Nat Plants , IF:15.793 , 2022 Jun , V8 (6) : P646-655 doi: 10.1038/s41477-022-01167-1
Deconvoluting signals downstream of growth and immune receptor kinases by phosphocodes of the BSU1 family phosphatases.
Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA.; Department of Biology, Stanford University, Stanford, CA, USA.; Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul, Republic of Korea.; Department of Life Science, College of Natural Sciences, Hanyang University, Seoul, Republic of Korea.; Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA.; Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul, Republic of Korea. skkimbio@cau.ac.kr.; Department of Life Science, College of Natural Sciences, Hanyang University, Seoul, Republic of Korea. twgibio@hanyang.ac.kr.; Research Institute for Convergence of Basic Science, Hanyang University, Seoul, South Korea. twgibio@hanyang.ac.kr.; Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA. zywang24@stanford.edu.
Hundreds of leucine-rich repeat receptor kinases (LRR-RKs) have evolved to control diverse processes of growth, development and immunity in plants, but the mechanisms that link LRR-RKs to distinct cellular responses are not understood. Here we show that two LRR-RKs, the brassinosteroid hormone receptor BRASSINOSTEROID INSENSITIVE 1 (BRI1) and the flagellin receptor FLAGELLIN SENSING 2 (FLS2), regulate downstream glycogen synthase kinase 3 (GSK3) and mitogen-activated protein (MAP) kinases, respectively, through phosphocoding of the BRI1-SUPPRESSOR1 (BSU1) phosphatase. BSU1 was previously identified as a component that inactivates GSK3s in the BRI1 pathway. We surprisingly found that the loss of the BSU1 family phosphatases activates effector-triggered immunity and impairs flagellin-triggered MAP kinase activation and immunity. The flagellin-activated BOTRYTIS-INDUCED KINASE 1 (BIK1) phosphorylates BSU1 at serine 251. Mutation of serine 251 reduces BSU1's ability to mediate flagellin-induced MAP kinase activation and immunity, but not its abilities to suppress effector-triggered immunity and interact with GSK3, which is enhanced through the phosphorylation of BSU1 at serine 764 upon brassinosteroid signalling. These results demonstrate that BSU1 plays an essential role in immunity and transduces brassinosteroid-BRI1 and flagellin-FLS2 signals using different phosphorylation sites. Our study illustrates that phosphocoding in shared downstream components provides signalling specificities for diverse plant receptor kinases.
PMID: 35697730
Mol Plant , IF:13.164 , 2022 Jun , V15 (6) : P991-1007 doi: 10.1016/j.molp.2022.05.002
Brassinosteroids enhance salicylic acid-mediated immune responses by inhibiting BIN2 phosphorylation of clade I TGA transcription factors in Arabidopsis.
Department of Life Science, Hanyang University, Seoul 04763, Republic of Korea.; Department of Life Science, Chung-Ang University, Seoul 06973, Republic of Korea.; Department of Life Science, Chung-Ang University, Seoul 06973, Republic of Korea. Electronic address: skkimbio@cau.ac.kr.; Department of Life Science, Hanyang University, Seoul 04763, Republic of Korea; Research Institute for Convergence of Basic Science, Hanyang University, Seoul 04763, Republic of Korea; Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul 04763, Republic of Korea. Electronic address: twgibio@hanyang.ac.kr.
Salicylic acid (SA) plays an important role in plant immune response, including resistance to pathogens and systemic acquired resistance. Two major components, NONEXPRESSOR OF PATHOGENESIS-RELATED GENES (NPRs) and TGACG motif-binding transcription factors (TGAs), are known to mediate SA signaling, which might also be orchestrated by other hormonal and environmental changes. Nevertheless, the molecular and functional interactions between SA signaling components and other cellular signaling pathways remain poorly understood. Here we showed that the steroid plant hormone brassinosteroid (BR) promotes SA responses by inactivating BR-INSENSITIVE 2 (BIN2), which inhibits the redox-sensitive clade I TGAs in Arabidopsis. We found that both BR and the BIN2 inhibitor bikinin synergistically increase SA-mediated physiological responses, such as resistance to Pst DC3000. Our genetic and biochemical analyses indicated that BIN2 functionally interacts with TGA1 and TGA4, but not with other TGAs. We further demonstrated that BIN2 phosphorylates Ser-202 of TGA4, resulting in the suppression of the redox-dependent interaction between TGA4 and NPR1 as well as destabilization of TGA4. Consistently, transgenic Arabidopsis overexpressing TGA4-YFP with a S202A mutation displayed enhanced SA responses compared to the wild-type TGA4-YFP plants. Taken together, these results suggest a novel crosstalk mechanism by which BR signaling coordinates the SA responses mediated by redox-sensitive clade I TGAs.
PMID: 35524409
Plant Cell , IF:11.277 , 2022 May , V34 (6) : P2266-2285 doi: 10.1093/plcell/koac092
The photomorphogenic repressors BBX28 and BBX29 integrate light and brassinosteroid signaling to inhibit seedling development in Arabidopsis.
Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.; Department of Biology, Institute of Plant and Food Sciences, Southern University of Science and Technology, Shenzhen 518055, China.; State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Advanced Agriculture Sciences and School of Life Sciences, Peking University, Beijing 100871, 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 100039, China.; State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China.; State Key Laboratory of Crop Genetics and Germplasm Enhancement, National Center for Soybean Improvement, College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China.; School of Life Sciences, Guangzhou University, Guangzhou 510006, China.
B-box containing proteins (BBXs) integrate light and various hormonal signals to regulate plant growth and development. Here, we demonstrate that the photomorphogenic repressors BBX28 and BBX29 positively regulate brassinosteroid (BR) signaling in Arabidopsis thaliana seedlings. Treatment with the BR brassinolide stabilized BBX28 and BBX29, which partially depended on BR INSENSITIVE1 (BRI1) and BIN2. bbx28 bbx29 seedlings exhibited larger cotyledon aperture than the wild-type when treated with brassinazole in the dark, which partially suppressed the closed cotyledons of brassinazole resistant 1-1D (bzr1-1D). Consistently, overexpressing BBX28 and BBX29 partially rescued the short hypocotyls of bri1-5 and bin2-1 in both the dark and light, while the loss-of-function of BBX28 and BBX29 partially suppressed the long hypocotyls of bzr1-1D in the light. BBX28 and BBX29 physically interacted with BR-ENHANCED EXPRESSION1 (BEE1), BEE2, and BEE3 and enhanced their binding to and activation of their target genes. Moreover, BBX28 and BBX29 as well as BEE1, BEE2, and BEE3 increased BZR1 accumulation to promote the BR signaling pathway. Therefore, both BBX28 and BBX29 interact with BEE1, BEE2, and BEE3 to orchestrate light and BR signaling by facilitating the transcriptional activity of BEE target genes. Our study provides insights into the pivotal roles of BBX28 and BBX29 as signal integrators in ensuring normal seedling development.
PMID: 35294019
Curr Biol , IF:10.834 , 2022 Jun , V32 (11) : P2454-2466.e7 doi: 10.1016/j.cub.2022.04.028
The receptor kinase OsWAK11 monitors cell wall pectin changes to fine-tune brassinosteroid signaling and regulate cell elongation in rice.
Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, 050024 Shijiazhuang, China; Institute of Cash Crops, Hebei Academy of Agriculture & Forestry Sciences, Shijiazhuang 050051, China.; Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, 050024 Shijiazhuang, China.; State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.; Institute of Cash Crops, Hebei Academy of Agriculture & Forestry Sciences, Shijiazhuang 050051, China.; Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.; Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, 050024 Shijiazhuang, China. Electronic address: swzhang@hebtu.edu.cn.
Rates of plant cell elongation change with day-night alternation, reflecting differences in metabolism related to cell wall remodeling. Information from cell wall surveillance pathways must be integrated with growth regulation pathways to provide feedback regulation of cell wall modification; such feedback regulation is important to ensure sufficient strength and prevent rupture of the cell wall during growth. Several lines of evidence suggest that cell wall perturbations often influence phytohormone signaling, but the identity of the nexus between these two processes remained elusive. Here, we show that wall-associated kinase11 (OsWAK11) acts as a linker connecting cell wall pectin methyl-esterification changes and brassinosteroid (BR) signaling in rice. Our data show that OsWAK11 controls several important agronomical traits by regulating cell elongation in rice. OsWAK11 directly binds and phosphorylates the BR receptor OsBRI1 at residue Thr752, within a motif conserved across most monocot graminaceous crops, thus hindering OsBRI1 interaction with its co-receptor OsSERK1/OsBAK1 and inhibiting BR signaling. The extracellular domain of OsWAK11 shows a much stronger interaction toward methyl-esterified pectin as compared with de-methyl-esterified pectin. OsWAK11 is stabilized in light but is degraded in darkness, in a process triggered by changes in the ratio of methyl-esterified to de-methyl-esterified pectin, creating fluctuations in plant BR signaling in response to day and night alternation. We conclude that OsWAK11 is a cell wall monitor that regulates cell elongation rates to adapt to the environment from the outside in, which complements the well-established inside-out signaling pathway affecting cell elongation in plants.
PMID: 35512695
New Phytol , IF:10.151 , 2022 May doi: 10.1111/nph.18228
Pan-brassinosteroid signaling revealed by functional analysis of NILR1 in land plants.
College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China.
Brassinosteroid (BR) signaling has been identified from the ligand BRs sensed by the receptor Brassinosteroid Insensitive 1 (BRI1) to the final activation of Brassinozole Resistant 1/bri1 EMS-Suppressor 1 through a series of transduction events. Extensive studies have been conducted to characterize the role of BR signaling in various biological processes. Our previous study has shown that Excess Microsporocytes 1 (EMS1) and BRI1 control different aspects of plant growth and development via conserved intracellular signaling. Here, we reveal that another receptor, NILR1, can complement the bri1 mutant in the absence of BRs, indicating a pathway that resembles BR signaling activated by NILR1. Genetic analysis confirms the intracellular domains of NILR1, BRI1 and EMS1 have a common signal output. Furthermore, we demonstrate that NILR1 and BRI1 share the coreceptor BRI1 Associated Kinase 1 and substrate BSKs. Notably, the NILR1-mediated downstream pathway is conserved across land plants. In summary, we provide evidence for the signaling cascade of NILR1, suggesting pan-brassinosteroid signaling initiated by a group of distant receptor-ligand pairs in land plants.
