摘要
FLAVIN-BINDING KELCH REPEAT F-BOX 1(FKF1)encodes an F-box protein that regulates photoperiod flowering in Arabidopsis under long-day conditions(LDs).Gibberellin(GA)is also important for regulating flowering under LDs.However,how FKF1 and the GA pathway work in concert in regulating flowering is not fully understood.Here,we showed that the mutation of FKF1 could cause accumulation of DELLA proteins,which are crucial repressors in GA signaling pathway,thereby reducing plant sensitivity to GA in flowering.Both in vitro and in vivo biochemical analyses demonstrated that FKF1 directly interacted with DELLA proteins.Furthermore,we showed that FKF1 promoted ubiquitination and degradation of DELLA proteins.Analysis of genetic data revealed that FKF1 acted partially through DELLAs to regulate flowering under LDs.In addition,DELLAs exerted a negative feedback on FKF1 expression.Collectively,these findings demonstrate that FKF1 promotes flowering partially by negatively regulating DELLA protein stability under LDs,and suggesting a potential mechanism linking the FKF1 to the GA signaling DELLA proteins.
基金
We thank Dr.Hongtao Liu for her kind advice on thiswork,Dr.Chentao Lin for providing fkf1-1 seeds,Dr.Taiping Sun for providing ga1-3(Col background),Dr.Xingwang Deng for 35S:TAP-RGA transgenic seedsand della mutant seeds,Dr.Xiangdong Fu for gaiseeds,Dr.Suiwen Hou for rga-28 seeds,Dr.DaoxinXie for ga1-3(Ler background),Q1,Q2,and pentamutant seeds.This work was supported by the Na-tional Natural Science Foundation of China(No.31171176)
Natural Science Foundation of HunanProvince(No.2018JJ3036)
the Basic Research Pro-gram of Shenzhen Municipal Science and Technologylnnovation Committee(No.JCYJ20170818112212721)
and the Basic Research Program of ChangshaMunicipal Science and Technology(No.kq1901o28).
