title: The putative Arabidopsis zinc transporter ZTP29 is involved in the response to salt stress.
abstract: Salt stress leads to a stress response, called the unfolded protein response (UPR), in the endoplasmic reticulum (ER). UPR is also induced in a wide range of organisms by zinc deficiency. However, it is not clear whether regulation of zinc levels is involved in the initiation of the UPR in plant response to salt stress. In this study, a putative zinc transporter, ZTP29, was identified in Arabidopsis thaliana. ZTP29 localizes to the ER membrane and is expressed primarily in hypocotyl and cotyledon tissues, but its expression can be induced in root tissue by salt stress. T-DNA insertion into the ZTP29 gene led to NaCl hypersensitivity in seed germination and seedling growth, leaf etiolation, and widening of cells in the root elongation zone. In addition, in ztp29 mutant plants, salt stress-induced upregulation of the UPR pathway genes BiP2 and bZIP60 was inhibited. Furthermore, under conditions of salt stress, upregulation of BiP2 and bZIP60 was inhibited by treatment with high concentrations of zinc in both control and ztp29 plants. However, zinc chelation restored salt stress-induced BiP2 and bZIP60 upregulation in ztp29 mutant plants. These experimental results suggest that ZTP29 is involved in the response to salt stress, perhaps through regulation of zinc levels required to induce the UPR pathway.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, Department of Plant Sciences, College of Biological Sciences, China Agricultural University, 100193 Beijing, China.
authors.forename: Miaoying
authors.initials: M
authors.lastname: Wang
authors.forename: Qiangyi
authors.initials: Q
authors.lastname: Xu
authors.forename: Jingjuan
authors.initials: J
authors.lastname: Yu
authors.forename: Ming
authors.initials: M
authors.lastname: Yuan
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D048430:Cell Shape / Q000187:drug effects; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D055786:Gene Knockout Techniques; D017343:Genes, Plant / Q000235:genetics; D018525:Germination / Q000187:drug effects; D008969:Molecular Sequence Data; D010802:Phylogeny; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects* / Q000235:genetics; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D056811:Unfolded Protein Response / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects; D015032:Zinc / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D027682:Cation Transport Proteins; D012333:RNA, Messenger; C550462:ZTP29 protein, Arabidopsis; C017800:zinc-binding protein; D012965:Sodium Chloride; D015032:Zinc