1. Hydrogen Sulfide Alleviates Oxidative Damage under Chilling Stress through Mitogen-Activated Protein Kinase in Tomato.
- Author
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Wu, Guoxiu, Niu, Xuxu, Chen, Jiahui, Wu, Changjiang, Li, Yang, Li, Yanman, Cui, Dandan, He, Xueying, Wang, Fan, and Li, Shengli
- Subjects
MITOGEN-activated protein kinases ,HYDROGEN sulfide ,LIPID peroxidation (Biology) ,PEROXIDASE ,TOMATOES ,GENE expression ,CATALASE ,LIPIDS - Abstract
Tomato is the vegetable with the largest greenhouse area in China, and low temperature is one of the main factors affecting tomato growth, yield, and quality. Hydrogen sulfide (H
2 S) plays an important role in regulating plant chilling tolerance, but its downstream cascade reaction and mechanism remain unclear. Mitogen-activated protein kinases (MAPK/MPKs) are closely related to a variety of signaling substances in stress signal transmission. However, whether H2 S is related to the MPK cascade pathway in response to low-temperature stress is rarely reported. In this study, NaHS treatment significantly decreased the electrolyte leakage (EL), superoxide anion (O2 − ) production rate, and hydrogen peroxide (H2 O2 ) content of seedlings at low temperatures. In addition, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were obviously increased; and the photochemical efficiency of PSII (Fv/Fm) was enhanced with treatment with NaHS, indicating that NaHS improved the seedlings' cold tolerance by alleviating the degree of membrane lipid peroxidation and oxidative damage. However, H2 S scavenger hypotaurine (HT) treatment showed the opposite effect. We found that H2 S content, L-cysteine desulfhydrase (LCD) activity, and mRNA expression were increased by chilling stress but reduced by MPK inhibitor PD98059; PD98059 reversed the alleviating effect of H2 S via increasing the EL and H2 O2 contents. The expression levels of MPK1–MPK7 at low temperatures showed that SlMPK4 was significantly induced by exogenous NaHS and showed a trend of first increasing and then decreasing, while the expression level of SlMPK4 in HT-treated seedlings was lower than that of the control. After SlMPK4 was silenced by virus-induced gene silencing, the H2 S-induced upregulation of C-repeat-Binding Factor (CBF1), inducer of CBF expression 1 (ICE1), respiratory burst oxidase homologs (RBOH1, RBOH2) at low temperatures disappeared, and tomato cold tolerance decreased. In conclusion, H2 S improves the cold tolerance of tomato plants by increasing the activity of antioxidant enzymes and reducing reactive oxygen species (ROS) accumulation and membrane lipid peroxidation. MPK4 may act as a downstream signaling molecule in this process. [ABSTRACT FROM AUTHOR]- Published
- 2024
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