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The pivotal function of dehydroascorbate reductase in glutathione homeostasis in plants
- Source :
- Journal of Experimental Botany. 71:3405-3416
- Publication Year :
- 2020
- Publisher :
- Oxford University Press (OUP), 2020.
-
Abstract
- Under natural conditions, plants are exposed to various abiotic and biotic stresses that trigger rapid changes in the production and removal of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). The ascorbate-glutathione pathway has been recognized to be a key player in H2O2 metabolism, in which reduced glutathione (GSH) regenerates ascorbate by reducing dehydroascorbate (DHA), either chemically or via DHA reductase (DHAR), an enzyme belonging to the glutathione S-transferase (GST) superfamily. Thus, DHAR has been considered to be important in maintaining the ascorbate pool and its redox state. Although some GSTs and peroxiredoxins may contribute to GSH oxidation, analysis of Arabidopsis dhar mutants has identified the key role of DHAR in coupling H2O2 to GSH oxidation. The reaction of DHAR has been proposed to proceed by a ping-pong mechanism, in which binding of DHA to the free reduced form of the enzyme is followed by binding of GSH. Information from crystal structures has shed light on the formation of sulfenic acid at the catalytic cysteine of DHAR that occurs with the reduction of DHA. In this review, we discuss the molecular properties of DHAR and its importance in coupling the ascorbate and glutathione pools with H2O2 metabolism, together with its functions in plant defense, growth, and development.
- Subjects :
- chemistry.chemical_classification
Reactive oxygen species
Physiology
Ascorbic Acid
Hydrogen Peroxide
Plant Science
Metabolism
Glutathione
Reductase
Redox
Oxidative Stress
chemistry.chemical_compound
Glutathione Reductase
Enzyme
Biochemistry
chemistry
Homeostasis
Sulfenic acid
Oxidoreductases
Cysteine
Subjects
Details
- ISSN :
- 14602431 and 00220957
- Volume :
- 71
- Database :
- OpenAIRE
- Journal :
- Journal of Experimental Botany
- Accession number :
- edsair.doi.dedup.....99ff9645759dcd7f63f379858c143dab