Nat Rev Mol Cell Biol , IF:94.444 , 2024 May , V25 (5) : P340-358 doi: 10.1038/s41580-023-00691-y
Structure and growth of plant cell walls.
Department of Biology, Pennsylvania State University, University Park, Pennsylvania, USA. dcosgrove@psu.edu.
Plant cells build nanofibrillar walls that are central to plant growth, morphogenesis and mechanics. Starting from simple sugars, three groups of polysaccharides, namely, cellulose, hemicelluloses and pectins, with very different physical properties are assembled by the cell to make a strong yet extensible wall. This Review describes the physics of wall growth and its regulation by cellular processes such as cellulose production by cellulose synthase, modulation of wall pH by plasma membrane H(+)-ATPase, wall loosening by expansin and signalling by plant hormones such as auxin and brassinosteroid. In addition, this Review discusses the nuanced roles, properties and interactions of cellulose, matrix polysaccharides and cell wall proteins and describes how wall stress and wall loosening cooperatively result in cell wall growth.
PMID: 38102449
Plant Cell , IF:11.277 , 2024 May doi: 10.1093/plcell/koae147
A transthyretin-like protein acts downstream of miR397 and LACCASE to regulate grain yield in rice.
Guangdong Provincial Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol, School of Life Science, Sun Yat-Sen University, Guangzhou 510275, P. R. China.; Guangdong Key Laboratory of Crop Germplasm Resources Preservation and Utilization, Key Laboratory of South China Modern Biological Seed Industry, Ministry of Agriculture and Rural Affairs, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, P. R. China.; Guangdong Key Laboratory of New Technology in Rice Breeding, Guangdong Rice Engineering Laboratory, Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, P. R. China.
Increasing grain yield is a major goal of breeders due to the rising global demand for food. We previously reported that the miR397-LACCASE (OsLAC) module regulates brassinosteroid (BR) signaling and grain yield in rice (Oryza sativa). However, the precise roles of laccase enzymes in the BR pathway remain unclear. Here, we report that OsLAC controls grain yield by preventing the turnover of TRANSTHYRETIN-LIKE (OsTTL), a negative regulator of BR signaling. Overexpressing OsTTL decreased BR sensitivity in rice, while loss-of-function of OsTTL led to enhanced BR signaling and increased grain yield. OsLAC directly binds to OsTTL and regulates its phosphorylation-mediated turnover. The phosphorylation site Ser226 of OsTTL is essential for its ubiquitination and degradation. Overexpressing the dephosphorylation-mimic form of OsTTL (OsTTLS226A) resulted in more severe defects than did overexpressing OsTTL. These findings provide insight into the role of an ancient laccase in BR signaling and suggest that the OsLAC-OsTTL module could serve as a target for improving grain yield.
PMID: 38735686
Plant Cell , IF:11.277 , 2024 May , V36 (6) : P2059-2060 doi: 10.1093/plcell/koae080
More Pi, anyone? Interplay between brassinosteroid signaling and the phosphate starvation response.
Assistant Features Editor, The Plant Cell, American Society of Plant Biologists.; Department of Developmental Genetics, Heinrich-Heine University, 40225 Dusseldorf, Germany.
PMID: 38478722
Plant Cell , IF:11.277 , 2024 May , V36 (6) : P2103-2116 doi: 10.1093/plcell/koae049
Heat-induced SUMOylation differentially affects bacterial effectors in plant cells.
Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou 510631, China.; Shenzhen Institute of Molecular Crop Design, Shenzhen 518107, China.; Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Bacterial pathogens deliver effectors into host cells to suppress immunity. How host cells target these effectors is critical in pathogen-host interactions. SUMOylation, an important type of posttranslational modification in eukaryotic cells, plays a critical role in immunity, but its effect on bacterial effectors remains unclear in plant cells. In this study, using bioinformatic and biochemical approaches, we found that at least 16 effectors from the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 are SUMOylated by the enzyme cascade from Arabidopsis thaliana. Mutation of SUMOylation sites on the effector HopB1 enhances its function in the induction of plant cell death via stability attenuation of a plant receptor kinase BRASSINOSTEROID INSENSITIVE 1 (BRI1)-ASSOCIATED RECEPTOR KINASE 1. By contrast, SUMOylation is essential for the function of another effector, HopG1, in the inhibition of mitochondria activity and jasmonic acid signaling. SUMOylation of both HopB1 and HopG1 is increased by heat treatment, and this modification modulates the functions of these 2 effectors in different ways in the regulation of plant survival rates, gene expression, and bacterial infection under high temperatures. Therefore, the current work on the SUMOylation of effectors in plant cells improves our understanding of the function of dynamic protein modifications in plant-pathogen interactions in response to environmental conditions.
PMID: 38445983
Plant Cell , IF:11.277 , 2024 May , V36 (6) : P2253-2271 doi: 10.1093/plcell/koae063
Brassinosteroid-dependent phosphorylation of PHOSPHATE STARVATION RESPONSE2 reduces its DNA-binding ability in rice.
Guangdong Laboratory for Lingnan Modern Agriculture, and the State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou 510642, China.; Key Laboratory for Enhancing Resource Use Efficiency of Crops in South China, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou 510642, China.; Guangdong Key Laboratory of Plant Molecular Breeding, South China Agricultural University, Guangzhou 510642, China.; State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.; Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518000, China.; Division of Hematology/Oncology, Department of Pediatrics, Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02138, USA.; State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Brassinosteroids (BRs) are widely used as plant growth regulators in modern agriculture. Understanding how BRs regulate nutrient signaling is crucial for reducing fertilizer usage. Here we elucidate that the central BR signaling inhibitor GSK3/SHAGGY-LIKE KINASE2 (GSK2) interacts directly with and phosphorylates PHOSPHATE STARVATION RESPONSE2 (OsPHR2), the key regulator of phosphate (Pi) signaling, to suppress its transcription factor activity in rice (Oryza sativa). We identify a critical phosphorylation site at serine residue S269 of OsPHR2 and demonstrate that phosphorylation by GSK2 or phosphor-mimic mutation of S269 substantially impairs the DNA-binding activity of OsPHR2, and thus diminishes expression of OsPHR2-induced genes and reduces Pi levels. Like BRs, Pi starvation noticeably induces GSK2 instability. We further show that this site-specific phosphorylation event is conserved in Arabidopsis (Arabidopsis thaliana), but varies among the PHR-family members, being present only in most land plants. These results unveil a distinctive post-transcriptional regulatory mechanism in Pi signaling by which BRs promote Pi acquisition, with a potential contribution to the environmental adaptability of plants during their evolution.
