title: GW5 acts in the brassinosteroid signalling pathway to regulate grain width and weight in rice.
abstract: Grain size is a major determinant of grain yield in cereal crops. qSW5/GW5, which exerts the greatest effect on rice grain width and weight, was fine-mapped to a 2,263-bp/21-kb genomic region containing a 1,212-bp deletion, respectively. Here, we show that a gene encoding a calmodulin binding protein, located ∼5 kb downstream of the 1,212-bp deletion, corresponds to qSW5/GW5. GW5 is expressed in various rice organs, with highest expression level detected in young panicles. We provide evidence that the 1,212-bp deletion affects grain width most likely through influencing the expression levels of GW5. GW5 protein is localized to the plasma membrane and can physically interact with and repress the kinase activity of rice GSK2 (glycogen synthase kinase 2), a homologue of Arabidopsis BIN2 (BRASSINOSTEROID INSENSITIVE2) kinase, resulting in accumulation of unphosphorylated OsBZR1 (Oryza sativa BRASSINAZOLE RESISTANT1) and DLT (DWARF AND LOW-TILLERING) proteins in the nucleus to mediate brassinosteroid (BR)-responsive gene expression and growth responses (including grain width and weight). Our results suggest that GW5 is a novel positive regulator of BR signalling and a viable target for genetic manipulation to improve grain yield in rice and perhaps in other cereal crops as well.
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Jiafan
authors.initials: J
authors.lastname: Liu
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zheng
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Fuqing
authors.initials: F
authors.lastname: Wu
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Qibing
authors.initials: Q
authors.lastname: Lin
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Yueqin
authors.initials: Y
authors.lastname: Heng
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Tian
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: ZhiJun
authors.initials: Z
authors.lastname: Cheng
authors.affiliation: National key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Yu
authors.affiliation: National key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Kunneng
authors.initials: K
authors.lastname: Zhou
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xiuping
authors.initials: X
authors.lastname: Guo
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Jiulin
authors.initials: J
authors.lastname: Wang
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Wang
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.|National key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Wan
mesh_terms: D060406:Brassinosteroids / Q000378:metabolism*; D002523:Edible Grain / Q000235:genetics* / Q000254:growth & development; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D060406:Brassinosteroids; D010940:Plant Proteins