2009 Fiscal Year Final Research Report

Analysis of transcriptional regulation of florigen gene expression in rice

Research Project

Project/Area Number	20770040
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Single-year Grants
Research Field	Plant molecular biology/Plant physiology
Research Institution	National Institute of Agrobiological Sciences
Principal Investigator	ITO Hironori National Institute of Agrobiological Sciences, 光環境応答研究ユニット, 任期付研究員 (00466012)
Project Period (FY)	2008 – 2009
Keywords	環境応答 / フロリゲン / 青色光受容体 / 転写制御
Research Abstract	Crop yields are strongly associated with flowering-time. Florigen triggers photoperiodic flowering in plants. In rice, a short-day plant, Ehd1, a B-type response regulator, up-regulates florigen Hd3a expression and mainly confers SD-dependent promotion of flowering. Previous studies indicate that the function of OsGI, a component of circadian clocks in rice, is necessary for the Ehd1 induction in response to blue light. This study demonstrated that Ehd1 was maximally induced by blue light given around subjective dawn. Since this induction was not occurred in osgi-deficient background, OsGI shapes a light sensitive phase around dawn to blue-lights signals for Ehd1 expression. These results strongly indicate that morning Ehd1 expression is occurred when blue-light coincide with the morning phase set by OsGI-dependent circadian clocks.