Poster: Reproductive development

Abs # 378: Functional analyses of the flowering time gene OsMADS50, the putative SUPPRESSOR OF OVEREXPRESSION OF CO 1/ AGAMOUS-LIKE 20 (SOC1/AGL20) ortholog in rice

Presenter:	Lee, Shinyoung , love@postech.ac.kr
Authors	Lee, Shinyoung  (A)   Kim, Joonyul  (A) (B)  Han, Jong-Jin  (A)   Han, Min-Jung  (A)   An, Gynheung  (A)
Affiliations:	(A): Pohang University of Science and Technology (B): Michigan State University

A late-flowering mutant was isolated from rice T-DNA tagging lines. T-DNA had been integrated into the K-box region of OsMADS50, which shares 50.6% amino acid identity with the Arabidopsis MADS-box gene, SOC1/AGL20. While overexpression of OsMADS50 caused extremely early flowering at the callus stage, OsMADS50 RNAi plants exhibited phenotypes of late flowering and an increase in the number of elongated internodes. This confirmed that the phenotypes observed in the KO plants are due to the mutation in OsMADS50. RT-PCR analyses of the OsMADS50 KO and ubiquitin (ubi):OsMADS50 plants showed that OsMADS50 is an upstream regulator of OsMADS1, OsMADS14, OsMADS15, OsMADS18, and Hd3a, but works either in parallel or downstream of Hd1 and OsGI. These results suggest that OsMADS50 is an important flowering activator that controls various floral regulators in rice.