title: Functional diversification of the two C-class MADS box genes OSMADS3 and OSMADS58 in Oryza sativa.
abstract: The C-class MADS box gene AGAMOUS (AG) plays crucial roles in Arabidopsis thaliana development by regulating the organ identity of stamens and carpels, the repression of A-class genes, and floral meristem determinacy. To examine the conservation and diversification of C-class gene function in monocots, we analyzed two C-class genes in rice (Oryza sativa), OSMADS3 and OSMADS58, which may have arisen by gene duplication before divergence of rice and maize (Zea mays). A knockout line of OSMADS3, in which the gene is disrupted by T-DNA insertion, shows homeotic transformation of stamens into lodicules and ectopic development of lodicules in the second whorl near the palea where lodicules do not form in the wild type but carpels develop almost normally. By contrast, RNA-silenced lines of OSMADS58 develop astonishing flowers that reiterate a set of floral organs, including lodicules, stamens, and carpel-like organs, suggesting that determinacy of the floral meristem is severely affected. These results suggest that the two C-class genes have been partially subfunctionalized during rice evolution (i.e., the functions regulated by AG have been partially partitioned into two paralogous genes, OSMADS3 and OSMADS58, which were produced by a recent gene duplication event in plant evolution).
authors.affiliation: Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Dong Yeon
authors.initials: DY
authors.lastname: Lee
authors.forename: Akio
authors.initials: A
authors.lastname: Miyao
authors.forename: Hikohiko
authors.initials: H
authors.lastname: Hirochika
authors.forename: Gynheung
authors.initials: G
authors.lastname: An
authors.forename: Hiro-Yuki
authors.initials: HY
authors.lastname: Hirano
mesh_terms: D000595:Amino Acid Sequence; D019143:Evolution, Molecular; D035264:Flowers / Q000033:anatomy & histology / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D018390:Gene Targeting; D017403:In Situ Hybridization; D026161:MADS Domain Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000033:anatomy & histology / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference
chemical_list: D026161:MADS Domain Proteins; D010940:Plant Proteins