In Arabidopsis,although studies have demonstrated that phytochrome A(phyA)and phyB are involved in blue light signaling,how blue light-activated phytochromes modulate the activity of the CONSTITUTIVELY PHOTOMORPHOGENI...In Arabidopsis,although studies have demonstrated that phytochrome A(phyA)and phyB are involved in blue light signaling,how blue light-activated phytochromes modulate the activity of the CONSTITUTIVELY PHOTOMORPHOGENIC1(COP1)-SUPPRESSOR OF PHYA-105(SPA1)E3 complex remains largely unknown.Here,we show that phyA responds to early and weak blue light,whereas phyB responds to sustainable and strong blue light.Activation of both phyA and phyB by blue light inhibits SPA1 activity.Specifically,blue light irradiation promoted the nuclear import of both phytochromes to stimulate their binding to SPA1,abolishing SPA1’s interaction with LONG HYPOCOTYL 5(HY5)to release HY5,which promoted seedling photomorphogenesis.展开更多
基金supported by funds from the National Natural Science Foundation of China 31871709,31570268,31400259,and 31170267。
文摘In Arabidopsis,although studies have demonstrated that phytochrome A(phyA)and phyB are involved in blue light signaling,how blue light-activated phytochromes modulate the activity of the CONSTITUTIVELY PHOTOMORPHOGENIC1(COP1)-SUPPRESSOR OF PHYA-105(SPA1)E3 complex remains largely unknown.Here,we show that phyA responds to early and weak blue light,whereas phyB responds to sustainable and strong blue light.Activation of both phyA and phyB by blue light inhibits SPA1 activity.Specifically,blue light irradiation promoted the nuclear import of both phytochromes to stimulate their binding to SPA1,abolishing SPA1’s interaction with LONG HYPOCOTYL 5(HY5)to release HY5,which promoted seedling photomorphogenesis.