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The glutamate carboxypeptidase AMP 1 mediates abscisic acid and abiotic stress responses in A rabidopsis
Author(s) -
Shi Yiting,
Wang Zheng,
Meng Pei,
Tian Siqi,
Zhang Xiaoyan,
Yang Shuhua
Publication year - 2013
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.12275
Subject(s) - abscisic acid , meristem , mutant , abiotic stress , biochemistry , reactive oxygen species , biology , oxidative stress , microbiology and biotechnology , chemistry , gene
SummaryALTERED MERISTEM PROGRAM 1 ( AMP 1 ) encodes a glutamate carboxypeptidase that plays an important role in shoot apical meristem development and phytohormone homeostasis. We isolated a new mutant allele of AMP 1 , amp1‐20 , from a screen for abscisic acid ( ABA ) hypersensitive mutants and characterized the function of AMP 1 in plant stress responses. amp1 mutants displayed ABA hypersensitivity, while overexpression of AMP 1 caused ABA insensitivity. Moreover, endogenous ABA concentration was increased in amp1‐20 ‐ and decreased in AMP 1 ‐overexpressing plants under stress conditions. Application of ABA reduced the AMP 1 protein level in plants. Interestingly, amp1 mutants accumulated excess superoxide and displayed hypersensitivity to oxidative stress. The hypersensitivity of amp1 to ABA and oxidative stress was partially rescued by reactive oxygen species ( ROS ) scavenging agent. Furthermore, amp1 was tolerant to freezing and drought stress. The ABA hypersensitivity and freezing tolerance of amp1 was dependent on ABA signaling. Moreover, amp1 had elevated soluble sugar content and showed hypersensitivity to high concentrations of sugar. By contrast, the contents of amino acids were changed in amp1 mutant compared to the wild‐type. This study suggests that AMP 1 modulates ABA , oxidative and abotic stress responses, and is involved in carbon and amino acid metabolism in A rabidopsis .