title: The OsMYB30 Transcription Factor Suppresses Cold Tolerance by Interacting with a JAZ Protein and Suppressing β-Amylase Expression.
abstract: Cold stress is one of the major limiting factors for rice (Oryza sativa) productivity. Several MYB transcriptional factors have been reported as important regulators in the cold stress response, but the molecular mechanisms are largely unknown. In this study, we characterized a cold-responsive R2R3-type MYB gene, OsMYB30, for its regulatory function in cold tolerance in rice. Functional analysis revealed that overexpression of OsMYB30 in rice resulted in increased cold sensitivity, while the osmyb30 knockout mutant showed increased cold tolerance. Microarray and quantitative real-time polymerase chain reaction analyses revealed that a few β-amylase (BMY) genes were down-regulated by OsMYB30. The BMY activity and maltose content, which were decreased and increased in the OsMYB30 overexpression and osmyb30 knockout mutant, respectively, were correlated with the expression patterns of the BMY genes. OsMYB30 was shown to bind to the promoters of the BMY genes. These results suggested that OsMYB30 exhibited a regulatory effect on the breakdown of starch through the regulation of the BMY genes. In addition, application of maltose had a protective effect for cell membranes under cold stress conditions. Furthermore, we identified an OsMYB30-interacting protein, OsJAZ9, that had a significant effect in suppressing the transcriptional activation of OsMYB30 and in the repression of BMY genes mediated by OsMYB30. These results together suggested that OsMYB30 might be a novel regulator of cold tolerance through the negative regulation of the BMY genes by interacting with OsJAZ9 to fine-tune the starch breakdown and the content of maltose, which might contribute to the cold tolerance as a compatible solute.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lv
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Yang
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Hu
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Zeyu
authors.initials: Z
authors.lastname: Yang
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Siqi
authors.initials: S
authors.lastname: Ma
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xianghua
authors.identifier: 0000-0003-1436-8108
authors.initials: X
authors.lastname: Li
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan 430070, China lizhongx@mail.hzau.edu.cn.
authors.forename: Lizhong
authors.identifier: 0000-0003-0490-1474
authors.initials: L
authors.lastname: Xiong
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D003080:Cold Temperature; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D008320:Maltose / Q000378:metabolism; D009154:Mutation; D012275:Oryza / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D013213:Starch / Q000378:metabolism; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D001614:beta-Amylase / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D008320:Maltose; D013213:Starch; D001614:beta-Amylase