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The role of the kinase OXI1 in cadmium‐ and copper‐induced molecular responses in A rabidopsis thaliana
Author(s) -
SMEETS KAREN,
OPDENAKKER KELLY,
REMANS TONY,
FORZANI CELINE,
HIRT HERIBERT,
VANGRONSVELD JACO,
CUYPERS ANN
Publication year - 2013
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.12056
Subject(s) - superoxide dismutase , arabidopsis thaliana , catalase , kinase , cadmium , microbiology and biotechnology , protein kinase a , chemistry , oxidative stress , oxylipin , dismutase , arabidopsis , biochemistry , sod1 , reactive oxygen species , intracellular , biology , wild type , enzyme , gene , mutant , organic chemistry
The hypothesis that mitogen‐activated protein kinase ( MAPK) signalling is important in plant defences against metal stress has become accepted in recent years. To test the role of oxidative signal‐inducible kinase ( OXI1) in metal‐induced oxidative signalling, the responses of oxi1 knockout lines to environmentally realistic cadmium ( Cd ) and copper ( Cu ) concentrations were compared with those of wild‐type plants. A relationship between OXI1 and the activation of lipoxygenases and other initiators of oxylipin production was observed under these stress conditions, suggesting that lipoxygenase‐1 may be a downstream component of OXI1 signalling. Metal‐specific differences in OXI1 action were observed. For example, OXI1 was required for the up‐regulation of antioxidative defences such as catalase in leaves and Fe ‐superoxide dismutase in roots, following exposure to Cu , processes that may involve the MEKK1 ‐ MKK2 ‐ WRKY25 cascade. Moreover, the induction of Cu/Zn superoxide dismutases in Cu ‐exposed leaves was regulated by OXI1 in a manner that involves fluctuations in the expression of miRNA398 . These observations contrast markedly with the responses to Cd exposure, which also involves OXI1 ‐independent pathways but rather involves changes in components mediating intracellular communication.