We studied the response of each ascorbate peroxidase (APX) isoenzyme in spinach leaves under stress conditions imposed by high light intensity, drought, salinity, and applications of methyl viologen and abscisic acid. The steady-state transcript level of cytosolic APX remarkably increased in response to high-light stress and methyl viologen treatment, but not in response to the other stress tre...

Members of the superfamily of plant, fungal, and bacterial peroxidases are known to be present in a wide variety of living organisms. Extensive searching within sequencing projects identified organisms containing sequences of this superfamily. Class I peroxidases, cytochrome c peroxidase (CcP), ascorbate peroxidase (APx), and catalase peroxidase (CP), are known to be present in bacteria, fungi,...

Abbreviations: ROS: Reactive oxygen species; H2O2: Hydrogen peroxide; CAT: Catalase; POD: peroxidase; APX: Ascorbic Acid Peroxidase; GR: Glutathione Reductase; AsA-GSH: Ascorbate-Glutathione; ASC: Reduced form of Ascorbate; DHA: Dehydroascorbate; MDHAR: Monodehydroascorbate Reductase; DHAR: Dehydroascorbate reductase; GSH: Reduced Glutathione; GSSG: Oxidized Glutathione; PDA: Potato Dextrose Ag...

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...

Bryophytes are poikilohydric organisms that can be used as model plants to study desiccation tolerance mechanisms. The main objective of this was examine the activities antioxidant enzymes ascorbate peroxidase (APX), catalase (CAT) and guaiacol (POD) in rehydrated desiccated states Syntrichia ruralis (Hedw.) Web. & Mohr. from two slopes, one North-east (NE) South-west (SW) facing collected ...

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...

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 ascorbate content declined rapidly in broccoli (Brassica oleracea L. var. italica) florets, but not in the stem tissue, during post-harvest senescence. Ascorbate peroxidase (APX), ascorbate oxidase (AO), l-galactono-1,4-lactone dehydrogenase (GLDH), monodehydroascorbate reductase (MDAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) were investigated in gene expression a...

Ascorbate peroxidase (APX) is a crucial, haeme-containing enzyme of the ascorbate glutathione cycle that detoxifies reactive oxygen species in plants by catalyzing the conversion of hydrogen peroxide to water using ascorbate as a specific electron donor. Different APX isoforms are present in discrete subcellular compartments in rice and their expression is stress regulated. We revealed the homo...

An Escherichia coli expression system has been developed for pea cytosolic ascorbate peroxidase (APX). The enzyme was expressed as a fusion product with the E. coli maltose-binding protein for rapid, affinity chromatography purification. Recombinant ascorbate peroxidase (rAPX) was purified by tryptic digestion to separate the maltose-binding protein from rAPX followed by three chromatographic s...