Search for photoreceptor-binding proteins mediating photomorphogenesis and their localization

筛选了具有向光性缺陷和叶绿体光取向运动缺陷的突变体。突变体分别由EMS和氮重离子束诱导。重离子束辐照获得的突变体中，有一个缺少拟南芥光敏色素发色基团结合域n端和nph1 c端几乎全长的嵌合基因AdiPHY3，表明这两种生理现象都是由PHY3介导的。研究了五种隐花苜蓿的表达模式。CRY1-3在配子体和孢子体的所有发育阶段均有表达。CRY4主要在孢子和暗生孢子体中表达。cry5主要存在于光生和暗生孢子体中。竞争性PCR结果显示，在红光诱导孢子萌发的条件下，CRY4表达下调，CRY5表达上调。隐花色素和GUS融合蛋白在洋葱表皮细胞中的表达模式表明，CRY3和cry4是在黑暗中转入细胞核的。采用双杂交方法筛选phy3结合蛋白候选基因。现在这些基因的特征正在进行中。

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.