Peroxidase Activity In Extracts Research Articles

Total peroxidase and catalase activity of luminous basidiomycetes Armillaria borealis and Neonothopanus nambi in comparison with the level of light emission

The peroxidase and catalase activities in the mycelium of luminous basidiomycetes Armillaria borealis and Neonothopanus nambi in normal conditions and under stress were compared. An increase in the luminescence level was observed under stress, as well as an increase in peroxidase and catalase activities. Moreover, the peroxidase activity in extracts of A. borealis mycelium was found to be almost one and a half orders of magnitude higher, and the catalase activity more than two orders of magnitude higher in comparison with the N. nambi mycelium. It can be suggested that the difference between the brightly luminescent and dimly luminescent mycelium of N. nambi is due to the content of H2O2 or other peroxide compounds.

Biochemical Evaluation of Resistance Responses of Potato to Different Isolates of Alternaria solani

The resistance phenotypes of nine potato cultivars to five isolates of Alternaria solani, causal agent of early blight, were studied after inoculation and growth under greenhouse conditions. We identified potato cultivars with both susceptible and resistant phenotypes as well as A. solani isolates with varying degrees of aggressiveness. Two potato cultivars and two pathogen isolates were selected for biochemical analysis of phenol production and peroxidase activity after inoculation. Phenol compounds were evaluated 2, 4, 6, and 8 days after inoculation, while peroxidase activities were monitored daily for 10 days. Native polyacrylamide electrophoresis was used to identify one protein with peroxidase activity in extracts taken 6 days after inoculation. Significantly higher peroxidase activity as well as total phenol content in potato was correlated with resistance in the Iranian potato cultivar Diamond. Variability of responses within the same cultivar to different isolates of A. solani suggests genotypic diversity between isolates that results in phenotypic diversity for pathogen aggressiveness.

Bromoperoxidase activity and vanadium level of the brown alga Ascophyllum nodosum

Vanadium-dependent peroxidase activity in extracts of Ascophyllum nodosum growing in the intertidal region close to Roscoff/France, and algal vanadium levels, followed approximately similar seasonal variation, as deduced from a study lasting from April 2005 to March 2006. High peroxidase (PO) activity was found in extracts obtained from algae collected in between midwinter to spring [∼100–190 U per g dry mass (dm), triiodide assay] with a maximum in April. Periods of reduced PO activity lasted from summer to early winter (∼50–90 U per g dm). High vanadium levels (1.5–2.2 mg kg −1 dm) were found in algae collected from midwinter to spring, whereas reduced levels (0.6–1.4 mg kg −1 dm) were found in summer to early winter.

Tissue Specificity of `Chandler' Strawberry Peroxidase Isozymes

Peroxidase activity in extracts from freeze-dried tissue of Fragaria × ananassa Duch. cv. Chandler was highest in tissue-cultured (TC) plants, followed by field-grown (FG) and lowest in greenhouse (GH) plants. Among tissue types, activity was highest in petioles, with leaves second highest. Fruit, root, and crown tissue all exhibited low or no activity. When subjected to isoelectric focusing (IEF), petiole tissue extracts exhibited more isozymes than extracts from other organs regardless of staining substrate. Using 4-chloro-1-naphthol and H2O2 as substrates, anionic and cationic isozymes were observed in TC petiole extract with nine isozyme bands ranging in pI from 3.9 to 9.5. In TC leaf extract an isozyme at pI 7.4 was observed that was not present in other organ extracts when H2O2 and benzidine, p-phenylenediamine or 3-amino-9-ethylcarbazole were used as substrates. Specific isozymes and number of isozymes varied according to plant organ and developmental stage. Mature leaves and over-ripe fruit appeared to exhibit more activity and a larger number of isozymes than developing tissues of those plant organs.

Lignin and manganese peroxidase activity in extracts from straw solid substrate fermentations

Manganese and lignin peroxidase (MnP, LiP) activities were measured in straw extracts from cultures of Phanerochaete chrysosporium. Out of six MnP substrates, the MBTH/DMAB (3-methyl-2-benzothiazolinone hydrazone/3-(dimethylamino)benzoic acid), gave the highest MnP activity. Detection of LiP activity as veratryl alcohol oxidation was inhibited by phenols in the straw culture extracts. Appropriate levels of veratryl alcohol and peroxide (4 mM and 0.4 mM, respectively), and a restricted sample volume (not larger than 10%) were necessary to detect activity.

