Mol Plant , IF:13.164 , 2021 Dec , V14 (12) : P2072-2087 doi: 10.1016/j.molp.2021.08.011
The BZR1-EDS1 module regulates plant growth-defense coordination.
State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, and Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou 450002, China; Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.; Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA; Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.; College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China.; State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, and Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou 450002, China.; Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266109, China.; Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, 266237 Qingdao, China.; Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China.; State Key Laboratory of Wheat and Maize Crop Science, College of Agronomy, and Center for Crop Genome Engineering, Henan Agricultural University, Zhengzhou 450002, China. Electronic address: dwwang@henau.edu.cn.; Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA. Electronic address: zfu@mailbox.sc.edu.
Plants have developed sophisticated strategies to coordinate growth and immunity, but our understanding of the underlying mechanism remains limited. In this study, we identified a novel molecular module that regulates plant growth and defense in both compatible and incompatible infections. This module consisted of BZR1, a key transcription factor in brassinosteroid (BR) signaling, and EDS1, an essential positive regulator of plant innate immunity. We found that EDS1 interacts with BZR1 and suppresses its transcriptional activities. Consistently, upregulation of EDS1 function by a virulent Pseudomonas syringae strain or salicylic acid treatment inhibited BZR1-regulated expression of BR-responsive genes and BR-promoted growth. Furthermore, we showed that the cytoplasmic fraction of BZR1 positively regulates effector-triggered immunity (ETI) controlled by the TIR-NB-LRR protein RPS4, which is attenuated by BZR1's nuclear translocation. Mechanistically, cytoplasmic BZR1 facilitated AvrRps4-triggered dissociation of EDS1 and RPS4 by binding to EDS1, thus leading to efficient activation of RPS4-controlled ETI. Notably, transgenic expression of a mutant BZR1 that accumulates exclusively in the cytoplasm improved pathogen resistance without compromising plant growth. Collectively, these results shed new light on plant growth-defense coordination and reveal a previously unknown function for the cytoplasmic fraction of BZR1. The BZR1-EDS1 module may be harnessed for the simultaneous improvement of crop productivity and pathogen resistance.
PMID: 34416351
Mol Plant , IF:13.164 , 2021 Dec , V14 (12) : P1985-1999 doi: 10.1016/j.molp.2021.07.021
A single-cell morpho-transcriptomic map of brassinosteroid action in the Arabidopsis root.
Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland.; Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9000 Ghent, Belgium; VIB Center for Plant Systems Biology, Technologiepark 71, 9000 Ghent, Belgium.; Bioinformatics Competence Center, University of Lausanne, Genopode Building, 1015 Lausanne, Switzerland.; School of Life Sciences, The University of Warwick, Coventry, CV4 7AL, UK.; Department of Plant Molecular Biology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland. Electronic address: christian.hardtke@unil.ch.
The effects of brassinosteroid signaling on shoot and root development have been characterized in great detail but a simple consistent positive or negative impact on a basic cellular parameter was not identified. In this study, we combined digital 3D single-cell shape analysis and single-cell mRNA sequencing to characterize root meristems and mature root segments of brassinosteroid-blind mutants and wild type. The resultant datasets demonstrate that brassinosteroid signaling affects neither cell volume nor cell proliferation capacity. Instead, brassinosteroid signaling is essential for the precise orientation of cell division planes and the extent and timing of anisotropic cell expansion. Moreover, we found that the cell-aligning effects of brassinosteroid signaling can propagate to normalize the anatomy of both adjacent and distant brassinosteroid-blind cells through non-cell-autonomous functions, which are sufficient to restore growth vigor. Finally, single-cell transcriptome data discern directly brassinosteroid-responsive genes from genes that can react non-cell-autonomously and highlight arabinogalactans as sentinels of brassinosteroid-dependent anisotropic cell expansion.
PMID: 34358681
Plant Cell , IF:11.277 , 2021 Dec doi: 10.1093/plcell/koab307
TOR promotes guard cell starch degradation by regulating the activity of beta-AMYLASE1 in Arabidopsis.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China.; Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan 250014, Shandong, China.; Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.; Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.; VIB Center for Plant Systems Biology, Ghent, Belgium.
