Hydrogen sulfide: a new endogenous player in an old mechanism of plant tolerance to high salinity

ABSTRACT High salinity affects plants due to stimulation of osmotic stress. Cell signaling triggered by nitric oxide (NO) and hydrogen sulfide (H2S) activates a cascade of biochemical events that culminate in plant tolerance to abiotic and biotic stresses. For instance, the NO/H2S-stimulated biochemical events that occur in plants during response to high salinity include the control of reactive oxygen species, activation of antioxidant system, accumulation of osmoprotectants in cytosol, induction of K+ uptake and Na+ cell extrusion or its vacuolar compartmentation among others. This review is a compilation of what we have learned in the last 10 years about NO participation during cell signaling in response to high salinity as well as the role of H2S, a new player in the mechanism of plant tolerance to salt stress. The main sources of NO and H2S in plant cells is also discussed together with the evidence of interplay between both signaling molecules during response to stress.

摘要：高盐胁迫可通过诱导渗透胁迫对植物产生不利影响。由一氧化氮（nitric oxide, NO）与硫化氢（hydrogen sulfide, H2S）介导的细胞信号转导通路，可激活一系列级联生化反应，最终赋予植物对非生物与生物胁迫的耐受性。例如，植物响应高盐胁迫过程中由NO与H2S触发的生化事件包括：活性氧的动态调控、抗氧化系统的激活、胞质内渗透保护物质的积累、钾离子（K+）摄取的诱导以及钠离子（Na+）的细胞外排或液泡区室化等。本综述总结了近十年来我们在一氧化氮参与高盐胁迫响应细胞信号转导方面的研究进展，同时探讨了硫化氢作为植物盐胁迫耐受机制中新调控因子的相关作用。本文还探讨了植物细胞内一氧化氮与硫化氢的主要来源，以及两种信号分子在胁迫响应过程中相互作用的相关证据。