Hydrogen peroxide (H2O2) has been implicated in many stress conditions. Control of H2O2 levels is complex and dissection of mechanisms generating and relieving H2O2 stress is difficult, particularly in intact plants. We have used transgenic tobacco with approximately 10% wild-type catalase activity to study the role of catalase and effects of H2O2 stress in plants. Catalase-deficient plants sho...

Background & Aim: Rosemary (Rosmarinus officinalis L.) includes species that have high drug and nutritional values. Considering the importance of the antioxidant enzyme system as an effective factor in increasing the resistance of plants to different environmental stresses, in this research, some biochemical properties of catalase and peroxidase enzymes of rosemary pla...

In order to investigate physiological and biochemical changes of wheat under stress residue of Imazethapyr herbicide (Imazethapyr), an experiment was conducted in a completely randomized design with four replications in greenhouse conditions at university of Mohaghegh Ardebili. The treatments consisted of five dose levels of herbicide Imazethapyr (0, 0.011, 0.022, 0.033 and 0.044 micrograms of ...

potato (solanum tuberosum l.) auxiliary buds c.v. white desiree were cultured in ms medium containing 0, 50, 100, 150 and 200 μm concentrations of silver thiosulfate (sts) under in vitro condition. after eight weeks, the effect of silver ions (ag+) in the form of silver thiosulfate complex (sts), as an ethylene action inhibitor, on chlorophyll contents of leaves, ascorbate peroxidase, guaiacol ...

It has been recently reported that catalytic quantities of crystalline catalase, in the presence of hydrogen peroxide, can rapidly oxidize a variety of molecules larger than hydrogen peroxide and aliphatic alcohols (1). The qualitative experiments have shown that oc-naphthol and p-phenylenediamine are condensed by oxidative coupling to indophenol purple; p-aminobenzoic acid, sulfathiazole, adre...

Winder, Frank G. (Trinity College, Dublin, Ireland). Peroxidatic activity of mycobacteria and relation to catalase. J. Bacteriol. 92:413-417. 1966.-Catalase from Mycobacterium smegmatis was purified about 50-fold. All fractions showed a ratio of peroxidatic activity to catalatic activity approximately the same as that of the crude extract, a ratio only about four times that given by catalase fr...

The immobilization of catalase was carried out from enzyme solutions in acid (pH < 3.5) and alkaline (pH > 1 1 ) medium on two kinds of soot differing by the average size of the particles. Under these conditions the peroxidase-like activity of immobilized catalase in the oxidation of phenol has been studied. The effect of the initial concentration of the substrate on the rate of the process cat...

We have previously reported that red blood cells contain high levels of a protein that supports the survival of a variety of CNS neurons in vitro for 24 hr. Here we report the isolation of this trophic activity from human red blood cells. The active material, purified over lOOO-fold by ion-exchange chromatography and isoelectric focusing, has been identified as catalase based on its isoelectric...

Enterococcus faecalis exhibits high resistance to oxidative stress. Several enzymes are responsible for this trait. The role of alkyl hydroperoxide reductase (Ahp), thiol peroxidase (Tpx), and NADH peroxidase (Npr) in oxidative stress defense was recently characterized. Enterococcus faecalis, in contrast to many other streptococci, contains a catalase (KatA), but this enzyme can only be formed ...

Mycobacterium tuberculosis has a relatively high resistance to killing by hydrogen peroxide and organic peroxides. Resistance may be mediated by mycobacterial catalase-peroxidase (KatG) and possibly by alkyl hydroperoxide reductase (AhpC). To determine the interrelationship between sensitivity to H2O2, catalase and peroxidase activities, and bacillary growth rates measured both intracellularly ...