PMID: 38416876
Curr Biol , IF:10.834 , 2024 May , V34 (9) : P1977-1986.e8 doi: 10.1016/j.cub.2024.03.029
A hemizygous supergene controls homomorphic and heteromorphic self-incompatibility systems in Oleaceae.
CRBE (Centre de Recherche sur la Biodiversite et l'Environnement), UMR 5300, CNRS, Universite Paul Sabatier, IRD, INP Toulouse, 118 Route de Narbonne, 31062 Toulouse, France; Yale Institute of Biospheric Studies, New Haven, CT 06520, USA.; CRBE (Centre de Recherche sur la Biodiversite et l'Environnement), UMR 5300, CNRS, Universite Paul Sabatier, IRD, INP Toulouse, 118 Route de Narbonne, 31062 Toulouse, France.; INRAE, Centre National de Ressources Genomiques Vegetales, 31326 Castanet-Tolosan, France.; CEFE (Centre d'Ecologie Fonctionnelle et Evolutive), UMR 5175, CNRS, Universite de Montpellier, Universite Paul Valery, EPHE, IRD, 34293 Montpellier, France.; INRAE, US 1426, GeT-PlaGe, Genotoul, 31326 Castanet-Tolosan, France.; Laboratoire de Recherche sur les Zones Arides, USTHB/ENSA, 16000 Alger, Algeria.; Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK.; CRBE (Centre de Recherche sur la Biodiversite et l'Environnement), UMR 5300, CNRS, Universite Paul Sabatier, IRD, INP Toulouse, 118 Route de Narbonne, 31062 Toulouse, France. Electronic address: guillaume.besnard@univ-tlse3.fr.
Self-incompatibility (SI) has evolved independently multiple times and prevents self-fertilization in hermaphrodite angiosperms. Several groups of Oleaceae such as jasmines exhibit distylous flowers, with two compatibility groups each associated with a specific floral morph.(1) Other Oleaceae species in the olive tribe have two compatibility groups without associated morphological variation.(2)(,)(3)(,)(4)(,)(5) The genetic basis of both homomorphic and dimorphic SI systems in Oleaceae is unknown. By comparing genomic sequences of three olive subspecies (Olea europaea) belonging to the two compatibility groups, we first locate the genetic determinants of SI within a 700-kb hemizygous region present only in one compatibility group. We then demonstrate that the homologous hemizygous region also controls distyly in jasmine. Phylogenetic analyses support a common origin of both systems, following a segmental genomic duplication in a common ancestor. Examination of the gene content of the hemizygous region in different jasmine and olive species suggests that the mechanisms determining compatibility groups and floral phenotypes (whether homomorphic or dimorphic) in Oleaceae rely on the presence/absence of two genes involved in gibberellin and brassinosteroid regulation.
PMID: 38626764
J Hazard Mater , IF:10.588 , 2024 May , V473 : P134625 doi: 10.1016/j.jhazmat.2024.134625
The role of OsBZR4 as a brassinosteroid-signaling component in mediating atrazine and isoproturon degradation in rice.
Research Institute of Plant Protection, Guangdong Academy of Agricultural Sciences & Key Laboratory of Green Prevention and Control of Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs & Key Laboratory of High Technology for Plant Protection of Guangdong Province, Guangzhou 510640, China. Electronic address: suxiangning@gdppri.com.; Research Institute of Plant Protection, Guangdong Academy of Agricultural Sciences & Key Laboratory of Green Prevention and Control of Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs & Key Laboratory of High Technology for Plant Protection of Guangdong Province, Guangzhou 510640, China.; Institute of Agricultural Facilities and Equipment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.; Research Institute of Plant Protection, Guangdong Academy of Agricultural Sciences & Key Laboratory of Green Prevention and Control of Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs & Key Laboratory of High Technology for Plant Protection of Guangdong Province, Guangzhou 510640, China. Electronic address: zhangyp@gdppri.cn.
Development of a biotechnological system for rapid degradation of pesticides is important to mitigate the environmental, food security, and health risks that they pose. Degradation of atrazine (ATZ) and isoproturon (IPU) in rice crops promoted by the brassinosteroid (BR) signaling component BRASSINAZOLE RESISTANT4 (OsBZR4) is explored. OsBZR4 is localized in the plasma membrane and nucleus, and is strongly induced by ATZ and IPU exposure. Transgenic rice OsBZR4-overexpression (OE) significantly enhances resistance to ATZ and IPU toxicity, improving growth, and reducing ATZ and IPU accumulation (particularly in grains) in rice crops. Genetic destruction of OsBZR4 (CRISPR/Cas9) increases rice sensitivity and leads to increased accumulation of ATZ and IPU. OE plants promote phase I, II, and III metabolic reactions, and expression of corresponding pesticide degradation genes under ATZ and IPU stress. UPLC-Q-TOF-MS/MS analysis reveals increased relative contents of ATZ and IPU metabolites and conjugates in OE plants, suggesting an increased OsBZR4 expression and consequent detoxification of ATZ and IPU in rice and the environment. The role of OsBZR4 in pesticide degradation is revealed, and its potential application in enhancing plant resistance to pesticides, and facilitating the breakdown of pesticides in rice and the environment, is discussed.
PMID: 38759408
J Hazard Mater , IF:10.588 , 2024 May , V469 : P133862 doi: 10.1016/j.jhazmat.2024.133862
Brassinosteroid decreases cadmium accumulation via regulating gibberellic acid accumulation and Cd fixation capacity of root cell wall in rice (Oryza sativa).
School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China.; School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China.; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China.; School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China. Electronic address: jhuang@cumt.edu.cn.
The precise mechanism behind the association between plants' reactions to cadmium (Cd) stress and brassinosteroid (BR) remains unclear. In the current investigation, Cd stress quickly increased the endogenous BR concentration in the rice roots. Exogenous BR also increased the hemicellulose level in the root cell wall, which in turn increased its capacity to bind Cd. Simultaneously, the transcription level of genes responsible for root Cd absorption was decreased, including Natural Resistance-Associated Macrophage Protein 1/5 (OsNRAMP1/5) and a major facilitator superfamily gene called OsCd1. Ultimately, the increased expression of Heavy Metal ATPase 3 (OsHMA3) and the decreased expression of OsHMA2, which was in charge of separating Cd into vacuoles and translocating Cd to the shoots, respectively, led to a decrease in the amount of Cd that accumulated in the rice shoots. In contrast, transgenic rice lines overexpressing OsGSK2 (a negative regulator in BR signaling) accumulated more Cd, while OsGSK2 RNA interference (RNAi) rice line accumulated less Cd. Furthermore, BR increased endogenous Gibberellic acid (GA) level, and applying GA could replicate its alleviative effect. Taken together, BR decreased Cd accumulation in rice by mediating the cell wall's fixation capacity to Cd, which might relied on the buildup of the GA.
