylates most BSK family members, thus integrating BR and SA signaling for the control of plant development. In summary, we show that BSK-mediated BR signaling is regulated by SA-induced protein de-S-acylation, which improves our understanding of the function of protein modifications in plant hormone cross talk.
PMID: 37211868
Plant Cell , IF:11.277 , 2023 Jul doi: 10.1093/plcell/koad200
The osmotic stress-activated receptor-like kinase DPY1 mediates SnRK2 kinase activation and drought tolerance in Setaria.
Key Laboratory of Agricultural Water Resources, Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, 050021, China.; Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China.; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.; Center for Agricultural Genetic Resources Research, Shanxi Agricultural University, Taiyuan 030031, China.; National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.; Hebei Collaboration Innovation Center for Cell Signaling, Hebei Normal University, Shijiazhuang, 050024, China.
Plant genomes encode many receptor-like kinases (RLKs) that localize to the cell surface and perceive a wide variety of environmental cues to initiate downstream signaling cascades. Whether these RLKs participate in dehydration stress signaling in plants is largely unknown. DROOPY LEAF 1 (DPY1), a leucine-rich repeat (LRR)-RLK, was recently shown to regulate plant architecture by orchestrating early brassinosteroid signaling in foxtail millet (Setaria italica). Here, we show that DPY1 is essential for the acclimation of foxtail millet to drought stress. DPY1 can be phosphorylated and activated in response to osmotic stress, and is required for more than half of osmotic stress-induced global phosphorylation events, including the phosphorylation of Sucrose non-fermenting kinase 2 s (SnRK2s), the central kinases involved in osmotic stress. DPY1 acts upstream of STRESS-ACTIVATED PROTEIN KINASE 6 (SAPK6, a subclass I SnRK2) and is required for full SAPK6 activation, thereby allowing regulation of downstream genes to mount a response against drought stress. These signaling events are largely independent of DPY1-mediated brassinosteroid signaling. The DPY1-SAPK6 module is specific to seed plants and is absent in ancestral non-seed plants. Our findings reveal a dehydration stress-activated RLK that plays an indispensable role in osmotic stress signaling and mediates SnRK2 activation at the cell surface.
PMID: 37462269
Plant Cell , IF:11.277 , 2023 Aug , V35 (8) : P2871-2886 doi: 10.1093/plcell/koad130
The transcriptional hub SHORT INTERNODES1 integrates hormone signals to orchestrate rice growth and development.
State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Plants have evolved sophisticated mechanisms to coordinate their growth and stress responses via integrating various phytohormone signaling pathways. However, the precise molecular mechanisms orchestrating integration of the phytohormone signaling pathways remain largely obscure. In this study, we found that the rice (Oryza sativa) short internodes1 (shi1) mutant exhibits typical auxin-deficient root development and gravitropic response, brassinosteroid (BR)-deficient plant architecture and grain size as well as enhanced abscisic acid (ABA)-mediated drought tolerance. Additionally, we found that the shi1 mutant is also hyposensitive to auxin and BR treatment but hypersensitive to ABA. Further, we showed that OsSHI1 promotes the biosynthesis of auxin and BR by activating the expression of OsYUCCAs and D11, meanwhile dampens ABA signaling by inducing the expression of OsNAC2, which encodes a repressor of ABA signaling. Furthermore, we demonstrated that 3 classes of transcription factors, AUXIN RESPONSE FACTOR 19 (OsARF19), LEAF AND TILLER ANGLE INCREASED CONTROLLER (LIC), and OsZIP26 and OsZIP86, directly bind to the promoter of OsSHI1 and regulate its expression in response to auxin, BR, and ABA, respectively. Collectively, our results unravel an OsSHI1-centered transcriptional regulatory hub that orchestrates the integration and self-feedback regulation of multiple phytohormone signaling pathways to coordinate plant growth and stress adaptation.
PMID: 37195873
New Phytol , IF:10.151 , 2023 Aug , V239 (4) : P1368-1383 doi: 10.1111/nph.19007
Phosphate deprivation-induced changes in tomato are mediated by an interaction between brassinosteroid signaling and zinc.
Department of Plant Biology and Genome Center, University of California Davis, Davis, CA, 95616, USA.; Department of Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.; Department of Horticulture, Zhejiang University, Hangzhou, Zhejiang, 310058, China.; Faculty of Biology, Technion-Israel Institute of Technology, Haifa, 3200003, Israel.; Lorey I. Lokey Interdisciplinary Center for Life Sciences and Engineering, Technion-Israel Institute of Technology, Haifa, 3200003, Israel.; Laboratory of Growth Regulators, Institute of Experimental Botany, Czech Academy of Sciences and Palacky University, Olomouc, CZ-78371, Czech Republic.
Inorganic phosphate (Pi) is a necessary macronutrient for basic biological processes. Plants modulate their root system architecture (RSA) and cellular processes to adapt to Pi deprivation albeit with a growth penalty. Excess application of Pi fertilizer, on the contrary, leads to eutrophication and has a negative environmental impact. We compared RSA, root hair elongation, acid phosphatase activity, metal ion accumulation, and brassinosteroid hormone levels of Solanum lycopersicum (tomato) and Solanum pennellii, which is a wild relative of tomato, under Pi sufficiency and deficiency conditions to understand the molecular mechanism of Pi deprivation response in tomato. We showed that S. pennellii is partially insensitive to phosphate deprivation. Furthermore, it mounts a constitutive response under phosphate sufficiency. We demonstrate that activated brassinosteroid signaling through a tomato BZR1 ortholog gives rise to the same constitutive phosphate deficiency response, which is dependent on zinc overaccumulation. Collectively, these results reveal an additional strategy by which plants can adapt to phosphate starvation.
PMID: 37306070
New Phytol , IF:10.151 , 2023 Sep , V239 (5) : P1804-1818 doi: 10.1111/nph.19049
Scaffold protein RACK1 regulates BR signaling by modulating the nuclear localization of BZR1.
Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China.; Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China.; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, 518055, China.
