plants are naturally exposed to frequent changes in environmental conditions such as salt stress affecting their growth and development, and consequently a considerable reduction in total productivity. monodehydroascorbate reductase (mdhar), a key enzyme in ascorbate-glutathione cycle, serves as an important antioxidative enzyme in scavenging of reactive oxygen spices (ros). in this study, mdha...

Heavy metals are the cause of major abiotic stresses in plants and a principal contributor to environmental pollution in recent decades. This study investigated the effects of exogenous hydrogen sulfide on the ascorbate-glutathione cycle in the leaves of coriander seedlings under copper stress. Results showed that copper stress not only reduced APX and GR activities but also decreased leaf AsA,...

We conducted a comparative analysis of biochemical parameters for the ascorbate-glutathione cycle in non-transgenic and transgenic Nicotiana tabacum, plants cultivated heavy metal polluted soils. Transgenic had their genome bacterial acdS-gene encoding 1-aminocyclopropane-1-carboxylate deaminase (ACC-deaminase) enzyme. The introduction elevated concentrations copper, chromium, lead ions into so...

The Arabidopsis thaliana ascorbate-deficient vtc-1 mutant has only 30% ascorbate contents of the wild type (WT). This ascorbate-deficient mutant was used here to study the physiological roles of ascorbate under salt stress in vivo. Salt stress resulted in a more significant decrease in CO2 assimilatory capacity in the vtc-1 mutant than in the WT. Photosystem II function in the Arabidopsis vtc-1...

Infection of tomato leaves with the necrotrophic fungus Botrytis cinerea resulted in substantial changes in enzymatic and non-enzymatic components of the ascorbate-glutathione cycle as well as in superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione transferase (GST), and l-galactono-gamma-lactone dehydrogenase (GLDH) activities. In the initial phase of the 5 d experiment CuZ...

To evaluate the environmental impact of uranium (U) contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress) were exposed for three days to differen...

The imposition of environmental stresses on plants brings about disturbance in their metabolism thereby negatively affecting their growth and development and leading to reduction in the productivity. One of the manifestations of different abiotic and biotic stress conditions in plants is the enhanced production of reactive oxygen species (ROS) which can be hazardous to cells. Therefore, in orde...

  Heavy metals are the cause of major abiotic stresses in plants and a principal contributor to environmental pollution in recent decades. This study investigated the effects of exogenous hydrogen sulfide on the ascorbate-glutathione cycle in the leaves of coriander seedlings under copper stress. Results showed that copper stress not only reduced APX and GR activities but also decreas...

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...

To investigate how high light affects the responses of photosynthesis to heat stress, the effects of high temperature (25-42.5 degrees C) either in the dark or in the light (1000 micromol m(-2) s(-1)) on photosystem II (PSII) photochemistry and the xanthophyll cycle were investigated in rice plants. At temperatures higher than 35 degrees C, there was a decrease in the CO(2) assimilation rate, a...