Plant Cell , IF:9.618 , 2019 Nov , V31 (11) : P2682-2696 doi: 10.1105/tpc.19.00058
BRASSINOSTEROID-INSENSITIVE2 Negatively Regulates the Stability of Transcription Factor ICE1 in Response to Cold Stress in Arabidopsis.
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.; Institute of Plant Stress Biology, Collaborative Innovation Center of Crop Stress Biology, Henan University, Kaifeng 475001, China.; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China yangshuhua@cau.edu.cn.
Cold acclimation is a crucial strategy for plant survival at freezing temperatures. C-REPEAT BINDING FACTOR (CBF) genes are rapidly and transiently induced by low temperature and play important roles in cold acclimation. However, the mechanism underlying the attenuation of CBF expression during the later stages of the cold stress response is obscure. Here, we show that the protein kinase BRASSINOSTEROID-INSENSITIVE2 (BIN2) interacts with and phosphorylates INDUCER OF CBF EXPRESSION1 (ICE1) in Arabidopsis (Arabidopsis thaliana) under prolonged cold stress, facilitating the interaction between ICE1 and the E3 ubiquitin ligase HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE1 and thereby promoting ICE1 degradation. The kinase activity of BIN2 is inhibited during the early stages of the cold stress response and is subsequently restored, suggesting that BIN2 mainly downregulates ICE1 abundance when CBF expression is attenuated. A loss-of-function mutation of ICE1 partially suppresses the cold-induced expression of CBFs and compromises the enhanced freezing tolerance of bin2-3 bil1 bil2 These findings reveal an important role for BIN2 in fine-tuning CBF expression, and thus in balancing plant growth and the cold stress response.
PMID: 31409630
Curr Biol , IF:9.601 , 2019 Nov , V29 (22) : P3778-3790.e8 doi: 10.1016/j.cub.2019.09.018
The Receptor Kinases BAK1/SERK4 Regulate Ca(2+) Channel-Mediated Cellular Homeostasis for Cell Death Containment.
Institute for Plant Genomics & Biotechnology, Texas A&M University, College Station, TX 77843, USA; Department of Plant Pathology & Microbiology, Texas A&M University, College Station, TX 77843, USA.; Institute for Plant Genomics & Biotechnology, Texas A&M University, College Station, TX 77843, USA; Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX 77843, USA; College of Plant Protection, China Agricultural University, Beijing 100193, P.R. China.; Institute for Plant Genomics & Biotechnology, Texas A&M University, College Station, TX 77843, USA; Department of Plant Pathology & Microbiology, Texas A&M University, College Station, TX 77843, USA; Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China.; College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P. R. China.; Department of Cell and Systems Biology, Center for the Analysis of Genome Evolution and Function (CAGEF), University of Toronto, Toronto, ON M5S 3B2, Canada.; Department of Biology, Genetics Institute, Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, FL 32610, USA.; Institute for Plant Genomics & Biotechnology, Texas A&M University, College Station, TX 77843, USA; Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX 77843, USA.; Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT 06269, USA.; Institute for Plant Genomics & Biotechnology, Texas A&M University, College Station, TX 77843, USA; Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX 77843, USA; College of Plant Protection, China Agricultural University, Beijing 100193, P.R. China. Electronic address: pinghe@tamu.edu.; Institute for Plant Genomics & Biotechnology, Texas A&M University, College Station, TX 77843, USA; Department of Plant Pathology & Microbiology, Texas A&M University, College Station, TX 77843, USA; College of Plant Protection, China Agricultural University, Beijing 100193, P.R. China. Electronic address: lshan@tamu.edu.
Cell death is a vital and ubiquitous process that is tightly controlled in all organisms. However, the mechanisms underlying precise cell death control remain fragmented. As an important shared module in plant growth, development, and immunity, Arabidopsis thaliana BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1 (BAK1) and somatic embryogenesis receptor kinase 4 (SERK4) redundantly and negatively regulate plant cell death. By deploying an RNAi-based genetic screen for bak1/serk4 cell death suppressors, we revealed that cyclic nucleotide-gated channel 20 (CNGC20) functions as a hyperpolarization-activated Ca(2+)-permeable channel specifically regulating bak1/serk4 cell death. BAK1 directly interacts with and phosphorylates CNGC20 at specific sites in the C-terminal cytosolic domain, which in turn regulates CNGC20 stability. CNGC19, the closest homolog of CNGC20 with a low abundance compared with CNGC20, makes a quantitative genetic contribution to bak1/serk4 cell death only in the absence of CNGC20, supporting the biochemical data showing homo- and heteromeric assembly of the CNGC20 and CNGC19 channel complexes. Transcripts of CNGC20 and CNGC19 are elevated in bak1/serk4 compared with wild-type plants, further substantiating a critical role of homeostasis of CNGC20 and CNGC19 in cell death control. Our studies not only uncover a unique regulation of ion channel stability by cell-surface-resident receptor kinase-mediated phosphorylation but also provide evidence for fine-tuning Ca(2+) channel functions in maintaining cellular homeostasis by the formation of homo- and heterotetrameric complexes.
