Abstract
Determination of floral organs in rice is controlled by mechanisms similar to the ABC model of Arabidopsis, but the detail is still unknown. OsMADS6, a member of rice MADS-box gene family, is classified in class G genes, and is expressed in lodicules, stamens, carpels, and so on. Also OsMADS6 is reported to interact with class A, B, E, G MADS-box proteins. In this study, we confirmed the expression profile of OsMADS6 using GUS reporter gene. OsMADS6 RNAi lines showed many defects in floral organs such like claw-shaped lemma/palea, palea-like lodicules, increase of lodicules and stigmas, decrease of stamens, and reduced fertility. In addition, the knocked-down mutants with the Tos17 insertion in OsMADS6 showed the phenotypes similar to those of the OsMADS6 RNAi lines. These results suggest that OsMADS6 participates in higher order MADS complexes with other MADS-box proteins to determine the identity and numbers of various floral organs.
