Nat Commun , IF:12.121 , 2019 Sep , V10 (1) : P4164 doi: 10.1038/s41467-019-12118-4
BES1 is activated by EMS1-TPD1-SERK1/2-mediated signaling to control tapetum development in Arabidopsis thaliana.
Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou, China.; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou, China. lijia@lzu.edu.cn.
BES1 and BZR1 were originally identified as two key transcription factors specifically regulating brassinosteroid (BR)-mediated gene expression. They belong to a family consisting of six members, BES1, BZR1, BEH1, BEH2, BEH3, and BEH4. bes1 and bzr1 single mutants do not exhibit any characteristic BR phenotypes, suggesting functional redundancy of these proteins. Here, by generating higher order mutants, we show that a quintuple mutant is male sterile due to defects in tapetum and microsporocyte development in anthers. Our genetic and biochemical analyses demonstrate that BES1 family members also act as downstream transcription factors in the EMS1-TPD1-SERK1/2 pathway. Ectopic expression of both TPD1 and EMS1 in bri1-116, a BR receptor null mutant, leads to the accumulation of non-phosphorylated, active BES1, similar to activation of BES1 by BRI1-BR-BAK1 signaling. These data suggest that two distinctive receptor-like kinase-mediated signaling pathways share BES1 family members as downstream transcription factors to regulate different aspects of plant development.
PMID: 31519953
Nat Commun , IF:12.121 , 2019 Sep , V10 (1) : P4165 doi: 10.1038/s41467-019-12112-w
EMS1 and BRI1 control separate biological processes via extracellular domain diversity and intracellular domain conservation.
College of Life Sciences, Shaanxi Normal University, 710119, Xi'an, Shaanxi Province, China.; College of Life Sciences, Shaanxi Normal University, 710119, Xi'an, Shaanxi Province, China. shexiaoping@snnu.edu.cn.; College of Life Sciences, Shaanxi Normal University, 710119, Xi'an, Shaanxi Province, China. gwu3@snnu.edu.cn.
In flowering plants, EMS1 (Excess Microsporocytes 1) perceives TPD1 (Tapetum Determinant 1) to specify tapeta, the last somatic cell layer nurturing pollen development. However, the signaling components downstream of EMS1 are relatively unknown. Here, we use a molecular complementation approach to investigate the downstream components in EMS1 signaling. We show that the EMS1 intracellular domain is functionally interchangeable with that of the brassinosteroid receptor BRI1 (Brassinosteroid Insensitive 1). Furthermore, expressing EMS1 together with TPD1 in the BRI1 expression domain could partially rescue bri1 phenotypes, and led to the dephosphorylation of BES1, a hallmark of active BRI1 signaling. Conversely, expressing BRI1 in the EMS1 expression domain could partially rescue ems1 phenotypes. We further show that PpEMS1 and PpTPD1 from the early land plant Physcomitrella patens could completely rescue ems1 and tpd1 phenotypes, respectively. We propose that EMS1 and BRI1 have evolved distinct extracellular domains to control different biological processes but can act via a common intracellular signaling pathway.
PMID: 31519884
Plant Physiol , IF:6.902 , 2019 Sep , V181 (1) : P179-194 doi: 10.1104/pp.19.00248
Wheat TaSPL8 Modulates Leaf Angle Through Auxin and Brassinosteroid Signaling.
State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing, 100193, China.; Key Laboratory of Crop Heterosis and Utilization (Ministry of Education), China Agricultural University, Beijing, 100193, China.; Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China.; Council for Agricultural Research and Economics, Research Centre for Cereal and Industrial Crops, I-24126 Bergamo, Italy.; State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing, 100193, China yingyin@cau.edu.cn.
In grass crops, leaf angle is determined by development of the lamina joint, the tissue connecting the leaf blade and sheath, and is closely related to crop architecture and yield. In this study, we identified a mutant generated by fast neutron radiation that exhibited an erect leaf phenotype caused by defects in lamina joint development. Map-based cloning revealed that the gene TaSPL8, encoding a SQUAMOSA PROMOTER BINDING-LIKE (SPL) protein, is deleted in this mutant. TaSPL8 knock-out mutants exhibit erect leaves due to loss of the lamina joint, compact architecture, and increased spike number especially in high planting density, suggesting similarity with its LIGULESS1 homologs in maize (Zea mays) and rice (Oryza sativa). Hence, LG1 could be a robust target for plant architecture improvement in grass species. Common wheat (Triticum aestivum, 2n = 6x = 42; BBAADD) is an allohexaploid containing A, B, and D subgenomes and the homeologous gene of TaSPL8 from the D subgenome contributes to the length of the lamina joint to a greater extent than that from the A and B subgenomes. Comparison of the transcriptome between the Taspl8 mutant and the wild type revealed that TaSPL8 is involved in the activation of genes related to auxin and brassinosteroid pathways and cell elongation. TaSPL8 binds to the promoters of the AUXIN RESPONSE FACTOR gene and of the brassinosteroid biogenesis gene CYP90D2 and activates their expression. These results indicate that TaSPL8 might regulate lamina joint development through auxin signaling and the brassinosteroid biosynthesis pathway.