PMID: 31679931
Sci Total Environ , IF:6.551 , 2019 Nov , V693 : P133650 doi: 10.1016/j.scitotenv.2019.133650
Facilitating effects of plant hormones on biomass production and nutrients removal by Tetraselmis cordiformis for advanced sewage treatment and its mechanism.
Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China.; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China. Electronic address: zhoujiantt@cqu.edu.cn.
Advanced sewage treatment by microalgae is regarded as a promising method for addressing eutrophication. To improve sewage treatment, three kinds of plant hormones including auxin (indole-3-acetic acid, IAA), cytokinin (Zeatin), and brassinosteroid, were chosen to measure the influence of plant hormones on nitrogen and phosphorus removal by Tetraselmis cordiformis and to analyze their mechanisms, including photosynthesis, nutrient metabolism, and gene transcription. The results indicated that the maximal removal efficiencies of total nitrogen and phosphate by T. cordiformis were elevated by the plant hormones by 184.3% and 53.2%, respectively. The chlorophyll a content was increased by 1.1 times by the plant hormones in comparison with the control. Moreover, after being stimulated by plant hormones, the activities of nitrate reductase (NR) and glutamine synthetase (GS) increased by 90.4% and 82.1%, respectively, in comparison with the control. Supplementation with plant hormones also significantly elevated the mRNA expression level of GS-related gene by 30.9%. This study demonstrated that plant hormones could significantly promote the nutrient removal of microalgae for sewage treatment in artificial laboratory conditions and provided theoretical support for its further practical full-scale application under variable conditions.
PMID: 31377356
J Integr Plant Biol , IF:4.885 , 2019 Nov , V61 (11) : P1171-1185 doi: 10.1111/jipb.12745
GW5-Like, a homolog of GW5, negatively regulates grain width, weight and salt resistance in rice.
Institute of Crop Sciences, the Chinese Academy of Agriculture Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Beijing, 100081, China.; Key Laboratory of Crop Genetics and Germplasm Enhancement/Jiangsu Provincial Center of Plant Gene Engineering, Nanjing Agricultural University, Nanjing, 210095, China.
Grain size is an important determinant of yield potential in crops. We previously demonstrated that natural mutations in the regulatory sequences of qSW5/GW5 confer grain width diversity in rice. However, the biological function of a GW5 homolog, named GW5-Like (GW5L), remains unknown. In this study, we report on GW5L knockout mutants in Kitaake, a japonica cultivar (cv.) considered to have a weak gw5 variant allele that confers shorter and wider grains. GW5L is evenly expressed in various tissues, and its protein product is localized to the plasma membrane. Biochemical assays verified that GW5L functions in a similar fashion to GW5. It positively regulates brassinosteroid (BR) signaling through repression of the phosphorylation activity of GSK2. Genetic data show that GW5L overexpression in either Kitaake or a GW5 knockout line, Kasa(orf3) (indica cv. Kasalath background), causes more slender, longer grains relative to the wild-type. We also show that GW5L could confer salt stress resistance through an association with calmodulin protein OsCaM1-1. These findings identify GW5L as a negative regulator of both grain size and salt stress tolerance, and provide a potential target for breeders to improve grain yield and salt stress resistance in rice.
PMID: 30450718
Mol Plant Microbe Interact , IF:3.696 , 2019 Nov , V32 (11) : P1496-1507 doi: 10.1094/MPMI-05-19-0121-R
Mai1 Protein Acts Between Host Recognition of Pathogen Effectors and Mitogen-Activated Protein Kinase Signaling.
Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, U.S.A.; School of Plant Sciences and Food Security, Tel-Aviv University, Tel-Aviv 69978, Israel.; Department of Horticultural Biotechnology, College of Life Sciences, Kyung Hee University, Yongin 17104, Korea.; Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A.
