Abstract
GAMYB is known to be a transcription factor that activates a gibberellin-inducible α-amylase gene expression at aleurone layer in germinating cereal seed. Recent studies for two long-day plants, Lolium and Arabidopsis, showed that GAMYB mRNA is expressed at inflorescence meristem and tapetum in premature anther after flower initiation . We found that OsGAMyb is also expressed at developing inflorescence in rice, and observed (1) delay of germination, (2) suppression of internode elongation, and (3) morphological changes of inflorescence (decrease of primary branch and secondary branch) in GAMyb mutant which showed the reduction of the OsGAMyb transcripts. Furthermore we analyzed that transgenic rice carrying with Ubi::OsGAMYB RNAi gene, and consequently found that the Ubi::OsGAMYB RNAi rice showed the similar phenotype to GAMyb mutant .We discuss about role for OsGAMyb in germination and formation of inflorescence.
