Blue Light Induces CRY2 To Regulate FT Transcription In Arabidopsis Thaliana

As a kind of flavin-binding protein,Cryptochrome is widely distributed in animals,plants,and microbe.It can regulate important biological processes such as light repair pyrimidine dimer,circadian clock,and light morphogenesis.In Arabidopsis,CRY1 and CRY2 play an important role in the regulation of light morphogenesis,among which CRY1 mainly inhibits the elongation of hypocotyl under blue light,and CRY2 mainly controls the photoperiod flowering initiation.CRY2 regulates flowering under blue light mainly through two pathways: 1.CRY2/SPAs/COP1/CO pathway;COP1 is E3 ligase of CO which act as a transcription factor,can form SPA1/CO/ COP1 protein complex under dark,that promotes degradation of CO.under blue light,CRY2/SPA1 interaction can form CRY2/SPA1/COP1 protein complex,which inhibits COP1-depent Ubiquitination of CO,which in turn causes CO to promote FT gene transcription.2.CIB1,as a b HLH transcription factor,interacts with CRY2 under blue light to promote FT gene transcription.In Arabidopsis,cryptochrome responds to light signal and transmits light signal almost simultaneously.In Arabidopsis,it is difficult to study the blue light signal transduction mediated by cryptochrome step by step.Therefore,based on previous studies,our lab used the human cell HEK293 T expression system to express proteins related to the CRY2-mediated blue light signal transduction pathway for detailed biochemical studies,and the following conclusions were obtained:1.In HEK293 T and Arabidopsis,CRY2 can form photobodies with SPA1.2.CRY2 can bind to specific areas of FT genes and promote FT transcription.3.Phosphorylation of CRY2 can enhance the ability of CRY2 to activate FT transcription and enhance the interaction between CRY2 and CIB1 to promote FT transcription.