title: Identification of putative target genes of bZIP19, a transcription factor essential for Arabidopsis adaptation to Zn deficiency in roots.
abstract: Zinc (Zn) depletion adversely affects plant growth. To avoid lethal depletion of cellular Zn, plants have evolved mechanisms to adjust the expression of genes associated with Zn homeostasis, the details of which are poorly understood. In the present study, we isolated an Arabidopsis thaliana T-DNA insertion mutant that exhibited hypersensitivity to Zn depletion. By monitoring root development under Zn-deficient conditions, we isolated a single mutant lacking the basic-region leucine-zipper transcription factor gene bZIP19. To identify proteins whose expression is affected by bZIP19, an iTRAQ-based quantitative proteomics analysis was performed using microsomal proteins from wild-type and the bzip19 mutant A. thaliana roots grown on Basal and Zn-deficient media. Of the 797 proteins identified, expression of two members of the Zrt- and Irt-related protein family, ZIP3 and ZIP9, and three defensin-like family proteins was markedly induced in wild-type but not in the bzip19 mutant under Zn-deficient conditions. Furthermore, selected reaction monitoring and quantitative real-time PCR revealed that ZIP9 expression is mediated by bZIP19 and may be partly supported by bZIP23, a homolog of bZIP19. Mutant analysis revealed that ZIP9 is involved in uptake of Zn by the roots, and the mutant lacking ZIP9 was significantly more sensitive to Zn depletion than the wild-type. These results demonstrate that bZIP19 mainly contributes to expression of genes, such as ZIP9, under Zn-deficient conditions.
authors: Department of Bioinformatics, Ritsumeikan University, Kusatsu, Shiga, 525-8577, Japan.|Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan.
authors: Shoko
authors: S
authors: Inaba
authors: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan.
authors: Rie
authors: R
authors: Kurata
authors: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan.
authors: Mami
authors: M
authors: Kobayashi
authors: Thermo Fisher Scientific, Yokohama, Kanagawa, 221-0022, Japan.
authors: Yoko
authors: Y
authors: Yamagishi
authors: Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan.
authors: Izumi
authors: I
authors: Mori
authors: Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, 599-8531, Japan.
authors: Yoshiyuki
authors: Y
authors: Ogata
authors: Department of Bioinformatics, Ritsumeikan University, Kusatsu, Shiga, 525-8577, Japan.|Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan.
authors: Yoichiro
authors: Y
authors: Fukao
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015032:Zinc / Q000172:deficiency*
chemical_list: D029681:Arabidopsis Proteins; D014157:Transcription Factors; D015032:Zinc
keywords: Arabidopsis thaliana; ZIP family transporter; bZIP transcription factor; quantitative proteomics; quantitative real-time PCR; zinc deficiency