PMID: 31209125
Ecotoxicol Environ Saf , IF:4.872 , 2019 Sep , V179 : P50-61 doi: 10.1016/j.ecoenv.2019.03.120
Castasterone attenuates insecticide induced phytotoxicity in mustard.
State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China. Electronic address: anketsharma@ymail.com.; State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China.; Department of Botany, DAV University, Sarmastpur, Jalandhar, 144012, Punjab, India.; Plant Stress Physiology Lab, Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab, 143005, India.; Plant Stress Physiology Lab, Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab, 143005, India; Department of Chemistry, Lovely Professional University, Jalandhar, Punjab, 144411, India.; State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, 311300, China. Electronic address: bszheng@zafu.edu.cn.
In the current investigation, we studied role of castasterone (CS), (a bioactive brassinosteroid) in Brassica juncea grown under imidacloprid (IMI) stress. We observed that CS-seed treatment resulted in the recovery of seedling growth under IMI toxicity. Seed treatment with CS, significantly enhanced the contents of pigments like chlorophylls, carotenoids, anthocyanins and xanthophylls under stress. Oxidative stress generated by the production of reactive oxygen species (ROS) like hydrogen peroxide and superoxide anion, was reduced after CS treatment under IMI toxicity. Antioxidative defense system got activated after CS-seed treatment, resulting in the increased activities of enzymes. Moreover, CS-seed treatment under IMI stress also stimulated the biosynthesis of organic acids of Krebs cycle (citrate, succinate, fumarate and malate) and phenolics. We also noticed that CS is also involved in the regulation of the gene expression of some key enzymes involved in pigment metabolism (CHLASE, PSY, CHS), carbon fixation (RUBISCO), Krebs cycle (CS, SUCLG1, SDH, FH), ROS generation (RBO), antioxidative enzymes (SOD, CAT, POD, DHAR, GR, GST), phenolic biosynthesis (PAL) and pesticide detoxification system (CXE, P450, NADH). This modulated gene expression after CS-treatment activated the insecticide detoxification, leading to the reduction of IMI residues. Data analysis using multivariate statistical technique i.e. multiple linear regression, also supported the fact that CS can efficiently reduce IMI induced phytotoxicity in B. juncea.
PMID: 31026750
J Agric Food Chem , IF:4.192 , 2019 Sep , V67 (35) : P9757-9771 doi: 10.1021/acs.jafc.9b02467
Transcriptome Analysis Reveals New Insights into MdBAK1-Mediated Plant Growth in Malus domestica.
BAK1 effects on plant stress responses have been well documented, but little is known regarding its effects on plant growth. In this study, we functionally characterized MdBAK1. Overexpressing MdBAK1 in Arabidopsis thaliana and apple trees promoted growth. Longitudinal stem cells were longer in transgenic plants than in wild-type plants. The size and number of cells and the area of the transverse stem were greater in the transgenic lines than in the wild-type plants. Moreover, transgenic A. thaliana and apple plants were more sensitive to an exogenous brassinosteroid. A transcriptome analysis of wild-type and transgenic apple revealed that MdBAK1 overexpression activated the brassinosteroid and ethylene signals, xylem production, and stress responses. Trend and Venn analyses indicated that carbohydrate, energy, and hormone metabolic activities were greater in transgenic plants during different periods. Moreover, a weighted gene coexpression network analysis proved that carbohydrate, hormone, and xylem metabolism as well as cell growth may be critical for MdBAK1-mediated apple tree growth and development. Compared with the corresponding levels in wild-type plants, the endogenous brassinosteroid, cytokinin, starch, sucrose, trehalose, glucose, fructose, and total sugar contents were considerably different in transgenic plants. Our results imply that MdBAK1 helps to regulate the growth of apple tree through the above-mentioned pathways. These findings provide new information regarding the effects of MdBAK1 onplant growth and development.
PMID: 31373492
Mol Plant Microbe Interact , IF:3.696 , 2019 Sep , V32 (9) : P1162-1174 doi: 10.1094/MPMI-12-18-0347-R
Plant Growth Promotion Driven by a Novel Caulobacter Strain.
Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.; Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium.; Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, 9000 Ghent, Belgium.; Plant Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), 9820 Merelbeke, Belgium.
