Premium
Zm CPK 1, a calcium‐independent kinase member of the Z ea mays CDPK gene family, functions as a negative regulator in cold stress signalling
Author(s) -
WECKWERTH PHILIPP,
EHLERT BRITTA,
ROMEIS TINA
Publication year - 2015
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12414
Subject(s) - gene family , arabidopsis thaliana , gene , biology , kinase , calcium , calcium signaling , microbiology and biotechnology , arabidopsis , gene expression , signal transduction , genetics , chemistry , mutant , organic chemistry
Abstract Calcium‐dependent protein kinases ( CDPKs ) have been shown to play important roles in plant environmental stress signal transduction. We report on the identification of Zm CPK 1 as a member of the maize ( Z ea mays ) CDPK gene family involved in the regulation of the maize cold stress response. Based upon in silico analysis of the Z . mays cv. B 73 genome, we identified that the maize CDPK gene family consists of 39 members. Two CDPK members were selected whose gene expression was either increased ( Zm cpk 1) or decreased ( Zm cpk 25) in response to cold exposure. Biochemical analysis demonstrated that Zm CPK 1 displays calcium‐independent protein kinase activity. The C ‐terminal calcium‐binding domain of Zm CPK 1 was sufficient to mediate calcium independency of a previously calcium‐dependent enzyme in chimeric Zm CPK 25‐ CPK 1 proteins. Furthermore, co‐transfection of maize mesophyll protoplasts with active full‐length Zm CPK 1 suppressed the expression of a cold‐induced marker gene, Zm erf3 ( ZmCOI 6.21 ). In accordance, heterologous overexpression of Zm CPK 1 in A rabidopsis thaliana yielded plants with altered acclimation‐induced frost tolerance. Our results identify Zm CPK 1 as a negative regulator of cold stress signalling in maize.