Starch is the main energy storage carbohydrate in plants and serves as an essential carbon storage molecule for plant metabolism and growth under changing environmental conditions. The TARGET of RAPAMYCIN (TOR) kinase is an evolutionarily conserved master regulator that integrates energy, nutrient, hormone, and stress signaling to regulate growth in all eukaryotes. Here, we demonstrate that TOR promotes guard cell starch degradation and induces stomatal opening in Arabidopsis thaliana. Starvation, caused by plants growing under short photoperiod or low light photon irradiance, as well as inactivation of TOR, impaired guard cell starch degradation and stomatal opening. Sugar and TOR induce the accumulation of beta-AMYLASE1 (BAM1), which is responsible for starch degradation in guard cells. The plant steroid hormone brassinosteroid (BR) and transcription factor BZR1 play crucial roles in sugar-promoted expression of BAM1. Furthermore, sugar supply induced BAM1 accumulation, but TOR inactivation led to BAM1 degradation, and the effects of TOR inactivation on BAM1 degradation were abolished by the inhibition of autophagy and proteasome pathways or by phospho-mimicking mutation of BAM1 at serine-31. Such regulation of BAM1 activity by sugar-TOR signaling allows carbon availability to regulate guard cell starch metabolism and stomatal movement, ensuring optimal photosynthesis efficiency of plants.
PMID: 34919720
Curr Biol , IF:10.834 , 2021 Dec doi: 10.1016/j.cub.2021.11.046
Female self-incompatibility type in heterostylous Primula is determined by the brassinosteroid-inactivating cytochrome P450 CYP734A50.
University of Potsdam, Institute for Biochemistry and Biology, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany.; Julius Kuhn-Institut (JKI) - Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Horticultural Crops, Erwin-Baur-Str. 27, 06484 Quedlinburg, Germany.; Leibniz Institute of Plant Genetics and Crop Plant Research, OT Gatersleben, Corrensstrasse 3, 06466 Stadt Seeland, Germany.; University of Potsdam, Institute for Biochemistry and Biology, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany. Electronic address: michael.lenhard@uni-potsdam.de.
Most flowering plants are hermaphrodites, with flowers having both male and female reproductive organs. One widespread adaptation to limit self-fertilization is self-incompatibility (SI), where self-pollen fails to fertilize ovules.(1)(,)(2) In homomorphic SI, many morphologically indistinguishable mating types are found, although in heteromorphic SI, the two or three mating types are associated with different floral morphologies.(3-6) In heterostylous Primula, a hemizygous supergene determines a short-styled S-morph and a long-styled L-morph, corresponding to two different mating types, and full seed set only results from intermorph crosses.(7-9) Style length is controlled by the brassinosteroid (BR)-inactivating cytochrome P450 CYP734A50,(10) yet it remains unclear what defines the male and female incompatibility types. Here, we show that CYP734A50 also determines the female incompatibility type. Inactivating CYP734A50 converts short S-morph styles into long styles with the same incompatibility behavior as L-morph styles, and this effect can be mimicked by exogenous BR treatment. In vitro responses of S- and L-morph pollen grains and pollen tubes to increasing BR levels could only partly explain their different in vivo behavior, suggesting both direct and indirect effects of the different BR levels in S- versus L-morph stigmas and styles in controlling pollen performance. This BR-mediated SI provides a novel mechanism for preventing self-fertilization. The joint control of morphology and SI by CYP734A50 has important implications for the evolutionary buildup of the heterostylous syndrome and provides a straightforward explanation for why essentially all of the derived self-compatible homostylous Primula species are long homostyles.(11).
PMID: 34906354
Plant Physiol , IF:8.34 , 2021 Dec , V187 (4) : P2350-2351 doi: 10.1093/plphys/kiab459
BRing on the fight! Brassinosteroid-related transcription factors modulate resistance to fungi attack in wheat.
Integrative Plant Research Laboratory, Departamento de Botanica e Ecologia, Instituto de Biociencias, Universidade Federal de Mato Grosso, Cuiaba, MT, Brazil.
PMID: 34890467
Plant Physiol , IF:8.34 , 2021 Dec , V187 (4) : P2837-2851 doi: 10.1093/plphys/kiab419
Melatonin functions in priming of stomatal immunity in Panax notoginseng and Arabidopsis thaliana.