PMID: 35570834
Plant Physiol , IF:8.34 , 2022 May doi: 10.1093/plphys/kiac237
Receptor-like protein kinase BAK1 promotes K+ uptake by regulating H+-ATPase AHA2 under low potassium stress.
State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, China Agricultural University, Beijing 100193, China.; School of Life Science, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei, 071002, China.
Potassium (K+) is one of the essential macronutrients for plant growth and development. However, the available K+ concentration in soil is relatively low. Plant roots can perceive low K+ (LK) stress, then enhance high-affinity K+ uptake by activating H+-ATPases in root cells, but the mechanisms are still unclear. Here, we identified the receptor-like protein kinase BAK1 (Brassinosteroid Insensitive 1-Associated Receptor Kinase 1) that is involved in LK response by regulating the Arabidopsis (Arabidopsis thaliana) PM (plasma membrane) H+-ATPase isoform 2 (AHA2). The bak1 mutant showed leaf chlorosis phenotype and reduced K+ content under LK conditions, which was due to the decline of K+ uptake capacity. BAK1 could directly interact with the AHA2 C terminus and phosphorylate T858 and T881, by which the H+ pump activity of AHA2 was enhanced. The bak1 aha2 double mutant also displayed a leaf chlorosis phenotype that was similar to their single mutants. The constitutively activated form AHA2Delta98 and phosphorylation-mimic form AHA2T858D or AHA2T881D could complement the LK sensitive phenotypes of both aha2 and bak1 mutants. Together, our data demonstrate that BAK1 phosphorylates AHA2 and enhances its activity, which subsequently promotes K+ uptake under LK conditions.
PMID: 35604103
Plant Physiol , IF:8.34 , 2022 May doi: 10.1093/plphys/kiac194
SAUR15 interaction with BRI1 activates plasma membrane H+-ATPase to promote organ development of Arabidopsis.
State Key Laboratory of Grassland Agro-ecosystems; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, People's Republic of China.; Department of Biology, Institute of Biochemistry, Carleton University, Ottawa, Ontario, K1S 5B6, Canada.; Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China.; School of Life Sciences, Guangzhou University, Guangzhou 510006, People's Republic of China.
Brassinosteroids (BRs) are an important group of plant steroid hormones that regulate growth and development. Several members of the SMALL AUXIN UP RNA (SAUR) family have roles in BR-regulated hypocotyl elongation and root growth. However, the mechanisms are unclear. Here, we show in Arabidopsis (Arabidopsis thaliana) that SAUR15 interacts with cell surface receptor-like kinase BRASSINOSTEROID-INSENSITIVE 1 (BRI1) in BR-treated plants, resulting in enhanced BRI1 phosphorylation status and recruitment of the co-receptor BRI1-ASSOCIATED RECEPTOR KINASE 1 (BAK1). Genetic and phenotypic assays indicated that the SAUR15 effect on BRI1 can be uncoupled from BRASSINOSTEROID INSENSITIVE 2 (BIN2) activity. Instead, we show that SAUR15 promotes BRI1 direct activation of plasma membrane H+-ATPase (PM H+-ATPase) via phosphorylation. Consequently, SAUR15-BRI1-PM H+-ATPase acts as a direct, PM-based mode of BR signaling that drives cell expansion to promote the growth and development of various organs. These data define an alternate mode of BR signaling in plants.
PMID: 35511168
Plant Physiol , IF:8.34 , 2022 Jun , V189 (3) : P1177-1179 doi: 10.1093/plphys/kiac185
Transcription factor OsNAC016: a convergent point of brassinosteroid and abscisic acid signaling in rice.
International Genome Center, Jiangsu University, Zhenjiang 212013, China.
PMID: 35460247
Plant Physiol , IF:8.34 , 2022 Jun , V189 (3) : P1757-1773 doi: 10.1093/plphys/kiac157
The interplay of auxin and brassinosteroid signaling tunes root growth under low and different nitrogen forms.
National Institute of Plant Genome Research, New Delhi, 110067, India.
The coordinated signaling activity of auxin and brassinosteroids (BRs) is critical for optimal plant growth and development. Nutrient-derived signals regulate root growth by modulating the levels and spatial distribution of growth hormones to optimize nutrient uptake and assimilation. However, the effect of the interaction of these two hormones and their signaling on root plasticity during low and differential availability of nitrogen (N) forms (NH4+/NO3-) remains elusive. We demonstrate that root elongation under low N (LN) is an outcome of the interdependent activity of auxin and BR signaling pathways in Arabidopsis (Arabidopsis thaliana). LN promotes root elongation by increasing BR-induced auxin transport activity in the roots. Increased nuclear auxin signaling and its transport efficiency have a distinct impact on root elongation under LN conditions. High auxin levels reversibly inhibit BR signaling via BRI1 KINASE INHIBITOR1. Using the tissue-specific approach, we show that BR signaling from root vasculature (stele) tissues is sufficient to promote cell elongation and, hence, root growth under LN condition. Further, we show that N form-defined root growth attenuation or enhancement depends on the fine balance of BR and auxin signaling activity. NH4+ as a sole N source represses BR signaling and response, which in turn inhibits auxin response and transport, whereas NO3- promotes root elongation in a BR signaling-dependent manner. In this study, we demonstrate the interplay of auxin and BR-derived signals, which are critical for root growth in a heterogeneous N environment and appear essential for root N foraging response and adaptation.
PMID: 35377445
Plant Physiol , IF:8.34 , 2022 Jun , V189 (3) : P1296-1313 doi: 10.1093/plphys/kiac146
OsNAC016 regulates plant architecture and drought tolerance by interacting with the kinases GSK2 and SAPK8.
Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044, China.
Ideal plant architecture and drought tolerance are important determinants of yield potential in rice (Oryza sativa). Here, we found that OsNAC016, a rice NAC (NAM, ATAF, and CUC) transcription factor, functions as a regulator in the crosslink between brassinosteroid (BR)-mediated plant architecture and abscisic acid (ABA)-regulated drought responses. The loss-of-function mutant osnac016 exhibited erect leaves and shortened internodes, but OsNAC016-overexpressing plants had opposite phenotypes. Further investigation revealed that OsNAC016 regulated the expression of the BR biosynthesis gene D2 by binding to its promoter. Moreover, OsNAC016 interacted with and was phosphorylated by GSK3/SHAGGY-LIKE KINASE2 (GSK2), a negative regulator in the BR pathway. Meanwhile, the mutant osnac016 had improved drought stress tolerance, supported by a decreased water loss rate and enhanced stomatal closure in response to exogenous ABA, but OsNAC016-overexpressing plants showed attenuated drought tolerance and reduced ABA sensitivity. Further, OSMOTIC STRESS/ABA-ACTIVATED PROTEIN KINASE8 (SAPK8) phosphorylated OsNAC016 and reduced its stability. The ubiquitin/26S proteasome system is an important degradation pathway of OsNAC016 via the interaction with PLANT U-BOX PROTEIN43 (OsPUB43) that mediates the ubiquitination of OsNAC016. Notably, RNA-sequencing analysis revealed global roles of OsNAC016 in promoting BR-mediated gene expression and repressing ABA-dependent drought-responsive gene expression, which was confirmed by chromatin immunoprecipitation quantitative PCR analysis. Our findings establish that OsNAC016 is positively involved in BR-regulated rice architecture, negatively modulates ABA-mediated drought tolerance, and is regulated by GSK2, SAPK8, and OsPUB43 through posttranslational modification. Our data provide insights into how plants balance growth and survival by coordinately regulating the growth-promoting signaling pathway and response under abiotic stresses.
PMID: 35333328
Plant Physiol , IF:8.34 , 2022 Jun , V189 (2) : P839-857 doi: 10.1093/plphys/kiac134
Sphingolipids with 2-hydroxy fatty acids aid in plasma membrane nanodomain organization and oxidative burst.
Graduate School of Science and Engineering, Saitama University, Sakuraku, Saitama 338-8570, Japan.; College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
Plant sphingolipids mostly possess 2-hydroxy fatty acids (HFA), the synthesis of which is catalyzed by FA 2-hydroxylases (FAHs). In Arabidopsis (Arabidopsis thaliana), two FAHs (FAH1 and FAH2) have been identified. However, the functions of FAHs and sphingolipids with HFAs (2-hydroxy sphingolipids) are still unknown because of the lack of Arabidopsis lines with the complete deletion of FAH1. In this study, we generated a FAH1 mutant (fah1c) using CRISPR/Cas9-based genome editing. Sphingolipid analysis of fah1c, fah2, and fah1cfah2 mutants revealed that FAH1 hydroxylates very long-chain FAs (VLCFAs), whereas the substrates of FAH2 are VLCFAs and palmitic acid. However, 2-hydroxy sphingolipids are not completely lost in the fah1cfah2 double mutant, suggesting the existence of other enzymes catalyzing the hydroxylation of sphingolipid FAs. Plasma membrane (PM) analysis and molecular dynamics simulations revealed that hydroxyl groups of sphingolipid acyl chains play a crucial role in the organization of nanodomains, which are nanoscale liquid-ordered domains mainly formed by sphingolipids and sterols in the PM, through hydrogen bonds. In the PM of the fah1cfah2 mutant, the expression levels of 26.7% of the proteins, including defense-related proteins such as the pattern recognition receptors (PRRs) brassinosteroid insensitive 1-associated receptor kinase 1 and chitin elicitor receptor kinase 1, NADPH oxidase respiratory burst oxidase homolog D (RBOHD), and heterotrimeric G proteins, were lower than that in the wild-type. In addition, reactive oxygen species (ROS) burst was suppressed in the fah1cfah2 mutant after treatment with the pathogen-associated molecular patterns flg22 and chitin. These results indicated that 2-hydroxy sphingolipids are necessary for the organization of PM nanodomains and ROS burst through RBOHD and PRRs during pattern-triggered immunity.