Brassinosteroids (BRs) are a group of plant-specific steroid hormones, which induces the rapid nuclear localization of the positive transcriptional factors BRASSINAZOLE RESISTANT1/2 (BZR1/2). However, the mechanisms underlying the regulation of nucleocytoplasmic shuttling of BZR1 remain to be fully elucidated. In this study, we show that the scaffold protein Receptor for Activated C Kinase 1 (RACK1) from Arabidopsis is involved in BR signaling cascades through mediating the nuclear localization of BZR1, which is tightly retained in the cytosol by the conserved scaffold protein 14-3-3s. RACK1 can interact with BZR1 and competitively decrease the 14-3-3 interaction with BZR1 in cytosol, which efficiently enhances the nuclear localization of BZR1. 14-3-3 also retains RACK1 in cytosol through their interaction. Conversely, BR treatment enhances the nuclear localization of BZR1 by disrupting the 14-3-3 interaction with RACK1 and BZR1. Our study uncovers a new mechanism that integrates two kinds of conserved scaffold proteins (RACK1 and 14-3-3) coordinating BR signaling event.
PMID: 37301989
Plant Biotechnol J , IF:9.803 , 2023 Jul doi: 10.1111/pbi.14117
PSW1, an LRR receptor kinase, regulates pod size in peanut.
College of Agronomy & Peanut Functional Genome and Molecular Breeding Engineering, Henan Agricultural University, Zhengzhou, China.; State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha, China.
Pod size is a key agronomic trait that greatly determines peanut yield, the regulatory genes and molecular mechanisms that controlling peanut pod size are still unclear. Here, we used quantitative trait locus analysis to identify a peanut pod size regulator, POD SIZE/WEIGHT1 (PSW1), and characterized the associated gene and protein. PSW1 encoded leucine-rich repeat receptor-like kinase (LRR-RLK) and positively regulated pod stemness. Mechanistically, this allele harbouring a 12-bp insertion in the promoter and a point mutation in the coding region of PSW1 causing a serine-to-isoleucine (S618I) substitution substantially increased mRNA abundance and the binding affinity of PSW1 for BRASSINOSTEROID INSENSITIVE1-ASSOCIATED RECEPTOR KINASE 1 (BAK1). Notably, PSW1(HapII) (super-large pod allele of PSW1) expression led to up-regulation of a positive regulator of pod stemness PLETHORA 1 (PLT1), thereby resulting in larger pod size. Moreover, overexpression of PSW1(HapII) increased seed/fruit size in multiple plant species. Our work thus discovers a conserved function of PSW1 that controls pod size and provides a valuable genetic resource for breeding high-yield crops.
PMID: 37431286
Plant Biotechnol J , IF:9.803 , 2023 Jul doi: 10.1111/pbi.14118
Wall-associated kinase BrWAK1 confers resistance to downy mildew in Brassica rapa.
Beijing Vegetable Research Center, Beijing Academy of Agriculture and Forestry Sciences (BAAFS), Beijing, China.; Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture, Beijing, China.; Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, China.; State Key Laboratory of Vegetable Biobreeding, Beijing, China.
The plant cell wall is the first line of defence against physical damage and pathogen attack. Wall-associated kinase (WAK) has the ability to perceive the changes in the cell wall matrix and transform signals into the cytoplasm, being involved in plant development and the defence response. Downy mildew, caused by Hyaloperonospora brassicae, can result in a massive loss in Chinese cabbage (Brassica rapa L. ssp. pekinensis) production. Herein, we identified a candidate resistant WAK gene, BrWAK1, in a major resistant quantitative trait locus, using a double haploid population derived from resistant inbred line T12-19 and the susceptible line 91-112. The expression of BrWAK1 could be induced by salicylic acid and pathogen inoculation. Expression of BrWAK1 in 91-112 could significantly enhance resistance to the pathogen, while truncating BrWAK1 in T12-19 increased disease susceptibility. Variation in the extracellular galacturonan binding (GUB) domain of BrWAK1 was found to mainly confer resistance to downy mildew in T12-19. Moreover, BrWAK1 was proved to interact with BrBAK1 (brassinosteroid insensitive 1 associated kinase), resulting in the activation of the downstream mitogen-activated protein kinase (MAPK) cascade to trigger the defence response. BrWAK1 is the first identified and thoroughly characterized WAK gene conferring disease resistance in Chinese cabbage, and the plant biomass is not significantly influenced by BrWAK1, which will greatly accelerate Chinese cabbage breeding for downy mildew resistance.
PMID: 37402218
Plant Physiol , IF:8.34 , 2023 Jul doi: 10.1093/plphys/kiad399
Jasmonates regulate apical hook development by repressing brassinosteroid biosynthesis and signaling.
Guangdong Provincial Key Laboratory of Plant Adaptation and Molecular Design, School of Life Sciences, Guangzhou University, Guangzhou 510006, China.; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.; National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; University of Chinese Academy of Sciences, Beijing 100049, China.
An apical hook is a special structure formed during skotomorphogenesis in dicotyledonous plant species. It is critical for protecting the shoot apical meristem from mechanical damage during seed germination and hypocotyl elongation in soil. Brassinosteroid (BR) and jasmonate (JA) phytohormones antagonistically regulate apical hook formation. However, the interrelationship between BRs and JAs in this process has not been well elucidated. Here, we reveal that JAs repress BRs to regulate apical hook development in Arabidopsis (Arabidopsis thaliana). Exogenous application of methyl jasmonate (MeJA) repressed the expression of the rate-limiting BR biosynthetic gene DWARF4 (DWF4) in a process relying on 3 key JA-dependent transcription factors, MYC2, MYC3, and MYC4. We demonstrated that MYC2 interacts with the critical BR-activated transcription factor BRASSINAZOLE RESISTANT 1 (BZR1), disrupting the association of BZR1 with its partner transcription factors, such as those of the PHYTOCHROME INTERACTING FACTOR (PIF) family and downregulating the expression of their target genes, such as WAVY ROOT GROWTH 2 (WAG2), encoding a protein kinase essential for apical hook development. Our results indicate that JAs not only repress the expression of BR biosynthetic gene DWF4 but, more importantly, attenuate BR signaling by inhibiting the transcriptional activation of BZR1 by MYC2 during apical hook development.
PMID: 37467431
Plant Physiol , IF:8.34 , 2023 Jul doi: 10.1093/plphys/kiad371
Brassinosteroid signaling regulator BIM1 integrates brassinolide and jasmonic acid signaling during cold tolerance in apple.
CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Hubei Hongshan Laboratory, The Innovative Academy of Seed Design of Chinese Academy of Sciences, Wuhan 430074, China.; College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, 271018, Shandong, China.; College of Agriculture, Shandong Agricultural University, Tai-An, 271018, Shandong, China.
Although brassinolide (BR) and jasmonic acid (JA) play essential roles in the regulation of cold stress responses, the molecular basis of their crosstalk remains elusive. Here, we show a key component of BR signaling in apple (Malus x domestica), BR INSENSITIVE1 (BRI1)-EMS-SUPPRESSOR1 (BES1)-INTERACTING MYC-LIKE PROTEIN1 (MdBIM1), increases cold tolerance by directly activating expression of C-REPEAT BINDING FACTOR1 (MdCBF1) and forming a complex with C-REPEAT BINDING FACTOR2 (MdCBF2) to enhance MdCBF2-activated transcription of cold-responsive genes. Two repressors of JA signaling, JAZMONATE ZIM-DOMAIN1 (MdJAZ1) and JAZMONATE ZIM-DOMAIN2 (MdJAZ2), interact with MdBIM1 to integrate BR and JA signaling under cold stress. MdJAZ1 and MdJAZ2 reduce MdBIM1-promoted cold stress tolerance by attenuating transcriptional activation of MdCBF1 expression by MdBIM1 and interfering with the formation of the MdBIM1-MdCBF2 complex. Furthermore, the E3 ubiquitin ligase ARABIDOPSIS TOXICOS en LEVADURA73 (MdATL73) decreases MdBIM1-promoted cold tolerance by targeting MdBIM1 for ubiquitination and degradation. Our results not only reveal crosstalk between BR and JA signaling mediated by a JAZ-BIM1-CBF module, but also provide insights into the post-translational regulatory mechanism of BR signaling.
PMID: 37392474
Plant Physiol , IF:8.34 , 2023 Jul , V192 (3) : P2356-2373 doi: 10.1093/plphys/kiad208
PbrBZR1 interacts with PbrARI2.3 to mediate brassinosteroid-regulated pollen tube growth during self-incompatibility signaling in pear.
Sanya Institute of Nanjing Agricultural University, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.; Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
S-RNase-mediated self-incompatibility (SI) prevents self-fertilization and promotes outbreeding to ensure genetic diversity in many flowering plants, including pear (Pyrus sp.). Brassinosteroids (BRs) have well-documented functions in cell elongation, but their molecular mechanisms in pollen tube growth, especially in the SI response, remain elusive. Here, exogenously applied brassinolide (BL), an active BR, countered incompatible pollen tube growth inhibition during the SI response in pear. Antisense repression of BRASSINAZOLE-RESISTANT1 (PbrBZR1), a critical component of BR signaling, blocked the positive effect of BL on pollen tube elongation. Further analyses revealed that PbrBZR1 binds to the promoter of EXPANSIN-LIKE A3 (PbrEXLA3) to activate its expression. PbrEXLA3 encodes an expansin that promotes pollen tube elongation in pear. The stability of dephosphorylated PbrBZR1 was substantially reduced in incompatible pollen tubes, where it is targeted by ARIADNE2.3 (PbrARI2.3), an E3 ubiquitin ligase that is strongly expressed in pollen. Our results show that during the SI response, PbrARI2.3 accumulates and negatively regulates pollen tube growth by accelerating the degradation of PbrBZR1 via the 26S proteasome pathway. Together, our results show that an ubiquitin-mediated modification participates in BR signaling in pollen and reveal the molecular mechanism by which BRs regulate S-RNase-based SI.
PMID: 37010117
J Integr Plant Biol , IF:7.061 , 2023 Aug doi: 10.1111/jipb.13554
The advantages of crosstalk during the evolution of the BZR1-ARF6-PIF4 (BAP) module.
College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.
The BAP module, comprising BRASSINAZOLE RESISTANT 1 (BZR1), AUXIN RESPONSE FACTOR 6 (ARF6), and PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), functions as a molecular hub to orchestrate plant growth and development. In Arabidopsis thaliana, components of the BAP module physically interact to form a complex system that integrates light, brassinosteroid (BR), and auxin signals. Little is known about the origin and evolution of the BAP module. Here, we conducted comparative genomic and transcriptomic analyses to investigate the evolution and functional diversification of the BAP module. Our results suggest that the BAP module originated in land plants and that the zeta, epsilon, and gamma whole-genome duplication/triplication events contributed to the expansion of BAP module components in seed plants. Comparative transcriptomic analysis suggested that the prototype BAP module arose in Marchantia polymorpha, experienced stepwise evolution, and became established as a mature regulatory system in seed plants. We developed a formula to calculate the signal transduction productivity of the BAP module and demonstrate that more crosstalk among components enables higher signal transduction efficiency. Our results reveal the evolutionary history of the BAP module and provide insights into the evolution of plant signaling networks and the strategies employed by plants to integrate environmental and endogenous signals. This article is protected by copyright. All rights reserved.
PMID: 37552560
J Integr Plant Biol , IF:7.061 , 2023 Jul , V65 (7) : P1794-1813 doi: 10.1111/jipb.13491
The brassinosteroid signaling component SlBZR1 promotes tomato fruit ripening and carotenoid accumulation.
Key Laboratory of Horticultural Plant Growth and Development, Ministry of Agriculture, Department of Horticulture, Zhejiang University, Hangzhou, 310058, China.; College of Plant Science, Jilin University, Changchun, 130062, China.
