Comparative Proteomic Analysis Reveals the Regulatory Effects of H2S on Salt Tolerance of Mangrove Plant Kandelia obovata

Abstract

As a dominant mangrove species, Kandelia obovata is distributed in an intertidal marsh with an active H2S release. Whether H2S participates in the salt tolerance of mangrove plants is still ambiguous, although increasing evidence has demonstrated that H2S functions in plant responses to multiple abiotic stresses. In this study, NaHS was used as an H2S donor to investigate the regulatory mechanism of H2S on the salt tolerance of K. obovata seedlings by using a combined physiological and proteomic analysis. The results showed that the reduction in photosynthesis (Pn) caused by 400 mM of NaCl was recovered by the addition of NaHS (200 μM). Furthermore, the application of H2S enhanced the quantum efficiency of photosystem II (PSII) and the membrane lipid stability, implying that H2S is beneficial to the survival of K. obovata seedlings under high salinity. We further identified 37 differentially expressed proteins by proteomic approaches under salinity and NaHS treatments. Among them, the proteins that are related to photosynthesis, primary metabolism, stress response and hormone biosynthesis were primarily enriched. The physiological and proteomic results highlighted that exogenous H2S up-regulated photosynthesis and energy metabolism to help K. obovata to cope with high salinity. Specifically, H2S increased photosynthetic electron transfer, chlorophyll biosynthesis and carbon fixation in K. obovata leaves under salt stress. Furthermore, the abundances of other proteins related to the metabolic pathway, such as antioxidation (ascorbic acid peroxidase (APX), copper/zinc superoxide dismutase (CSD2), and pancreatic and duodenal homeobox 1 (PDX1)), protein synthesis (heat-shock protein (HSP), chaperonin family protein (Cpn) 20), nitrogen metabolism (glutamine synthetase 1 and 2 (GS2), GS1:1), glycolysis (phosphoglycerate kinase (PGK) and triosephosphate isomerase (TPI)), and the ascorbate–glutathione (AsA–GSH) cycle were increased by H2S under high salinity. These findings provide new insights into the roles of H2S in the adaptations of the K. obovata mangrove plant to high salinity environments.

Hydrogen sulfide (H2S) signaling in plant development and stress responses

“…H 2 S could promote photosynthetic electron transfer, chlorophyll biosynthesis and carbon fixation in Kandelia obovata leaves and cucumber under salt stress (Jiang et al 2020 ; Liu et al 2020d ). In addition, the abundance of other proteins related to the metabolic pathways, such as antioxidation (APX, copper/zinc superoxide dismutase, pancreatic and duodenal homeobox 1), protein synthesis (heat-shock protein (HSP), chaperonin family protein 20 and Cysteine synthase 1), nitrogen metabolism (glutamine synthetase 1 and 2), glycolysis (phosphoglycerate kinase and triosephosphate isomerase), and the AsA-GSH cycle (glutathione S-transferase U25-like), was increased by H 2 S under high salinity (Jiang et al 2020 ; Liu et al 2020d ). However, the mechanism underlying the effect of H 2 S on such huge proteins remains unclear (Guo et al 2018 ; Li et al 2014a , 2020c ).…”

Physiological and Proteomic Analyses of Two Acanthus Species to Tidal Flooding Stress

“…The DEPs were obtained by pairwise comparison with a fold change ≥ 2.0 and a Student’s t-test ( p < 0.05). In-gel tryptic digestion and protein identification were performed according to the method of Liu et al [ 61 ].…”

Physiological and Comparative Proteomic Analyses Provide Insight Into the Differential Responses of Acanthus Ilicifolius and Its Relative, Acanthus Mollis, to Tidal Flooding Stress

“…The DEPs were obtained by pairwise comparison with a fold change ≥2.0 and a Student's t-test (p<0.05). In-gel tryptic digestion and protein identification were performed according to the method of Liu et al [70].…”