PMID: 35312013
Plant Physiol , IF:8.34 , 2022 Jun , V189 (2) : P628-643 doi: 10.1093/plphys/kiac088
The bHLH/HLH transcription factors GhFP2 and GhACE1 antagonistically regulate fiber elongation in cotton.
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.
Basic helix-loop-helix/helix-loop-helix (bHLH/HLH) transcription factors play important roles in cell elongation in plants. However, little is known about how bHLH/HLH transcription factors antagonistically regulate fiber elongation in cotton (Gossypium hirsutum). In this study, we report that two bHLH/HLH transcription factors, fiber-related protein 2 (GhFP2) and ACTIVATOR FOR CELL ELONGATION 1 (GhACE1), function in fiber development of cotton. GhFP2 is an atypical bHLH protein without the basic region, and its expression is regulated by brassinosteroid (BR)-related BRASSINAZOLE RESISTANT 1 (GhBZR1). Overexpression of GhFP2 in cotton hindered fiber elongation, resulting in shortened fiber length. In contrast, suppression of GhFP2 expression in cotton promoted fiber development, leading to longer fibers compared with the wild-type. GhFP2 neither contains a DNA-binding domain nor has transcriptional activation activity. Furthermore, we identified GhACE1, a bHLH protein that interacts with GhFP2 and positively regulates fiber elongation. GhACE1 could bind to promoters of plasma membrane intrinsic protein 2;7 (GhPIP2;7) and expansions 8 (GhEXP8) for directly activating their expression, but the interaction between GhFP2 and GhACE1 suppressed transcriptional activation of these target genes by GhACE1. Taken together, our results indicate that GhACE1 promotes fiber elongation by activating expressions of GhPIP2;7 and GhEXP8, but its transcription activation on downstream genes may be obstructed by BR-modulated GhFP2. Thus, our data reveal a key mechanism for fiber cell elongation through a pair of antagonizing HLH/bHLH transcription factors in cotton.
PMID: 35226094
Plant Physiol , IF:8.34 , 2022 Jun , V189 (2) : P441-443 doi: 10.1093/plphys/kiac080
Branching out underground: brassinosteroid signaling promotes lateral root development in rice.
Cold Spring Harbor Laboratory, Howard Hughes Medical Institute, Cold Spring Harbor, NY 11724, USA.
PMID: 35212723
Plant Physiol , IF:8.34 , 2022 May , V189 (1) : P402-418 doi: 10.1093/plphys/kiac043
Brassinosteroids regulate rice seed germination through the BZR1-RAmy3D transcriptional module.
Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and Physiology/Sate Key Laboratory of Hybrid Rice, College of Agriculture, Yangzhou University, Yangzhou 225009, Jiangsu, China.; Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province/Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou 225009, Jiangsu, China.
Seed dormancy and germination, two physiological processes unique to seed-bearing plants, are critical for plant growth and crop production. The phytohormone brassinosteroid (BR) regulates many aspects of plant growth and development, including seed germination. The molecular mechanisms underlying BR control of rice (Oryza sativa) seed germination are mostly unknown. We investigated the molecular regulatory cascade of BR in promoting rice seed germination and post-germination growth. Physiological assays indicated that blocking BR signaling, including introducing defects into the BR-insensitive 1 (BRI1) receptor or overexpressing the glycogen synthase kinase 2 (GSK2) kinase delayed seed germination and suppressed embryo growth. Our results also indicated that brassinazole-resistant 1 (BZR1) is the key downstream transcription factor that mediates BR regulation of seed germination by binding to the alpha-Amylase 3D (RAmy3D) promoter, which affects alpha-amylase expression and activity and the degradation of starch in the endosperm. The BZR1-RAmy3D module functions independently from the established Gibberellin MYB-alpha-amylase 1A (RAmy1A) module of the gibberellin (GA) pathway. We demonstrate that the BZR1-RAmy3D module also functions in embryo-related tissues. Moreover, RNA-sequencing (RNA-seq) analysis identified more potential BZR1-responsive genes, including those involved in starch and sucrose metabolism. Our study successfully identified the role of the BZR1-RAmy3D transcriptional module in regulating rice seed germination.
PMID: 35139229
Plant Physiol , IF:8.34 , 2022 May , V189 (1) : P285-300 doi: 10.1093/plphys/kiac046
The CCCH zinc finger protein C3H15 negatively regulates cell elongation by inhibiting brassinosteroid signaling.
College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, China.; Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.; Academy of Dongying Efficient Agricultural Technology and Industry on Saline and Alkaline Land in Collaboration with Qingdao Agricultural University, Dongying 257000, China.; State Key Laboratory of Wheat and Maize Crop Science and College of Agronomy, Henan Agricultural University, Zhengzhou 450002, China.; College of Agronomy, Qingdao Agricultural University, Qingdao 266109, China.; Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan 430062, China.; Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, China.; College of Grassland Science, Qingdao Agricultural University, Qingdao 266109, China.
Plant CCCH proteins participate in the control of multiple developmental and adaptive processes, but the regulatory mechanisms underlying these processes are not well known. In this study, we showed that the Arabidopsis (Arabidopsis thaliana) CCCH protein C3H15 negatively regulates cell elongation by inhibiting brassinosteroid (BR) signaling. Genetic and biochemical evidence showed that C3H15 functions downstream of the receptor BR INSENSITIVE 1 (BRI1) as a negative regulator in the BR pathway. C3H15 is phosphorylated by the GLYCOGEN SYNTHASE KINASE 3 -like kinase BR-INSENSITIVE 2 (BIN2) at Ser111 in the cytoplasm in the absence of BRs. Upon BR perception, C3H15 transcription is enhanced, and the phosphorylation of C3H15 by BIN2 is reduced. The dephosphorylated C3H15 protein accumulates in the nucleus, where C3H15 regulates transcription via G-rich elements (typically GGGAGA). C3H15 and BRASSINAZOLE RESISTANT 1 (BZR1)/BRI1-EMS-SUPPRESSOR 1 (BES1), two central transcriptional regulators of BR signaling, directly suppress each other and share a number of BR-responsive target genes. Moreover, C3H15 antagonizes BZR1 and BES1 to regulate the expression of their shared cell elongation-associated target gene, SMALL AUXIN-UP RNA 15 (SAUR15). This study demonstrates that C3H15-mediated BR signaling may be parallel to, or even attenuate, the dominant BZR1 and BES1 signaling pathways to control cell elongation. This finding expands our understanding of the regulatory mechanisms underlying BR-induced cell elongation in plants.
PMID: 35139225
Plant Physiol , IF:8.34 , 2022 Jun , V189 (2) : P858-873 doi: 10.1093/plphys/kiac015
The histone deacetylase 1/GSK3/SHAGGY-like kinase 2/BRASSINAZOLE-RESISTANT 1 module controls lateral root formation in rice.
State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Lateral roots (LRs) are a main component of the root system of rice (Oryza sativa) that increases root surface area, enabling efficient absorption of water and nutrients. However, the molecular mechanism regulating LR formation in rice remains largely unknown. Here, we report that histone deacetylase 1 (OsHDAC1) positively regulates LR formation in rice. Rice OsHDAC1 RNAi plants produced fewer LRs than wild-type plants, whereas plants overexpressing OsHDAC1 exhibited increased LR proliferation by promoting LR primordia formation. Brassinosteroid treatment increased the LR number, as did mutation of GSK3/SHAGGY-like kinase 2 (OsGSK2), whereas overexpression of OsGSK2 decreased the LR number. Importantly, OsHDAC1 could directly interact with and deacetylate OsGSK2, inhibiting its activity. OsGSK2 deacetylation attenuated the interaction between OsGSK2 and BRASSINAZOLE-RESISTANT 1 (OsBZR1), leading to accumulation of OsBZR1. The overexpression of OsBZR1 increased LR formation by regulating Auxin/IAA signaling genes. Taken together, the results indicate that OsHDAC1 regulates LR formation in rice by deactivating OsGSK2, thereby preventing degradation of OsBZR1, a positive regulator of LR primordia formation. Our findings suggest that OsHDAC1 is a breeding target in rice that can improve resource capture.
PMID: 35078247
Elife , IF:8.14 , 2022 May , V11 doi: 10.7554/eLife.74687
Perception of a conserved family of plant signalling peptides by the receptor kinase HSL3.
The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom.; The Plant Signaling Mechanisms Laboratory, Department of Plant Molecular Biology, University of Lausanne, Lausanne, Switzerland.; Institute of Plant Molecular Biology, Zurich-Basel Plant Science Center, University of Zurich, Zurich, Switzerland.; MWSchmid GmbH, Glarus, Switzerland.
Plant genomes encode hundreds of secreted peptides; however, relatively few have been characterised. We report here an uncharacterised, stress-induced family of plant signalling peptides, which we call CTNIPs. Based on the role of the common co-receptor BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED KINASE 1 (BAK1) in CTNIP-induced responses, we identified in Arabidopsis thaliana the orphan receptor kinase HAESA-LIKE 3 (HSL3) as the CTNIP receptor via a proteomics approach. CTNIP-binding, ligand-triggered complex formation with BAK1, and induced downstream responses all involve HSL3. Notably, the HSL3-CTNIP signalling module is evolutionarily conserved amongst most extant angiosperms. The identification of this novel signalling module will further shed light on the diverse functions played by plant signalling peptides and will provide insights into receptor-ligand co-evolution.
PMID: 35617122
Sci Total Environ , IF:7.963 , 2022 Sep , V838 (Pt 4) : P156503 doi: 10.1016/j.scitotenv.2022.156503
OsBR6ox, a member in the brassinosteroid synthetic pathway facilitates degradation of pesticides in rice through a specific DNA demethylation mechanism.
Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China.; Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China; Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.; Syngenta Crop Protection AG, Rosentalstrasse 67, CH-4002 Basel, Switzerland.; Syngenta Ltd, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK.; Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: hongyang@njau.edu.cn.