PMID: 38432090
Plant Physiol , IF:8.34 , 2024 May doi: 10.1093/plphys/kiae286
Effector Cs02526 from Ciboria shiraiana induces cell death and modulates plant immunity.
State Key Laboratory of Resource Insects, Institute of Sericulture and Systems Biology, Southwest University, Chongqing 400715, China.; Resource Institute for Chinese & Ethnic Materia Medica, Guizhou University of Traditional Chinese Medicine, Guiyang 550025, China.; Institute of Environment and Plant Protection, Chinese Academy of Tropical Agricultural Sciences, Haikou 570100, China.
Sclerotinia disease is one of the most devastating fungal diseases worldwide, as it reduces the yields of many economically important crops. Pathogen-secreted effectors play crucial roles in infection processes. However, key effectors of Ciboria shiraiana, the pathogen primarily responsible for sclerotinia disease in mulberry (Morus spp.), remain poorly understood. In this study, we identified and functionally characterized the effector Cs02526 in C. shiraiana and found that Cs02526 could induce cell deathin a variety of plants. Moreover, Cs02526-induced cell death was mediated by the central immune regulator BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1 (BAK1), dependent on a 67-amino acid fragment. Notably, Cs02526 homologues were widely distributed in hemibiotrophic and necrotrophic phytopathogenic fungi, but the homologues failed to induce cell death in plants. Pre-treatment of plants with recombinant Cs02526 protein enhanced resistance against both C. shiraiana and Sclerotinia sclerotiorum. Furthermore, the pathogenicity of C. shiraiana was diminished upon spraying plants with synthetic dsRNA-Cs02526. In conclusion, our findings highlight the cell death-inducing effector Cs02526 as a potential target for future biological control strategies against plant diseases.
PMID: 38753366
Plant Physiol , IF:8.34 , 2024 May doi: 10.1093/plphys/kiae147
A maize semidwarf mutant reveals a GRAS transcription factor involved in brassinosteroid signaling.
Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907 USA.; Center for Plant Biology, Purdue University, West Lafayette, Indiana 47907 USA.; Plant Genetics Research Unit, USDA-ARS, Columbia, Missouri 65211 USA.; Institute for Molecular Physiology, Heinrich-Heine-Universitat Dusseldorf, 40225 Dusseldorf, Germany.; Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, USA.; University of Maryland, Department of Plant Science and Landscape Architecture, College Park, MD 20742 USA.
Brassinosteroids (BR) and gibberellins (GA) regulate plant height and leaf angle in maize (Zea mays). Mutants with defects in BR or GA biosynthesis or signaling identify components of these pathways and enhance our knowledge about plant growth and development. In this study, we characterized three recessive mutant alleles of GRAS transcription factor 42 (gras42) in maize, a GRAS transcription factor gene orthologous to the DWARF AND LOW TILLERING (DLT) gene of rice (Oryza sativa). These maize mutants exhibited semi-dwarf stature, shorter and wider leaves, and more upright leaf angle. Transcriptome analysis revealed a role for GRAS42 as a determinant of BR signaling. Analysis of the expression consequences from loss of GRAS42 in the gras42-mu1021149 mutant indicated a weak loss of BR signaling in the mutant, consistent with its previously demonstrated role in BR signaling in rice. Loss of BR signaling was also evident by the enhancement of weak BR biosynthetic mutant alleles in double mutants of nana plant1-1 and gras42-mu1021149. The gras42-mu1021149 mutant had little effect on GA-regulated gene expression, suggesting that GRAS42 is not a regulator of core GA signaling genes in maize. Single cell expression data identified gras42 expressed among cells in the G2/M phase of the cell cycle consistent with its previously demonstrated role in cell cycle gene expression in Arabidopsis (Arabidopsis thaliana). Cis-acting natural variation controlling GRAS42 transcript accumulation was identified by expression genome-wide association study (eGWAS) in maize. Our results demonstrate a conserved role for GRAS42/SCARECROW-LIKE 28 (SCL28)/DLT in BR signaling, clarify the role of this gene in GA signaling, and suggest mechanisms of tillering and leaf angle control by BR.
PMID: 38709680
Sci Total Environ , IF:7.963 , 2024 Jun , V928 : P172449 doi: 10.1016/j.scitotenv.2024.172449
The Oryza sativa transcriptome responds spatiotemporally to polystyrene nanoplastic stress.
Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan 523808, China; Institute of Environmental Research at Greater Bay Area, Guangzhou University, Guangzhou 510006, China. Electronic address: xuchanchan@whu.edu.cn.
Nanoplastic represents an emerging abiotic stress facing modern agriculture, impacting global crop production. However, the molecular response of crop plants to this stress remains poorly understood at a spatiotemporal resolution. We therefore used RNA sequencing to profile the transcriptome expressed in rice (Oryza sativa) root and leaf organs at 1, 2, 4, and 8 d post exposure with nanoplastic. We revealed a striking similarity between the rice biomass dynamics in aboveground parts to that in belowground parts during nanoplastic stress, but transcriptome did not. At the global transcriptomic level, a total of 2332 differentially expressed genes were identified, with the majority being spatiotemporal specific, reflecting that nanoplastics predominantly regulate three processes in rice seedlings: (1) down-regulation of chlorophyll biosynthesis, photosynthesis, and starch, sucrose and nitrogen metabolism, (2) activation of defense responses such as brassinosteroid biosynthesis and phenylpropanoid biosynthesis, and (3) modulation of jasmonic acid and cytokinin signaling pathways by transcription factors. Notably, the genes involved in plant-pathogen interaction were shown to be successively modulated by both root and leaf organs, particularly plant disease defense genes (OsWRKY24, OsWRKY53, Os4CL3, OsPAL4, and MPK5), possibly indicating that nanoplastics affect rice growth indirectly through other biota. Finally, we associated biomass phenotypes with the temporal reprogramming of rice transcriptome by weighted gene co-expression network analysis, noting a significantly correlation with photosynthesis, carbon metabolism, and phenylpropanoid biosynthesis that may reflect the mechanisms of biomass reduction. Functional analysis further identified PsbY, MYB, cytochrome P450, and AP2/ERF as hub genes governing these pathways. Overall, our work provides the understanding of molecular mechanisms of rice in response to nanoplastics, which in turn suggests how rice might behave in a nanoplastic pollution scenario.
PMID: 38615784
Plant Cell Environ , IF:7.228 , 2024 May doi: 10.1111/pce.14958
The interplay of growth-regulating factor 5 and BZR1 in coregulating chlorophyll degradation in poplar.
State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.; National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China.; Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.