Increased Activity of a Cationic Peroxidase Associated with an Incompatible Interaction Between Xanthomonas oryzae pv oryzae and Rice (Oryza sativa)

Rice (Oryza sativa L.) cultivar Cas 209 carries the gene Xa-10 for resistance to race 2 of Xanthomonas oryzae pv oryzae, the bacterial blight pathogen. When seedling leaves of Cas 209 plants were infiltrated with bacterial cell suspensions of strain PXO86(Rif) (race 2, incompatible), total peroxidase activity in extracts from extracellular spaces increased almost threefold between 16 and 24 hours after inoculation. The increase in total peroxidase activity in extracellular extracts was correlated with the appearance of a 43-kilodalton peroxidase isoenzyme with an isoelectric point of 8.6. Increases in the activities of two anionic peroxidase isoenzymes also were associated with the incompatible interaction. Later during the interactions, total peroxidase activities increased in both compatible (cv Cas 209 infiltrated with race 1, PXO61(Sm)) and control (Cas 209 infiltrated with water) treatments, but final activity levels were less than that observed in the incompatible combination. Similarly, the cationic peroxidase was detected in all three treatments by 48 hours after infiltration, but at reduced levels in compatible and water-infiltrated control treatments relative to the incompatible combination. Accumulation of this peroxidase in extracellular spaces thus may play a role in the defense response in cultivar Cas 209.

ACIDIC PEROXIDASES OF APPLE ROOTSTOCKS

The peroxidase activity in extracts of shoot bark from Michigan State Apple Clone (MAC) 24 and in extracts of roots of MAC 24, East Mailing Long Ashton (EMLA) 27, and Oregon Apple Rootstock (OAR) 1 were characterized as being primarily acidic by broad range sucrose gradient isoelectric focusing. Gel isoelectric focusing (GIEF) using a narrower conventional or immobilized pH gradient showed that this activity could be separated into about a dozen isoenzymes. The GIEF isoenzyme patterns of MAC 24 shoot bark extract peroxidase and root extract peroxidases of MAC 24, EMLA 27, and OAR 1 differed. Similar values were obtained for the molecular weight of the peroxidase activity of these extracts. The results indicate that the acidic isoenzymes of apple peroxidase are of similar size.Key words: Apple, rootstocks (apple), peroxidase, molecular weight, isoenzymes

Enzyme Changes Associated with Host‐Parasite Interactions between Pearl Millet and Downy Mildew Fungus

AbstractDuring the pathogenesis of pearl millet by the downy mildew (Sclerospora graminicola [Sacc.] Schroet.), the activities of peroxidase (PO) and indoleacetic acid oxidase (IAAO) and their isozyme pattern determined by isoelectric focusing on polyacrylamide gels, were observed in extracts of leaves and ears at different stages of development. The PO activity in extracts from infected plants of a susceptible cultivar was found to be higher than in healthy plants. The higher activity was most probably due to the acceleration of host senescence by the pathogen. Quantitative differences in the isozyme patterns of PO and IAAO were found. In inoculated plants of the resistant cultivar, no symptoms developed under the conditions used for infection of the susceptible cultivar and the changes in enzyme activities after inoculation were not significant. The results indicated that different proteins are synthesized in the two cultivars.

Effect of Far Red and Red Light on a Pelletable Peroxidase Activity in Extracts from Spinach Leaves

AbstractThe effect of in vitro irradiations on ihe pelletability of peroxitlase activity was tested in extracts prepared from leaves of light‐grown spinach (Spinacia oleracea). It appeared that far red light increased the pelletable activity and that red light reversed this effect. This phytochrome‐mediated effect occurred in a particulate fraction which banded at 39% (w/w) sucrose on an isopycnic density gradient.

Peroxidase from Meloidogyne incognita

Peroxidase activity in extracts of adult female Meloidogyne incognita was influenced by the host plant on which the nematode was propagated. Extracts of nematodes propagated on tobacco contained only 56% as much peroxidase activity as extracts from nematodes propagated on tomato. Two peroxidase isoenzymes separated by polyacrylamide-gel electrophoresis from extracts of adult female nematodes propagated on tomato had the capacity to oxidize several aromatic amines and phenols. A positive reaction for peroxidase in stylet exudates of adult female nematodes was obtained cytochemically with o-dianisidine in the presence of hydrogen peroxide. This reaction was inhibited by 5 m m-potassium cyanide.