Four plasma membrane-localized MGR transporters mediate xylem Mg^(2+)loading for root-to-shoot Mg^(2+)translocation in Arabidopsis  

作　　者：Su-Fang Meng Bin Zhang Ren-Jie Tang Xiao-Jiang Zheng Rui Chen Cong-Ge Liu Yan-Ping Jing Hai-Man Ge Chi Zhang Yan-Li Chu Ai-Gen Fu Fu-Geng Zhao Sheng Luan Wen-Zhi Lan 

机构地区：[1]State Key Laboratory for Pharmaceutical Biotechnology,School of Life Sciences,Nanjing University,Nanjing 210023,Jiangsu,China [2]Institute of Future Agriculture,Northwest A&F University,Yangling 712100,Shaanxi,China [3]The Key Laboratory of Western Resources Biology and Biological Technology,College of Life Sciences,Northwest University,Xi'an 710069,China [4]Department of Plant and Microbial Biology,University of California,Berkeley,CA 94720,USA

出　　处：《Molecular Plant》2022年第5期805-819,共15页分子植物（英文版）

基　　金：supported by the National Natural Science Foundation of China(31770267);the National Science Foundation(MCB-1715764).

摘　　要：Magnesium(Mg^(2+)),an essential structural component of chlorophyll,is absorbed from the soil by roots and transported to shoots to support photosynthesis in plants.However,the molecular mechanisms underlying root-to-shoot Mg^(2+)translocation remain largely unknown.We describe here the identification of four plasma membrane(PM)-localized transporters,named Mg^(2+)release transporters(MGRs),that are critical for root-to-shoot Mg transport in Arabidopsis.Functional complementation assays in a Mg^(2+)-uptake-defi-cient bacterial strain confirmed that these MGRs conduct Mg^(2+)transport.PM-localized MGRs(MGR4,MGR5,MGR6,and MGR7)were expressed primarily in root stellar cells and participated in the xylem loading step of the long-distance Mg^(2+)transport process.In particular,MGR4 and MGR6 played a major role in shoot Mg homeostasis,as their loss-of-function mutants were hypersensitive to low Mg^(2+)but tolerant to high Mg^(2+)conditions.Reciprocal grafting analysis further demonstrated that MGR4 functions in the root to determine shoot Mg^(2+)accumulation and physiological phenotypes caused by both low-and high-Mg^(2+)stress.Taken together,our study has identified the long-sought transporters responsible for root-to-shoot Mg^(2+)translocation in plants.

关 键 词：functional conservation metal nutrient magnesium long-distance transport PHENOTYPING 

分 类 号：Q94[生物学—植物学]