Chlorophyll (Chl) is essential for plants to carry out photosynthesis, growth and development processes. Growth-regulating factors (GRFs) play a vital role in regulating Chl degradation in plants. However, the molecular mechanism by which GRF5 regulates Chl degradation in poplar remains unknown. Here we found that overexpression of PpnGRF5-1 increased Chl content in leaves and promoted chloroplast development in poplar. Overexpression of PpnGRF5-1 in poplar delayed Chl degradation induced by external factors, such as hormones, darkness and salt stress. PpnGRF5-1 responded to brassinosteroid (BR) signalling during BR-induced Chl degradation and reduced the expression levels of Chl degradation and senescence-related genes. PpnGRF5-1 inhibited the expression of Chl b reductases PagNYC1 and PagNOL. PpnGRF5-1 could interact with PagBZR1 in the nucleus. PagBZR1 also inhibited the expression of PagNYC1. In addition, we found that the protein-protein interaction between PagBZR1 and PpnGRF5-1 enhanced the inhibitory effect of PpnGRF5-1 on the Chl b reductases PagNYC1 and PagNOL. BZR1 and GRF5-1 were upregulated, and NOL and NYC1 were downregulated in triploid poplars compared to diploids. This study revealed a new mechanism by which PpnGRF5-1 regulates Chl degradation in poplars and lays the foundation for comprehensively analysing the molecular mechanism of Chl metabolism in triploid poplars.
PMID: 38783695
Hortic Res , IF:6.793 , 2024 May , V11 (5) : Puhae074 doi: 10.1093/hr/uhae074
CsEXL3 regulate mechanical harvest-related droopy leaves under the transcriptional activation of CsBES1.2 in tea plant.
Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute of the Chinese Academy of Agricultural Sciences, Hangzhou 310008, China.
Due to a labor shortage, the mechanical harvesting of tea plantations has become a focal point. However, mechanical harvest efficiency was hampered by droopy leaves, leading to a high rate of broken tea shoots and leaves. Here, we dissected the genetic structure of leaf droopiness in tea plants using genome-wide association studies (GWAS) on 146 accessions, combined with transcriptome from two accessions with contrasting droopy leaf phenotypes. A set of 16 quantitative trait loci (QTLs) containing 54 SNPs and 34 corresponding candidate genes associated with droopiness were then identified. Among these, CsEXL3 (EXORDIUM-LIKE 3) from Chromosome 1 emerged as a candidate gene. Further investigations revealed that silencing CsEXL3 in tea plants resulted in weaker vascular cell malformation and brassinosteroid-induced leaf droopiness. Additionally, brassinosteroid signal factor CsBES1.2 was proved to participate in CsEXL3-induced droopiness and vascular cell malformation via using the CsBES1.2-silencing tea plant. Notably, CsBES1.2 bound on the E-box of CsEXL3 promoter to transcriptionally activate CsEXL3 expression as CUT&TAG based ChIP-qPCR and ChIP-seq suggested in vivo as well as EMSA and Y1H indicated in vitro. Furthermore, CsEXL3 instead of CsBES1.2 decreased lignin content and the expressing levels of lignin biosynthesis genes. Overall, our findings suggest that CsEXL3 regulates droopy leaves, partially through the transcriptional activation of CsBES1.2, with the potential to improve mechanical harvest efficiency in tea plantations.
PMID: 38738211
Plant J , IF:6.417 , 2024 May doi: 10.1111/tpj.16806
miR394 modulates brassinosteroid signaling to regulate hypocotyl elongation in Arabidopsis.
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, People's Republic of China.; Shandong Provincial Key Laboratory of Applied Microbiology, Ecology Institute of Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250013, China.
The interplay between microRNAs (miRNAs) and phytohormones allows plants to integrate multiple internal and external signals to optimize their survival of different environmental conditions. Here, we report that miR394 and its target gene LEAF CURLING RESPONSIVENESS (LCR), which are transcriptionally responsive to BR, participate in BR signaling to regulate hypocotyl elongation in Arabidopsis thaliana. Phenotypic analysis of various transgenic and mutant lines revealed that miR394 negatively regulates BR signaling during hypocotyl elongation, whereas LCR positively regulates this process. Genetically, miR394 functions upstream of BRASSINOSTEROID INSENSITIVE2 (BIN2), BRASSINAZOLEs RESISTANT1 (BZR1), and BRI1-EMS-SUPPRESSOR1 (BES1), but interacts with BRASSINOSTEROID INSENSITIVE1 (BRI1) and BRI1 SUPRESSOR PROTEIN (BSU1). RNA-sequencing analysis suggested that miR394 inhibits BR signaling through BIN2, as miR394 regulates a significant number of genes in common with BIN2. Additionally, miR394 increases the accumulation of BIN2 but decreases the accumulation of BZR1 and BES1, which are phosphorylated by BIN2. MiR394 also represses the transcription of PACLOBUTRAZOL RESISTANCE1/5/6 and EXPANSIN8, key genes that regulate hypocotyl elongation and are targets of BZR1/BES1. These findings reveal a new role for a miRNA in BR signaling in Arabidopsis.
PMID: 38761364
Int J Mol Sci , IF:5.923 , 2024 May , V25 (10) doi: 10.3390/ijms25105425
Lon1 Inactivation Downregulates Autophagic Flux and Brassinosteroid Biogenesis, Modulating Mitochondrial Proportion and Seed Development in Arabidopsis.
Frontiers Science Center for Cell Responses, Department of Plant Biology and Ecology, College of Life Sciences, Nankai University, Tianjin 300071, China.
Mitochondrial protein homeostasis is crucially regulated by protein degradation processes involving both mitochondrial proteases and cytosolic autophagy. However, it remains unclear how plant cells regulate autophagy in the scenario of lacking a major mitochondrial Lon1 protease. In this study, we observed a notable downregulation of core autophagy proteins in Arabidopsis Lon1 knockout mutant lon1-1 and lon1-2, supporting the alterations in the relative proportions of mitochondrial and vacuolar proteins over total proteins in the plant cells. To delve deeper into understanding the roles of the mitochondrial protease Lon1 and autophagy in maintaining mitochondrial protein homeostasis and plant development, we generated the lon1-2atg5-1 double mutant by incorporating the loss-of-function mutation of the autophagy core protein ATG5, known as atg5-1. The double mutant exhibited a blend of phenotypes, characterized by short plants and early senescence, mirroring those observed in the individual single mutants. Accordingly, distinct transcriptome alterations were evident in each of the single mutants, while the double mutant displayed a unique amalgamation of transcriptional responses. Heightened severity, particularly evident in reduced seed numbers and abnormal embryo development, was observed in the double mutant. Notably, aberrations in protein storage vacuoles (PSVs) and oil bodies were evident in the single and double mutants. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of genes concurrently downregulated in lon1-2, atg5-1, and lon1-2atg5-1 unveiled a significant suppression of genes associated with brassinosteroid (BR) biosynthesis and homeostasis. This downregulation likely contributes to the observed abnormalities in seed and embryo development in the mutants.