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.; Key Laboratory of Sustainable Utilization of Panax Notoginseng Resources, Sanqi Research Institute of Yunnan province, Kunming University of Science and Technology, Kunming 650500, China.; School of Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China.; UWA School of Agriculture and Environment, Faculty of Science, The University of Western Australia, Perth, Western Australia 6009, Australia.; Institute for Adriatic Crops and Karst Reclamation, Split 21000, Croatia.; State Key Laboratory Breeding Base of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
Melatonin (MT) plays important roles in plant disease response, but the mechanisms are largely unknown. Here, we show that MT functions in stomatal immunity in Panax notoginseng and Arabidopsis thaliana. Biochemical analyses showed that MT-induced stomatal closure plays a prominent role in preventing invasion of bacteria Pseudomonas syringe pv. tomato (Pst) DC3000 via activation of mitogen-activated protein kinase (MAPK) and NADPH oxidase-mediated reactive oxygen species production in P. notoginseng. The first putative phytomelatonin receptor 1 (PMTR1) is a plasma membrane protein required for perceiving MT signaling in stomatal closure and activation of MAPK. Biochemical and genetic tests found PMTR1 is essential for flg22- and MT-induced MAPK activation in a heterotrimeric GTP-binding protein Galpha subunit GPA1-independent manner. GPA1 functions in the same genetic pathways of FLS2/BAK1 (Flagellin Sensing 2/Brassinosteroid Insensitive 1-associated kinase 1)- as well as PMTR1-mediated flg22 and MT signaling in stomatal closure. The stomata in pmtr1 are insensitive to MT and flg22, but the application of MT induces stomatal closure and reduces the bacterial growth in fls2 and bak1 plants, indicating that PMTR1 might be a downstream signaling component in FLS2- and BAK1-mediated stomatal immunity. In summary, our results (i) demonstrate that phytomelatonin functions in the priming of stomatal immunity and (ii) provide insights into the phytomelatonin signaling transduction pathway.
PMID: 34618091
Plant Physiol , IF:8.34 , 2021 Dec , V187 (4) : P2563-2576 doi: 10.1093/plphys/kiab394
Diversification of plant agronomic traits by genome editing of brassinosteroid signaling family genes in rice.
National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.; Rice Research Institute of Anhui Academy of Agricultural Sciences, Hefei, Anhui Province 230001, China.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China.
Brassinosteroids (BRs) regulate various agronomic traits such as plant height, leaf angle, and grain size in rice (Oryza sativa L.); thus, BR signaling components are promising targets for molecular rational design. However, genetic materials for BR-signaling genes or family members remain limited in rice. Here, by genome editing using clustered regularly interspaced short palindromic repeats (CRSPR)/Cas9 tools, we generated a panel of single, double, triple, or quadruple mutants within three BR signaling gene families, including GSK3/SHAGGY-LIKE KINASE1 (GSK1)-GSK4, BRASSINAZOLE-RESISTANT1 (OsBZR1)-OsBZR4, and protein phosphatases with kelch-like (PPKL)1-PPKL3, under the same background (Zhonghua11, japonica). The high-order mutants were produced by either simultaneously targeting multiple sites on different genes of one family (GSKs and PPKLs) or targeting the overlapping sequences of family members (OsBZRs). The mutants exhibited a diversity of plant height, leaf angle, and grain morphology. Comparison analysis of the phenotypes together with BR sensitivity tests suggested the existence of functional redundancy, differentiation, or dominancy among the members within each family. In addition, we generated a set of transgenic plants overexpressing GSK2, OsBZR1/2, and PPKL2, respectively, in wild-type or activated forms with fusion of different tags, and also verified the protein response to BR application. Collectively, these plants greatly enriched the diversity of important agronomic traits in rice. We propose that editing of BR-related family genes could be a feasible approach for screening of desired plants to meet different requirements. Release of these materials as well as the related information also provides valuable resources for further BR research and utilization.
PMID: 34618079
Plant Physiol , IF:8.34 , 2021 Dec , V187 (4) : P2749-2762 doi: 10.1093/plphys/kiab383
Transcription factor BZR2 activates chitinase Cht20.2 transcription to confer resistance to wheat stripe rust.
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, P.R. China.; Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/ Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing 100081, P.R. China.