The plant hormone ethylene is essential for climacteric fruit ripening, although it is unclear how other phytohormones and their interactions with ethylene might affect fruit ripening. Here, we explored how brassinosteroids (BRs) regulate fruit ripening in tomato (Solanum lycopersicum) and how they interact with ethylene. Exogenous BR treatment and increased endogenous BR contents in tomato plants overexpressing the BR biosynthetic gene SlCYP90B3 promoted ethylene production and fruit ripening. Genetic analysis indicated that the BR signaling regulators Brassinazole-resistant1 (SlBZR1) and BRI1-EMS-suppressor1 (SlBES1) act redundantly in fruit softening. Knocking out SlBZR1 inhibited ripening through transcriptome reprogramming at the onset of ripening. Combined transcriptome deep sequencing and chromatin immunoprecipitation followed by sequencing identified 73 SlBZR1-repressed targets and 203 SlBZR1-induced targets involving major ripening-related genes, suggesting that SlBZR1 positively regulates tomato fruit ripening. SlBZR1 directly targeted several ethylene and carotenoid biosynthetic genes to contribute to the ethylene burst and carotenoid accumulation to ensure normal ripening and quality formation. Furthermore, knock-out of Brassinosteroid-insensitive2 (SlBIN2), a negative regulator of BR signaling upstream of SlBZR1, promoted fruit ripening and carotenoid accumulation. Taken together, our results highlight the role of SlBZR1 as a master regulator of tomato fruit ripening with potential for tomato quality improvement and carotenoid biofortification.
PMID: 37009849
J Exp Bot , IF:6.992 , 2023 Jun , V74 (12) : P3684-3699 doi: 10.1093/jxb/erad115
High temperature defense pathways mediate lodicule expansion and spikelet opening in maize tassels.
College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China.
High temperature (HT) at flowering hinders pollen shedding, but the mechanisms underlying stress-induced spikelet closure are poorly understood in maize. In this study, yield components, spikelet opening, and lodicule morphology/protein profiling upon HT stress during flowering were examined in two contrasting maize inbred lines, Chang 7-2 and Qi 319. HT induced spikelet closure and reduced pollen shed weight (PSW) and seed set in both lines, but Qi 319 had a 7-fold lower PSW than Chang 7-2, and was thus more susceptible to HT. In Qi 319, a smaller lodicule size reduced the spikelet opening rate and angle, and relatively more vascular bundles hastened lodicule shrinking compared with Chang 7-2. Lodicules were collected for proteomics analysis. In lodicules of HT-stressed plants, proteins involved in stress signals, cell wall, cell constructure, carbohydrate metabolism, and phytohormone signaling were associated with stress tolerance. HT down-regulated the expression of ADP-ribosylation factor GTPase-activating protein domain2, SNAP receptor complex member11, and sterol methyltransferase2 in Qi 319 but not in Chang 7-2, which was in good agreement with the observed changes in protein abundance. Exogenous epibrassinolide increased the spikelet opening angle and extended the duration of spikelet opening. These results suggest that dysfunction of the actin cytoskeleton and membrane remodeling induced by HT probably limits lodicule expansion. In addition, a reduction in the vascular bundles in the lodicules and application of epibrassinolide might confer spikelet tolerance to HT stress.
PMID: 36967717
Sci China Life Sci , IF:6.038 , 2023 Jun doi: 10.1007/s11427-023-2401-3
Redesigning green revolution trait with increased grain yield and nitrogen utilization efficiency by reducing brassinosteroid signaling in semidwarf wheat.
Department of Genetics, Development and Cell Biology, Plant Sciences Institute, Iowa State University, Ames Iowa, 50011, USA.; Department of Genetics, Development and Cell Biology, Plant Sciences Institute, Iowa State University, Ames Iowa, 50011, USA. yin@iastate.edu.
PMID: 37395894
Int J Mol Sci , IF:5.923 , 2023 Jul , V24 (15) doi: 10.3390/ijms241512255
Distinct Clades of Protein Phosphatase 2A Regulatory B'/B56 Subunits Engage in Different Physiological Processes.
IKBM, Department of Chemistry, Bioscience and Environmental Engineering, University of Stavanger, 4036 Stavanger, Norway.
Protein phosphatase 2A (PP2A) is a strongly conserved and major protein phosphatase in all eukaryotes. The canonical PP2A complex consists of a catalytic (C), scaffolding (A), and regulatory (B) subunit. Plants have three groups of evolutionary distinct B subunits: B55, B' (B56), and B''. Here, the Arabidopsis B' group is reviewed and compared with other eukaryotes. Members of the B'alpha/B'beta clade are especially important for chromatid cohesion, and dephosphorylation of transcription factors that mediate brassinosteroid (BR) signaling in the nucleus. Other B' subunits interact with proteins at the cell membrane to dampen BR signaling or harness immune responses. The transition from vegetative to reproductive phase is influenced differentially by distinct B' subunits; B'alpha and B'beta being of little importance, whereas others (B'gamma, B'zeta, B'eta, B'theta, B'kappa) promote transition to flowering. Interestingly, the latter B' subunits have three motifs in a conserved manner, i.e., two docking sites for protein phosphatase 1 (PP1), and a POLO consensus phosphorylation site between these motifs. This supports the view that a conserved PP1-PP2A dephosphorelay is important in a variety of signaling contexts throughout eukaryotes. A profound understanding of these regulators may help in designing future crops and understand environmental issues.
PMID: 37569631
Int J Mol Sci , IF:5.923 , 2023 Jun , V24 (13) doi: 10.3390/ijms241310715
Transcriptome Landscape Analyses of the Regulatory Network for Zygotic Embryo Development in Paeonia ostii.
College of Landscape Architecture and Art, Henan Agricultural University, Zhengzhou 450002, China.; Henan Institute of Science and Technology, Xinxiang 453000, China.
Paeonia ostii is a worldwide ornamental flower and an emerging oil crop. Zyotic embryogenesis is a critical process during seed development, and it can provide a basis for improving the efficiency of somatic embryogenesis (SE). In this study, transcriptome sequencing of embryo development was performed to investigate gene expression profiling in P. ostii and identified Differentially expressed genes (DEGs) related to transcription factors, plant hormones, and antioxidant enzymes. The results indicated that IAA (Indole-3-acetic acid), GA (Gibberellin), BR (Brassinosteroid) and ETH (Ethylene) were beneficial to early embryonic morphogenesis, while CTK (Cytokinin) and ABA (Abscisic Acid) promoted embryo morphogenesis and maturation. The antioxidant enzymes' activity was the highest in early embryos and an important participant in embryo formation. The high expression of the genes encoding fatty acid desaturase was beneficial to fast oil accumulation. Representative DEGs were selected and validated using qRT-PCR. Protein-protein interaction network (PPI) was predicted, and six central node proteins, including AUX1, PIN1, ARF6, LAX3, ABCB19, PIF3, and PIF4, were screened. Our results provided new insights into the formation of embryo development and even somatic embryo development in tree peonies.
