title: The novel quantitative trait locus GL3.1 controls rice grain size and yield by regulating Cyclin-T1;3.
abstract: Increased crop yields are required to support rapid population growth worldwide. Grain weight is a key component of rice yield, but the underlying molecular mechanisms that control it remain elusive. Here, we report the cloning and characterization of a new quantitative trait locus (QTL) for the control of rice grain length, weight and yield. This locus, GL3.1, encodes a protein phosphatase kelch (PPKL) family - Ser/Thr phosphatase. GL3.1 is a member of the large grain WY3 variety, which is associated with weaker dephosphorylation activity than the small grain FAZ1 variety. GL3.1-WY3 influences protein phosphorylation in the spikelet to accelerate cell division, thereby resulting in longer grains and higher yields. Further studies have shown that GL3.1 directly dephosphorylates its substrate, Cyclin-T1;3, which has only been rarely studied in plants. The downregulation of Cyclin-T1;3 in rice resulted in a shorter grain, which indicates a novel function for Cyclin-T in cell cycle regulation. Our findings suggest a new mechanism for the regulation of grain size and yield that is driven through a novel phosphatase-mediated process that affects the phosphorylation of Cyclin-T1;3 during cell cycle progression, and thus provide new insight into the mechanisms underlying crop seed development. We bred a new variety containing the natural GL3.1 allele that demonstrated increased grain yield, which indicates that GL3.1 is a powerful tool for breeding high-yield crops.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics and National Center for Plant Gene Research (Shanghai), Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Qi
authors.forename: You-Shun
authors.initials: YS
authors.lastname: Lin
authors.forename: Xian-Jun
authors.initials: XJ
authors.lastname: Song
authors.forename: Jin-Bo
authors.initials: JB
authors.lastname: Shen
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Jun-Xiang
authors.initials: JX
authors.lastname: Shan
authors.forename: Mei-Zhen
authors.initials: MZ
authors.lastname: Zhu
authors.forename: Liwen
authors.initials: L
authors.lastname: Jiang
authors.forename: Ji-Ping
authors.initials: JP
authors.lastname: Gao
authors.forename: Hong-Xuan
authors.initials: HX
authors.lastname: Lin
mesh_terms: D000483:Alleles; D002455:Cell Division; D003001:Cloning, Molecular; D056906:Cyclin T / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D017343:Genes, Plant; D012275:Oryza / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D010766:Phosphorylation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D040641:Quantitative Trait Loci; D012639:Seeds / Q000235:genetics / Q000378:metabolism
chemical_list: D056906:Cyclin T; D010940:Plant Proteins; D017346:Protein Serine-Threonine Kinases