The brassinosteroid pathway promotes a variety of physiological processes in plants and the brassinosteroid insensitive1-ethylmethane sulfonate suppressor (BES)/brassinazole-resistant (BZR) functions as one of its key regulators. We previously showed that the BES/BZR-type transcription factor TaBZR2 mediates the drought stress response in wheat (Triticum aestivum) by directly upregulating the transcriptional activity of glutathione S-transferase 1. However, the function of TaBZR2 in plants under biotic stresses is unknown. In this study, we found that transcript levels of TaBZR2 were upregulated in response to inoculation with wheat stripe rust fungus (Puccinia striiformis f. sp. tritici, Pst) and treatment with flg22 or an elicitor-like protein of Pst, Pst322. Wheat lines overexpressing TaBZR2 conferred increased resistance, whereas TaBZR2-RNAi lines exhibited decreased resistance to multiple races of Pst. TaBZR2 targeted the promoter of the chitinase gene TaCht20.2, activating its transcription. Knockdown of TaCht20.2 in wheat resulted in enhanced susceptibility to Pst, indicating the positive role of TaCht20.2 in wheat resistance. Upon Pst infection in vivo, the overexpression of TaBZR2 increased total chitinase activity, whereas RNAi-mediated silencing of TaBZR2 reduced total chitinase activity. Taken together, our results suggest that TaBZR2 confers broad-spectrum resistance to the stripe rust fungus by increasing total chitinase activity in wheat.
PMID: 34618056
J Exp Bot , IF:6.992 , 2021 Dec doi: 10.1093/jxb/erab530
Fungal oxysterol-binding protein-related proteins promote pathogen virulence and activate plant immunity.
Department of Plant Pathology, MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China.; State Key Laboratory of Agrobiotechnology, China Agricultural University, 100193 Beijing, China.; Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, 100193 Beijing, China.
Oxysterol-binding protein-related proteins (ORPs) are a conserved class of lipid transfer proteins that are closely involved in multiple cellular processes in eukaryotes but their roles in plant-pathogen interactions are mostly unknown. We showed that transient expression of ORPs of Magnaporthe oryzae (MoORPs) in Nicotiana benthamina plants triggered oxidative burst and cell death; treatment of tobacco Bright Yellow-2 suspension cells with recombinant MoORPs elicited the production of reactive oxygen species. Despite that ORPs are normally described as intracellular proteins, we detected MoORPs in fungal cultural filtrates and intercellular fluids from barley plants infected with the fungus. More importantly, infiltration of Arabidopsis plants with recombinant Arabidopsis or fungal ORPs activated oxidative burst, callose deposition, PR1 gene expression, and enhanced plant disease resistance, implying that ORPs may function as endogenous and exogenous danger signals triggering plant innate immunity. Extracellular application of fungal ORPs exerted an opposite impact on salicylic acid and jasmonic acid/ethylene signaling pathways. The Brassinosteroid Insensitive 1-associated Kinase 1 was dispensable for the ORP-activated defense. Besides, simultaneous knockout of MoORP1 and MoORP3 abolished fungal colony radial growth and conidiation, whereas double knockout of MoORP1 and MoORP2 compromised fungal virulence on barley and rice plants. These observations collectively highlight the multifaceted role of MoORPs in the modulation of plant innate immunity and promotion of fungal development and virulence in M. oryzae.
PMID: 34864987
J Exp Bot , IF:6.992 , 2021 Dec , V72 (22) : P7808-7825 doi: 10.1093/jxb/erab365
Small molecule inhibitors of mammalian GSK-3beta promote in vitro plant cell reprogramming and somatic embryogenesis in crop and forest species.
Pollen Biotechnology of Crop Plants group, Margarita Salas Center of Biological Research, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.; Translational Medicinal and Biological Chemistry group, Margarita Salas Center of Biological Research, CIB-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
Plant in vitro regeneration systems, such as somatic embryogenesis, are essential in breeding; they permit propagation of elite genotypes, production of doubled-haploids, and regeneration of whole plants from gene editing or transformation events. However, in many crop and forest species, somatic embryogenesis is highly inefficient. We report a new strategy to improve in vitro embryogenesis using synthetic small molecule inhibitors of mammalian glycogen synthase kinase 3beta (GSK-3beta), never used in plants. These inhibitors increased in vitro embryo production in three different systems and species, microspore embryogenesis of Brassica napus and Hordeum vulgare, and somatic embryogenesis of Quercus suber. TDZD-8, a representative compound of the molecules tested, inhibited GSK-3 activity in microspore cultures, and increased expression of embryogenesis genes FUS3, LEC2, and AGL15. Plant GSK-3 kinase BIN2 is a master regulator of brassinosteroid (BR) signalling. During microspore embryogenesis, BR biosynthesis and signalling genes CPD, GSK-3-BIN2, BES1, and BZR1 were up-regulated and the BAS1 catabolic gene was repressed, indicating activation of the BR pathway. TDZD-8 increased expression of BR signalling elements, mimicking BR effects. The findings support that the small molecule inhibitors promoted somatic embryogenesis by activating the BR pathway, opening up the way for new strategies using GSK-3beta inhibitors that could be extended to other species.