Soil microbial communities hold great potential for sustainable and ecologically compatible agriculture. Although numerous plant-beneficial bacterial strains from a wide range of taxonomic groups have been reported, very little evidence is available on the plant-beneficial role of bacteria from the genus Caulobacter. Here, the mode of action of a Caulobacter strain, designated RHG1, which had originally been identified through a microbial screen for plant growth-promoting (PGP) bacteria in maize (Zea mays), is investigated in Arabidopsis thaliana. RHG1 colonized both roots and shoots of Arabidopsis, promoted lateral root formation in the root, and increased leaf number and leaf size in the shoot. The genome of RHG1 was sequenced and was utilized to look for PGP factors. Our data revealed that the bacterial production of nitric oxide, auxins, cytokinins, or 1-aminocyclopropane-1-carboxylate deaminase as PGP factors could be excluded. However, the analysis of brassinosteroid mutants suggests that an unknown PGP mechanism is involved that impinges directly or indirectly on the pathway of this growth hormone.
PMID: 30933667
Biochem Biophys Res Commun , IF:2.985 , 2019 Sep , V517 (1) : P118-124 doi: 10.1016/j.bbrc.2019.07.030
Transcription factor WRKY30 mediates resistance to Cucumber mosaic virus in Arabidopsis.
Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, Sichuan, 637009, China; Ecological Security and Protection Key Laboratory of Sichuan Province and Life Science and Technology College, Mianyang Normal University, Mianyang, Sichuan, 621000, China.; Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, China; Rice and Sorghum Institute, Sichuan Academy of Agricultural Sciences, Deyang, 618000, Sichuan, China.; Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, Sichuan, 637009, China.; Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, Sichuan, 637009, China; Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, Hainan, China. Electronic address: yikexian@21cn.com.; Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, Sichuan, 637009, China; Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, China. Electronic address: zhdawei@scu.edu.cn.
WRKY transcription factors are key regulators in regulating abiotic or biotic stress response in Arabidopsis. Previous studies showed that WRKY30 expression was induced by oxidative stress treatment, fungal elicitor, SA and ABA. However, functions of WRKY30 on viral defense are not well studied. Here, we found that Arabidopsis WRKY DNA binding protein 30 (WRKY30) plays essential roles in regulating Cucumber mosaic virus (CMV) resistance. The expression of WRKY30 was induced by CMV infection and wrky30 mutant displayed more susceptibility (including higher oxidative damages, induced reactive oxygen species synthesis and more PSII photochemistry compromise), while WRKY30 overexpression plants (WRKY30OX) exhibited more resistance to CMV infection. Moreover BRs-induced CMV tolerance is partly dependent on WRKY30. And WRKY30 expression increased after BL treatment. All these demonstrated that WRKY30 works as a positive regulator in plant CMV resistance process.
PMID: 31311650
Chem Biodivers , IF:2.039 , 2019 Sep , V16 (9) : Pe1900332 doi: 10.1002/cbdv.201900332
Biological Evaluation of a New Brassinosteroid: Antiproliferative Effects and Targeting Estrogen Receptor alpha Pathways.
Department of Experimental Tumor Biology, Blokhin N.N. National Medical Research Center of Oncology Ministry of Health of Russia, Kashirskoe shosse 24, 115522, Moscow, Russia.; Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Kuprevich str. 5/2, 220141, Minsk, Belarus.; Institute of Biomedical Chemistry, 10 building 8, Pogodinskaya str., 119121, Moscow, Russia.; Department of Molecular Technologies, Pirogov Russian National Research Medical University, 117997, Moscow, Russia.
Brassinosteroids (BS), a class of plant-specific steroid hormones, are considered as new potential anticancer agents for the treatment of tumors of different origin, including hormone-dependent cancers. Effects of a synthetic brassinosteroid BS4 ((22R,23R,24R)-22,23-dihydroxy-24-methyl-B-homo-7-oxa-5alpha-cholest-2-en-6-one ((3aS,7aR,7bS,9aS,10R,12aS,12bS)-10-[(2S,3R,4R,5R)-3,4-dihydroxy-5,6-dimethylhept an-2-yl]-7a,9a-dimethyl-1,3a,4,7,7a,7b,8,9,9a,10,11,12,12a,12b-tetradecahydro-3H- benzo[c]indeno[5,4-e]oxepin-3-one)) on hormone-dependent breast cancer cells and normal epithelial cells and its impact on the estrogen receptor signaling were evaluated. Cytotoxicity was assessed by MTT-test; expression of estrogen receptor alpha and survivin was measured by immunoblotting. Transactivation analysis of luciferase reporter gene was performed for ERalpha and AP-1 factors after the brassinosteroid treatment. Dock6 and Autodock Vina were used for molecular docking. BS4 revealed a significant antiproliferative effect towards the hormone-dependent breast cancer cells and was not active against normal epithelial cells. BS4 action on MCF-7 breast cancer cells was found to be complex: a decrease in ERalpha expression as well as in its transcription activity was accompanied by inhibition of ERalpha-related signaling pathways (AP-1 complex and survivin). BS4 binding mode to ERalpha ligand-binding domain was analyzed by molecular docking. The obtained results show that antiproliferative and antiestrogenic properties of the brassinosteroid BS4, as well as its ability to inhibit the anti-apoptotic protein survivin may be of interest for further development of anticancer agents.
