Identification of putative target genes of bZIP19, a transcription factor essential for Arabidopsis adaptation to Zn deficiency in roots. (October 2015)

• Record Type: Journal Article
• Authors: Inaba, Shoko; Kurata, Rie; Kobayashi, Mami; Yamagishi, Yoko; Mori, Izumi; Ogata, Yoshiyuki; Fukao, Yoichiro
• Is Part Of: Plant journal. Volume 84:Number 2(2015:Oct.)
• Page Start: 323
• Page End: 334
• Publication Date: 2015-10
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12996
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12996-abs-0001"> <title>Summary</title> <p>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 <italic>Arabidopsis thaliana</italic> 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 <italic>bZIP19</italic>. 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 <italic>bzip19</italic> mutant <italic>A. thaliana</italic> 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 <italic>bzip19</italic> mutant under Zn‐deficient conditions. Furthermore, selected reaction monitoring and quantitative real‐time PCR revealed that <italic>ZIP9</italic> 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 <italic>ZIP9</italic> was significantly more sensitive to Zn depletion than the wild‐type. These results demonstrate that bZIP19 mainly contributes to expression of genes, such as <italic>ZIP9</italic>, under Zn‐deficient conditions.</p> </abstract>