Abstract
Rice (SDP) has the three key regulators of flowering time, OsGI, Hd1 and Hd3a have been shown to play important roles in the photoperiodic control of flowering in rice. Overexpression of Hd3a in rice was shown early flowering phenotype, therefore Hd3a is considered as switch gene of induction of the flowering. Although Hd3a encodes a protein with sequence similarity to the PEBP (phosphatidylethanolamine-binding protein) protein, Hd3a biochemical function is unknown. We have obtained transgenic rice expressing Hd3a :: gus and found that GUS activity was detected in an area surrounding the vascular tissue in the leaf. Hence, we introduced Hd3a cDNA fragment and Hd3a:GFP fusion cDNA into rice under the control of rolC, Cab and RPP16 promoter. The transgenic plants show early flowering phenotype. These results suggest that the expression of Hd3a in the leaf and cells surrounding the vascular tissue might be sufficient to promote the induction of flowering.
