H 2 S Alleviates Salinity Stress in Cucumber by Maintaining the Na + /K + Balance and Regulating H 2 S Metabolism and Oxidative Stress Response

• Published in: Frontiers in plant science Vol. 10; p. 678
• Main Authors: Jiang, Jing-Long, Tian, Yun, Li, Li, Yu, Miao, Hou, Ru-Ping, Ren, Xu-Ming
• Format: Journal Article
• Language: English
• Published: Switzerland 2019
• Subjects: expression of SKOR gene; hydrogen hulfide; salt stress; Cucumis sativus L; lipid peroxidation; Na+/K+ balance
• ISSN: 1664-462X; 1664-462X

Salinity stress from soil or irrigation water can significantly limit the growth and development of plants. Emerging evidence suggests that hydrogen sulfide (H S), as a versatile signal molecule, can ameliorate salt stress-induced adverse effects. However, the possible physiological mechanism underlying H S-alleviated salt stress in cucumber remains unclear. Here, a pot experiment was conducted with an aim to examine the possible mechanism of H S in enhancement of cucumber salt stress tolerance. The results showed that H S ameliorated salt-induced growth inhibition and alleviated the reduction in photosynthetic attributes, chlorophyll fluorescence and stomatal parameters. Meanwhile H S increased the endogenous H S level concomitant with increased activities of D/L-cysteine desulfhydrase and β-cyanoalanine synthase and decreased activities of O-acetyl-L-serine(thiol)lyase under excess NaCl. Notably, H S maintained Na and K homeostasis via regulation of the expression of , and at the transcriptional level under excess NaCl. Moreover, H S alleviated salt-induced oxidative stress as indicated by lowered lipid peroxidation and reactive oxygen species accumulation through an enhanced antioxidant system. Altogether, these results demonstrated that application of H S could protect cucumber seedlings against salinity stress, likely by keeping the Na /K balance, controlling the endogenous H S level by regulating the H S synthetic and decomposition enzymes, and preventing oxidative stress by enhancing the antioxidant system under salinity stress.