PMID: 37445891
Int J Mol Sci , IF:5.923 , 2023 Jun , V24 (13) doi: 10.3390/ijms241310666
Molecular Network for Regulation of Seed Size in Plants.
National Key Laboratory of Wheat and Maize Crop Science, College of Life Sciences, Henan Agricultural University, Zhengzhou 450046, China.
The size of seeds is particularly important for agricultural development, as it is a key trait that determines yield. It is controlled by the coordinated development of the integument, endosperm, and embryo. Large seeds are an important way of improving the ultimate "sink strength" of crops, providing more nutrients for early plant growth and showing certain tolerance to abiotic stresses. There are several pathways for regulating plant seed size, including the HAIKU (IKU) pathway, ubiquitin-proteasome pathway, G (Guanosine triphosphate) protein regulatory pathway, mitogen-activated protein kinase (MAPK) pathway, transcriptional regulators pathway, and phytohormone regulatory pathways including the auxin, brassinosteroid (BR), gibberellin (GA), jasmonic acid (JA), cytokinin (CK), Abscisic acid (ABA), and microRNA (miRNA) regulatory pathways. This article summarizes the seed size regulatory network and prospective ways of improving yield. We expect that it will provide a valuable reference to researchers in related fields.
PMID: 37445843
Front Plant Sci , IF:5.753 , 2023 , V14 : P1197776 doi: 10.3389/fpls.2023.1197776
Hormonal regulation of ethylene response factors in tomato during storage and distribution.
Postharvest Research Division, National Institute of Horticultural and Herbal Science, Wanju, Republic of Korea.
INTRODUCTION: Ethylene response factors (ERFs) play a critical role in regulating hormone interactions that affect the shelf life of tomatoes. Understanding their regulation during storage and distribution can be highly beneficial. METHODS: This study examined the effects of treatment with ethylene (ET), brassinosteroid (BR), auxin (AUX), and gibberellin (GA) on fruit ripening and the expression of 18 ripening-associated ERFs in tomato stored at 20 degrees C (room temperature) for 10 d or 4 degrees C (cold storage) for 14 d followed by 2 d at 20 degrees C (retailer conditions). RESULTS: The results showed that ripening was accelerated by ET and BR but was delayed by AUX and GA at room temperature. Cold storage delayed ripening in all groups, with ET and GA treatments showing the highest and lowest a* values, respectively. The effects of hormone treatment were consistent with room temperature when the fruits were transferred from cold storage to retail conditions. At room temperature, ERFs responsive to ET (ERF.B1, B2, B6, E2, and F1) and BR (ERF.E5, F2, and F3) were inhibited by AUX. ET-induced genes (ERF.C1, E1, F4, and H7) could be co-regulated by other hormones at cold storage. When the fruits were transferred from cold storage to retailer conditions, ERFs responsive to ET and BR were inhibited by GA. Additionally, ET-responsive ERFs could be inhibited by BR at room temperature, whereas ET could inhibit BR-responsive ERFs at retailer conditions. The same ERFs that were regulated by ET at room temperature were instead regulated by BR under retailer conditions, and vice versa. DISCUSSION: These findings can help provide a better understanding of the complex hormone interactions regulating the postharvest physiology of tomato and in maintaining its quality and shelf life during storage and distribution.
PMID: 37448864
Plant Cell Physiol , IF:4.927 , 2023 Jul , V64 (7) : P826-838 doi: 10.1093/pcp/pcad043
MpDWF5A-Encoded Sterol Delta7-Reductase Is Essential for the Normal Growth and Development of Marchantia polymorpha.
Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501 Japan.; Graduate School of Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501 Japan.
Sterols are essential components of eukaryotic cell membranes. However, studies on sterol biosynthesis in bryophytes are limited. This study analyzed the sterol profiles in the bryophyte model plant Marchantia polymorpha L. The thalli contained typical phytosterols such as campesterol, sitosterol and stigmasterol. BLASTX analysis of the M. polymorpha genome against the Arabidopsis thaliana sterol biosynthetic genes confirmed the presence of all the enzymes responsible for sterol biosynthesis in M. polymorpha. We further focused on characterizing two genes, MpDWF5A and MpDWF5B, which showed high homology with A. thaliana DWF5, encoding Delta5,7-sterol Delta7-reductase (C7R). Functional analysis using a yeast expression system revealed that MpDWF5A converted 7-dehydrocholesterol to cholesterol, indicating that MpDWF5A is a C7R. Mpdwf5a-knockout (Mpdwf5a-ko) lines were constructed using CRISPR/Cas9-mediated genome editing. Gas chromatography-mass spectrometry analysis of Mpdwf5a-ko revealed that phytosterols such as campesterol, sitosterol and stigmasterol disappeared, and instead, the corresponding Delta7-type sterols accumulated. The thalli of Mpdwf5a-ko grew smaller than those of the wild type, and excessive formation of apical meristem in the thalli was observed. In addition, the gemma cups of the Mpdwf5a-ko were incomplete, and only a limited number of gemma formations were observed. Treatment with 1 microM of castasterone or 6-deoxocastasterone, a bioactive brassinosteroid (BR), partly restored some of these abnormal phenotypes, but far from complete recovery. These results indicate that MpDWF5A is essential for the normal growth and development of M. polymorpha and suggest that the dwarfism caused by the Mpdwf5a-ko defect is due to the deficiency of typical phytosterols and, in part, a BR-like compound derived from phytosterols.
PMID: 37178336
Plant Sci , IF:4.729 , 2023 Jul , V335 : P111788 doi: 10.1016/j.plantsci.2023.111788
Brassinosteroid catabolic enzyme CYP734A129 regulates the morphologies of leaves and floral organs in woodland strawberry.
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.; National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China.; National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China.; National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China. Electronic address: ckang@mail.hzau.edu.cn.
