Search for photoreceptor-binding proteins mediating photomorphogenesis and their localization

我们筛选出了铁线莲原丝体细胞中缺乏向光性和叶绿体光向性运动的突变体。突变体经EMS或重离子束氮离子诱变。其中一个突变体缺少AdiPHY3，AdiPHY3是N端的光敏色素发色团结合域与C端的几乎全长的拟南芥NPH1的嵌合基因，表明这两种生理现象都是由PHY3介导的。Cry1-3在所有发育阶段的配子体和孢子体中都有表达。CRY4主要在孢子和暗生长的孢子体中表达。Cry5主要存在于生长在光照和黑暗条件下的孢子体中。竞争性聚合酶链式反应显示，红光照射诱导孢子萌发时，CRY4基因表达下调，CRY5基因表达上调。隐色素和GUS融合蛋白在洋葱表皮细胞中的表达模式表明，CRY3和CRY4在黑暗中转移到细胞核中。现在，这些基因的特征描述正在进行中。

We screened mutants which are in defect of phototropism and chloroplast photoorientation movement in Adiantum protonemal cells. The mutants were induced by EMS or heavy ion beam of nitrogen. One of the mutants obtained by heavy ion beam irradiation lack AdiPHY3, which is a chimeric gene of phytochrome chromophore binding domain at N-terminus and almost full length of Arabidopsis NPH1at C-terminus, suggesting that the both physiological phenomena are mediated by PHY3.Expression pattern of five Adiantum cryptochromes were studied. CRY1-3 are expressed in all developmental stages tested both in gametophytes and in sporophytes. CRY4 is mainly expressed in spores and dark-grown sporophytes. CRY 5 is mainly in sporophytes grown both in the light and darkness. Competitive PCR shows that CRY4 is down- regulated and CRY5 is up-regulated when spores were irradiated with red light for the induction of spore germination. The expression pattern of fusion proteins of cryptochrome and GUS in onion epidermal cells suggests that CRY3 and 4 are transferred into nuclei in the dark.Candidates of genes of PHY3-binding proteins were screened by two-hybrid method. Now characterization of those genes are underway.