PMID: 38791463
Int J Mol Sci , IF:5.923 , 2024 May , V25 (10) doi: 10.3390/ijms25105100
RNA-Seq Reveals That Multiple Pathways Are Involved in Tuber Expansion in Tiger Nuts (Cyperus esculentus L.).
Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.; State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.; University of Chinese Academy of Sciences, Beijing 100049, China.; Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Menglun 666303, China.
The tiger nut (Cyperus esculentus L.) is a usable tuber and edible oil plant. The size of the tubers is a key trait that determines the yield and the mechanical harvesting of tiger nut tubers. However, little is known about the anatomical and molecular mechanisms of tuber expansion in tiger nut plants. This study conducted anatomical and comprehensive transcriptomics analyses of tiger nut tubers at the following days after sowing: 40 d (S1); 50 d (S2); 60 d (S3); 70 d (S4); 90 d (S5); and 110 d (S6). The results showed that, at the initiation stage of a tiger nut tuber (S1), the primary thickening meristem (PTM) surrounded the periphery of the stele and was initially responsible for the proliferation of parenchyma cells of the cortex (before S1) and then the stele (S2-S3). The increase in cell size of the parenchyma cells occurred mainly from S1 to S3 in the cortex and from S3 to S4 in the stele. A total of 12,472 differentially expressed genes (DEGs) were expressed to a greater extent in the S1-S3 phase than in S4-S6 phase. DEGs related to tuber expansion were involved in cell wall modification, vesicle transport, cell membrane components, cell division, the regulation of plant hormone levels, signal transduction, and metabolism. DEGs involved in the biosynthesis and the signaling of indole-3-acetic acid (IAA) and jasmonic acid (JA) were expressed highly in S1-S3. The endogenous changes in IAA and JAs during tuber development showed that the highest concentrations were found at S1 and S1-S3, respectively. In addition, several DEGs were related to brassinosteroid (BR) signaling and the G-protein, MAPK, and ubiquitin-proteasome pathways, suggesting that these signaling pathways have roles in the tuber expansion of tiger nut. Finally, we come to the conclusion that the cortex development preceding stele development in tiger nut tubers. The auxin signaling pathway promotes the division of cortical cells, while the jasmonic acid pathway, brassinosteroid signaling, G-protein pathway, MAPK pathway, and ubiquitin protein pathway regulate cell division and the expansion of the tuber cortex and stele. This finding will facilitate searches for genes that influence tuber expansion and the regulatory networks in developing tubers.
PMID: 38791140
Front Plant Sci , IF:5.753 , 2024 , V15 : P1387321 doi: 10.3389/fpls.2024.1387321
BZR1 and BES1 transcription factors mediate brassinosteroid control over root system architecture in response to nitrogen availability.
School of Science, Western Sydney University, Richmond, NSW, Australia.; Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, Australia.; Faculty of Life Sciences, Graphic Era Deemed to be University, Dehradun, Uttarakhand, India.
Plants modify their root system architecture (RSA) in response to nitrogen (N) deficiency. The plant steroidal hormone, brassinosteroid (BR), plays important roles in root growth and development. This study demonstrates that optimal levels of exogenous BR impact significant increases in lateral root length and numbers in Arabidopsis seedlings under mild N-deficient conditions as compared to untreated seedlings. The impact of BR on RSA was stronger under mild N deficiency than under N-sufficient conditions. The BR effects on RSA were mimicked in dominant mutants of BZR1 and BES1 (bzr1-1D and bes1-D) transcription factors, while the RSA was highly reduced in the BR-insensitive mutant bri1-6, confirming that BR signaling is essential for the development of RSA under both N-sufficient and N-deficient conditions. Exogenous BR and constitutive activity of BZR1 and BES1 in dominant mutants led to enhanced root meristem, meristematic cell number, and cortical cell length. Under mild N deficiency, bzr1-1D displayed higher fresh and dry shoot weights, chlorophyll content, and N levels in the shoot, as compared to the wild type. These results indicate that BR modulates RSA under both N-sufficient and N-deficient conditions via the transcription factors BES1/BZR1 module and confers tolerance to N deficiency.
PMID: 38779077
Plant Cell Physiol , IF:4.927 , 2024 May doi: 10.1093/pcp/pcae056
Mechanistic insights into the function of 14-3-3 proteins as negative regulators of brassinosteroid signaling in Arabidopsis.
Structural Plant Biology Laboratory, Department of Plant Sciences, University of Geneva, 1211 Geneva, Switzerland.; Biozentrum, University of Basel, 4056 Basel, Switzerland.; Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA) & Austria Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), 1030 Vienna, Austria.; Creoptix - Malvern Panalytical, 8820 Wadenswil, Switzerland.
Brassinosteroids (BRs) are vital plant steroid hormones sensed at the cell surface by a membrane signaling complex comprising the receptor kinase BRI1 and a SERK-family co-receptor kinase. Activation of this complex lead to dissociation of the inhibitor protein BKI1 from the receptor and to differential phosphorylation of BZR1/BES1 transcription factors by the glycogen synthase kinase 3 protein BIN2. Many phosphoproteins of the BR signaling pathway, including BRI1, SERKs, BKI1 and BZR1/BES1 can associate with 14-3-3 proteins. In this study, we use quantitative ligand binding assays to define the minimal 14-3-3 binding sites in the N-terminal lobe of the BRI1 kinase domain, in BKI1, and in BZR1 from Arabidopsis thaliana. All three motifs require to be phosphorylated to specifically bind 14-3-3s with mid- to low micromolar affinity. BR signaling components display minimal isoform preference within the 14-3-3 non-epsilon subgroup. 14-3-3lambda and 14-3-3omega isoform complex crystal structures reveal that BKI1 and BZR1 bind as canonical type II 14-3-3 linear motifs. Disruption of key amino acids in the phosphopeptide binding site through mutation impairs the interaction of 14-3-3lambda with all three linear motifs. Notably, quadruple loss-of-function mutants from the non-epsilon group exhibit gain-of-function brassinosteroid signaling phenotypes, suggesting a role for 14-3-3 proteins as overall negative regulators of the BR pathway. Collectively, our work provides further mechanistic and genetic evidence for the regulatory role of 14-3-3 proteins at various stages of the brassinosteroid signaling cascade.
PMID: 38783418
Plant Cell Physiol , IF:4.927 , 2024 May doi: 10.1093/pcp/pcae054
Title: Bona Fide Plant Steroid Receptors Are Innovated in Seed Plants and Angiosperms through Successive Whole Genome Duplication Events.
