CLUSTERED PRIMARY BRANCH 1, a new allele of DWARF11, controls panicle architecture and seed size in rice.
Panicle architecture and seed size are important agronomic traits that directly determine grain yield in rice (Oryza sativa L.). Although a number of key genes controlling panicle architecture and seed size have been cloned and characterized in recent years, their genetic and molecular mechanisms remain unclear. In this study, we identified a mutant that produced panicles with fascicled primary branching and reduced seeds in size. We isolated the underlying CLUSTERED PRIMARY BRANCH 1 (CPB1) gene, a new allele of DWARF11 (D11) encoding a cytochrome P450 protein involved in brassinosteroid (BR) biosynthesis pathway. Genetic transformation experiments confirmed that a His360Leu amino acid substitution residing in the highly conserved region of CPB1/D11 was responsible for the panicle architecture and seed size changes in the cpb1 mutants. Overexpression of CPB1/D11 under the background of cpb1 mutant not only rescued normal panicle architecture and plant height, but also had a larger leaf angle and seed size than the controls. Furthermore, the CPB1/D11 transgenic plants driven by panicle-specific promoters can enlarge seed size and enhance grain yield without affecting other favourable agronomic traits. These results demonstrated that the specific mutation in CPB1/D11 influenced development of panicle architecture and seed size, and manipulation of CPB1/D11 expression using the panicle-specific promoter could be used to increase seed size, leading to grain yield improvement in rice.
Department of Plant Genetics and Breeding, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China.
Yongzhen
Y
Wu
Department of Plant Genetics and Breeding, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China.
Yongcai
Y
Fu
Department of Plant Genetics and Breeding, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China.
Shuangshuang
S
Zhao
Department of Plant Genetics and Breeding, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China.
Ping
P
Gu
Department of Plant Genetics and Breeding, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China.
Zuofeng
Z
Zhu
Department of Plant Genetics and Breeding, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China.|State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing, China.
Chuanqing
C
Sun
Department of Plant Genetics and Breeding, National Center for Evaluation of Agricultural Wild Plants (Rice), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, China.
Lubin
L
Tan
D000483:Alleles; D000595:Amino Acid Sequence; D060406:Brassinosteroids / Q000378:metabolism; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D025461:Feedback, Physiological; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D009154:Mutation / Q000235:genetics; D009929:Organ Size / Q000235:genetics; D009928:Organ Specificity / Q000235:genetics; D012275:Oryza / Q000033:anatomy & histology* / Q000235:genetics*; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018547:Plant Stems / Q000033:anatomy & histology*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D015203:Reproducibility of Results; D012639:Seeds / Q000033:anatomy & histology* / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D025801:Ubiquitin / Q000235:genetics
D060406:Brassinosteroids; D010940:Plant Proteins; D025801:Ubiquitin
Oryza sativa; brassinosteroid; panicle architecture; seed size; transgenic plants