the production of reactive oxygen species (ros) in plants under low temperature stress cause damage to plants. in order to evaluate of antioxidant responses of page mandarin young trees (two years old) on different rootstocks under low temperatures, an experiment was conducted in a factorial plan based on completely randomized design. treatment of temperatures were at seven levels include 9, 6,...

Background Ascorbate peroxidase (APx) is a key enzyme of the antioxidant metabolism, catalyzing the decomposition of hydrogen peroxide (H2O2) in water, using ascorbate as an electron donor. The H2O2 is a reactive oxygen species (ROS) produced constantly by aerobic metabolism. Under biotic and abiotic stress the level of H2O2 increases and, in large quantities, can cause cellular damage. In rice...

When plants are exposed to stressful environmental conditions, the production of Reactive Oxygen Species (ROS) increases and can cause significant damage to the cells. Antioxidant defenses, which can detoxify ROS, are present in plants. A major hydrogen peroxide detoxifying system in plant cells is the ascorbate-glutathione cycle, in which, ascorbate peroxidase (APX) enzymes play a key role cat...

The photosynthetic performance of leaf discs of transgenic cotton with fourfold elevated activity of ascorbate peroxidase in the chloroplast stroma (APX / plants) was compared to that of wild type (Gossypium hirsutum L. cv. Coker 312) during exposure to 10 8C and 500 mmol photons m 2 s . APX / leaves did not exhibit as large of an increase in cellular H2O2 that was evident in wildtype leaves sh...

The effect of salinity on the antioxidative system of root mitochondria and peroxisomes of a cultivated tomato Lycopersicon esculentum (Lem) and its wild salt-tolerant related species L. pennellii (Lpa) was studied. Salt stress induced oxidative stress in Lem mitochondria, as indicated by the increased levels of lipid peroxidation and H(2)O(2). These changes were associated with decreased activ...

Haem-containing enzymes (peroxidase and catalase) are widely distributed among prokaryotes and eukaryotes and play a vital role in H2O2 detoxification. But, to date, no haem-containing enzymatic defence against toxic H2O2 has been discovered in Leishmania species. We cloned, expressed and purified an unusual plant-like APX (ascorbate peroxidase) from Leishmania major (LmAPX) and characterized i...

BACKGROUND AND AIMS Boron (B) toxicity triggers the formation of reactive oxygen species in plant tissues. However, there is still a lack of knowledge as to how B toxicity affects the plant antioxidant defence system. It has been suggested that ascorbate could be important against B stress, although existing information is limited in this respect. The objective of this study was to analyse how ...

Application of nanotechnology is crucial for a sustainable increase in food production to cope with the increasing demand burgeoning population. Wheat has significantly security Pakistan help nanotechnology. In biological systems, utilization nanoparticles been increased due their growth-promoting effects on germination, photosynthetic attributes, nutrient use efficiency and metabolic activitie...

Over-production of reactive oxygen species (ROS) in plants under stress conditions is a common phenomenon. Plants tend to counter this problem through their ability to synthesize ROS neutralizing substances including non-enzymatic and enzymatic antioxidants. In this context, ascorbic acid (AsA) is one of the universal non-enzymatic antioxidants having substantial potential of not only scavengin...