PMID: 34338766
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
Int J Mol Sci , IF:5.923 , 2021 Dec , V22 (24) doi: 10.3390/ijms222413588
Exogenous Application of Low-Concentration Sugar Enhances Brassinosteroid Signaling for Skotomorphogenesis by Promoting BIN2 Degradation.
Biomass Energy Center for Arid and Semi-Arid Lands, Northwest A&F University, Xianyang 712100, China.; College of Life Sciences, Northwest A&F University, Xianyang 712100, China.
In plants, seedling growth is subtly controlled by multiple environmental factors and endogenous phytohormones. The cross-talk between sugars and brassinosteroid (BR) signaling is known to regulate plant growth; however, the molecular mechanisms that coordinate hormone-dependent growth responses with exogenous sucrose in plants are incompletely understood. Skotomorphogenesis is a plant growth stage with rapid elongation of the hypocotyls. In the present study, we found that low-concentration sugars could improve skotomorphogenesis in a manner dependent on BR biosynthesis and TOR activation. However, accumulation of BZR1 in bzr1-1D mutant plants partially rescued the defects of skotomorphogenesis induced by the TOR inhibitor AZD, and these etiolated seedlings displayed a normal phenotype like that of wild-type seedlings in response to both sucrose and non-sucrose treatments, thereby indicating that accumulated BZR1 sustained, at least partially, the sucrose-promoted growth of etiolated seedlings (skotomorphogenesis). Moreover, genetic evidence based on a phenotypic analysis of bin2-3bil1bil2 triple-mutant and gain-of-function bin2-1 mutant plant indicated that BIN2 inactivation was conducive to skotomorphogenesis in the dark. Subsequent biochemical and molecular analyses enabled us to confirm that sucrose reduced BIN2 levels via the TOR-S6K2 pathway in etiolated seedlings. Combined with a determination of the cellulose content, our results indicated that sucrose-induced BIN2 degradation led to the accumulation of BZR1 and the enhancement of cellulose synthesis, thereby promoting skotomorphogenesis, and that BIN2 is the converging node that integrates sugar and BR signaling.
PMID: 34948385
Int J Mol Sci , IF:5.923 , 2021 Dec , V22 (24) doi: 10.3390/ijms222413191
Elucidating the Molecular Mechanisms by which Seed-Borne Endophytic Fungi, Epichloe gansuensis, Increases the Tolerance of Achnatherum inebrians to NaCl Stress.
State Key Laboratory of Grassland Agro-Ecosystems, Center for Grassland Microbiome, Lanzhou University, Lanzhou 730000, China.; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China.; State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining 810016, China.; Collaborative Innovation Center for Western Ecological Safety, Lanzhou University, Lanzhou 730000, China.; Tibetan Medicine Research Center, College of Tibetan Medicine, Qinghai University, Xining 810016, China.; School of Life Science and Technology, Lingnan Normal University, Zhanjiang 524048, China.
