title: Emergence of a Novel Chimeric Gene Underlying Grain Number in Rice.
abstract: Grain number is an important factor in determining grain production of rice (Oryza sativa L.). The molecular genetic basis for grain number is complex. Discovering new genes involved in regulating rice grain number increases our knowledge regarding its molecular mechanisms and aids breeding programs. Here, we identified GRAINS NUMBER 2 (GN2), a novel gene that is responsible for rice grain number, from "Yuanjiang" common wild rice (O. rufipogon Griff.). Transgenic plants overexpressing GN2 showed less grain number, reduced plant height, and later heading date than control plants. Interestingly, GN2 arose through the insertion of a 1094-bp sequence from LOC_Os02g45150 into the third exon of LOC_Os02g56630, and the inserted sequence recruited its nearby sequence to generate the chimeric GN2 The gene structure and expression pattern of GN2 were distinct from those of LOC_Os02g45150 and LOC_Os02g56630 Sequence analysis showed that GN2 may be generated in the natural population of Yuanjiang common wild rice. In this study, we identified a novel functional chimeric gene and also provided information regarding the molecular mechanisms regulating rice grain number.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Lubin
authors.initials: L
authors.lastname: Tan
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Jiahuan
authors.initials: J
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Mumu
authors.initials: M
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Zuofeng
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Xianyou
authors.initials: X
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, National Center for Evaluation of Agricultural Wild Plants (Rice), Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China suncq@cau.edu.cn.
authors.forename: Chuanqing
authors.initials: C
authors.lastname: Sun
mesh_terms: D017343:Genes, Plant; D016254:Mutagenesis, Insertional; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D030821:Plants, Genetically Modified; D012639:Seeds / Q000235:genetics* / Q000254:growth & development
keywords: GN2; chimeric gene; gene emergence; grain number; rice