Brassinosteroids (BRs) play critical roles in plant growth and development and regulate many important agronomic traits. However, the functions of BRs in strawberry are unclear. This study identified two mutants, named P6 and R87, in woodland strawberry (Fragaria vesca) from EMS mutagenesis populations that exhibit narrow leaves, petals and sepals. Mapping by sequencing and genetic studies revealed that the F. vesca CYP734A129, encoding a putative BR catabolic enzyme, is the causative gene for both P6 and R87. Overexpression of CYP734A129 in both F. vesca and Arabidopsis causes a severe dwarf phenotype, and the BRI1-EMS-SUPPRESSOR 1 (BES1) protein is less abundant in the CYP734A129-overexpressing Arabidopsis seedlings. This suggests that CYP734A129 is functionally conserved with CYP734A1, as a BR-inactivating enzyme. Transcriptome analysis of young leaves revealed that four BR biosynthetic genes were significantly downregulated in P6 (cyp734a129), and photosynthesis-related genes were highly enriched among the up-regulated genes in P6 compared to the wild type. This further supports that CYP734A129 inactivates BRs in F. vesca. Furthermore, we showed that mutations in CYP734A129 do not affect fruit shape and color during ripening in strawberry. Overall, our results suggest that F. vesca CYP734A129 is a BR catabolic enzyme, and provide insights into the roles of CYP734A129 in strawberry.
PMID: 37421982
Plant Sci , IF:4.729 , 2023 Sep , V334 : P111764 doi: 10.1016/j.plantsci.2023.111764
Improved production and quality of peppers irrigated with regenerated water by the application of 24-epibrassinolide.
Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain. Electronic address: martapinto@ub.edu.; Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain.; Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain; Research Institute of Nutrition and Food Safety, University of Barcelona, Barcelona, Spain.
Water shortage for crop irrigation is reducing agricultural production worldwide and the use of sewage treatment plant (STP) water to irrigate horticultural fields is a solution to avoid the use of drinkable water in agriculture. In this study, two different genotypes of pepper (Red Cherry Small and Italian green) were irrigated with STP water, as an alternative to potable water. Moreover, the foliar application of a molecule with biostimulant properties (24-epibrassinolide; EBR) was tested as a strategy to ameliorate the production and quality of fruits. Both genotypes differed on their tolerance to the suffered oxidative stress due to their different salinity tolerance, but fruit commercial weight was reduced by 49% on the salt sensitive and by 37% on the salt tolerant. Moreover, ascorbic acid was also decreased by 37% after STP water irrigation in the Red Cherry Small peppers. However, EBR applications alleviated STP watering stress effects improving pepper plants fruit production and quality parameters, such as ascorbic acid and capsaicinoids. These results have important economic and environmental relevance to overcome present and future water deficiencies in the agricultural sector derived from climate change, guaranteeing the maintenance of production in peppers irrigated with STP water for a more sustainable agriculture following relevant circular economy actions.
PMID: 37301327
Plant Sci , IF:4.729 , 2023 Jul , V332 : P111724 doi: 10.1016/j.plantsci.2023.111724
Analyses of genes encoding the Glycogen Synthase Kinases in rice and Arabidopsis reveal mechanisms which regulate their expression during development and responses to abiotic stresses.
Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia, Jagiellonska 28, 40-032 Katowice, Poland.; Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia, Jagiellonska 28, 40-032 Katowice, Poland. Electronic address: damian.gruszka@us.edu.pl.
Plant Glycogen Synthase Kinases (GSKs) enable a crosstalk among the brassinosteroid signaling and phytohormonal- and stress-response pathways to regulate various physiological processes. Initial information about regulation of the GSK proteins' activity was obtained, however, mechanisms that modulate expression of the GSK genes during plant development and stress responses remain largely unknown. Taking into account the importance of the GSK proteins, combined with the lack of in-depth knowledge about modulation of their expression, research in this area may provide a significant insight into mechanisms regulating these aspects of plant biology. In the current study, a detailed analysis of the GSK promoters in rice and Arabidopsis was performed, including identification of the CpG/CpNpG islands, tandem repeats, cis-acting regulatory elements, conserved motifs, and transcription factor-binding sites. Moreover, characterization of expression profiles of the GSK genes in different tissues, organs and under various abiotic stress conditions was performed. Additionally, protein-protein interactions between products of the GSK genes were predicted. Results of this study provided intriguing information about these aspects and insight into various regulatory mechanisms that influence non-redundant and diverse functions of the GSK genes during development and stress responses. Therefore, they may constitute a reference for future research in other plant species.
PMID: 37142096
Plant Genome , IF:4.089 , 2023 Aug : Pe20376 doi: 10.1002/tpg2.20376
Temporally gene knockout using heat shock-inducible genome-editing system in plants.
School of Life Science, Shanxi University, Taiyuan, Shanxi, China.; Research Institute of Big Data Science and Industry, Shanxi University, Taiyuan, Shanxi, China.
Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 (Cas9) has emerged as a powerful tool to generate targeted loss-of-function mutations for functional genomic studies. As a next step, tools to generate genome modifications in a spatially and temporally precise manner will enable researchers to further dissect gene function. Here, we present two heat shock-inducible genome-editing (IGE) systems that efficiently edit target genes when the system is induced, thus allowing us to target specific developmental stages. For this conditional editing system, we chose the natural heat-inducible promoter from heat-shock protein 18.2 (HSP18.2) from Arabidopsis thaliana and the synthetic heat-inducible promoter heat shock-response element HSE-COR15A to drive the expression of Cas9. We tested these two IGE systems in Arabidopsis using cyclic or continuous heat-shock treatments at the seedling and bolting stages. A real-time quantitative polymerase chain reaction analysis revealed that the HSP18.2 IGE system exhibited higher Cas9 expression levels than the HSE-COR15A IGE system upon both cyclic and continuous treatments. By targeting brassinosteroid-insensitive 1 (BRI1) and phytoene desaturase (PDS), we demonstrate that both cyclic and continuous heat inductions successfully activated the HSP18.2 IGE system at the two developmental stages, resulting in highly efficient targeted mutagenesis and clear phenotypic outcomes. By contrast, the HSE-COR15A IGE system was only induced at the seedling stage and was less effective than the HSP18.2 IGE system in terms of mutagenesis frequencies. The presented heat shock-IGE systems can be conditionally induced to efficiently inactivate genes at any developmental stage and are uniquely suited for the dissection and systematic characterization of essential genes.
