CDPKs enhance Cd tolerance through intensifying H sub(2)S signal in Arabidopsis thaliana

• Published in: Plant and soil 2016-01, Vol.398 (1-2), p.99-110
• Main Authors: Qiao, Zengjie, Jing, Tao, Jin, Zhuping, Liang, Yali, Zhang, Liping, Liu, Zhiqiang, Liu, Danmei, Pei, Yanxi
• Format: Article
• Language: English
• Subjects: Arabidopsis; Arabidopsis thaliana
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-015-2643-x

Hydrogen sulfide (H sub(2)S) acting as the third gasotransmitter following NO and CO has important physiological functions in both animals and plants. In plants, H sub(2)S plays a critical role in alleviating toxicity of Cd stresses. It is well known that Calcium-Dependent Protein Kinases (CDPKs) can regulate cell recognition and signal transduction through reversible protein phosphorylation, but how CDPKs regulate H sub(2)S signal remains unclear. The genetic and pharmacological method together with spectrophotometry and LC-MS/MS were used in this study. Our results indicated that Arabidopsis pretreated with H sub(2)S exhibited enhanced tolerance to Cd. After treatment by trifluoroperazine (TFP), the toxicity of Cd was exacerbated. Meanwhile, the activity of L-cysteine desulfhydrase (LCD) was reduced and the content of endogenous H sub(2)S decreased. In vitro experiments demonstrated that CDPK3 could raise LCD activity. Interestingly, expressions of Cd associated genes could not normally respond to Cd stress in cdpk3 whereas increased when this mutant was pretreated with H sub(2)S. S-sulfhydration results revealed that the content of glutathione persulfide (GSSH) was significantly lower in lcd and cdpk3 mutants. The results indicated that the decrease in GSSH content was mainly due to the reduction in H sub(2)S, which further caused the increased sensitivity to Cd. CDPKs can enhance the tolerance to Cd in Arabidopsis through the way of intensifying H sub(2)S signal.