PHYTOCHROME-INTERACTING FACTORS Interact with the ABA Receptors PYL8 and PYL9 to Orchestrate ABA Signaling in Darkness  

作　　者：Lijuan Qi Shan Liu Cong Li Jingying Fu Yanjun Jing Jinkui Cheng Hong Li Dun Zhang Xiaoji Wang Xiaojing Dong Run Han Bosheng Li Yu Zhang Zhen Li William Terzaghi Chun-Peng Song Rongcheng Lin Zhizhong Gong Jigang Li 

机构地区：[1]State Key Laboratory of Plant Physiology and Biochemistry,College of Biological Sciences,China Agricultural University,Beijing 100193,China [2]Key Laboratory of Photobiology,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China [3]Institute of Plant and Food Science,Department of Biology,Southern University of Science and Technology,Shenzhen,Guangdong 518055,China [4]Department of Plant and Microbial Biology,University of California,Berkeley,CA 94720,USA [5]Plant Gene Expression Center,Agriculture Research Service,U.S.Department of Agriculture,Albany,CA 94710,USA [6]Department of Biology,Wilkes University,Wilkes-Barre,PA 18766,USA [7]Institute of Plant Stress Biology,Collaborative Innovation Center of Crop Stress Biology,Henan University,Kaifeng 475001,China

出　　处：《Molecular Plant》2020年第3期414-430,共17页分子植物（英文版）

基　　金：supported by grants from the National Natural Science Foundation of China(31970262 and 31770321);the Ministry of Agriculture of China for Transgenic Research(2019ZX08010003-002-005);Beijing Outstanding University Discipline Program,and the Recruitm ent Program of Global Youth Experts of China.

摘　　要：PHYTOCHROME-INTERACTING FACTORS(PIFs)are a group of basic helix-loop-helix transcription factors that can physically interact with photoreceptors,including phytochromes and cryptochromes.It was previously demonstrated that PIFs accumulated in darkness and repressed seedling photomorphogenesis,and that PIFs linked different photosensory and hormonal pathways to control plant growth and development.In this study,we show that PIFs positively regulate the ABA signaling pathway during the seedling stage specifically in darkness.We found that PIFs positively regulate ABI5 transcript and protein levels in darkness in response to exogenous ABA treatment by binding directly to the G-box motifs in the ABI5 promoter.Consistently,PIFs and the G-box motifs in the ABI5 promoter determine ABI5 expression in darkness,and overexpression of ABI5 could rescue the ABA-insensitive phenotypes of pifq mutants in the dark.Moreover,we discovered that PIFs can physically interact with the ABA receptors PYL8 and PYL9,and that this interaction is not regulated by ABA.Further analyses showed that PYL8 and PYL9 promote PIF4 protein accumulation in the dark and enhance PIF4 binding to the ABI5 promoter,but negatively regulate PIF4-mediated ABI5 activation.Taken together,our data demonstrate that PIFs interact with ABA receptors to orchestrate ABA signaling in darkness by controlling ABI5 expression,providing new insights into the pivotal roles of PIFs as signal integrators in regulating plant growth and development.

关 键 词：ARABIDOPSIS transcription factor PIFs ABA ABI5 DARKNESS 

分 类 号：Q94[生物学—植物学]