The molecular mechanisms acting between host recognition of pathogen effectors by nucleotide-binding leucine-rich repeat receptor (NLR) proteins and mitogen-activated protein kinase (MAPK) signaling cascades are unknown. MAPKKKalpha (M3Kalpha) activates MAPK signaling leading to programmed cell death (PCD) associated with NLR-triggered immunity. We identified a tomato M3Kalpha-interacting protein, SlMai1, that has 80% amino acid identity with Arabidopsis brassinosteroid kinase 1 (AtBsk1). SlMai1 has a protein kinase domain and a C-terminal tetratricopeptide repeat domain that interacts with the kinase domain of M3Kalpha. Virus-induced gene silencing of Mai1 homologs in Nicotiana benthamiana increased susceptibility to Pseudomonas syringae and compromised PCD induced by four NLR proteins. PCD was restored by expression of a synthetic SlMai1 gene that resists silencing. Expression of AtBsk1 did not restore PCD in Mai1-silenced plants, suggesting SlMai1 is functionally divergent from AtBsk1. PCD caused by overexpression of M3Kalpha or MKK2 was unaffected by Mai1 silencing, suggesting Mai1 acts upstream of these proteins. Coexpression of Mai1 with M3Kalpha in leaves enhanced MAPK phosphorylation and accelerated PCD. These findings suggest Mai1 is a molecular link acting between host recognition of pathogens and MAPK signaling.
PMID: 31251114
Molecules , IF:3.267 , 2019 Nov , V24 (23) doi: 10.3390/molecules24234372
Inhibitors of Brassinosteroid Biosynthesis and Signal Transduction.
Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Liesel-Beckmann-Strasse 1, 85354 Freising, Germany.
Chemical inhibitors are invaluable tools for investigating protein function in reverse genetic approaches. Their application bears many advantages over mutant generation and characterization. Inhibitors can overcome functional redundancy, their application is not limited to species for which tools of molecular genetics are available and they can be applied to specific tissues or developmental stages, making them highly convenient for addressing biological questions. The use of inhibitors has helped to elucidate hormone biosynthesis and signaling pathways and here we review compounds that were developed for the plant hormones brassinosteroids (BRs). BRs are steroids that have strong growth-promoting capacities, are crucial for all stages of plant development and participate in adaptive growth processes and stress response reactions. In the last two decades, impressive progress has been made in BR inhibitor development and application, which has been instrumental for studying BR modes of activity and identifying and characterizing key players. Both, inhibitors that target biosynthesis, such as brassinazole, and inhibitors that target signaling, such as bikinin, exist and in a comprehensive overview we summarize knowledge and methodology that enabled their design and key findings of their use. In addition, the potential of BR inhibitors for commercial application in plant production is discussed.
PMID: 31795392
DNA Cell Biol , IF:3.191 , 2019 Nov , V38 (11) : P1292-1302 doi: 10.1089/dna.2019.4896
Identification and Analysis of Genes Involved in Auxin, Abscisic Acid, Gibberellin, and Brassinosteroid Metabolisms Under Drought Stress in Tender Shoots of Tea Plants.
Tea Science Research Institute, College of Horticulture, Nanjing Agricultural University, Nanjing, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, China.; College of Agriculture, Nanjing Agricultural University, Nanjing, China.
Endogenous phytohormones auxin (indole-3-acetic acid [IAA]), abscisic acid (ABA), gibberellin (GA3), and brassinosteroid (BR) play a role in responses to drought stress in higher plants. Tea plant is one of the major economic corps worldwide. The tender shoots of tea plants are the main source for tea production. The effects of drought stress on endogenous IAA, ABA, GA3, and BR metabolisms in tender shoots of tea plants need to be illustrated. In this study, a total of 17 IAA-related genes, 17 ABA-related genes, 18 GA3-related genes, and 8 BR-related genes were identified under drought stress in tender shoots of tea plants, respectively. By using a combination of phytohormone determination, phylogenetic tree construction and sequence analysis, gene expression profiles, functional classification, Kyoto encyclopedia of genes and genomes enrichment, and distribution of genes analysis, we have demonstrated that IAA, ABA, GA3, and BR metabolisms might participate in the regulation of the response to drought stress in tender shoots of tea plants. The expression level of CsLYCE negatively correlated with ABA accumulation under drought stress. Our findings could shed new light on the effects of drought stress on the IAA, ABA, GA3, and BR metabolisms in tender shoots of tea plants.