This manuscript described a comprehensive study on a pesticide degradation factor OsBR6ox that promoted the degradation of pesticides atrazine (ATZ) and acetochlor (ACT) in rice tissues and grains through an epigenetic mechanism. OsBR6ox was transcriptionally induced under ATZ and ACT stress. Genetic disruption of OsBR6ox increased rice sensitivity and led to more accumulation of ATZ and ACT, whereas transgenic rice overexpressing OsBR6ox lines (OEs) showed opposite effects with improved growth and lower ATZ and ACT accumulation in various tissues, including grains. OsBR6ox-mediated detoxification of ATZ and ACT was associated with the increased abundance of brassinolide (one of the brassinosteroids, BRs), a plant growth regulator for stress responses. Some Phase I-II reaction protein genes for pesticide detoxification such as genes encoding laccase, O-methyltransferase and glycosyltransferases were transcriptionally upregulated in OE lines under ATZ and ACT stress. HPLC-Q-TOF-MS/MS analysis revealed an enhanced ATZ/ATC metabolism in OE plants, which removed 1.21-1.49 fold ATZ and 1.31-1.44 fold ACT from the growth medium but accumulated only 83.1-87.1 % (shoot) and 71.7-84.1 % (root) of ATZ and 69.4-83.4 % of ACT of the wild-type. Importantly, an ATZ-responsive demethylated region in the upstream of OsBR6ox was detected. Such an epigenetic modification marker was responsible for the increased OsBR6ox expression and consequent detoxification of ATZ/ACT in rice and environment. Overall, this work uncovered a new model showing that plants utilize two mechanisms to co-regulate the detoxification and metabolism of pesticides in rice and provided a new approach for building up cleaner crops and eliminating residual pesticides in environments.
PMID: 35688248
J Integr Plant Biol , IF:7.061 , 2022 Jun doi: 10.1111/jipb.13311
OsCPL3 is involved in brassinosteroid signaling by regulating OsGSK2 stability.
State Key Laboratory of Hybrid Rice, Department of Plant Sciences, College of Life Sciences, Wuhan University, Wuhan, 430072, China.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, the Innovative Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.; Hubei Hongshan Laboratory, Wuhan, 430070, China.
Glycogen synthase kinase 3 (GSK3) proteins play key roles in brassinosteroid (BR) signaling during plant growth and development by phosphorylating various substrates. However, how GSK3 protein stability and activity are themselves modulated is not well understood. Here, we demonstrate in vitro and in vivo that C-TERMINAL DOMAIN PHOSPHATASE-LIKE 3 (OsCPL3), a member of the RNA Pol II CTD phosphatase-like family, physically interacts with OsGSK2 in rice (Oryza sativa). OsCPL3 expression was widely detected in various tissues and organs including roots, leaves and lamina joints, and was induced by exogenous BR treatment. OsCPL3 localized to the nucleus, where it dephosphorylated OsGSK2 at the Ser-222 and Thr-284 residues to modulate its protein turnover and kinase activity, in turn affecting the degradation of BRASSINAZOLE-RESISTANT 1 (BZR1) and BR signaling. Loss of OsCPL3 function resulted in higher OsGSK2 abundance and lower OsBZR1 levels, leading to decreased BR responsiveness and alterations in plant morphology including semi-dwarfism, leaf erectness and grain size, which are of fundamental importance to crop productivity. These results reveal a previously unrecognized role for OsCPL3 and add another layer of complexity to the tightly controlled BR signaling pathway in plants. This article is protected by copyright. All rights reserved.
PMID: 35665602
J Integr Plant Biol , IF:7.061 , 2022 Jun , V64 (6) : P1264-1280 doi: 10.1111/jipb.13257
BAK1 plays contrasting roles in regulating abscisic acid-induced stomatal closure and abscisic acid-inhibited primary root growth in Arabidopsis.
State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.; College of Life Sciences, Qingdao University, Qingdao, 266071, China.; Collaborative Innovation Center of Crop Stress Biology, Institute of Plant Stress Biology, Henan University, Kaifeng, 475001, Henan, China.; Institute of Life Science and Green Development, School of Life Sciences, Hebei University, Baoding, 071002, China.
The mechanisms that balance plant growth and stress responses are poorly understood, but they appear to involve abscisic acid (ABA) signaling mediated by protein kinases. Here, to explore these mechanisms, we examined the responses of Arabidopsis thaliana protein kinase mutants to ABA treatment. We found that mutants of BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE 1 (BAK1) were hypersensitive to the effects of ABA on both seed germination and primary root growth. The kinase OPEN STOMATA 1 (OST1) was more highly activated by ABA in bak1 mutant than the wild type. BAK1 was not activated by ABA treatment in the dominant negative mutant abi1-1 or the pyr1 pyl4 pyl5 pyl8 quadruple mutant, but it was more highly activated by this treatment in the abi1-2 abi2-2 hab1-1 loss-of-function triple mutant than the wild type. BAK1 phosphorylates OST1 T146 and inhibits its activity. Genetic analyses suggested that BAK1 acts at or upstream of core components in the ABA signaling pathway, including PYLs, PP2Cs, and SnRK2s, during seed germination and primary root growth. Although the upstream brassinosteroid (BR) signaling components BAK1 and BR INSENSITIVE 1 (BRI1) positively regulate ABA-induced stomatal closure, mutations affecting downstream components of BR signaling, including BRASSINOSTEROID-SIGNALING KINASEs (BSKs) and BRASSINOSTEROID-INSENSITIVE 2 (BIN2), did not affect ABA-mediated stomatal movement. Thus, our study uncovered an important role of BAK1 in negatively regulating ABA signaling during seed germination and primary root growth, but positively modulating ABA-induced stomatal closure, thus optimizing the plant growth under drought stress.
PMID: 35352463
Food Res Int , IF:6.475 , 2022 Jul , V157 : P111296 doi: 10.1016/j.foodres.2022.111296
Comparative transcriptomic analysis reveals the potential mechanism of hot water treatment alleviated-chilling injury in banana fruit.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/Engineering Research Center of Southern Horticultural Products Preservation, Ministry of Education, College of Horticulture, South China Agricultural University, Guangzhou 510642, China.; Key Laboratory of Postharvest Biology of Subtropical Special Agricultural Products/Institute of Postharvest Technology of Agricultural Products, College of Food Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China. Electronic address: fanzqi@fafu.edu.cn.; Tea Research Institute, Guizhou Academy of Agricultural Sciences, Guiyang, Guizhou 550006, China.; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/Engineering Research Center of Southern Horticultural Products Preservation, Ministry of Education, College of Horticulture, South China Agricultural University, Guangzhou 510642, China. Electronic address: chenjianye@scau.edu.cn.
Banana fruit is prone to chilling injury (CI) during cold storage, resulting in quality deterioration and commodity reduction. The hot water treatment (HWT), dipping banana fruit in hot water (52 degrees C) for 3 min, reduced CI symptom at 7 degrees C storage. The purpose of this study was to investigate the potential molecular mechanism of HWT on the alleviation of CI of postharvest banana fruit. It was found that HWT treatment obviously inhibited the increases in CI index, relative electrolytic leakage, and the contents of malonaldehyde (MDA) and O2(*-), while enhanced proline accumulation. Further transcriptome analysis in the pericarp of banana fruit was evaluated during storage. The results showed that differentially expressed genes (DEGs) in the comparison between control and HWT group were mainly enriched in photosynthesis, chlorophyll metabolism, lipid metabolism, glutathione metabolism, and brassinosteroid and carotenoid biosynthesis. Moreover, transcriptome expression profiles and RT-qPCR analyses exhibited that the corresponding genes involved in these metabolism pathways and heat shock proteins (HSPs) were upregulated by HWT during cold storage. In general, our findings clearly reveal the potential pathways by which HWT alleviates CI in banana fruit, enriching the theoretical basis for the application of hot water to reduce CI in fruits.
PMID: 35761601
Plant J , IF:6.417 , 2022 Jun doi: 10.1111/tpj.15852
GhBZR3 suppresses cotton fiber elongation by inhibiting very-long-chain fatty acid biosynthesis.
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.; College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China.; School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.; School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, 710012, China.; College of Life Sciences, Shaanxi Normal University, Xi'an, 710062, China.
The BRASSINAZOLE-RESISTANT (BZR) transcription factor is a core component of brassinosteroid (BR) signaling and is involved in the development of many plant species. BR is essential for the initiation and elongation of cotton fibers. However, the mechanism of BR-regulating fiber development and the function of BZR is poorly understood in Gossypium hirsutum L. (cotton). Here, we identified a BZR family transcription factor protein referred to as GhBZR3 in cotton. Overexpression of GhBZR3 in Arabidopsis caused shorter root hair length, hypocotyl length, and hypocotyl cell length, indicating that GhBZR3 negatively regulates cell elongation. Pathway enrichment analysis from VIGS-GhBZR3 cotton plants found that fatty acid metabolism and degradation might be the regulatory pathway that is primarily controlled by GhBZR3. Silencing GhBZR3 expression in cotton resulted in taller plant height as well as longer fibers. The very-long-chain fatty acid (VLCFA) content was also significantly increased in silenced GhBZR3 plants compared with the wild type. The GhKCS13 promoter, a key gene for VLCFA biosynthesis, contains two GhBZR3 binding sites. The results of yeast one-hybrid, electrophoretic mobility shift, and luciferase assays revealed that GhBZR3 directly interacted with the GhKCS13 promoter to suppress gene expression. Taken together, these results indicate that GhBZR3 negatively regulates cotton fiber development by reducing VLCFA biosynthesis. This study not only deepens our understanding of GhBZR3 function in cotton fiber development, but also highlights the potential of improving cotton fiber length and plant growth using GhBZR3 and its related genes in future cotton breeding programs.
PMID: 35653239
Antioxidants (Basel) , IF:6.312 , 2022 May , V11 (5) doi: 10.3390/antiox11050918
Molecular Regulation of Antioxidant Melatonin Biosynthesis by Brassinosteroid Acting as an Endogenous Elicitor of Melatonin Induction in Rice Seedlings.
Department of Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea.