College of Life Science, Shaanxi Normal University, Xi'an, Shaanxi Province, 710119 China.
Whole genome duplication (WGD) events are widespread in plants and animals, thus their long-term evolutionary contribution has long been speculated, yet a specific contribution is difficult to verify. Here, we show that varepsilon-WGD and zeta-WGD contribute to the origin and evolution of bona fide brassinosteroid (BR) signaling through the innovation of active BR biosynthetic enzymes and active BR receptors from their respective ancestors. We found that BR receptors BRI1 (BR Insensitive 1) and BRL1/3 (BRI1-likes 1/3) derived by varepsilon-WGD and zeta-WGD, which occurred in the common ancestor of angiosperms and seed plants, respectively, while orphan BR receptor BRL2 first appeared in stomatophytes. Additionally, CYP85A enzymes synthesizing the bioactive BRs derived from a common ancestor of seed plants while its sister enzymes CYP90 synthesizing BR precursors presented in all land plants, implying possible ligand-receptor coevolution. Consistently, the island domains (IDs) responsible for BR perception in BR receptors were most divergent among different receptor branches, supporting ligand-driven evolution. As a result, BRI1 was the most diversified BR receptor in angiosperms. Importantly, relative to the BR biosynthetic DET2 gene presented in all land plants, BRL2, BRL1/3 and BRI1 had high expression in vascular plants ferns, gymnosperms and angiosperms, respectively. Notably, BRI1 is the most diversified BR receptor with the most abundant expression in angiosperms, suggesting potential positive selection. Therefore, WGDs initiate a neofunctionalization process diverged by ligand-perception and transcriptional expression, which might optimize both BR biosynthetic enzymes and BR receptors, likely contributing to the evolution of land plants, especially seed plants and angiosperms.
PMID: 38757845
Rice (N Y) , IF:4.783 , 2024 May , V17 (1) : P36 doi: 10.1186/s12284-024-00715-x
OsEXPA7 Encoding an Expansin Affects Grain Size and Quality Traits in Rice (Oryza sativa L.).
State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology (Ministry of Education), School of Life Sciences, Fudan University, Shanghai, China.; Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Department of Ecology and Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai, China.; Institute of Crop Breeding and Cultivation, Shanghai Academy of Agricultural Sciences, Shanghai, China.; State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology (Ministry of Education), School of Life Sciences, Fudan University, Shanghai, China. luoxj@fudan.edu.cn.; Ministry of Education, Key Laboratory of Crop Physiology, Ecology and Genetic Breeding College of Agronomy, Jiangxi Agricultural University, Nanchang, China. luoxj@fudan.edu.cn.
BACKGROUND: Yield and quality are the two most important traits in crop breeding. Exploring the regulatory mechanisms that affect both yield and quality traits is of great significance for understanding the molecular genetic networks controlling these key crop attributes. Expansins are cell wall loosening proteins that play important roles in regulating rice grain size. RESULTS: We investigated the effect of OsEXPA7, encoding an expansin, on rice grain size and quality. OsEXPA7 overexpression resulted in increased plant height, panicle length, grain length, and thousand-grain weight in rice. OsEXPA7 overexpression also affected gel consistency and amylose content in rice grains, thus affecting rice quality. Subcellular localization and tissue expression analyses showed that OsEXPA7 is localized on the cell wall and is highly expressed in the panicle. Hormone treatment experiments revealed that OsEXPA7 expression mainly responds to methyl jasmonate, brassinolide, and gibberellin. Transcriptome analysis and RT-qPCR experiments showed that overexpression of OsEXPA7 affects the expression of OsJAZs in the jasmonic acid pathway and BZR1 and GE in the brassinosteroid pathway. In addition, OsEXPA7 regulates the expression of key quantitative trait loci related to yield traits, as well as regulates the expression levels of BIP1 and bZIP50 involved in the seed storage protein biosynthesis pathway. CONCLUSIONS: These results reveal that OsEXPA7 positively regulates rice yield traits and negatively regulates grain quality traits by involving plant hormone pathways and other trait-related pathway genes. These findings increase our understanding of the potential mechanism of expansins in regulating rice yield and quality traits and will be useful for breeding high-yielding and high-quality rice cultivars.
PMID: 38780864
Plant Sci , IF:4.729 , 2024 May , V342 : P112033 doi: 10.1016/j.plantsci.2024.112033
BRASSINOSTEROID-SIGNALING KINASE1 associates with and is required for cysteine protease RESPONSE TO DEHYDRATION 19-mediated disease resistance in Arabidopsis.
State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China.; State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: dztang@fafu.edu.cn.; State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China; State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory of Agro-Biodiversity and Pest Management of Education Ministry of China, Yunnan Agricultural University, Kunming 650201, China. Electronic address: shihua_2004@163.com.
The receptor-like cytoplasmic kinase BRASSINOSTEROID-SIGNALING KINASE1 (BSK1) interacts with pattern recognition receptor (PRR) FLAGELLIN SENSING2 (FLS2) and positively regulates plant innate immunity in Arabidopsis thaliana. However, the molecular components involved in BSK1-mediated immune signaling remain largely unknown. To further explore the molecular mechanism underlying BSK1-mediated disease resistance, we screened two cysteine proteases, RESPONSE TO DEHYDRATION 19 (RD19) and RD19-LIKE 2 (RDL2), as BSK1-binding partners. Overexpression of RD19, but not RDL2, displayed an autoimmune phenotype, presenting programmed cell death and enhanced resistance to multiple pathogens. Interestingly, RD19-mediated immune activation depends on BSK1, as knockout of BSK1 in RD19-overexpressing plants rescued their autoimmunity and abolished the increased resistance. Furthermore, we found that BSK1 plays a positive role in maintaining RD19 protein abundance in Arabidopsis. Our results provide new insights into BSK1-mediated immune signaling and reveal a potential mechanism by which BSK1 stabilizes RD19 to promote effective immune output.
PMID: 38354753
Sci Rep , IF:4.379 , 2024 May , V14 (1) : P10654 doi: 10.1038/s41598-024-61062-x
Genomic analysis of a spontaneous unifoliate mutant reveals gene candidates associated with compound leaf development in Vigna unguiculata [L] Walp.
Arid Land Research Center, Tottori University, Tottori, 680-0001, Japan. offiongue@yahoo.com.; Department of Crop Science, University of Calabar, PMB 1115, Calabar, Cross River State, Nigeria. offiongue@yahoo.com.; Department of Biotechnology, Ebonyi State University, Abakaliki, Ebonyi State, Nigeria.; Arid Land Research Center, Tottori University, Tottori, 680-0001, Japan. ishii.t@tottori-u.ac.jp.
