Kumar Smita, Trivedi Prabodh K
Council of Scientific and Industrial Research-National Botanical Research Institute, Lucknow, India.
Front Plant Sci. 2018 Jun 7;9:751. doi: 10.3389/fpls.2018.00751. eCollection 2018.
Arsenic (As), naturally occurring metalloid and a potential hazardous material, is found in low concentrations in the environment and emerges from natural sources and anthropogenic activities. The presence of As in ground water, which is used for irrigation, is a matter of great concern since it affects crop productivity and contaminates food chain. In plants, As alters various metabolic pathways in cells including the interaction of substrates/enzymes with the sulfhydryl groups of proteins and the replacement of phosphate in ATP for energy. In addition, As stimulates the generation of free radicals and reactive oxygen species (ROS), resulting in oxidative stress. Glutathione S-transferases (GSTs) quench reactive molecules with the addition of glutathione (GSH) and protect the cell from oxidative damage. GSTs are a multigene family of isozymes, known to catalyze the conjugation of GSH to miscellany of electrophilic and hydrophobic substrates. GSTs have been reported to be associated with plant developmental processes and are responsive to multitude of stressors. In past, several studies suggested involvement of plant GST gene family in As response due to the requirement of sulfur and GSH in the detoxification of this toxic metalloid. This review provides updated information about the role of GSTs in abiotic and biotic stresses with an emphasis on As uptake, metabolism, and detoxification in plants. Further, the genetic manipulations that helped in enhancing the understanding of the function of GSTs in abiotic stress response and heavy metal detoxification has been reviewed.
砷（As）是一种天然存在的类金属，也是一种潜在的有害物质，在环境中以低浓度存在，来源于自然源和人为活动。用于灌溉的地下水中存在砷是一个备受关注的问题，因为它会影响作物生产力并污染食物链。在植物中，砷会改变细胞内的各种代谢途径，包括底物/酶与蛋白质巯基的相互作用以及ATP中磷酸根的替代以获取能量。此外，砷会刺激自由基和活性氧（ROS）的产生，导致氧化应激。谷胱甘肽S-转移酶（GSTs）通过添加谷胱甘肽（GSH）来淬灭反应性分子，保护细胞免受氧化损伤。GSTs是一个多基因的同工酶家族，已知可催化GSH与多种亲电和亲水底物的结合。据报道，GSTs与植物发育过程有关，并对多种应激源有反应。过去，几项研究表明植物GST基因家族参与砷的响应，因为在这种有毒类金属的解毒过程中需要硫和GSH。本综述提供了关于GSTs在非生物和生物胁迫中的作用的最新信息，重点是植物中砷的吸收、代谢和解毒。此外，还综述了有助于增强对GSTs在非生物胁迫响应和重金属解毒功能理解的基因操作。