Gibberellic acid (GA) was recently shown to induce melatonin synthesis in rice. Here, we examined whether brassinosteroids (BRs) also induce melatonin synthesis because BRs and GA show redundancy in many functions. Among several plant hormones, exogenous BR treatment induced melatonin synthesis by twofold compared to control treatment, whereas ethylene, 6-benzylaminopurine (BA), and indole-3-acetic acid (IAA) showed negligible effects on melatonin synthesis. Correspondingly, BR treatment also induced a number of melatonin biosynthetic genes in conjunction with the suppression of melatonin catabolic gene expression. Several transgenic rice plants with downregulated BR biosynthesis-related genes, such as DWARF4, DWARF11, and RAV-Like1 (RAVL1), were generated and exhibited decreased melatonin synthesis, indicating that BRs act as endogenous elicitors of melatonin synthesis. Notably, treatment with either GA or BR fully restored melatonin synthesis in the presence of paclobutrazol, a GA biosynthesis inhibitor. Moreover, exogenous BR treatment partially restored melatonin synthesis in both RAVL1 and Galpha RNAi transgenic rice plants, whereas GA treatment fully restored melatonin synthesis comparable to wild type in RAVL1 RNAi plants. Taken together, our results highlight a role of BR as an endogenous elicitor of melatonin synthesis in a GA-independent manner in rice plants.
PMID: 35624782
Int J Mol Sci , IF:5.923 , 2022 Jun , V23 (12) doi: 10.3390/ijms23126795
Evolutionary Analysis and Functional Identification of Ancient Brassinosteroid Receptors in Ceratopteris richardii.
College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China.
Phytohormones play an important role in the adaptive evolution of terrestrial plants. Brassinosteroids (BRs) are essential hormones that regulate multiple aspects of plant growth and development in angiosperms, but the presence of BR signaling in non-seed plants such as ferns remains unknown. Here, we found that BR promotes the growth of Ceratopteris richardii, while the synthetic inhibitor PCZ inhibits the growth. Using full-length transcriptome sequencing, we identified four BRI1-like receptors. By constructing chimeric receptors, we found that the kinase domains of these four receptors could trigger BR downstream signaling. Further, the extracellular domains of two receptors were functionally interchangeable with that of BRI1. In addition, we identified a co-receptor, CtSERK1, that could phosphorylate with CtBRL2s in vitro. Together, these proved the presence of a receptor complex in Ceratopteris richardii that might perceive BR and activate downstream hormone signaling. Our results shed light on the biological and molecular mechanisms of BR signaling in ferns and the role of BR hormone signaling in the adaptive evolution of terrestrial plants.
PMID: 35743240
Int J Mol Sci , IF:5.923 , 2022 May , V23 (10) doi: 10.3390/ijms23105811
The Role of SBI2/ALG12/EBS4 in the Regulation of Endoplasmic Reticulum-Associated Degradation (ERAD) Studied by a Null Allele.
College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China.
Redundancy and lethality is a long-standing problem in genetics but generating minimal and lethal phenotypes in the knockouts of the same gene by different approaches drives this problem to a new high. In Asn (N)-linked glycosylation, a complex and ubiquitous cotranslational and post-translational protein modification required for the transfer of correctly folded proteins and endoplasmic reticulum-associated degradation (ERAD) of misfolded proteins, ALG12 (EBS4) is an alpha 1, 6-mannosyltransferase catalyzing a mannose into Glc3Man9GlcNAc2. In Arabidopsis, T-DNA knockout alg12-T is lethal while likely ebs4 null mutants isolated by forward genetics are most healthy as weak alleles, perplexing researchers and demanding further investigations. Here, we isolated a true null allele, sbi2, with the W258Stop mutation in ALG12/EBS4. sbi2 restored the sensitivity of brassinosteroid receptor mutants bri1-5, bri1-9, and bri1-235 with ER-trapped BRI1 to brassinosteroids. Furthermore, sbi2 maturated earlier than the wild-type. Moreover, concomitant with impaired and misfolded proteins accumulated in the ER, sbi2 had higher sensitivity to tunicamycin and salt than the wild-type. Our findings thus clarify the role of SBI2/ALG12/EBS4 in the regulation of the ERAD of misfolded glycoproteins, and plant growth and stress response. Further, our study advocates the necessity and importance of using multiple approaches to validate genetics study.
PMID: 35628619
Int J Mol Sci , IF:5.923 , 2022 May , V23 (10) doi: 10.3390/ijms23105551
Genome-Wide Identification of Gramineae Brassinosteroid-Related Genes and Their Roles in Plant Architecture and Salt Stress Adaptation.
School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.
Brassinosteroid-related genes are involved in regulating plant growth and stress responses. However, systematic analysis is limited to Gramineae species, and their roles in plant architecture and salt stress remain unclear. In this study, we identified brassinosteroid-related genes in wheat, barley, maize, and sorghum and investigated their evolutionary relationships, conserved domains, transmembrane topologies, promoter sequences, syntenic relationships, and gene/protein structures. Gene and genome duplications led to considerable differences in gene numbers. Specific domains were revealed in several genes (i.e., HvSPY, HvSMOS1, and ZmLIC), indicating diverse functions. Protein-protein interactions suggested their synergistic functions. Their expression profiles were investigated in wheat and maize, which indicated involvement in adaptation to stress and regulation of plant architecture. Several candidate genes for plant architecture (ZmBZR1 and TaGSK1/2/3/4-3D) and salinity resistance (TaMADS22/47/55-4B, TaGRAS19-4B, and TaBRD1-2A.1) were identified. This study is the first to comprehensively investigate brassinosteroid-related plant architecture genes in four Gramineae species and should help elucidate the biological roles of brassinosteroid-related genes in crops.
PMID: 35628372
Int J Mol Sci , IF:5.923 , 2022 May , V23 (9) doi: 10.3390/ijms23095224
Deacclimation-Induced Changes of Photosynthetic Efficiency, Brassinosteroid Homeostasis and BRI1 Expression in Winter Oilseed Rape (Brassica napus L.)-Relation to Frost Tolerance.
The Franciszek Gorski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Krakow, Poland.; Department of Plant Physiology, Faculty of Agriculture and Economics, University of Agriculture in Krakow, Podluzna 3, 30-239 Krakow, Poland.; Institute of Technology and Life Sciences-National Research Institute, Falenty, Al. Hrabska 3, 05-090 Raszyn, Poland.; Department of Plant Physiology, Institute of Biology, Warsaw University of Life Sciences-SGGW, 02-766 Warsaw, Poland.; Institute of Environmental Engineering, Warsaw University of Life Sciences-SGGW, 02-766 Warsaw, Poland.; Laboratory of Growth Regulators, Faculty of Science, Institute of Experimental Botany of the Czech Academy of Sciences, Palacky University, Slechtitelu 27, CZ-78371 Olomouc, Czech Republic.
The objective of this study was to answer the question of how the deacclimation process affects frost tolerance, photosynthetic efficiency, brassinosteroid (BR) homeostasis and BRI1 expression of winter oilseed rape. A comparative study was conducted on cultivars with different agronomic and physiological traits. The deacclimation process can occur when there are periods of higher temperatures, particularly in the late autumn or winter. This interrupts the process of the acclimation (hardening) of winter crops to low temperatures, thus reducing their frost tolerance and becoming a serious problem for agriculture. The experimental model included plants that were non-acclimated, cold acclimated (at 4 degrees C) and deacclimated (at 16 degrees C/9 degrees C, one week). We found that deacclimation tolerance (maintaining a high frost tolerance despite warm deacclimating periods) was a cultivar-dependent trait. Some of the cultivars developed a high frost tolerance after cold acclimation and maintained it after deacclimation. However, there were also cultivars that had a high frost tolerance after cold acclimation but lost some of it after deacclimation (the cultivars that were more susceptible to deacclimation). Deacclimation reversed the changes in the photosystem efficiency that had been induced by cold acclimation, and therefore, measuring the different signals associated with photosynthetic efficiency (based on prompt and delayed chlorophyll fluorescence) of plants could be a sensitive tool for monitoring the deacclimation process (and possible changes in frost tolerance) in oilseed rape. Higher levels of BR were characteristic of the better frost-tolerant cultivars in both the cold-acclimated and deacclimated plants. The relative expression of the BRI1 transcript (encoding the BR-receptor protein) was lower after cold acclimation and remained low in the more frost-tolerant cultivars after deacclimation. The role of brassinosteroids in oilseed rape acclimation/deacclimation is briefly discussed.
PMID: 35563614
Front Plant Sci , IF:5.753 , 2022 , V13 : P905148 doi: 10.3389/fpls.2022.905148
OsNAC129 Regulates Seed Development and Plant Growth and Participates in the Brassinosteroid Signaling Pathway.
Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genetics and Physiology/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, College of Agriculture, Yangzhou University, Yangzhou, China.; National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.; University of Chinese Academy of Sciences, Beijing, China.; Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China.
Grain size and the endosperm starch content determine grain yield and quality in rice. Although these yield components have been intensively studied, their regulatory mechanisms are still largely unknown. In this study, we show that loss-of-function of OsNAC129, a member of the NAC transcription factor gene family that has its highest expression in the immature seed, greatly increased grain length, grain weight, apparent amylose content (AAC), and plant height. Overexpression of OsNAC129 had the opposite effect, significantly decreasing grain width, grain weight, AAC, and plant height. Cytological observation of the outer epidermal cells of the lemma using a scanning electron microscope (SEM) revealed that increased grain length in the osnac129 mutant was due to increased cell length compared with wild-type (WT) plants. The expression of OsPGL1 and OsPGL2, two positive grain-size regulators that control cell elongation, was consistently upregulated in osnac129 mutant plants but downregulated in OsNAC129 overexpression plants. Furthermore, we also found that several starch synthase-encoding genes, including OsGBSSI, were upregulated in the osnac129 mutant and downregulated in the overexpression plants compared with WT plants, implying a negative regulatory role for OsNAC129 both in grain size and starch biosynthesis. Additionally, we found that the expression of OsNAC129 was induced exclusively by abscisic acid (ABA) in seedlings, but OsNAC129-overexpressing plants displayed reduced sensitivity to exogenous brassinolide (BR). Therefore, the results of our study demonstrate that OsNAC129 negatively regulates seed development and plant growth, and further suggest that OsNAC129 participates in the BR signaling pathway.