PMID: 37529831
J Plant Physiol , IF:3.549 , 2023 Aug , V287 : P154052 doi: 10.1016/j.jplph.2023.154052
Uncovering mechanisms governing stem growth in peanut (Arachis hypogaea L.) with varying plant heights through integrated transcriptome and metabolomics analyses.
College of Agronomy, Shandong Agricultural University, Tai'an, 271018, Shandong, China.; Industrial Crops Research Institute, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China. Electronic address: liujuanviolet@163.com.; College of Agronomy, Shandong Agricultural University, Tai'an, 271018, Shandong, China. Electronic address: chengyang2364@126.com.
The mechanisms responsible for stem growth in peanut (Arachis hypogaea L.) cultivars with varying plant heights remain unclear, despite the significant impact of plant height on peanut yield. Therefore, this study aimed to investigate the underlying mechanisms of peanut stem growth using phenotypic, physiological, transcriptomic, and metabolomic analyses. The findings revealed that the tallest cultivar, HY33, exhibited the highest rate of stem growth and accumulated the most stem dry matter, followed by the intermediate cultivar, SH108, while the dwarf cultivar, Df216, displayed the lowest values. Furthermore, SH108 exhibited a higher harvest index, as well as superior pod and kernel yields compared to both HY33 and Df216. Transcriptome and metabolome analyses identified differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) associated with phenylpropanoid and flavonoid biosynthesis. Notably, downregulated DEGs in Df216/HY33 and Df216/SH108 included phenylalanine ammonia-lyase (PAL), caffeoyl-CoA O-methyltransferase (COMT), and ferulate-5-hydroxylase (F5H), while downregulated DEMs included p-coumaryl alcohol, chlorogenic acid, and L-epicatechin. Compared to HY33, the reduced activities of PAL, COMT, and F5H resulted in a decreased stem lignin content in Df216. Additionally, downregulated DEGs involved in gibberellin (GA) and brassinosteroid (BR) biosynthesis were identified in Df216/HY33, which contributed to the lowest levels of GA(1), GA(3), and BR contents in Df216. The results suggest that the dwarf phenotype arises from impaired GA and BR biosynthesis and signaling, resulting in a slower stem growth rate and reduced lignin accumulation.
PMID: 37454530
Plant Direct , IF:3.038 , 2023 Jul , V7 (7) : Pe501 doi: 10.1002/pld3.501
Genetic evidence that brassinosteroids suppress pistils in the maize tassel independent of the jasmonic acid pathway.
Agriculture Research Service, Plant Genetics Research Unit USDA Columbia Missouri USA.; Department of Biochemistry Purdue University West Lafayette Indiana USA.; Center for Plant Biology Purdue University West Lafayette Indiana USA.
The developmental genetics of reproductive structure control in maize must consider both the staminate florets of the tassel and the pistillate florets of the ear synflorescences. Pistil abortion takes place in the tassel florets, and stamen arrest is affected in ear florets to give rise to the monoecious nature of maize. Gibberellin (GA) deficiency results in increased tillering, a dwarfed plant syndrome, and the retention of anthers in the ear florets of maize. The silkless1 mutant results in suppression of silks in the ear. We demonstrate in this study that jasmonic acid (JA) and GA act independently and show additive phenotypes resulting in androecious dwarf1;silkless1 double mutant plants. The persistence of pistils in the tassel can be induced by multiple mechanisms, including JA deficiency, GA excess, genetic control of floral determinacy, and organ identity. The silkless1 mutant can suppress both silks in the ear and the silks in the tassel of JA-deficient and AP2 transcription factor tasselseed mutants. We previously demonstrated that GA production was required for brassinosteroid (BR) deficiency to affect persistence of pistils in the tassel. We find that BR deficiency affects pistil persistence by an independent mechanism from the silkless1 mutant and JA pathway. The silkless1 mutant did not prevent the formation of pistils in the tassel by nana plant2 in double mutants. In addition, we demonstrate that there is more to the silkless1 mutant than just a suppression of pistil growth. We document novel phenotypes of silkless1 mutants including weakly penetrant ear fasciation and anther persistence in the ear florets. Thus, the JA/AP2 mechanism of pistil retention in the tassel and silk growth in the ear are similarly sensitive to loss of the SILKLESS1 protein, while the BR/GA mechanism is not.
PMID: 37440932
Steroids , IF:2.668 , 2023 Aug , V196 : P109248 doi: 10.1016/j.steroids.2023.109248
Methyl esters of 23,24-Dinor-5alpha-cholan-22-oic acids as brassinosteroid Analogues. Synthesis, evaluation of plant growth promoting activity and Molecular docking.
Departamento de Quimica, Universidad Tecnica Federico Santa Maria, Av. Espana No. 1680, Valparaiso 2340000, Chile.; Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico D.F., Mexico, United States.; Departamento de Quimica Organica, Instituto Universitario de Bio-Organica Antonio Gonzalez, Universidad de La Laguna, Av. Astrofisico Fco. Sanchez 2, 38206 La Laguna, Spain.; Departamento de Quimica, Universidad Tecnica Federico Santa Maria, Av. Espana No. 1680, Valparaiso 2340000, Chile. Electronic address: luis.espinozac@usm.cl.; Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, 04510 Mexico D.F., Mexico, United States. Electronic address: martin.iglesias@unam.mx.
Five new brassinosteroid analogues were synthetized from 3beta-acetoxy-23,24-dinorchol-4-en-22-oic acid. All the obtained compound showed significant activity in the Rice Lamina Inclination Test. Interestingly the effects of the methyl ester of 3beta-hydroxy-6-oxo-23,24-dinorcholan-22-oic acid (14) at concentrations of 1 x 10(-7) and 1 x 10(-6) M proved to be higher than those produced by brassinolide. In silico Molecular Docking and Induced fit docking (IFD) simulations for the compounds with the highest biological activity data were carried out to investigate the binding mode interactions into the brassinolide-binding groove which revealed that the compound 14 had high binding energy values and a good affinity.