PMID: 31381816
Physiol Mol Biol Plants , IF:2.005 , 2019 Sep , V25 (5) : P1283-1299 doi: 10.1007/s12298-019-00686-0
Opposite physiological effects upon jasmonic acid and brassinosteroid treatment on laticifer proliferation and co-occurrence of differential expression of genes involved in vascular development in rubber tree.
1Department of Biotechnology, Faculty of Science, Mahidol University, Rama 6 Rd., Rajthewee, Bangkok, 10400 Thailand.0000 0004 1937 0490grid.10223.32; Center of Excellence on Agricultural Biotechnology: (AG-BIO/PERDO-CHE), Bangkok, Thailand.; Rubber Research Institute of Thailand (RRIT), Bangkok, Thailand.; 4Department of Plant Science, Faculty of Science, Mahidol University, Phayathai, Bangkok, Thailand.0000 0004 1937 0490grid.10223.32
During growth of woody plant-trunk, the secondary meristem functions in giving rise the xylem and phloem. Rubber tree (Hevea brasiliensis Muell. Arg.), in addition, contains laticifers (latex producing vessels) in the vicinity of phloem. Insights into regulatory mechanisms of gene networks underlying laticifer proliferation in rubber tree has remained very limited. The candidate vascular development-related genes were selected to investigate for expression profile in phloem and xylem tissues of high latex yield- and high wood yield-clones of rubber tree. The differential gene expression between the mature branch-xylem and -phloem tissues was clearly observed. The cis-regulatory motif analysis revealed the existent of putative jasmonic acid (JA)- and brassinosteroid (BR)-responsive regulatory motifs in promoter regions of these genes, and consequently the effect of exogenous application of JA, BR or their respective signaling inhibitors, on the formation of laticifers in rubber tree was demonstrated. Interestingly, the laticifer numbers were significantly increased in JA-treatment, correlated with up-regulation of phloem development-related genes in both rubber tree clones. On the contrary, the laticifers were decreased in BR-treatment accompanying by up-regulation of xylem development-related genes, especially in high wood yield-rubber tree clone. BR-inhibitor treatment also enhanced laticifer numbers, while JA-inhibitor suppressed laticifer differentiation. Taken together, this study unveils the molecular interplay between JA/BR on vascular development in rubber tree and how this impacts the appearance of laticifers in this plant. This process is vital for a better understanding on laticifer differentiation and its impact in the manipulation of wood and latex yield in rubber tree improvement program.
PMID: 31564789
Plant Direct , IF:1.725 , 2019 Sep , V3 (9) : Pe00166 doi: 10.1002/pld3.166
Auxin promotion of seedling growth via ARF5 is dependent on the brassinosteroid-regulated transcription factors BES1 and BEH4.
Department of Biology University of Washington Seattle WA USA.; Present address: Max Planck Institute for Plant Breeding Research Carl-von-Linne-Weg 10 Cologne 50829 Germany.
Seedlings must continually calibrate their growth in response to the environment. Auxin and brassinosteroids (BRs) are plant hormones that work together to control growth responses during photomorphogenesis. We used our previous analysis of promoter architecture in an auxin and BR target gene to guide our investigation into the broader molecular bases and biological relevance of transcriptional co-regulation by these hormones. We found that the auxin-regulated transcription factor Auxin Responsive Factor 5 (ARF5) and the brassinosteroid-regulated transcription factor BRI1-EMS-Suppressor 1/Brassinazole Resistant 2 (BES1) co-regulated a subset of growth-promoting genes via conserved bipartite cis-regulatory elements. Moreover, ARF5 binding to DNA could be enriched by increasing BES1 levels. The evolutionary loss of bipartite elements in promoters results in loss of hormone responsiveness. We also identified another member of the BES1/BZR1 family called BEH4 that acts partially redundantly with BES1 to regulate seedling growth. Double mutant analysis showed that BEH4 and not BZR1 were required alongside BES1 for normal auxin response during early seedling development. We propose that an ARF5-BES1/BEH4 transcriptional module acts to promote growth via modulation of a diverse set of growth-associated genes.
PMID: 31508562