title: OVATE Family Protein 8 Positively Mediates Brassinosteroid Signaling through Interacting with the GSK3-like Kinase in Rice.
abstract: OVATE gene was first identified as a key regulator of fruit shape in tomato. OVATE family proteins (OFPs) are characterized as plant-specific transcription factors and conserved in Arabidopsis, tomato, and rice. Roles of OFPs involved in plant development and growth are largely unknown. Brassinosteroids (BRs) are a class of steroid hormones involved in diverse biological functions. OsGKS2 plays a critical role in BR signaling by phosphorylating downstream components such as OsBZR1 and DLT. Here we report in rice that OsOFP8 plays a positive role in BR signaling pathway. BL treatment induced the expression of OsOFP8 and led to enhanced accumulation of OsOFP8 protein. The gain-of-function mutant Osofp8 and OsOFP8 overexpression lines showed enhanced lamina joint inclination, whereas OsOFP8 RNAi transgenic lines showed more upright leaf phenotype, which suggest that OsOFP8 is involved in BR responses. Further analyses indicated that OsGSK2 interacts with and phosphorylates OsOFP8. BRZ treatment resulted in the cytoplasmic distribution of OsOFP8, and bikinin treatment reduced the cytoplasmic accumulation of OsOFP8. Phosphorylation of OsOFP8 by OsGSK2 is needed for its nuclear export. The phospphorylated OsOFP8 shuttles to the cytoplasm and is targeted for proteasomal degradation. These results indicate that OsOFP8 is a substrate of OsGSK2 and the function of OsOFP8 in plant growth and development is at least partly through the BR signaling pathway.
authors.affiliation: University of Chinese Academy of Sciences, 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, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Yang
authors.affiliation: University of Chinese Academy of Sciences, 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, China.
authors.forename: Wenjin
authors.initials: W
authors.lastname: Shen
authors.affiliation: College of Life Science, Yangtze University, Jingzhou, China.|Hubei Collaborative Innovation Center for Grain Industry, Yangtze University, Jingzhou, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: He
authors.affiliation: College of Life Science, Yangtze University, Jingzhou, China.|Hubei Collaborative Innovation Center for Grain Industry, Yangtze University, Jingzhou, China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Tian
authors.affiliation: University of Chinese Academy of Sciences, 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, China.|College of Life Science, Yangtze University, Jingzhou, China.
authors.forename: Jianxiong
authors.initials: J
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D060406:Brassinosteroids / Q000378:metabolism*; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D012275:Oryza / Q000235:genetics* / Q000378:metabolism*; D010766:Phosphorylation / Q000235:genetics; D063245:Plant Development / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D060406:Brassinosteroids; D009687:Nuclear Proteins; D010940:Plant Proteins; D014157:Transcription Factors; D011494:Protein Kinases; D038362:Glycogen Synthase Kinase 3; D046988:Proteasome Endopeptidase Complex