Premium
Identification of putative target genes of bZIP19, a transcription factor essential for Arabidopsis adaptation to Zn deficiency in roots
Author(s) -
Inaba Shoko,
Kurata Rie,
Kobayashi Mami,
Yamagishi Yoko,
Mori Izumi,
Ogata Yoshiyuki,
Fukao Yoichiro
Publication year - 2015
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12996
Subject(s) - biology , mutant , arabidopsis , transcription factor , gene , zinc finger , wild type , arabidopsis thaliana , genetics , gene expression , forward genetics , microbiology and biotechnology , zinc finger transcription factor
Summary 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 bZIP 19 . To identify proteins whose expression is affected by bZIP 19, 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, ZIP 3 and ZIP 9, 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 ZIP 9 expression is mediated by bZIP 19 and may be partly supported by bZIP 23, a homolog of bZIP 19. Mutant analysis revealed that ZIP 9 is involved in uptake of Zn by the roots, and the mutant lacking ZIP 9 was significantly more sensitive to Zn depletion than the wild‐type. These results demonstrate that bZIP 19 mainly contributes to expression of genes, such as ZIP 9 , under Zn‐deficient conditions.