Molecular mechanisms which underpin compound leaf development in some legumes have been reported, but there is no previous study on the molecular genetic control of compound leaf formation in Vigna unguiculata (cowpea), an important dryland legume of African origin. In most studied species with compound leaves, class 1 KNOTTED-LIKE HOMEOBOX genes expressed in developing leaf primordia sustain morphogenetic activity, allowing leaf dissection and the development of leaflets. Other genes, such as, SINGLE LEAFLET1 in Medicago truncatula and Trifoliate in Solanum lycopersicum, are also implicated in regulating compound leaf patterning. To set the pace for an in-depth understanding of the genetics of compound leaf development in cowpea, we applied RNA-seq and whole genome shotgun sequence datasets of a spontaneous cowpea unifoliate mutant and its trifoliate wild-type cultivar to conduct comparative reference-based gene expression, de novo genome-wide isoform switch, and genome variant analyses between the two genotypes. Our results suggest that genomic variants upstream of LATE ELONGATED HYPOCOTYL and down-stream of REVEILLE4, BRASSINOSTERIOD INSENSITIVE1 and LATERAL ORGAN BOUNDARIES result in down-regulation of key components of cowpea circadian rhythm central oscillator and brassinosteroid signaling, resulting in unifoliate leaves and brassinosteroid-deficient-like phenotypes. We have stated hypotheses that will guide follow-up studies expected to provide more insights.
PMID: 38724579
Planta , IF:4.116 , 2024 May , V260 (1) : P5 doi: 10.1007/s00425-024-04429-8
BR regulates wheat root salt tolerance by maintaining ROS homeostasis.
Key Laboratory of Anyang Wheat Breeding Engineering Research Center, Anyang Institute of Technology, Anyang, 455000, Henan, China.; College of Agronomy, Northwest A&F University, Yangling, Shaanxi, China.; Department of Biochemistry, Baoding University, Baoding, 071000, Hebei, China.; College of Life Sciences and Engineering, Hexi University, Zhangye, Gansu, 734000, China.; College of Agronomy, Xinyang Agriculture and Forestry University, Xinyang, 464000, Henan, China.; Xinyang Academy of Agricultural Sciences, Xinyang, 464000, Henan, China.; College of Agronomy, Northwest A&F University, Yangling, Shaanxi, China. wjw@nwsuaf.edu.cn.
Trace amounts of epibrassinolide (EpiBL) could partially rescue wheat root length inhibition in salt-stressed situation by scavenging ROS, and ectopic expression of TaDWF4 or TaBAK1 enhances root salt tolerance in Arabidopsis by balancing ROS level. Salt stress often leads to ion toxicity and oxidative stress, causing cell structure damage and root development inhibition in plants. While prior research indicated the involvement of exogenous brassinosteroid (BR) in plant responses to salt stress, the precise cytological role and the function of BR in wheat root development under salt stress remain elusive. Our study demonstrates that 100 mM NaCl solution inhibits wheat root development, but 5 nM EpiBL partially rescues root length inhibition by decreasing H(2)O(2) content, oxygen free radical (OFR) content, along with increasing the peroxidase (POD) and catalase (CAT) activities in salt-stressed roots. The qRT-PCR experiment also shows that expression of the ROS-scavenging genes (GPX2 and CAT2) increased in roots after applying BR, especially during salt stress situation. Transcriptional analysis reveals decreased expression of BR synthesis and root meristem development genes under salt stress in wheat roots. Differential expression gene (DEG) enrichment analysis highlights the significant impact of salt stress on various biological processes, particularly "hydrogen peroxide catabolic process" and "response to oxidative stress". Additionally, the BR biosynthesis pathway is enriched under salt stress conditions. Therefore, we investigated the involvement of wheat BR synthesis gene TaDWF4 and BR signaling gene TaBAK1 in salt stress responses in roots. Our results demonstrate that ectopic expression of TaDWF4 or TaBAK1 enhances salt tolerance in Arabidopsis by balancing ROS (Reactive oxygen species) levels in roots.
PMID: 38777878
Plants (Basel) , IF:3.935 , 2024 May , V13 (10) doi: 10.3390/plants13101345
Effects of Lactone- and Ketone-Brassinosteroids of the 28-Homobrassinolide Series on Barley Plants under Water Deficit.
Department of Plant Physiology, Biotechnology and Bioinformatics, Biological Institute, National Research Tomsk State University, Lenin Avenue 36, Tomsk 634050, Russia.; Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Kuprevich Street 5/2, 220084 Minsk, Belarus.; K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia.
The aim of this work was to study the ability of 28-homobrassinolide (HBL) and 28-homocastasterone (HCS) to increase the resistance of barley (Hordeum vulgare L.) plants to drought and to alter their endogenous brassinosteroid status. Germinated barley seeds were treated with 0.1 nM HBL or HCS solutions for two hours. A water deficit was created by stopping the watering of 7-day-old plants for the next two weeks. Plants responded to drought through growth inhibition, impaired water status, increased lipid peroxidation, differential effects on antioxidant enzymes, intense proline accumulation, altered expression of genes involved in metabolism, and decreased endogenous contents of hormones (28-homobrassinolide, B-ketones, and B-lactones). Pretreatment of plants with HBL reduced the inhibitory effect of drought on fresh and dry biomass accumulation and relative water content, whereas HCS partially reversed the negative effect of drought on fresh biomass accumulation, reduced the intensity of lipid peroxidation, and increased the osmotic potential. Compared with drought stress alone, pretreatment of plants with HCS or HBL followed by drought increased superoxide dismutase activity sevenfold or threefold and catalase activity (by 36%). The short-term action of HBL and HCS in subsequent drought conditions partially restored the endogenous B-ketone and B-lactone contents. Thus, the steroidal phytohormones HBL and HCS increased barley plant resistance to subsequent drought, showing some specificity of action.
PMID: 38794416
Gene , IF:3.688 , 2024 Jun , V910 : P148336 doi: 10.1016/j.gene.2024.148336
Genome-wide identification and expression analysis of the Dof gene family reveals their involvement in hormone response and abiotic stresses in sunflower (Helianthus annuus L.).
Department of Life Sciences, Changzhi University, Changzhi 046011, China.; School of Life Science, Shanxi Normal University, Taiyuan 030031, China.; Department of Life Sciences, Changzhi University, Changzhi 046011, China. Electronic address: tznius@126.com.; Department of Life Sciences, Changzhi University, Changzhi 046011, China. Electronic address: akeliu@126.com.
