title: Overexpression of Peptide-Encoding OsCEP6.1 Results in Pleiotropic Effects on Growth in Rice (O. sativa).
abstract: Plant peptide hormones play an important role in regulating plant developmental programs via cell-to-cell communication in a non-cell autonomous manner. To characterize the biological relevance of C-TERMINALLY ENCODED PEPTIDE (CEP) genes in rice, we performed a genome-wide search against public databases using a bioinformatics approach and identified six additional CEP members. Expression analysis revealed a spatial-temporal pattern of OsCEP6.1 gene in different tissues and at different developmental stages of panicle. Interestingly, the expression level of the OsCEP6.1 was also significantly up-regulated by exogenous cytokinin. Application of a chemically synthesized 15-amino acid OsCEP6.1 peptide showed that OsCEP6.1 had a negative role in regulating root and seedling growth, which was further confirmed by transgenic lines. Furthermore, the constitutive expression of OsCEP6.1 was sufficient to lead to panicle architecture and grain size variations. Scanning electron microscopy analysis revealed that the phenotypic variation of OsCEP6.1 overexpression lines resulted from decreased cell size but not reduced cell number. Moreover, starch accumulation was not significantly affected. Taken together, these data suggest that the OsCEP6.1 peptide might be involved in regulating the development of panicles and grains in rice.
authors.affiliation: Key Laboratory of Crop Heterosis and Utilization (MOE) and State Key Laboratory for Agrobiotechnology, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China; National Center for Plant Gene Research-BeijingBeijing, China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Sui
authors.affiliation: Key Laboratory of Crop Heterosis and Utilization (MOE) and State Key Laboratory for Agrobiotechnology, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China; National Center for Plant Gene Research-BeijingBeijing, China.
authors.forename: Tianya
authors.initials: T
authors.lastname: Wang
authors.affiliation: Key Laboratory of Crop Heterosis and Utilization (MOE) and State Key Laboratory for Agrobiotechnology, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China; National Center for Plant Gene Research-BeijingBeijing, China.
authors.forename: Hongjian
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory of Crop Heterosis and Utilization (MOE) and State Key Laboratory for Agrobiotechnology, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China; National Center for Plant Gene Research-BeijingBeijing, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Crop Heterosis and Utilization (MOE) and State Key Laboratory for Agrobiotechnology, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China; National Center for Plant Gene Research-BeijingBeijing, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Qingdao Agricultural University Qingdao, China.
authors.forename: Ruibin
authors.initials: R
authors.lastname: Xu
authors.affiliation: Shanxi Agricultural University Taigu, China.
authors.forename: Guofang
authors.initials: G
authors.lastname: Xing
authors.affiliation: Key Laboratory of Crop Heterosis and Utilization (MOE) and State Key Laboratory for Agrobiotechnology, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China; National Center for Plant Gene Research-BeijingBeijing, China.
authors.forename: Zhongfu
authors.initials: Z
authors.lastname: Ni
authors.affiliation: Key Laboratory of Crop Heterosis and Utilization (MOE) and State Key Laboratory for Agrobiotechnology, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural UniversityBeijing, China; National Center for Plant Gene Research-BeijingBeijing, China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Xin
keywords: CEP; cell size; grain size; rice; signaling peptide