Chemico-Proteomics Reveal the Enhancement of Salt Tolerance in an Invasive Plant Species via H(2)S Signaling

[Image: see text] H(2)S is a small molecule known to have multiple signaling roles in animals. Recently, evidence shows that H(2)S also has signaling functions in plants; however, the role of H(2)S in invasive plants is unknown. Spartina alterniflora is a typical invasive species growing along the beaches of southern China. A physiological comparison proves that S. alterniflora is highly tolerant to salinity stress compared with the native species Cyperus malaccensis. To decipher the mechanism that enables S. alterniflora to withstand salinity stress, a chemico-proteomics analysis was performed to examine the salt stress response of the two species; an inhibitor experiment was additionally designed to investigate H(2)S signaling on salinity tolerance in S. alterniflora. A total of 86 proteins belonging to nine categories were identified and differentially expressed in S. alterniflora exposed to salt stress. Moreover, the expression level of enzymes responsible for the H(2)S biosynthesis was markedly upregulated, indicating the potential role of H(2)S signaling in the plant’s response to salt stress. The results suggested that salt triggered l-CD enzyme activity and induced the production of H(2)S, therefore upregulating expression of the antioxidants ascorbate peroxidase, superoxide dismutase, and S-nitrosoglutathione reductase, which mitigates damage from reactive nitrogen species. Additionally, H(2)S reduced the potassium efflux, thereby sustaining intracellular sodium/potassium ion homeostasis and enhancing S. alterniflora salt tolerance. These findings indicate that H(2)S plays an important role in the adaptation of S. alterniflora to saline environments, which provides greater insight into the function of H(2)S signaling in the adaptation of an invasive plant species.