PMID: 31560570
J Plant Res , IF:2.185 , 2019 Nov , V132 (6) : P881-901 doi: 10.1007/s10265-019-01143-5
Exogenous application of beta-sitosterol mediated growth and yield improvement in water-stressed wheat (Triticum aestivum) involves up-regulated antioxidant system.
Botany Department, Faculty of Science, Suez Canal University, Ismailia, 41522, Egypt.; Agricultural Botany Department, Faculty of Agriculture, Suez Canal University, Ismailia, 41522, Egypt.; Biology Department, Faculty of Science, Taibah University, Yanbu, Kingdom of Saudi Arabia. monahsh1@gmail.com.; Botany and Microbiology Department, Faculty of Science, Cairo University, Giza, 12613, Egypt. monahsh1@gmail.com.; Botany Department, National Research Centre, 33 Al Behoos Street, Dokki, Cairo, Egypt.
Water stress reduces crop production significantly, and climate change has further aggravated the problem mainly in arid and semi-arid regions. This was the first study on the possible effects of beta-sitosterol application in ameliorating the deleterious changes in wheat induced by water stress under field condition and drip irrigation regimes. A field experiment with the split-plot design was conducted, and wheat plants were foliar sprayed with four beta-sitosterol (BBS) concentrations (0, 25, 75, and 100 mg L(-1)) and two irrigation regimes [50 and 100% of crop evapotranspiration (ETc)]. Water stress without BBS treatment reduced biological yield, grain yield, harvest index, and photosynthetic efficiency significantly by 28.9%, 42.8%, 19.6%, and 20.5% compared with the well-watered plants, respectively. Proline content increased in water-stressed and BSS-treated plants, owing to a significant role in cellular osmotic adjustment. Application of BSS was effective in reducing the generation of hydrogen peroxide (H2O2) and hence the malondialdehyde content significantly in water-stressed and well-watered wheat plants. Application of BSS up-regulated the activity of antioxidant enzymes (SOD, CAT, POD, and APX) significantly and increased the content of tocopherol, ascorbic acid, and carotene thereby reducing the levels of reactive oxygen species. The increased antioxidant system in BSS treated plants was further supported by the expression level of SOD and dehydrin genes in both water-stressed and well-watered plants. In the present study, the application of BBS at 100 mg L(-1) was beneficial and can be recommended for improving the growth and yield of the wheat crop under water stress.
PMID: 31606785
Steroids , IF:1.948 , 2019 Nov , V151 : P108468 doi: 10.1016/j.steroids.2019.108468
Brassinosteroid analogues from the fruiting bodies of Laetiporus sulphureus and their anti-inflammatory activity.
The Key Laboratory of Plant Resources and Chemistry of Arid Zone, and State Key Laboratory of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, Beijing 10009, China.; Institute of Microbial Pharmaceuticals, College of Life and Health Sciences, Northeastern University, Shenyang 110819, China.; The Key Laboratory of Plant Resources and Chemistry of Arid Zone, and State Key Laboratory of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China; Chinese Tajik Innovation Center for Natural Products, Dushanbe 734063, Tajikistan.; The Key Laboratory of Plant Resources and Chemistry of Arid Zone, and State Key Laboratory of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China. Electronic address: haji@ms.xjb.ac.cn.; The Key Laboratory of Plant Resources and Chemistry of Arid Zone, and State Key Laboratory of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China. Electronic address: yuantao@ms.xjb.ac.cn.
Three new brassinosteroid analogues, named sulphurenolide A, sulphurenolide B and sulphurenolide C, were isolated from the methanolic extract of fruiting bodies of Laetiporus sulphureus. Their structures were established on the basis of extensive spectroscopic analysis (1D, 2D NMR, and HRESIMS) and ECD calculation. Sulphurenolides A and B are a pair of C-20 epimer, and sulphurenolide B represents the first naturally occurring 20R-brassinosteroid. Moreover, sulphurenolides A-C are firstly reported 5-hydroxylation and homo-6-oxa derivatives of brassinosteroids from natural sources. Anti-inflammatory assay revealed that sulphurenolides B and C exhibited significant inhibitory effects on NO production in lipopolysaccharide-induced RAW264.7 cells, and sulphurenolide C showed stronger inhibition than that of positive control, minocycline.
PMID: 31400389