The purified glutathione reductase was homogeneous on polyacrylamide-gel electrophoresis. It had an Mr of 79,000 and consisted of two subunits with a Mr of 40,000. The activity was maximum at pH 8.2 and 52 degrees C. It was specific for NADPH but not for NADH as the electron donor; the reverse reaction was not observed. The Km values for NADPH and GSSG were 14 and 55 microM respectively. The en...

Dehydroascorbate reductase (DHAR) is a key enzyme involved in the recycling of ascorbate, which catalyses the glutathione (GSH)-dependent reduction of oxidized ascorbate (dehydroascorbate, DHA). As a result, DHAR regenerates a pool of reduced ascorbate and detoxifies reactive oxygen species (ROS). In previous experiments involving transgenic rice, we observed that overexpression of DHAR enhance...

Fruit from three genotypes (‘B-76’, ‘B-59’ and ‘SHF-3A’) of deerberry [Vaccinium stamineum L.] were evaluated for fruit quality, total anthocyanin and phenolic contents, antioxidants, antioxidant capacity, and antioxidant enzyme activity. The fruit soluble solids, titratable acids, total anthocyanins, and total phenolic contents varied with genotypes. Cyanidin 3-galactoside and cyanidin 3-arabi...

// / The present investigation demonstrates the existence of NADH-dependent dehydroascorbate (DHA) recluctase activity in the soluble fraction of the rabbit lens. This DHA reductase was specific for NADH, and its apparent Km values for DHA and NADH were 5.7 mM and 4.0 uM, respectively. In a gel filtration of the lens soluble fraction on a Sephadex G-75 superfine column, the NADH-dependent DHA r...

Recycling of ascorbic acid from its oxidized forms helps to maintain the vitamin in human erythrocytes. To determine the relative contributions of recycling from the ascorbate radical and dehydroascorbic acid, we studied erythrocytes exposed to a trans-membrane oxidant stress from ferricyanide. Ferricyanide was used both to induce oxidant stress across the cell membrane and to quantify ascorbat...

When drought occurs during the maize-filling period, probability of yield decline increases. Abscisic acid (ABA) plays a regulatory role in physiological and metabolic activities plant development. However, its effect on antioxidant system maize leaves grain-filling stage is unclear. Maize plants (Zhengdan958) were used as an experimental material, ABA was sprayed stage. The placed under condit...

Ascorbate oxidase (AO) plays an important role in cell growth through the modulation of reduction/oxidation (redox) control of the apoplast. Here, a cotton (Gossypium hirsutum) apoplastic ascorbate oxidase gene (GhAO1) was obtained from fast elongating fiber tissues. GhAO1 belongs to the multicopper oxidase (MCO) family and includes a signal peptide and several transmembrane regions. Analyses o...

Two wheat cultivars, C306 and PBW343 contrasting in drought tolerance were compared for their antioxidant response and Lea genes' expression under salt stress (SS) and combined stress (CS) of salt stress plus water stress during seedlings growth. The drought susceptible cultivar (PBW343) behaved different towards SS/CS than towards WS. It accumulated more dry masses in shoots, more ascorbate, h...