Glutathione S-Transferases: Role in Combating Abiotic Stresses Including Arsenic Detoxification in Plants

Abstract

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.

The Moss Leptodictyum riparium Counteracts Severe Cadmium Stress by Activation of Glutathione Transferase and Phytochelatin Synthase, but Slightly by Phytochelatins

“…[10][11][12][13][39][40][41]. This conjugation is usually followed by vacuolar compartmentalization [39,42] and further intravacuolar degradation [43,44]. Interestingly, an hemerythrin class of GST that can bind metals, such as Fe and Cd [45], by means of a thiolate complex, has been discovered in P. patens [39].…”

Glutathione and hydrogen sulfide are required for sulfur‐mediated mitigation of Cr(VI) toxicity in tomato, pea and brinjal seedlings

“…The results show that BSO further increased Cr(VI) toxicity in studied vegetables even in the presence of additional S while addition of GSH reversed the negative effect of BSO (Table ). These results indicate that GSH might have been derived from additional S and is essential for mitigation of Cr(VI) toxicity, as GSH serves as a substrate for the synthesis of phytochelatins which help in binding and sequestering cellular toxic metal into the vacuoles (Cobbett , Kumar and Trivedi ). Cr(VI) has the capacity of either directly damaging cellular structures in the cytosol by oxidizing them (Eleftheriou et al ) or inducing generation of ROS which cause damage to macromolecules (Singh and Prasad ).…”

“…Moreover, upon addition of GSH and H 2 S together with Cr(VI), GST activity was further stimulated (Table ). In plants, GSTs catalyze binding of electrophilic substances with GSH for rendering electrophilic substances less or non‐toxic and thus protect plants from oxidative damage (Kumar and Trivedi ). Thus, under additional S supply, stimulation in GST activity can be linked with increased Cr(VI) tolerance in tomato, pea and brinjal seedlings as improved growth and qP, and decreased ROS and their associated damage were noticed under this condition (Tables and , Figs ).…”

The barley stripe mosaic virus expression system reveals the wheat C2H2 zinc finger protein TaZFP1B as a key regulator of drought tolerance

“…Different classes of glutathione S-transferase (GSTs) up-regulated in 1B-OEX plants (#12, #98 #123, #128, and Additional file 4: Fig. S3E and S3F) are known to promote detoxification of xenobiotics and to participate in the response to various abiotic stresses including oxidative stresses [95,96]. Some theta, phy and tau GSTs have been shown to have glutathione peroxidase activity to reduce organic hydroperoxides of fatty acids, preventing oxidative damage [97].…”