Glutathione in plants: an integrated overview (original) (raw)
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Frontiers in plant science, 2013
Glutathione is a small redox-active molecule existing in two main stable forms: the thiol (GSH) and the disulphide (GSSG). In plants growing in optimal conditions, the GSH:GSSG ratio is high in most cell compartments. Challenging environmental conditions are known to alter this ratio, notably by inducing the accumulation of GSSG, an effect that may be influential in the perception or transduction of stress signals. Despite the potential importance of glutathione status in redox signaling, the reactions responsible for the oxidation of GSH to GSSG have not been clearly identified. Most attention has focused on the ascorbate-glutathione pathway, but several other candidate pathways may couple the availability of oxidants such as H2O2 to changes in glutathione and thus impact on signaling pathways through regulation of protein thiol-disulfide status. We provide an overview of the main candidate pathways and discuss the available biochemical, transcriptomic, and genetic evidence relating to each. Our analysis emphasizes how much is still to be elucidated on this question, which is likely important for a full understanding of how stress-related redox regulation might impinge on phytohormone-related and other signaling pathways in plants.
Glutathione homeostasis in plants: implications for environmental sensing and plant development
Journal of Experimental Botany, 1998
for life (Grant and Dawes, 1996). Analysis of the an oxidative burst during elicitation of cultured plant cells. responses of existing mutants and those arising from new Plant Physiology 90, 109-16. screens to diverse stresses will allow the genetic dissection Asada K. 1994. Production and action of active oxygen species of signal transduction pathways and will permit rigorous in photosynthetic tissues. In: Foyer CH, Mullineaux PM, eds. Causes of photooxidative stress and amelioration of defence discrimination between those specific for a particular systems in plants. Boca Raton: CRC Press Inc., 77-104. stress and those common to many. The finding that Atzori L, Dypbukt PF, Hybbinette SS, Moldéus P, Grafstrom redox-regulated kinases (Link, 1996) and phosphatases RC. 1994. Modifications of cellular thiols during growth and (Haring et al., 1995) and transcription factors (Yang and squamous differentiation of cultured human bronchial epithe-Klessig, 1996; Yang and Klessig, personal communicalial cells. Experimental Cell Research 211, 115-20. Babiychuk E, Kushnir S, Belles-Boix E, Van Montagu M, Inzé tion) function in the transcription of plant genes during D. 1995. Arabidopsis thaliana NADPH oxidoreductase homostress responses underlines the ubiquity of redox in the logs confer tolerance of yeasts toward the thiol-oxidizing fine tuning and reversible activation of signal transduction drug diamide.
Role of glutathione and glutathione-related enzymes in response of plants to environmental stress
Published in: Annals of the New York Academy of Sciences. 02/2006; 851(1):251 - 258. DOI: 10.1111/j.1749-6632.1998.tb09000.x The tripeptide glutathione (GSH, gamma-L-glutamyl-L-cysteinylglycine), and its structural analogues are the principal nonprotein thiol compounds in plants. Following the elucidation of its chemical structure, GSH was soon identified as an antioxidant and later recognized as an essential component of antioxidative and detoxification systems in plant cells. In most tissues, GSH is predominantly present in its reduced form. The regeneration of GSH from oxidized glutathione (GSSG) is catalyzed by glutathione reductase (GR, E.C. 1.6.4.2) enzyme. Elevated GSH levels, GR, and glutathione S-transferase (GST, EC 2.5.1.18) activities were found in plants exposed to a wide range of environmental stress effects2,3 and microbial infections. The physiological basis of the damage suffered by a plant during stress can often be explained as perturbations in oxygen metabolism. An increased production of reactive oxygen species (ROS) has been shown to occur in plants exposed to various abiotic and biotic stress effects. Although the adaptive significance of the elevated level of GSH in plants exposed to various stress effects has not been unequivocally established yet, this increased production of GSH seems to contribute to the antioxidative protection of plant cells against stress caused by ROS. In this paper we shall attempt to evaluate the possible roles of GSH and GSH related enzymes in the defense reactions of plants exposed to peroxidizing herbi cides, heavy metals, and biotic stress effects.
Plant Physiology and Biochemistry, 2013
Abiotic stresses such as salinity, drought, clilling, heavy metal are the major limiting factors for crop productivity. These stresses induce the overproduction of reactive oxygen species (ROS) which are highly reactive and toxic, which must be minimized to protect the cell from oxidative damage. The cell organelles, particularly chloroplast and mitochondria are the major sites of ROS production in plants where excessive rate of electron flow takes place. Plant cells are well equipped to efficiently scavenge ROS and its reaction products by the coordinated and concerted action of antioxidant machinery constituted by vital enzymatic and non-enzymatic antioxidant components. Glutathione reductase (GR, EC 1.6.4.2) and tripeptide glutathione (GSH, g-Glutamyl-Cysteinyl-Glycine) are two major components of ascorbate eglutathione (AsAeGSH) pathway which play significant role in protecting cells against ROS and its reaction products-accrued potential anomalies. Both GR and GSH are physiologically linked together where, GR is a NAD(P)H-dependent enzymatic antioxidant and efficiently maintains the reduced pool of GSH e a cellular thiol. The differential modulation of both GR and GSH in plants has been widely implicated for the significance of these two enigmatic antioxidants as major components of plant defense operations. Considering recent informations gained through molecular-genetic studies, the current paper presents an overview of the structure, localization, biosynthesis (for GSH only), discusses GSH and GR significance in abiotic stress (such as salinity, drought, clilling, heavy metal)-exposed crop plants and also points out unexplored aspects in the current context for future studies.
Frontiers in Plant Science, 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 p...