PMID: 35651773
Front Plant Sci , IF:5.753 , 2022 , V13 : P830349 doi: 10.3389/fpls.2022.830349
MdJa2 Participates in the Brassinosteroid Signaling Pathway to Regulate the Synthesis of Anthocyanin and Proanthocyanidin in Red-Fleshed Apple.
State Key Laboratory of Crop Biology, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, China.; Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production in Shandong, Tai'an, China.; College of Continuing Education, Shandong Agricultural University, Tai'an, China.
Anthocyanin and proanthocyanidin play important roles in plant secondary metabolism. Although previous studies identified many transcription factors involved in anthocyanin and proanthocyanidin synthesis, the effects of MADS-box transcription factors are unclear in apple. Brassinosteroids (BRs) are steroid hormones that affect plant flavonoid biosynthesis, but the underlying regulatory mechanism is not yet well established. In this study, we identified a MADS-box transcription factor, MdJa2, which contained a highly conserved MADS-box domain and belonged to the STMADS11 subfamily. Additionally, MdJa2 was responsive to BR signal, and the overexpression of MdJa2 inhibited the synthesis of anthocyanin and proanthocyanidin. The silencing of MdJa2 in "Orin" calli promoted anthocyanin and proanthocyanidin accumulations. Moreover, MdJa2 interacted with MdBZR1. MdJa2 was revealed to independently regulate anthocyanin and proanthocyanidin synthesis pathways. The MdJa2-MdBZR1 complex enhanced the binding of MdJa2 to the promoters of downstream target genes. Our research provides new insights into how MADS-box transcription factors in the BR signaling pathway control the accumulations of anthocyanin and proanthocyanidin in red-fleshed apple.
PMID: 35615132
Front Plant Sci , IF:5.753 , 2022 , V13 : P894710 doi: 10.3389/fpls.2022.894710
Overexpression of a Zea mays Brassinosteroid-Signaling Kinase Gene ZmBSK1 Confers Salt Stress Tolerance in Maize.
Provincial Key Laboratory of Agrobiology, Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, China.; College of Life Sciences, Nanjing Agricultural University, Nanjing, China.
Salinity has become a crucial environmental factor seriously restricting maize (Zea mays L.) growth, development and productivity. However, how plants respond to salt stress is still poorly understood. In this study, we report that a maize brassinosteroid-signaling kinase gene ZmBSK1 plays a significant role in salt stress response. Expression pattern analysis revealed that the transcript level of ZmBSK1 was upregulated by NaCl treatment both in maize leaves, roots, and stems. Phenotypic and physiological analysis showed that overexpression of ZmBSK1 in maize improved salt tolerance by reducing the malondialdehyde (MDA) content, the percentage of electrolyte leakage, O2 (-) and H2O2 accumulation under salt stress, relying on the increases of antioxidant defense enzyme activities and proline content. qRT-PCR analysis showed that overexpression of ZmBSK1 also positively modulated the expression levels of reactive oxygen species (ROS)-scavenging and proline biosynthesis-related genes under salt stress. Moreover, immunoprecipitation-mass spectrometry (IP-MS) assay and firefly luciferase complementation imaging (LCI) assay showed that ZmBSK1 could associate with heat shock protein ZmHSP8 and 14-3-3-like protein ZmGF14-6, and their gene expression levels could be significantly induced by NaCl treatment in different maize tissues. Our findings unravel the new function of ZmBSK1 in salt stress response, which provides the theoretical bases for the improvement of maize salt resistance.
PMID: 35599886
Plant Physiol Biochem , IF:4.27 , 2022 Jun , V185 : P325-335 doi: 10.1016/j.plaphy.2022.06.011
ZmBSK1 positively regulates BR-induced H2O2 production via NADPH oxidase and functions in oxidative stress tolerance in maize.
Provincial Key Laboratory of Agrobiology, Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, China.; Provincial Key Laboratory of Agrobiology, Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, China; College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.; Provincial Key Laboratory of Agrobiology, Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, China. Electronic address: chenyp@jaas.ac.cn.; Provincial Key Laboratory of Agrobiology, Institute of Food Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, China. Electronic address: yuanjh1123@163.com.
Brassinosteroid (BR) has been indicated to induce the production of hydrogen peroxide (H2O2) in plants in response to various environmental stimuli. However, it remains largely unknown how BR induces H2O2 production. In this study, we found that BR treatment significantly raised the kinase activity of maize (Zea mays L.) brassinosteroid-signaling kinase 1 (ZmBSK1) using the immunoprecipitation kinase assay. ZmBSK1 could modulate the gene expressions and activities of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (EC 1.6.3.1) to modulate BR-induced H2O2 production. BR could enhance the interaction between ZmBSK1 and maize calcium/calmodulin-dependent protein kinase (ZmCCaMK), a previously identified substrate of ZmBSK1. The BR-induced phosphorylation and kinase activity of ZmCCaMK are dependent on ZmBSK1. Moreover, we showed that ZmBSK1 regulated the NADPH oxidase gene expression and activity via directly phosphorylating ZmCCaMK. Genetic analysis suggested that ZmBSK1-ZmCCaMK module strengthened plant tolerance to oxidative stress induced by exogenous application of H2O2 through improving the activities of antioxidant defense enzyme and alleviating the malondialdehyde (MDA) accumulation and electrolyte leakage rate. In conclusion, these findings provide the new insights of ZmBSK1 functioning in BR-induced H2O2 production and the theoretical supports for breeding stress-tolerant crops.
PMID: 35738188
Plant Physiol Biochem , IF:4.27 , 2022 May , V185 : P69-79 doi: 10.1016/j.plaphy.2022.05.034
Integrated transcriptomic and gibberellin analyses reveal genes related to branch development in Eucalyptus urophylla.
Guangdong Provincial Key Laboratory of Silviculture, Protection and Utilization/Guangdong Academy of Forestry, Guangzhou, 510520, China.; Guangdong Provincial Key Laboratory of Silviculture, Protection and Utilization/Guangdong Academy of Forestry, Guangzhou, 510520, China. Electronic address: panwen@sinogaf.cn.; Guangdong Provincial Key Laboratory of Silviculture, Protection and Utilization/Guangdong Academy of Forestry, Guangzhou, 510520, China. Electronic address: xiaohuiyang@sinogaf.cn.
Tree branches affect the planting density and basal scab, which act as important attributes in the yield and quality of trees. Eucalyptus urophylla is an important pioneer tree with characteristics of strong adaptability, fast growth, short rotation period, and low disease and pest pressures. In this study, we collected ZQUC14 and LDUD26 clones and compared their transcriptomes and metabolomes from mature xylem, phloem, and developing tissues to identify factors that may influence branch development. In total, 32,809 differentially expressed genes (DEGs) and 18 gibberellin (GA) hormones were detected in the five sampled tissues. Searches of the kyoto Encyclopedia of Genes and Genomes pathways identified mainly genes related to diterpenoid biosynthesis, plant MAPK signaling pathways, plant hormone signal transduction, glycerolipid metabolism, peroxisome, phenylpropanoid biosynthesis, ABC transporters, and brassinosteroid biosynthesis. Furthermore, gene expression trend analysis and weighted gene co-expression network analysis revealed 13 genes likely involved in diterpenoid biosynthesis, including five members of the 2OG-Fe(II) oxygenase superfamily, four cytochrome P450 genes, and four novel genes. In GA signal transduction pathways, 24 DEGs were found to positively regulate branch formation. These results provide a comprehensive analysis of branch development based on the transcriptome and metabolome, and help clarify the molecular mechanisms of E. urophylla.
PMID: 35661587
BMC Plant Biol , IF:4.215 , 2022 May , V22 (1) : P246 doi: 10.1186/s12870-022-03619-4
Brassinosteroid-lipid membrane interaction under low and high temperature stress in model systems.
Institute of Biology, Pedagogical University, Podchorazych 2, 30-084, Krakow, Poland. elzbieta.rudolphi-szydlo@up.krakow.pl.; Institute of Biology, Pedagogical University, Podchorazych 2, 30-084, Krakow, Poland.; Polish Academy of Sciences, The Franciszek Gorski Institute of Plant Physiology, 30-239, Krakow, Poland.; Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Krakow, Poland.
BACKGROUND: In earlier studies [1], we indicated that applying brassinosteroids (BRs) to lipids that had been isolated from plants altered the physicochemical properties of the monolayers. A continuation of these dependencies using the defined model lipid systems is presented in this paper. The influence of homocastasterone (HCS) and castasterone (CS) (BRs for which the increase in concentration were characteristic of plants grown at low temperatures) on the membrane properties of their polar and the hydrophobic parts were studied. RESULTS: Changes in the electrokinetic potential indicate that both BRs decreased the negative charge of the surface, which is an important factor in modifying the contacts with the polar substances. This property of BRs has not yet been described. The studies of the interactions that occur in the hydrophobic part of the membrane were investigated using the EPR methods and Langmuir techniques. The physicochemical parameters of the lipid structure were determined, and the excess of Gibbs free energy was calculated. CONCLUSION: We conclude that examined BRs modify both the hydrophilic and hydrophobic properties of the membranes, but to a greater extent HCS. The consequence of these changes may be the attempt to maintain the stability of the membranes in stressful temperature conditions and / or to the possibility of adsorption of other substances on membranes surfaces. The change of plant metabolism towards increasing the amount of BR, mainly HCS (under cooling) may by an important factor for maintaining optimal structural properties of membranes and their functionality despite temperature changes.
PMID: 35585507
Membranes (Basel) , IF:4.106 , 2022 Jun , V12 (6) doi: 10.3390/membranes12060606
Plasma Membrane-Associated Proteins Identified in Arabidopsis Wild Type, lbr2-2 and bak1-4 Mutants Treated with LPSs from Pseudomonas syringae and Xanthomonas campestris.
Department of Biochemistry, University of Johannesburg, Auckland Park, Johannesburg 2006, South Africa.
