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Nitric oxide promotes MPK6‐mediated caspase‐3‐like activation in cadmium‐induced Arabidopsis thaliana programmed cell death
Author(s) -
YE YUN,
LI ZHE,
XING DA
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/j.1365-3040.2012.02543.x
Subject(s) - arabidopsis thaliana , caspase , mapk/erk pathway , nitric oxide , microbiology and biotechnology , arabidopsis , protease , programmed cell death , chemistry , caspase 3 , biochemistry , protein kinase a , kinase , apoptosis , mutant , biology , enzyme , organic chemistry , gene
Nitric oxide (NO), a vital cell‐signalling molecule, has been reported to regulate toxic metal responses in plants. This work investigated the effects of NO and the relationship between NO and mitogen‐activated protein kinase (MAPK) in Arabidopsis ( Arabidopsis thaliana ) programmed cell death (PCD) induced by cadmium (Cd 2+ ) exposure. With fluorescence resonance energy transfer (FRET) analysis, caspase‐3‐like protease activation was detected after Cd 2+ treatment. This was further confirmed with a caspase‐3 substrate assay. Cd 2+ ‐induced caspase‐3‐like activity was inhibited in the presence of the NO‐specific scavenger 2‐(4‐carboxyphenyl)‐4,4,5,5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide (cPTIO), suggesting that NO mediated caspase‐3‐like protease activation under Cd 2+ stress conditions. Pretreatment with cPTIO effectively inhibited Cd 2+ ‐induced MAPK activation, indicating that NO also affected the MAPK pathway. Interestingly, Cd 2+ ‐induced caspase‐3‐like activity was significantly suppressed in the mpk6 mutant, suggesting that MPK6 was required for caspase‐3‐like protease activation. To our knowledge, this is the first demonstration that NO promotes Cd 2+ ‐induced Arabidopsis PCD by promoting MPK6‐mediated caspase‐3‐like activation.