Mostofa Mohammad G, Saegusa Daisuke, Fujita Masayuki, Tran Lam-Son Phan
Department of Biochemistry and Molecular Biology, Bangabandhu Sheikh Mujibur Rahman Agricultural University Gazipur, Bangladesh.
Laboratory of Plant Stress Responses, Department of Applied Biological Science, Faculty of Agriculture, Kagawa University Miki, Japan.
Front Plant Sci. 2015 Dec 21;6:1055. doi: 10.3389/fpls.2015.01055. eCollection 2015.
Being a salt sensitive crop, rice growth and development are frequently affected by soil salinity. Hydrogen sulfide (H2S) has been recently explored as an important priming agent regulating diverse physiological processes of plant growth and development. Despite its enormous prospects in plant systems, the role of H2S in plant stress tolerance is still elusive. Here, a combined pharmacological, physiological and biochemical approach was executed aiming to examine the possible mechanism of H2S in enhancement of rice salt stress tolerance. We showed that pretreating rice plants with H2S donor sodium bisulfide (NaHS) clearly improved, but application of H2S scavenger hypotaurine with NaHS decreased growth and biomass-related parameters under salt stress. NaHS-pretreated salt-stressed plants exhibited increased chlorophyll, carotenoid and soluble protein contents, as well as suppressed accumulation of reactive oxygen species (ROS), contributing to oxidative damage protection. The protective mechanism of H2S against oxidative stress was correlated with the elevated levels of ascorbic acid, glutathione, redox states, and the enhanced activities of ROS- and methylglyoxal-detoxifying enzymes. Notably, the ability to decrease the uptake of Na(+) and the Na(+)/K(+) ratio, as well as to balance mineral contents indicated a role of H2S in ion homeostasis under salt stress. Altogether, our results highlight that modulation of the level of endogenous H2S genetically or exogenously could be employed to attain better growth and development of rice, and perhaps other crops, under salt stress. Furthermore, our study reveals the importance of the implication of gasotransmitters like H2S for the management of salt stress, thus assisting rice plants to adapt to adverse environmental changes.
水稻作为对盐分敏感的作物，其生长发育经常受到土壤盐分的影响。硫化氢（H₂S）最近被探索为一种调节植物生长发育多种生理过程的重要引发剂。尽管H₂S在植物系统中有巨大的应用前景，但其在植物抗逆性中的作用仍不明确。在此，我们采用药理学、生理学和生物化学相结合的方法，旨在研究H₂S增强水稻耐盐性的可能机制。我们发现，用H₂S供体硫氢化钠（NaHS）预处理水稻植株，明显改善了其生长状况，但在盐胁迫下，将H₂S清除剂次牛磺酸与NaHS一起施用会降低生长和与生物量相关的参数。经NaHS预处理的盐胁迫植株叶绿素、类胡萝卜素和可溶性蛋白含量增加，同时活性氧（ROS）积累受到抑制，有助于保护其免受氧化损伤。H₂S对氧化应激的保护机制与抗坏血酸、谷胱甘肽水平的升高、氧化还原状态以及ROS和甲基乙二醛解毒酶活性的增强有关。值得注意的是，降低Na⁺吸收和Na⁺/K⁺比值以及平衡矿物质含量的能力表明，H₂S在盐胁迫下的离子稳态中发挥作用。总之，我们的结果表明，在遗传或外源水平上调节内源性H₂S水平，可用于使水稻以及其他作物在盐胁迫下实现更好的生长发育。此外，我们的研究揭示了像H₂S这样的气体信号分子在盐胁迫管理中的重要性，从而帮助水稻植株适应不利的环境变化。