Seed-borne endophyte Epichloe gansuensis enhance NaCl tolerance in Achnatherum inebrians and increase its biomass. However, the molecular mechanism by which E. gansuensis increases the tolerance of host grasses to NaCl stress is unclear. Hence, we firstly explored the full-length transcriptome information of A. inebrians by PacBio RS II. In this work, we obtained 738,588 full-length non-chimeric reads, 36,105 transcript sequences and 27,202 complete CDSs from A. inebrians. We identified 3558 transcription factors (TFs), 15,945 simple sequence repeats and 963 long non-coding RNAs of A. inebrians. The present results show that 2464 and 1817 genes were differentially expressed by E. gansuensis in the leaves of E+ and E- plants at 0 mM and 200 mM NaCl concentrations, respectively. In addition, NaCl stress significantly regulated 4919 DEGs and 502 DEGs in the leaves of E+ and E- plants, respectively. Transcripts associated with photosynthesis, plant hormone signal transduction, amino acids metabolism, flavonoid biosynthetic process and WRKY TFs were differentially expressed by E. gansuensis; importantly, E. gansuensis up-regulated biology processes (brassinosteroid biosynthesis, oxidation-reduction, cellular calcium ion homeostasis, carotene biosynthesis, positive regulation of proteasomal ubiquitin-dependent protein catabolism and proanthocyanidin biosynthesis) of host grass under NaCl stress, which indicated an increase in the ability of host grasses' adaptation to NaCl stress. In conclusion, our study demonstrates the molecular mechanism for E. gansuensis to increase the tolerance to salt stress in the host, which provides a theoretical basis for the molecular breed to create salt-tolerant forage with endophytes.
PMID: 34947985
Ann Bot , IF:4.357 , 2021 Dec doi: 10.1093/aob/mcab152
MYB42 inhibits hypocotyl cell elongation by coordinating brassinosteroid homeostasis and signaling in Arabidopsis thaliana.
College of Resources and Environment, Qingdao Agricultural University, Qingdao, China.; Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.; State Key Laboratory of Wheat and Maize Crop Science and College of Agronomy, Henan Agricultural University, Zhengzhou, China.; College of Agronomy, Qingdao Agricultural University, Qingdao, China.
BACKGROUND AND AIMS: The precise control of brassinosteroids (BRs) homeostasis and signaling is a prerequisite for hypocotyl cell elongation in plants. Arabidopsis MYB42 and its paralog MYB85 were previously identified to be positive regulators of secondary cell wall formation during mature stages. Here, we aim to reveal the role of MYB42 and MYB85 in hypocotyl elongation during the seedling stage and clarify how MYB42 coordinates BR homeostasis and signaling to regulate this process. METHODS: Histochemical analysis of proMYB42-GUS transgenic plants was used for determination of the MYB42 expression pattern. The MYB42, 85 overexpression, double mutant and some crossing lines were generated for phenotypic observation and transcriptome analysis. Transcription activation assays, quantitative PCR, chromatin immunoprecipitation (ChIP)-qPCR and electrophoretic mobility shift assays (EMSA) were conducted to determine the relationship of MYB42 and BRASSINAZOLE-RESISTANT 1 (BZR1), a master switch activating BR signaling. KEY RESULTS: MYB42 and MYB85 redundantly and negatively regulate hypocotyl cell elongation. They function in hypocotyl elongation by mediating BR signaling. MYB42 transcription was suppressed by BR treatment or in bzr1-1D (a gain-of-function mutant of BZR1), and mutation of both MYB42 and MYB85 enhanced the dwarf phenotype of the BR receptor mutant bri1-5. BZR1 directly repressed MYB42 expression in response to BR. Consistently, hypocotyl length of bzr1-1D was increased by simultaneous mutation of MYB42 and MYB85, but reduced by overexpression of MYB42. Expression of a number of BR-regulated BZR1 (non-) targets associated with hypocotyl elongation was suppressed by MYB42, 85. Furthermore, MYB42 enlarged its action in BR signaling through feedback repression of BR accumulation and activation of DOGT1/UGT73C5, a BR-inactivating enzyme. CONCLUSIONS: MYB42 inhibits hypocotyl elongation by coordinating BR homeostasis and signaling during primary growth. The present study shows a MYB42, 85-mediated multilevel system that contributes to fine regulation of BR-induced hypocotyl elongation.
PMID: 34922335
BMC Genomics , IF:3.969 , 2021 Dec , V22 (1) : P885 doi: 10.1186/s12864-021-08198-6
Transcriptomic and metabolomic changes triggered by Macrosiphum rosivorum in rose (Rosa longicuspis).
Flower Research Institute, Yunnan Academy of Agricultural Sciences/National Engineering Research Center for Ornamental Horticulture, Kunming, 650205, China.; Southwest Forestry University, Kunming, 650024, China.; Flower Research Institute, Yunnan Academy of Agricultural Sciences/National Engineering Research Center for Ornamental Horticulture, Kunming, 650205, China. kxtang@hotmail.com.; Flower Research Institute, Yunnan Academy of Agricultural Sciences/National Engineering Research Center for Ornamental Horticulture, Kunming, 650205, China. xianqin711@hotmail.com.
