Poster: Reproductive development
Abs #
358: OsDAPD3, a double AP2 domain gene, plays a major role in the transition of spikelet meristem to floral meristem in rice
In higher plants, the aboveground structure is determined by the two antagonistic functions of the shoot apical meristem (SAM), the maintenance in an indeterminate state and the successive organ formation. Although transition of SAM into reproductive stage and floral organ specification has been extensively studied by molecular genetic approaches, little is known about the genetic mechanisms during transition of inflorescence meristem to floral meristems due to absence of mutants. In this study, we report identification of the OsDAPD3 gene as the main regluator in spikelet meristem transition to floral meristem. The gene encodes a putative transcription factor carrying two AP2 domains. The gene is expressed in the all the tissue examined. In DAPD3 knockout plants, transition from spikelet meristems into floral meristems was delayed, resulting in production of more rudimentary glumes in alternative phyllotaxy. In addition, the empty glumes were transformed into the lemma/palea-like organs due to the increased expression of the OsMADS1 gene. The lodicules were altered into the lemma/palea-like organs. These results indicate that OsDAPD3 play a major roles in the transition of spikelet meristem to floral meristem and in floral organ specifications.