DNA binding with one finger (Dof), plant-specific zinc finger transcription factors, can participate in various physiological and biochemical processes during the life of plants. As one of the most important oil crops in the world, sunflower (Helianthus annuus L.) has significant economic and ornamental value. However, a systematic analysis of H. annuus Dof (HaDof) members and their functions has not been extensively conducted. In this study, we identified 50 HaDof genes that are unevenly distributed on 17 chromosomes of sunflower. We present a comprehensive overview of the HaDof genes, including their chromosome locations, phylogenetic analysis, and expression profile characterization. Phylogenetic analysis classified the 366 Dof members identified from 11 species into four groups (further subdivided into nine subfamilies). Segmental duplications are predominantly contributed to the expansion of sunflower Dof genes, and all segmental duplicate gene pairs are under purifying selection due to strong evolutionary constraints. Furthermore, we observed differential expression patterns for HaDof genes in normal tissues as well as under hormone treatment or abiotic stress conditions by analyzing RNA-seq data from previous studies and RT-qPCR data in our current study. The expression of HaDof04 and HaDof43 were not detected in any samples, which implied that they may be gradually undergoing pseudogenization process. Some HaDof genes, such as HaDof25 and HaDof30, showed responsiveness to exogenous plant hormones, such as kinetin, brassinosteroid, auxin or strigolactone, while others like HaDof15 and HaDof35 may participate in abiotic stress resistance of sunflower seedling. Our study represents the initial step towards understanding the phylogeny and expression characterization of sunflower Dof family genes, which may provide valuable reference information for functional studies on hormone response, abiotic stress resistance, and molecular breeding in sunflower and other species.
PMID: 38447680
Biochem Biophys Res Commun , IF:3.575 , 2024 May , V710 : P149871 doi: 10.1016/j.bbrc.2024.149871
Association mechanism between Arabidopsis immune coreceptor BAK1 and Pseudomonas syringae effector HopF2.
State Key Laboratory of Maize Bio-breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China.; State Key Laboratory of Maize Bio-breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China. Electronic address: wdl@cau.edu.cn.; State Key Laboratory of Maize Bio-breeding, Ministry of Agriculture Key Laboratory for Crop Pest Monitoring and Green Control, College of Plant Protection, China Agricultural University, Beijing, 100193, China; Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, Beijing, 100193, China. Electronic address: jliu@cau.edu.cn.
Brassinosteroid activated kinase 1 (BAK1) is a cell-surface coreceptor which plays multiple roles in innate immunity of plants. HopF2 is an effector secreted by the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 into Arabidopsis and suppresses host immune system through interaction with BAK1 as well as its downstream kinase MKK5. The association mechanism of HopF2 to BAK1 remains unclear, which prohibits our understanding and subsequent interfering of their interaction for pathogen management. Herein, we found the kinase domain of BAK1 (BAK1-KD) is sufficient for HopF2 association. With a combination of hydrogen/deuterium exchange mass spectrometry and mutational assays, we found a region of BAK1-KD N-lobe and a region of HopF2 head subdomain are critical for intermolecular interaction, which is also supported by unbiased protein-protein docking with ClusPro and kinase activity assay. Collectively, this research presents the interaction mechanism between Arabidopsis BAK1 and P. syringae HopF2, which could pave the way for bactericide development that blocking the functioning of HopF2 toward BAK1.
PMID: 38579538
Plant Commun , 2024 May : P100982 doi: 10.1016/j.xplc.2024.100982
Brassinosteroid biosynthesis and signaling: Conserved and diversified functions of core genes across multiple plant species.
Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa 50011, USA; Interdepartmental Genetics and Genomics Graduate Program, Iowa State University, Ames, Iowa 50011, USA.; Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa 50011, USA; Interdepartmental Genetics and Genomics Graduate Program, Iowa State University, Ames, Iowa 50011, USA. Electronic address: norman.best@usda.gov.; USDA-ARS, Plant Genetics Research Unit, Columbia, Missouri, 65201, USA. Electronic address: norman.best@usda.gov.
Brassinosteroids (BRs) are important regulators that control myriad aspects of plant growth and development, including biotic and abiotic stress responses, such that modulating BR homeostasis and signaling presents abundant opportunities for plant breeding and crop improvement. Enzymes and other proteins involved in the biosynthesis and signaling of BRs are well understood from molecular genetics and phenotypic analysis in Arabidopsis thaliana; however, knowledge of molecular functions of these genes in other plant species, especially cereal crop plants, is minimal. In this manuscript, we comprehensively review functional studies of BR genes in Arabidopsis, maize, rice, Setaria, Brachypodium, and soybean to identify conserved and diversified functions across plant species and to highlight cases where additional research is in order. We performed phylogenetic analysis of gene families involved in the biosynthesis and signaling of BRs and re-analyzed publicly available transcriptomic data. Gene trees coupled with expression data provide a valuable guide to supplement future research on BRs in these important crop species, allowing researchers to identify genes to target through gene editing techniques to perform BR-related functional studies.
PMID: 38816993
ISME Commun , 2024 Jan , V4 (1) : Pycae073 doi: 10.1093/ismeco/ycae073
Widespread horizontal gene transfer between plants and bacteria.
The Department of Plant Pathology and Microbiology, Institute of Environmental Science, Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel.; Faculty of Biology, Technion-Israel Institute of Technology, Haifa 3200003, Israel.
Plants host a large array of commensal bacteria that interact with the host. The growth of both bacteria and plants is often dependent on nutrients derived from the cognate partners, and the bacteria fine-tune host immunity against pathogens. This ancient interaction is common in all studied land plants and is critical for proper plant health and development. We hypothesized that the spatial vicinity and the long-term relationships between plants and their microbiota may promote cross-kingdom horizontal gene transfer (HGT), a phenomenon that is relatively rare in nature. To test this hypothesis, we analyzed the Arabidopsis thaliana genome and its extensively sequenced microbiome to detect events of horizontal transfer of full-length genes that transferred between plants and bacteria. Interestingly, we detected 75 unique genes that were horizontally transferred between plants and bacteria. Plants and bacteria exchange in both directions genes that are enriched in carbohydrate metabolism functions, and bacteria transferred to plants genes that are enriched in auxin biosynthesis genes. Next, we provided a proof of concept for the functional similarity between a horizontally transferred bacterial gene and its Arabidopsis homologue in planta. The Arabidopsis DET2 gene is essential for biosynthesis of the brassinosteroid phytohormones, and loss of function of the gene leads to dwarfism. We found that expression of the DET2 homologue from Leifsonia bacteria of the Actinobacteria phylum in the Arabidopsis det2 background complements the mutant and leads to normal plant growth. Together, these data suggest that cross-kingdom HGT events shape the metabolic capabilities and interactions between plants and bacteria.
PMID: 38808121