Plants recognise bacterial microbe-associated molecular patterns (MAMPs) from the environment via plasma membrane (PM)-localised pattern recognition receptor(s) (PRRs). Lipopolysaccharides (LPSs) are known as MAMPs from gram-negative bacteria that are most likely recognised by PRRs and trigger defence responses in plants. The Arabidopsis PRR(s) and/or co-receptor(s) complex for LPS and the associated defence signalling remains elusive. As such, proteomic identification of LPS receptors and/or co-receptor complexes will help to elucidate the molecular mechanisms that underly LPS perception and defence signalling in plants. The Arabidopsis LPS-binding protein (LBP) and bactericidal/permeability-increasing protein (BPI)-related-2 (LBR2) have been shown to recognise LPS and trigger defence responses while brassinosteroid insensitive 1 (BRI1)-associated receptor kinase 1 (BAK1) acts as a co-receptor for several PRRs. In this study, Arabidopsis wild type (WT) and T-DNA knock out mutants (lbr2-2 and bak1-4) were treated with LPS chemotypes from Pseudomonas syringae pv. tomato DC3000 (Pst) and Xanthomonas campestris pv. campestris 8004 (Xcc) over a 24 h period. The PM-associated protein fractions were separated by liquid chromatography and analysed by tandem mass spectrometry (LC-MS/MS) followed by data analysis using Byonic(TM) software. Using Gene Ontology (GO) for molecular function and biological processes, significant LPS-responsive proteins were grouped according to defence and stress response, perception and signalling, membrane transport and trafficking, metabolic processes and others. Venn diagrams demarcated the MAMP-responsive proteins that were common and distinct to the WT and mutant lines following treatment with the two LPS chemotypes, suggesting contributions from differential LPS sub-structural moieties and involvement of LBR2 and BAK1 in the LPS-induced MAMP-triggered immunity (MTI). Moreover, the identification of RLKs and RLPs that participate in other bacterial and fungal MAMP signalling proposes the involvement of more than one receptor and/or co-receptor for LPS perception as well as signalling in Arabidopsis defence responses.
PMID: 35736313
Genes (Basel) , IF:4.096 , 2022 May , V13 (5) doi: 10.3390/genes13050853
Overexpression of LT, an Oncoprotein Derived from the Polyomavirus SV40, Promotes Somatic Embryogenesis in Cotton.
Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Zhongguancun, Nandajie No. 12, Haidian District, Beijing 100081, China.; College of Life Sciences, Inner Mongolia University, University West Street No. 235, Saihan District, Hohhot 010000, China.
Although genetic transformation has opened up a new era for cotton molecular breeding, it still suffers from the limitation problem of long transformation periods, which slows down the generation of new cotton germplasms. In this study, LT gene (SV40 large T antigen), which promotes the transformation efficiency of animal cells, was codon-optimized. Its overexpression vector was transformed into cotton. It was observed that EC (embryogenic callus) formation period was 33% shorter and transformation efficiency was slightly higher in the LT T0 generation than that of control. RNA-seq data of NEC (non-embryonic callus) and EC from LT and control revealed that more DEGs (differential expression genes) in NEC were identified than that of EC, indicating LT mainly functioned in NEC. Further KEGG, GO, and transcription factor analyses showed that DEGs were significantly enriched in brassinosteroid biosynthesis pathways and that bHLH, MYB, and AP2/ERF were the top three gene families, which are involved in EC formation. In addition, the key genes related to the auxin pathway were differentially expressed only in LT overexpression NEC, which caused early response, biosynthesis, and transportation of the hormone, resulting in EC earlier formation. In summary, the results demonstrated that LT can promote somatic embryogenesis in cotton, which provides a new strategy for improving cotton transformation and shortening EC formation time.
PMID: 35627238
Plant Mol Biol , IF:4.076 , 2022 Jun , V109 (3) : P249-269 doi: 10.1007/s11103-020-01033-8
Integrative omics approaches revealed a crosstalk among phytohormones during tuberous root development in cassava.
RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan. yoshinori.utsumi@riken.jp.; RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.; RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.; Faculty of Agriculture, Yamagata University, Tsuruoka, Japan.; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan.; Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Chiba, 260-8675, Japan.; Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601, Japan.; Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok, Thailand.; RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan. motoaki.seki@riken.jp.; RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan. motoaki.seki@riken.jp.; Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-cho, Totsuka-ku, Yokohama, Kanagawa, 244-0813, Japan. motoaki.seki@riken.jp.
KEY MESSAGE: Integrative omics approaches revealed a crosstalk among phytohormones during tuberous root development in cassava. Tuberous root formation is a complex process consisting of phase changes as well as cell division and elongation for radial growth. We performed an integrated analysis to clarify the relationships among metabolites, phytohormones, and gene transcription during tuberous root formation in cassava (Manihot esculenta Crantz). We also confirmed the effects of the auxin (AUX), cytokinin (CK), abscisic acid (ABA), jasmonic acid (JA), gibberellin (GA), brassinosteroid (BR), salicylic acid, and indole-3-acetic acid conjugated with aspartic acid on tuberous root development. An integrated analysis of metabolites and gene expression indicated the expression levels of several genes encoding enzymes involved in starch biosynthesis and sucrose metabolism are up-regulated during tuberous root development, which is consistent with the accumulation of starch, sugar phosphates, and nucleotides. An integrated analysis of phytohormones and gene transcripts revealed a relationship among AUX signaling, CK signaling, and BR signaling, with AUX, CK, and BR inducing tuberous root development. In contrast, ABA and JA inhibited tuberous root development. These phenomena might represent the differences between stem tubers (e.g., potato) and root tubers (e.g., cassava). On the basis of these results, a phytohormonal regulatory model for tuberous root development was constructed. This model may be useful for future phytohormonal studies involving cassava.
PMID: 32757126
BMC Genomics , IF:3.969 , 2022 Jun , V23 (1) : P453 doi: 10.1186/s12864-022-08684-5
Genome-wide identification and expression analysis reveals spinach brassinosteroid-signaling kinase (BSK) gene family functions in temperature stress response.
Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China.; Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China. zhangheng1029@163.com.; Key Laboratory of Saline-alkali Vegetation Ecology Restoration (Northeast Forestry University), Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin, 150040, China.; State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, China.; Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China. daishaojun@shnu.edu.cn.
BACKGROUND: Brassinosteroid (BR)- signaling kinase (BSK) is a critical family of receptor-like cytoplasmic kinase for BR signal transduction, which plays important roles in plant development, immunity, and abiotic stress responses. Spinach (Spinacia oleracea) is cold- tolerant but heat- sensitive green leafy vegetable. A study on BSK family members and BSKs- mediated metabolic processes in spinach has not been performed. RESULTS: We identified and cloned seven SoBSKs in spinach. Phylogenetic and collinearity analyses suggested that SoBSKs had close relationship with dicotyledonous sugar beet (Beta vulgaris) rather than monocotyledons. The analyses of gene structure and conserved protein domain/ motif indicated that most SoBSKs were relative conserved, while SoBSK6 could be a truncated member. The prediction of post-translation modification (PTM) sites in SoBSKs implied their possible roles in signal transduction, redox regulation, and protein turnover of SoBSKs, especially the N-terminal myristoylation site was critical for BSK localization to cell periphery. Cis-acting elements for their responses to light, drought, temperature (heat and cold), and hormone distributed widely in the promoters of SoBSKs, implying the pivotal roles of SoBSKs in response to diverse abiotic stresses and phytohormone stimuli. Most SoBSKs were highly expressed in leaves, except for SoBSK7 in roots. Many SoBSKs were differentially regulated in spinach heat- sensitive variety Sp73 and heat- tolerant variety Sp75 under the treatments of heat, cold, as well as exogenous brassinolide (BL) and abscisic acid (ABA). The bsk134678 mutant Arabidopsis seedlings exhibited more heat tolerance than wild- type and SoBSK1- overexpressed seedlings. CONCLUSIONS: A comprehensive genome- wide analysis of the BSK gene family in spinach presented a global identification and functional prediction of SoBSKs. Seven SoBSKs had relatively- conserved gene structure and protein function domains. Except for SoBSK6, all the other SoBSKs had similar motifs and conserved PTM sites. Most SoBSKs participated in the responses to heat, cold, BR, and ABA. These findings paved the way for further functional analysis on BSK- mediated regulatory mechanisms in spinach development and stress response.
PMID: 35725364
Plants (Basel) , IF:3.935 , 2022 May , V11 (10) doi: 10.3390/plants11101307
Genome-Wide Identification and Expression Analysis of Homeodomain Leucine Zipper Subfamily IV (HD-ZIP IV) Gene Family in Cannabis sativa L.
Agricultural Biotechnology Laboratory, Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, CT 06269, USA.; Mydecine Innovations Group Inc., Denver, CO 80231, USA.
The plant-specific homeodomain zipper family (HD-ZIP) of transcription factors plays central roles in regulating plant development and environmental resistance. HD-ZIP transcription factors IV (HDZ IV) have been involved primarily in the regulation of epidermal structure development, such as stomata and trichomes. In our study, we identified nine HDZ IV-encoding genes in Cannabis sativa L. by conducting a computational analysis of cannabis genome resources. Our analysis suggests that these genes putatively encode proteins that have all the conserved domains of HDZ IV transcription factors. The phylogenetic analysis of HDZ IV gene family members of cannabis, rice (Oryza sativa), and Arabidopsis further implies that they might have followed distinct evolutionary paths after divergence from a common ancestor. All the identified cannabis HDZ IV gene promoter sequences have multiple regulation motifs, such as light- and hormone-responsive elements. Furthermore, experimental evidence shows that different HDZ IV genes have different expression patterns in root, stem, leaf, and flower tissues. Four genes were primarily expressed in flowers, and the expression of CsHDG5 (XP_030501222.1) was also correlated with flower maturity. Fifty-nine genes were predicted as targets of HDZ IV transcription factors. Some of these genes play central roles in pathogen response, flower development, and brassinosteroid signaling. A subcellular localization assay indicated that one gene of this family is localized in the Arabidopsis protoplast nucleus. Taken together, our work lays fundamental groundwork to illuminate the function of cannabis HDZ IV genes and their possible future uses in increasing cannabis trichome morphogenesis and secondary metabolite production.
PMID: 35631732
Biosci Biotechnol Biochem , IF:2.043 , 2022 Jun doi: 10.1093/bbb/zbac074
Structure modification of nonsteroidal brassinolide-like compound, NSBR1.
