title: Curved chimeric palea 1 encoding an EMF1-like protein maintains epigenetic repression of OsMADS58 in rice palea development.
abstract: Floral organ specification is controlled by various MADS-box genes in both dicots and monocots, whose expression is often subjected to both genetic and epigenetic regulation in Arabidopsis thaliana. However, little information is known about the role of epigenetic modification of MADS-box genes during rice flower development. Here, we report the characterization of a rice gene, curved chimeric palea 1 (CCP1) that functions in palea development. Mutation in CCP1 resulted in abnormal palea with ectopic stigmatic tissues and other pleiotropic phenotypes. We found that OsMADS58, a C-class gene responsible for carpel morphogenesis, was ectopically expressed in the ccp1 palea, indicating that the ccp1 palea was misspecified and partially acquired carpel-like identity. Constitutive expression of OsMADS58 in the wild-type rice plants caused morphological abnormality of palea similar to that of ccp1, whereas OsMADS58 knockdown by RNAi in ccp1 could rescue the abnormal phenotype of mutant palea, suggesting that the repression of OsMADS58 expression by CCP1 is critical for palea development. Map-based cloning revealed that CCP1 encodes a putative plant-specific emBRYONIC flower1 (EMF1)-like protein. Chromatin immunoprecipitation assay showed that the level of the H3K27me3 at the OsMADS58 locus was greatly reduced in ccp1 compared with that in the wild-type. Taken together, our results show that CCP1 plays an important role in palea development through maintaining H3K27me3-mediated epigenetic silence of the carpel identity-specifying gene OsMADS58, shedding light on the epigenetic mechanism in floral organ development.
authors: National Key Laboratory of Plant Molecular Genetics, National Center for Plant Gene Research (Shanghai), Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
authors: Dawei
authors: D
authors: Yan
authors: Xiaoming
authors: X
authors: Zhang
authors: Lin
authors: L
authors: Zhang
authors: Shenghai
authors: S
authors: Ye
authors: Longjun
authors: L
authors: Zeng
authors: Jiyun
authors: J
authors: Liu
authors: Qun
authors: Q
authors: Li
authors: Zuhua
authors: Z
authors: He
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D001483:Base Sequence; D063185:Epigenetic Repression; D035264:Flowers / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D008745:Methylation; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011993:Recombinant Fusion Proteins; D017422:Sequence Analysis, DNA; D020798:Two-Hybrid System Techniques
chemical_list: D006657:Histones; D026161:MADS Domain Proteins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins
keywords: EMF1-like; H3K27 trimethylation; MADS-box; epigenetic regulation; floral organ identity; rice