Abstract
Red- and far-red-sensing photoreceptors; phytochromes are encoded by small gene families in higher plants. The phytochrome gene family consists of only three members known as PHYA, PHYB and PHYC in rice while it contains five genes in Arabidopsis. Each member of phytochromes has distinct as well as cooperative roles in monitoring and responding to the environmental light signals. In this study, we isolated the promoter region of each phytochrome gene from rice genome and analyzed the distinct expression patterns of each phytochrome. Transgenes composed of each promoter and cDNA were introduced to appropriate phytochrome mutants. Photomorphogenesis of the T1 seedlings indicated that the isolated promoters regulated downstream cDNAs accordingly. We also made promoter-GUS transgenic rice plants and found the different patterns of GUS expression among these promoters. Moreover, we monitored nucleocytoplasmic partitioning of rice phytochromes by using phytochrome-GFP fusion proteins.
