Quantitative imaging reveals the role of MpARF proteasomal degradation during gemma germination  

作　　者：Shubhajit Das Martijn de Roij Simon Bellows Melissa Dipp Alvarez Sumanth Mutte Wouter Kohlen Etienne Farcot Dolf Weijers Jan Willem Borst 

机构地区：[1]Laboratory of Biochemistry,Wageningen University and Research,Stippeneng 4,6708WE Wageningen,the Netherlands [2]School of Mathematical Sciences,University of Nottingham,University Park,NG72RD Nottingham,UK [3]Laboratory of Molecular Biology,Wageningen University and Research,Droevendaalsesteeg 1,6708PB Wageningen,the Netherlands [4]Present address:Institute of Science and Technology,3400 Klosterneuburg,Austria

出　　处：《Plant Communications》2024年第11期116-127,共12页植物通讯（英文）

基　　金：Netherlands Organisation for Scientific Research,the Netherlands(grants ALWOP.402 and OCENW.M20.031 to J.W.B.);Human Frontiers Research Program(grant RGP0015/2022 to D.W.).

摘　　要：The auxin signaling molecule controls a variety of growth and developmental processes in land plants. Auxin regulates gene expression through a nuclear auxin signaling pathway (NAP) consisting of the ubiquitin ligase auxin receptor TIR1/AFB, its Aux/IAA degradation substrate, and DNA-binding ARF transcription factors. Although extensive qualitative understanding of the pathway and its interactions has been obtained, mostly by studying the flowering plant Arabidopsis thaliana, it remains unknown how these translate to quantitative system behavior in vivo, a problem that is confounded by the large NAP gene families in most species. Here, we used the minimal NAP of the liverwort Marchantia polymorpha to quantitatively map NAP protein accumulation and dynamics in vivo through the use of knockin fluorescent fusion proteins. Beyond revealing the dynamic native accumulation profile of the entire NAP protein network, we discovered that the two central ARFs, MpARF1 and MpARF2, are proteasomally degraded. This auxin-independent degradation tunes ARF protein stoichiometry to favor gene activation, thereby reprogramming auxin response during the developmental progression. Thus, quantitative analysis of the entire NAP has enabled us to identify ARF degradation and the stoichiometries of activator and repressor ARFs as a potential mechanism for controlling gemma germination.

关 键 词：auxin signaling ARF degradation Marchantia polymorpha live cell imaging 

分 类 号：Q94[生物学—植物学]