Poster: Late and Moved Abstracts

Abs # 1015: Functional analysis of FT-like genes in flower induction of rice

Presenter:	Komiya, Reina , r-komiya@bs.naist.jp
Authors	Komiya, Reina  (A)   Ikegami, Akiko  (A)   Yokoi, Shuji  (A)   Shimamoto, Ko  (A)
Affiliations:	(A): Nara Institute of Science and Technology

Flowering time of many plants is regulated by day length. Recently, it became clear that genes involved in the signaling pathway for flowering are highly conserved in the long-day plant (Arabidopsis : GI-CO-FT) and the short-day plant (Rice : OsGI-Hd1-Hd3a). In Arabidopsis, FT is the only functional FT-like gene of this pathway. However, in rice, eleven FT-like genes (FT-L1~11) are present. Previously, over expression for FT-like genes in rice indicated that some FT-like genes (FT-L1, 2, 3) are involved in flowering. To examine functions of other FT-like genes besides Hd3a (FT-L2) in rice, we analyzed the expression of FT-like genes and examined their function by RNAi. Expression analysis of FT-like genes every 10 days during the growth of rice showed that in se5, a mutant lacking the phytocrome function, Hd3a (FT-L2) mRNA was increased and FT-L1, 3, 5, 6 were also increased compared with WT. To further study functions of FT-like genes in flowering, we made two types of RNAi constructs and introduced them into rice. One group of the RNAi constructs was designed to specifically suppress the expression of individual FT-like genes (FT-L1, 2, 3, 5 or 6). The second group of RNAi constructs was designed to simultaneously suppress multiple FT-like genes (FT-L1~3 or FT-L5~6) by using conserved sequences. We are currently investigating the phenotype, particularly the flowering date, of the transgenic plants to examine whether Hd3a and other FT-like genes promote flowering.