BACKGROUND: Rose is one of the most popular flowers in the wold. Its field growth and quality are negatively affected by aphids. However, the defence mechanisms used by rose plants against aphids are unclear. Therefore, to understand the defence mechanism of rose under aphid stress, transcriptome and metabolome techniques were used to investigate the regulation mechanism in R. longicuspis infected with M. rosivorum. RESULT: In our study, after inoculation with M. rosivorum, M. rosivorum quickly colonized R. longicuspis. A total of 34,202 genes and 758 metabolites were detected in all samples. Under M. rosivorum stress, R. longicuspis responded by MAPK cascades, plant hormone signal transduction pathway activation, RlMYBs and RlERFs transcription factors expression and ROS production. Interestingly, the 'brassinosteroid biosynthesis' pathway was significantly enriched in A3 d-vs.-A5 d. Further analysis showed that M. rosivorum induced the biosynthesis of secondary metabolites such as terpenoids, tannins and phenolic acids, among others. Importantly, the 'glutathione metabolic' and 'glucosinolate biosynthesis' pathways were significantly enriched, which involved in the rose against aphids. CONCLUSION: Our study provides candidate genes and metabolites for Rosa defence against aphids. This study provides a theoretical basis for further exploring the molecular regulation mechanism of rose aphid resistance and aphid resistance breeding in the future.
PMID: 34886808
Biochem Biophys Res Commun , IF:3.575 , 2021 Dec , V585 : P117-123 doi: 10.1016/j.bbrc.2021.11.042
Sheath blight resistance in rice is negatively regulated by WRKY53 via SWEET2a activation.
College of Plant Protection, Shenyang Agricultural University, Shenyang, 110866, China. Electronic address: gaoyue@stu.syau.edu.cn.; College of Plant Protection, Shenyang Agricultural University, Shenyang, 110866, China. Electronic address: syauxue@syau.edu.cn.; Southern Zhejiang Key Laboratory of Crop Breeding, Wenzhou Vocational College of Science and Technology (Wenzhou Academy of Agricultural Sciences), Wenzhou, Zhejiang, 325006, China. Electronic address: liujingmiao@hotmail.com.; Foreign Language Teaching Department, Shenyang Agricultural University, Shenyang, 110866, China. Electronic address: 1994500028@syau.edu.cn.; College of Plant Protection, Shenyang Agricultural University, Shenyang, 110866, China. Electronic address: meiqiong@syau.edu.cn.; College of Plant Protection, Shenyang Agricultural University, Shenyang, 110866, China. Electronic address: songhongw125@163.com.; College of Plant Protection, Shenyang Agricultural University, Shenyang, 110866, China. Electronic address: xuanyuanhu115@syau.edu.cn.
Sheath blight (ShB) is one of the most common diseases in rice that significantly affects yield production. However, the underlying mechanisms of rice defense remain largely unknown. Our previous transcriptome analysis identified that infection with Rhizoctonia solani significantly induced the expression level of SWEET2a, a member of the SWEET sugar transporter. The sweet2a genome-editing mutants were less susceptible to ShB. Further yeast-one hybrid, ChIP, and transient assays demonstrated that WRKY53 binds to the SWEET2a promoter to activate its expression. WRKY53 is a key brassinosteroid (BR) signaling transcription factor. Similar to the BR receptor gene BRI1 and biosynthetic gene D2 mutants, the WRKY53 mutant and overexpressor were less and more susceptible to ShB compared to wild-type, respectively. Inoculation with R. solani induced expression of BRI1, D2, and WRKY53, but inhibited MPK6 (a BR-signaling regulator) activity. Also, MPK6 is known to phosphorylate WRKY53 to enhance its transcription activation activity. Transient assay results indicated that co-expression of MPK6 and WRKY53 enhanced WRKY53 trans-activation activity to SWEET2a. Furthermore, expression of WRKY53 SD (the active phosphorylated forms of WRKY53) but not WRKY53 SA (the inactive phosphorylated forms of WRKY53), enhanced WRKY53-mediated activation of SWEET2a compared to expression of WRKY53 alone. Taken together, our analyses showed that R. solani infection may activate BR signaling to induce SWEET2a expression via WRKY53 through negative regulation of ShB resistance in rice.
PMID: 34801931