title: A Kelch motif-containing serine/threonine protein phosphatase determines the large grain QTL trait in rice.
abstract: A thorough understanding of the genetic basis of rice grain traits is critical for the improvement of rice (Oryza sativa L.) varieties. In this study, we generated an F₂ population by crossing the large-grain japonica cultivar CW23 with Peiai 64 (PA64), an elite indica small-grain cultivar. Using QTL analysis, 17 QTLs for five grain traits were detected on four different chromosomes. Eight of the QTLs were newly-identified in this study. In particular, qGL3-1, a newly-identified grain length QTL with the highest LOD value and largest phenotypic variation, was fine-mapped to the 17 kb region of chromosome 3. A serine/threonine protein phosphatase gene encoding a repeat domain containing two Kelch motifs was identified as the unique candidate gene corresponding to this QTL. A comparison of PA64 and CW23 sequences revealed a single nucleotide substitution (C→A) at position 1092 in exon 10, resulting in replacement of Asp (D) in PA64 with Glu (E) in CW23 for the 364(th) amino acid. This variation is located at the D position of the conserved sequence motif AVLDT of the Kelch repeat. Genetic analysis of a near-isogenic line (NIL) for qGL3-1 revealed that the allele qGL3-1 from CW23 has an additive or partly dominant effect, and is suitable for use in molecular marker-assisted selection.
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, China.
authors.forename: Zejun
authors.initials: Z
authors.lastname: Hu
authors.forename: Haohua
authors.initials: H
authors.lastname: He
authors.forename: Shiyong
authors.initials: S
authors.lastname: Zhang
authors.forename: Fan
authors.initials: F
authors.lastname: Sun
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Xin
authors.forename: Wenxiang
authors.initials: W
authors.lastname: Wang
authors.forename: Xi
authors.initials: X
authors.lastname: Qian
authors.forename: Jingshui
authors.initials: J
authors.lastname: Yang
authors.forename: Xiaojin
authors.initials: X
authors.lastname: Luo
mesh_terms: D001483:Base Sequence; D032461:Chromosomes, Plant; D017931:DNA Primers; D012275:Oryza / Q000235:genetics*; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D040641:Quantitative Trait Loci
chemical_list: D017931:DNA Primers; D010749:Phosphoprotein Phosphatases