Glutathione reductase a unique enzyme: molecular cloning, expression and biochemical characterization from the stress adapted C4 plant, Pennisetum glaucum (L.) R. Br (original) (raw)
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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.
INTRODUCTION AND MECHANISM - GLUTATHIONE REDUCTASE IN PLANT STRESS TOLERANCE
Glutathione reductase (GR) is an essential enzyme which plays an important role in the Ascorbate Glutathione metabolic pathway for the oxidative tolerance in plants. It acts as an anti-oxidant enzyme preserving a reduced intracellular environment and protection of cellular macromolecules like DNA, proteins and lipids. During exposure to the biotic stresses, the differential modulation of GR in plants has been widely implicated in the significance of antioxidants as the major components of plant defense operations. How the stress factor affects the plant leaves and what is the role of GR as a defense mechanism to protect the plants from these stresses, will be studied in this review in a gross detail. This review lays emphasis on the overview about structure, localization, biosynthesis and mechanism of GR from the abiotic stress for exposed crop plants and also points-out unexplored aspects in the current context. It draws inspiration from a number of observations and research papers by scientists across the molecular biology world to understand and assert that GR is a vital enzyme without which a plant’s survival is difficult and impossible. We hope that this review would enlighten the reader to think broadly about the plant’s life cycle and importance of GR as a performance enhancing-agent in plants to help maintain the balance between plant and animals in the environment.
Role of Glutathione Reductase in Plant Abiotic Stress
Abiotic Stress Responses …, 2012
Abiotic stresses severely affect the growth, development, and ultimately yield of the plant, which results in heavy economic losses and food crisis. Oxidative stress, which is associated with almost all the abiotic stresses, is due to over production of toxic reactive oxygen species (ROS) including superoxide ion, hydrogen peroxide, and hydroxyl radicals. Plants combat the oxidative stress via enzymatic and non-enzymatic machinery. Glutathione reductase (GR) is one of the potential enzymes of the enzymatic antioxidant system, which sustains the reduced status of GSH via Ascorbate-Glutathione pathway and plays a vital role in maintenance of sulfhydryl (-SH) group and acts as a substrate for glutathione-S -transferases. GR has been characterised and has been used in the transgenics to provide the plants with tolerance against the oxidative stress.
Role of Glutathione reductase in abiotic stress.
Abiotic stresses severely affect the growth, development, and ultimately yield of the plant, which results in heavy economic losses and food crisis. Oxidative stress, which is associated with almost all the abiotic stresses, is due to over production of toxic reactive oxygen species (ROS) including superoxide ion, hydrogen peroxide, and hydroxyl radicals. Plants combat the oxidative stress via enzymatic and non-enzymatic machinery. Glutathione reductase (GR) is one of the potential enzymes of the enzymatic antioxidant system, which sustains the reduced status of GSH via Ascorbate-Glutathione pathway and plays a vital role in maintenance of sulfhydryl (-SH) group and acts as a substrate for glutathione-S -transferases. GR has been characterised and has been used in the transgenics to provide the plants with tolerance against the oxidative stress.
Agronomy
Plants, due to their sessile nature, face several environmental adversities. Abiotic stresses such as heat, cold, drought, heavy metals, and salinity are serious threats to plant production and yield. To cope with these stresses, plants have developed sophisticated mechanisms to avoid or resist stress conditions. A proper response to abiotic stress depends primarily on how plants perceive the stress signal, which in turn leads to initiation of signaling cascades and induction of resistance genes. New biotechnological tools such as RNA-seq and CRISPR-cas9 are quite useful in identifying target genes on a global scale, manipulating these genes to achieve tolerance, and helping breeders to develop stress-tolerant cultivars. In this review, we will briefly discuss the adverse effects of key abiotic stresses such as cold, heat, drought, and salinity. We will also discuss how plants sense various stresses and the importance of biotechnological tools in the development of stress-tolerant c...
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.