Dehydroascorbate reductase (DHAR) is present in the cytoplasm, mitochondria, and chloroplasts. DHAR catalyzes the reduction of dehydroascorbic acid (DHA) by reduced glutathione (GSH) to produce ascorbic acid (AsA) and oxidized glutathione (GSSG). It regulates the cellular AsA/DHA ratio and is a key enzyme in the ascorbate-glutathione redox cycle. Increasing DHAR activity in plants can elevate the AsA content in plant-based foods, thereby enhancing their nutritional quality.
Assay Principle: DHAR catalyzes the reduction of DHA by GSH to generate AsA. The activity of DHAR is calculated by measuring the rate of decrease in DHA.