Abstract
In northern part of Japan, rice crop production is occasionally damaged severely by cool temperature in summer due to the disturbance in pollen formation. Rice is most chilling sensitive at the onset of microspore release. Through the application of chilling stress in rice anther, the expression of OPDAR1 and Radc1 was repressed and the expression of SAMDC1 was induced. A new cis element that includes a DNA transposon Castaway sequence was found in the 5' upstream region of Radc1 and OsSalT which were conspicuously down-regulated by chilling temperatures in rice anther. Expression patterns of these genes were histochemically examined in anthers from transgenic rice plants bearing individual gene promoter::(GUS or GFP) fusions. Functional analyses of these genes are now being conducted by producing transgenic rice plants which are over-expressing these genes and by observing in situ hybridization of transcripts.
