The AFB1 auxin receptor controls the cytoplasmic auxin response pathway in Arabidopsis thaliana  

作　　者：Shiv Mani Dubey Soeun Han Nathan Stutzman Michael J.Prigge Eva Medvecka Matthieu Pierre Platre Wolfgang Busch Matyas Fendrych Mark Estelle 

机构地区：[1]Department of Experimental Plant Biology,Faculty of Sciences,Charles University,Prague,Czech Republic [2]Section of Cell and Developmental Biology,University of California San Diego,La Jolla,CA,USA [3]Plant Molecular and Cellular Biology Laboratory and Integrative Biology Laboratory,Salk Institute for Biological Studies,La Jolla,CA,USA [4]Department of Biology,Chungbuk National University,Cheongju,Korea

出　　处：《Molecular Plant》2023年第7期1120-1130,共11页分子植物（英文版）

基　　金：the National Institute of General Medical Sciences(NIGMS)with grants to M.E.(R35GM141892)and to W.B.(R01GM127759);by the European Research Council(grant no.803048);M.F.M.P.P.was supported by a long-term postdoctoral fellowship(LT000340/2019 L)by the Human Frontier Science Program Organization.

摘　　要：The phytohormone auxin triggers root growth inhibition within seconds via a non-transcriptionalpathway.Among members of the TIR1/AFB auxin receptor family,AFB1 has a primary role in this rapidresponse. However, the unique features that confer this specific function have not been identified.Here we show that the N-terminal region of AFB1, including the F-box domain and residues thatcontribute to auxin binding,is essential and sufficient for its specific role in the rapid response. Substitutionof the N-terminal region of AFB1 with that of TIR1 disrupts its distinct cytoplasm-enriched localizationand activity in rapid root growth inhibition by auxin. Importantly, the N-terminal region of AFB1 isindispensable for auxin-triggered calcium influx, which is a prerequisite for rapid root growth inhibition.Furthermore, AFB1 negatively regulates lateral root formation and transcription of auxin-induced genes,suggesting that it plays an inhibitory role in canonical auxin signaling. These results suggest that AFB1may buffer the transcriptional auxin response, whereas it regulates rapid changes in cell growth thatcontributeto rootgravitropism.

关 键 词：GRAVITROPISM calcium auxin signaling ARABIDOPSIS lateral root 

分 类 号：Q94[生物学—植物学]