Koh Yi Sze, Wong See Kiat, Ismail Nor Hadiani, Zengin Gokhan, Duangjai Acharaporn, Saokaew Surasak, Phisalprapa Pochamana, Tan Khang Wei, Goh Bey Hing, Tang Siah Ying
Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, Subang Jaya, Malaysia.
Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), Shah Alam, Malaysia.
Front Plant Sci. 2021 Dec 22;12:791205. doi: 10.3389/fpls.2021.791205. eCollection 2021.
Glutathione (GSH; γ-glutamyl-cysteinyl-glycine), a low-molecular-weight thiol, is the most pivotal metabolite involved in the antioxidative defense system of plants. The modulation of GSH on the plant in response to environmental stresses could be illustrated through key pathways such as reactive oxygen species (ROS) scavenging and signaling, methylglyoxal (MG) detoxification and signaling, upregulation of gene expression for antioxidant enzymes, and metal chelation and xenobiotic detoxification. However, under extreme stresses, the biosynthesis of GSH may get inhibited, causing an excess accumulation of ROS that induces oxidative damage on plants. Hence, this gives rise to the idea of exploring the use of exogenous GSH in mitigating various abiotic stresses. Extensive studies conducted borne positive results in plant growth with the integration of exogenous GSH. The same is being observed in terms of crop yield index and correlated intrinsic properties. Though, the improvement in plant growth and yield contributed by exogenous GSH is limited and subjected to the glutathione pool [GSH/GSSG; the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG)] homeostasis. Therefore, recent studies focused on the sequenced application of GSH was performed in order to complement the existing limitation. Along with various innovative approaches in combinatory use with different bioactive compounds (proline, citric acid, ascorbic acid, melatonin), biostimulants (putrescine, leaf extract, selenium, humic acid), and microorganisms (cyanobacteria) have resulted in significant improvements when compared to the individual application of GSH. In this review, we reinforced our understanding of biosynthesis, metabolism and consolidated different roles of exogenous GSH in response to environmental stresses. Strategy was also taken by focusing on the recent progress of research in this niche area by covering on its individualized and combinatory applications of GSH prominently in response to the abiotic stresses. In short, the review provides a holistic overview of GSH and may shed light on future studies and its uses.
谷胱甘肽（GSH；γ-谷氨酰-半胱氨酰-甘氨酸）是一种低分子量硫醇，是植物抗氧化防御系统中最关键的代谢物。谷胱甘肽对植物响应环境胁迫的调节作用可通过活性氧（ROS）清除与信号传导、甲基乙二醛（MG）解毒与信号传导、抗氧化酶基因表达上调以及金属螯合与外源物质解毒等关键途径来体现。然而，在极端胁迫下，谷胱甘肽的生物合成可能会受到抑制，导致ROS过量积累，从而对植物造成氧化损伤。因此，这引发了探索外源谷胱甘肽用于减轻各种非生物胁迫的想法。大量关于外源谷胱甘肽整合应用的研究在植物生长方面取得了积极成果。在作物产量指数和相关内在特性方面也观察到了同样的情况。尽管如此，外源谷胱甘肽对植物生长和产量的改善是有限的，并且受谷胱甘肽库[GSH/GSSG；还原型谷胱甘肽（GSH）与氧化型谷胱甘肽（GSSG）的比率]稳态的影响。因此，最近的研究集中在谷胱甘肽的顺序施用，以弥补现有的局限性。与谷胱甘肽单独施用相比，将其与不同生物活性化合物（脯氨酸、柠檬酸、抗坏血酸、褪黑素）、生物刺激剂（腐胺、叶提取物、硒、腐殖酸）和微生物（蓝细菌）组合使用的各种创新方法取得了显著改善。在这篇综述中，我们加深了对外源谷胱甘肽生物合成、代谢的理解，并巩固了其在响应环境胁迫时的不同作用。还通过重点关注这一特定领域的最新研究进展，突出了谷胱甘肽在应对非生物胁迫时的个体化和组合应用。简而言之，这篇综述提供了谷胱甘肽的全面概述，并可能为未来的研究及其应用提供启示。