PMID: 37169217
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2229957 doi: 10.1080/15592324.2023.2229957
The RGI1-BAK1 module acts as the main receptor-coreceptor pair for regulating primary root gravitropism and meristem activity in response to RGF1 peptide in Arabidopsis.
Department of Bioenergy Science and Technology, Chonnam National University, Gwangju, Korea.; Kumho Life Science Laboratory, Chonnam National University, Gwangju, Korea.; Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, Korea.
ROOT MERISTEM GROWTH FACTOR1 (RGF1) and its receptors RGF1 INSENSITIVEs (RGIs), a group of leucine-rich repeat receptor kinases, promote primary root meristem activity via a mitogen-activated protein kinase (MPK) signaling cascade and control root gravitropism in Arabidopsis. Genetic analyses and in vitro binding assays have indicated that among five RGIs identified in Arabidopsis, RGI1, RGI2, and RGI3 recognize RGF1 peptides. However, it remains unclear whether the RGF1 peptide is redundantly recognized by these RGIs or mainly by a single RGI in the regulation of primary root meristem activity. In the present study, we analyzed root meristem growth of the rgi1, rgi2, and rgi3 single mutants in response to RGF1 treatment and observed a significantly decreased sensitivity in meristem growth of rgi1 and complete insensitivity in rgi1 rgi2 rgi3 triple mutant compared with the wild type but not in the rgi1 and rgi2 single mutants. We also observed that both root gravitropism and meristem growth in the BRASSINOSTEROID INSENSITIVE1-ASSOCIATED RECEPTOR KINASE 1 (bak1) single mutant were insensitive to RGF1 peptide treatment, whereas other serk mutants, such as serk1, serk2, and serk4, were fully sensitive to RGF1 peptide like the wild type. These mutant analyses suggest that RGI1-BAK1 pair acts as the main receptor-coreceptor pair for regulating primary root gravitropism and meristem activity in response to RGF1 peptide in Arabidopsis.
PMID: 37382066
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2186640 doi: 10.1080/15592324.2023.2186640
Exogenous Brassinosteroid Enhances Zinc tolerance by activating the Phenylpropanoid Biosynthesis pathway in Citrullus lanatus L.
College of Resources and Environmental Engineering, Yangzhou Polytechnic College, Yangzhou, China.; Jiangsu Safety & Environment Technology and Equipment for Planting and Breeding Industry Engineering Research Center, Yangzhou, China.
Zinc (Zn) is an important element in plants, but over-accumulation of Zn is harmful. The phytohormone brassinosteroids (BRs) play a key role in regulating plant growth, development, and response to stress. However, the role of BRs in watermelon (Citrullus lanatus L.) under Zn stress, one of the most important horticultural crops, remains largely unknown. In this study, we revealed that 24-epibrassinolide (EBR), a bioactive BR enhanced Zn tolerance in watermelon plants, which was related to the EBR-induced increase in the fresh weight, chlorophyll content, and net photosynthetic rate (Pn) and decrease in the content of hydrogen peroxide (H(2)O(2)), malondialdehyde (MDA), and Zn in watermelon leaves. Through RNA deep sequencing (RNA-seq), 350 different expressed genes (DEG) were found to be involved in the response to Zn stress after EBR treatment, including 175 up-regulated DEGs and 175 down-regulated DEGs. The up-regulated DEGs were significantly enriched in 'phenylpropanoid biosynthesis' pathway (map00940) using KEGG enrichment analysis. The gene expression levels of PAL, 4CL, CCR, and CCoAOMT, key genes involved in phenylpropanoid pathway, were significantly induced after EBR treatment. In addition, compared with Zn stress alone, EBR treatment significantly promoted the activities of PAL, 4CL, and POD by 30.90%, 20.69%, and 47.28%, respectively, and increased the content of total phenolic compounds, total flavonoids, and lignin by 23.02%, 40.37%, and 29.26%, respectively. The present research indicates that EBR plays an active role in strengthening Zn tolerance, thus providing new insights into the mechanism of BRs enhancing heavy metal tolerance.
PMID: 37083111
Plant Signal Behav , IF:2.247 , 2023 Dec , V18 (1) : P2163337 doi: 10.1080/15592324.2022.2163337
Arabidopsis clathrin adaptor EPSIN1 but not MODIFIED TRANSPORT TO THE VACOULE1 contributes to effective plant immunity against pathogenic Pseudomonas bacteria.
University of Missouri-Columbia, Division of Biochemistry, Interdisciplinary Plant Group (IPG), Columbia, MO, USA.; Department of Plant Physiology, University of Potsdam, Potsdam, Germany.
In eukaryotes, EPSINs are Epsin N-terminal Homology (ENTH) domain-containing proteins that serve as monomeric clathrin adaptors at the plasma membrane (PM) or the trans-Golgi Network (TGN)/early endosomes (EE). The model plant Arabidopsis thaliana encodes for seven ENTH proteins, of which so far, only AtEPSIN1 (AtEPS1) and MODIFIED TRANSPORT TO THE VACUOLE1 (AtMTV1) localize to the TGN/EE and contribute to cargo trafficking to both the cell surface and the vacuole. However, relatively little is known about role(s) of any plant EPSIN in governing physiological responses. We have recently shown that AtEPS1 is a positive modulator of plant immune signaling and pattern-triggered immunity against flagellated Pseudomonas syringae pv. tomato (Pto) DC3000 bacteria. In eps1 mutants, impaired immune responses correlate with reduced accumulation of the receptor FLAGELLIN SENSING2 (AtFLS2) and the convergent immune co-receptor BRASSINOSTEROID INSENTIVE1-ASSOCIATED RECEPTOR KINASE1 (AtBAK1) in the PM. Here, we report that in contrast to AtEPS1, the TGN/EE-localized AtMTV1 did not contribute significantly to immunity against pathogenic Pto DC3000 bacteria. We also compared the amino acid sequences, peptide motif structures and in silico tertiary structures of the ENTH domains of AtEPS1 and AtMTV1 in more detail. We conclude that despite sharing the classical tertiary alpha helical ENTH-domain structure and clathrin-binding motifs, the overall low amino acid identity and differences in peptide motifs may explain their role(s) in trafficking of some of the same as well as distinct cargo components to their site of function, with the latter potentially contributing to differences in physiological responses.
PMID: 36603596