Induces Flowering in Rice by Modulating Expression of .

Rice is a facultative short-day (SD) plant in which flowering is induced under SD conditions or by other environmental factors and internal genetic programs. Overexpression of () accelerates flowering in hybrid rice. In this study, mutants defective in flowered late under both SD and long-day conditions. Expression levels of florigens () and (), and their immediate upstream floral activator (), were significantly decreased in the mutants, indicating that functions upstream of in controlling flowering time. Transcript levels of (), an upstream repressor of , were significantly increased in the mutants while those of and were reduced. Chromatin-immunoprecipitation assays revealed that HDT701 directly binds to the promoter region of . These results suggest that HDT701 induces flowering by suppressing