title: A chloroplast envelope membrane protein containing a putative LrgB domain related to the control of bacterial death and lysis is required for chloroplast development in Arabidopsis thaliana.
abstract: • A protein encoded by At1g32080 was consistently identified in proteomic studies of Arabidopsis chloroplast envelope membranes, but its function remained unclear. The protein, designated AtLrgB, may have evolved from a gene fusion of lrgA and lrgB. In bacteria, two homologous operons, lrgAB and cidAB, participate in an emerging mechanism to control cell death and lysis. • We aim to characterize AtLrgB using reverse genetics and cell biological and biochemical analysis. • AtLrgB is expressed in leaves, but not in roots. T-DNA insertion mutation of AtLrgB produced plants with interveinal chlorotic and premature necrotic leaves. Overexpression of full-length AtLrgB (or its LrgA and LrgB domains, separately), under the control of CaMV 35S promoter, produced plants exhibiting veinal chlorosis and delayed greening. At the end of light period, the T-DNA mutant had high starch and low sucrose contents in leaves, while the 35S:AtLrgB plants had low starch and high sucrose contents. Metabolite profiling revealed that AtLrgB appeared not to directly transport triose phosphate or hexose phosphates. In yeast cells, AtLrgB could augment nystatin-induced membrane permeability. • Our work indicates that AtLrgB is a new player in chloroplast development, carbon partitioning and leaf senescence, although its molecular mechanism remains to be established.
authors.affiliation: Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Jin
authors.affiliation: Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Lin
authors.affiliation: Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Chaoqun
authors.initials: C
authors.lastname: Wang
authors.affiliation: Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Zhehao
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Han
authors.affiliation: Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Hongwu
authors.initials: H
authors.lastname: Bian
authors.affiliation: Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Muyuan
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Institute of Genetics, College of Life Sciences, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
authors.forename: Junhui
authors.initials: J
authors.lastname: Wang
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000382:microbiology* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001433:Bacteriolysis / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D060365:Chloroplast Proteins / Q000737:chemistry / Q000378:metabolism; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D004269:DNA, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D050296:Microbial Viability / Q000187:drug effects; D016254:Mutagenesis, Insertional / Q000235:genetics; D009761:Nystatin / Q000494:pharmacology; D009876:Operon / Q000235:genetics; D010641:Phenotype; D010710:Phosphates / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics; D013213:Starch / Q000378:metabolism; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D060365:Chloroplast Proteins; D004269:DNA, Bacterial; C571061:LrgB protein, Arabidopsis; D008565:Membrane Proteins; D010710:Phosphates; C036483:T-DNA; D009761:Nystatin; D013395:Sucrose; D013213:Starch