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.; Central Pharmaceutical Research Institute, Japan Tobacco Inc., 1-1 Murasaki-cho, Takatsuki, Osaka, Japan.; Graduate School of Biostudies, Kyoto University, Kyoto, Japan.
Brassinolide (BL) is a possible plant growth regulator in agriculture, but the presence of a steroid skeleton hampers the field application of BL in agriculture because of its high synthetic cost. We discovered NSBR1 as the first nonsteroidal BL-like compound using in silico technology. Searching for more potent BL-like compounds, we modified the structure of NSBR1 with respect to two benzene rings and the piperazine ring. The activity of synthesized compounds was measured in Arabidopsis hypocotyl elongation. The propyl group of butyryl moiety of NSBR1 was changed to various alkyl groups, such as straight, branched, and cyclic alkyl chains. Another substituent, F, at the ortho-position of the B-ring toward the piperazine ring was changed to other substituents. A methyl group was introduced to the piperazine ring. Most of the newly synthesized compounds with the 3,4-(OH)2 group at the A-ring significantly elongated the hypocotyl of Arabidopsis.
PMID: 35687006
Biosci Biotechnol Biochem , IF:2.043 , 2022 May doi: 10.1093/bbb/zbac071
BRZ-INSENSITIVE-PALE GREEN 1 is encoded by chlorophyll biosynthesis enzyme gene that functions in the downstream of brassinosteroid signaling.
Graduate School of Biostudies, Kyoto University, KItashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, Japan.; Department of Biology, Ochanomizu University, Bunkyo-ku, Tokyo, Japan.; RIKEN, CSRS, Tsurumi-ku, Yokohama, Japan.; The Institute of Oncology, Riga Stradins University, 16 Dzirciema Street, Riga, LV-1007, Latvia.; Organization for the Strategic Coordination of Research and Intellectual Properties, Meiji University, Tama-ku, Kawasaki, Japan.; Institute of Low Temperature Science, Hokkaido University, Kita-ku, Sapporo, Japan.; Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Brassinosteroids (BRs), a kind of phytohormone, have various biological activities such as promoting of plant growth, increasing of stress resistance, and chloroplast development. Though BRs have been known to have physiological effects on chloroplast, the detailed mechanism of chloroplast development and chlorophyll biosynthesis in BR signaling remains unknown. Here we identified a recessive pale green Arabidopsis mutant, Brz-insensitive-pale green1 (bpg1), which was insensitive to promoting of greening by BR biosynthesis-specific inhibitor Brz in the light. BPG1 gene encoded chlorophyll biosynthesis enzyme, 3, 8-divinyl protochlorophyllide a 8-vinyl reductase (DVR), and bpg1 accumulated divinyl chlorophylls. Chloroplast development was suppressed in bpg1. Brz dramatically increased the expression of chlorophyll biosynthesis enzyme genes, including BPG1. These results suggest that chlorophyll biosynthesis enzymes are regulated by BR signaling in the aspect of gene expression and BPG1 plays an important role in regulating of chloroplast development.
PMID: 35583242
Genes Genomics , IF:1.839 , 2022 Jul , V44 (7) : P833-841 doi: 10.1007/s13258-022-01266-5
Role of tyrosine autophosphorylation and methionine residues in BRI1 function in Arabidopsis thaliana.
Department of Biological Sciences, Chungnam National University, Daejeon, 34134, Korea.; Department of Environmental Horticulture, Dankook University, Cheonan, 31116, Korea.; Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, USA.; Department of Biological Sciences, Chungnam National University, Daejeon, 34134, Korea. manhooh@cnu.ac.kr.
BACKGROUND: Brassinosteroids (BRs), a group of plant growth hormones, control biomass accumulation and biotic and abiotic stress tolerance, and therefore are highly relevant to agriculture. BRs bind to the BR receptor protein, brassinosteroid insensitive 1 (BRI1), which is classified as a serine/threonine (Ser/Thr) protein kinase. Recently, we reported that BRI1 acts as a dual-specificity kinase both in vitro and in vivo by undergoing autophosphorylation at tyrosine (Tyr) residues. OBJECTIVE: In this study, we characterized the increased leaf growth and early flowering phenotypes of transgenic lines expressing the mutated recombinant protein, BRI1(Y831F)-Flag, compared with those expressing BRI1-Flag. BRI1(Y831F)-Flag transgenic plants showed a reduction in hypocotyl and petiole length compared with BRI1-Flag seedlings. Transcriptome analysis revealed differential expression of flowering time-associated genes (AP1, AP2, AG, FLC, and SMZ) between BRI1(Y831F)-Flag and BRI1-Flag transgenic seedlings. We also performed site-directed mutagenesis of the BRI1 gene, and investigated the effect of methionine (Met) substitution in the extracellular domain (ECD) of BRI1 on plant growth and BR sensitivity by evaluating hypocotyl elongation and root growth inhibition. METHODS: The pBIB-Hyg(+)-pBR-BRI1-Flag construct(Li et al. 2002) was used as the template for SDM with QuickChange XL Site Directed Mutagenesis Kit (Stratagene, La Jolla, CA, USA) to make the SDM mutants. After PCR with SDM kit, add 1 mul of Dpn1 to PCR reaction. Incubate at 37 degrees C for 2 h to digest parental DNA and then transformed into XL10-gold competent cells. Transcriptome analysis was carried out at the University of Illinois (Urbana-Champaign, Illinois, USA). RNA was prepared and hybridized to the Affymetrix GeneChip Arabidopsis ATH1 Genome Array using the Gene Chip Express Kit (Ambion, Austin, TX, USA). RESULTS: Tyrosine 831 autophosphorylation of BRI1 regulates Arabidopsis flowering time, and mutation of methionine residues in the extracellular domain of BRI1 affects hypocotyl and root length. BRI1(M656Q)-Flag, BRI1(M657Q)-Flag, and BRI1(M661Q)-Flag seedlings were insensitive to the BL treatment and showed no inhibition of root elongation. However, BRI1(M665Q)-Flag and BRI1(M671Q)-Flag seedlings were sensitive to the BL treatment, and exhibited root elongation inhibition. the early flowering phenotype of BRI1(Y831F)-Flag transgenic plants is consistent with the expression levels of key flowering-related genes, including those promoting flowering (AP1, AP2, and AG) and repressing flowering (FLC and SMZ).
PMID: 35598220
Plant Commun , 2022 Jun : P100348 doi: 10.1016/j.xplc.2022.100348
Deubiquitination of BES1 by UBP12/UBP13 promotes brassinosteroid signaling and plant growth.
Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore.; Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore; Present address: Wilmar International Limited, 28 Biopolis Road, Singapore 138568, Singapore.; Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore. Electronic address: chua@rockefeller.edu.
As a key transcription factor of the brassinosteroid (BR) signaling pathway, BES1 (BRI1-EMS-SUPPRESSOR 1) activity and expression are stringently regulated. BES1 degradation is mediated by ubiquitin-related 26S proteasomal and autophagy pathways, which attenuate and terminate BR signaling; however, the opposing deubiquitinases (DUBs) are still unknown. Here, we showed that the ubp12-2w/13-3 double mutant phenocopies BR-deficient dwarf mutant suggesting the two DUBs, UBP12/UBP13, antagonize ubiquitin-mediated degradation to stabilize BES1. These two DUBs can trim tetraubiquitin with K46- and K63-linkages in vitro. UBP12/BES1 and UBP13/BES1 complexes are localized in both cytosol and nuclei. UBP12/13 can deubiquitinate polyubiquitinated BES1 in vitro and in planta, and UBP12 interacts with and deubiquitinates both inactive, phosphorylated BES1 and active, dephosphorylated BES1 in vivo. UBP12 overexpression in BES1(OE) plants significantly enhances cell elongation in hypocotyls and petioles and increases the ratio of leaf length to width compared to BES1(OE) or UBP12(OE) plants. The hypocotyl elongation and etiolation result from elevated BES1 levels because BES1 degradation is retarded by UBP12 in darkness or in the light with BR. Protein degradation inhibitor experiments show the majority of BES1 can be degraded by either the proteasomal or the autophagy pathway but a minor BES1 fraction remains pathway-specific. In conclusion, UBP12/UBP13 deubiquitinate BES1 to stabilize the latter as a positive regulator for BR responses.
PMID: 35706355
Proteomes , 2022 May , V10 (2) doi: 10.3390/proteomes10020017
Wheat Proteomics for Abiotic Stress Tolerance and Root System Architecture: Current Status and Future Prospects.
UWA School of Agriculture and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.; The UWA Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.; Department of Genetics and Plant Breeding, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka 1207, Bangladesh.; ICAR-Indian Institute of Maize Research, Ludhiana 141001, India.
Wheat is an important staple cereal for global food security. However, climate change is hampering wheat production due to abiotic stresses, such as heat, salinity, and drought. Besides shoot architectural traits, improving root system architecture (RSA) traits have the potential to improve yields under normal and stressed environments. RSA growth and development and other stress responses involve the expression of proteins encoded by the trait controlling gene/genes. Hence, mining the key proteins associated with abiotic stress responses and RSA is important for improving sustainable yields in wheat. Proteomic studies in wheat started in the early 21st century using the two-dimensional (2-DE) gel technique and have extensively improved over time with advancements in mass spectrometry. The availability of the wheat reference genome has allowed the exploration of proteomics to identify differentially expressed or abundant proteins (DEPs or DAPs) for abiotic stress tolerance and RSA improvement. Proteomics contributed significantly to identifying key proteins imparting abiotic stress tolerance, primarily related to photosynthesis, protein synthesis, carbon metabolism, redox homeostasis, defense response, energy metabolism and signal transduction. However, the use of proteomics to improve RSA traits in wheat is in its infancy. Proteins related to cell wall biogenesis, carbohydrate metabolism, brassinosteroid biosynthesis, and transportation are involved in the growth and development of several RSA traits. This review covers advances in quantification techniques of proteomics, progress in identifying DEPs and/or DAPs for heat, salinity, and drought stresses, and RSA traits, and the limitations and future directions for harnessing proteomics in wheat improvement.
PMID: 35645375