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The PalWRKY77 transcription factor negatively regulates salt tolerance and abscisic acid signaling in Populus
Author(s) -
Jiang Yuanzhong,
Tong Shaofei,
Chen Ningning,
Liu Bao,
Bai Qiuxian,
Chen Yang,
Bi Hao,
Zhang Zhiyang,
Lou Shangling,
Tang Hu,
Liu Jianquan,
Ma Tao,
Liu Huanhuan
Publication year - 2021
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.15109
Subject(s) - abscisic acid , wrky protein domain , transcription factor , biology , abiotic stress , signal transduction , microbiology and biotechnology , repressor , salinity , abiotic component , jasmonate , botany , photosynthesis , gene , arabidopsis , biochemistry , mutant , ecology
Summary High salinity, one of the most widespread abiotic stresses, inhibits photosynthesis, reduces vegetation growth, blocks respiration and disrupts metabolism in plants. In order to survive their long‐term lifecycle, trees, such as Populus species, recruit the abscisic acid (ABA) signaling pathway to adapt to a saline environment. However, the molecular mechanism behind the ABA‐mediated salt stress response in woody plants remains elusive. We have isolated a WRKY transcription factor gene, PalWRKY77 , from Populus alba var. pyramidalis (poplar), the expression of which is repressed by salt stress. PalWRKY77 decreases salt tolerance in poplar. Furthermore, PalWRKY77 negatively regulated ABA‐responsive genes and relieved ABA‐mediated growth inhibition, indicating that PalWRKY77 is a repressor of the ABA response. In vivo and in vitro assays revealed that PalWRKY77 targets the ABA‐ and salt‐induced PalNAC002 and PalRD26 genes by binding to the W‐boxes in their promoters. In addition, overexpression of both PalNAC002 and PalRD26 could elevate salt tolerance in transgenic poplars. These findings reveal a novel negative regulation mechanism for the ABA signaling pathway mediated by PalWRKY77 that results in more sensitivity to salt stress in poplar. This deepens our understanding of the complex responses of woody species to salt stress.