scholarly journals EFFECT OF BETA-AMINOBUTYRIC ACID ON ACTIVITY OF PEROXIDASE AND POLYPHENOL OXIDASE ENZYMES IN CUCUMBER INFECTED WITH NEMATODE MELOIDOGYNE JAVANICA

2019 ◽  
Vol 14 (1) ◽  
pp. 7-17 ◽  
Author(s):  
Niloufar Mahmoudi
Keyword(s):  
Polyphenol Oxidase ◽  
Plant Pathogens ◽  
Meloidogyne Javanica ◽  
Root Knot Nematode ◽  
Peroxidase Isozymes ◽  
Significant Difference ◽  
Peroxidase Enzyme ◽  
Oxidase Enzyme ◽  
Cucumber Roots ◽  
Activity Induction

Beta-amino-butyric acid is introduced as an inducer of resistance in plants against plant pathogens. In this research, the induction of some defensive compounds including peroxidase and polyphenol oxidase enzymes by this compound against the rootstock node-producing nematode Meloidogyne javanica in cucumber was investigated. The results showed that inoculation of cucumber roots infected with root-knot nematode with the chemical composition of BABA from the first day after inoculation increased the activity of peroxidase enzyme and reached its maximum on the fourth day of this activity. Induction of the activity of polyphenol oxidase enzyme showed a gradual increase with a significant difference in comparison to the control and healthy plants and reached the maximum on the fourth day. The electrophoresis of peroxidase isozymes showed that isozyme peroxidase forms in cucumber roots induced by BABA were much more potent than pathogen-induced isozymes. In plants treated with nematode plus BABA, two isozymes were Rf = 00.31 and Rf = 34/0, which were stronger than control (inoculated with nematode).

Assessment of plant defence induction and biocontrol potential of Bacillus megaterium wr101 against Meloidogyne javanica

Nematology ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1091-1099
Author(s):  
Navazollah Sahebani ◽  
Fahime Omranzade
Keyword(s):  
Phenolic Compounds ◽  
Polyphenol Oxidase ◽  
Bacillus Megaterium ◽  
Plant Defence ◽  
Meloidogyne Javanica ◽  
Activity Level ◽  
Total Phenolic ◽  
Total Phenolic Compounds ◽  
Cucumber Roots ◽  
Biocontrol Potential

Summary The aim of this study was to evaluate biological control ability and induction of plant defence by Bacillus megaterium wr101, isolated from wheat rhizosphere, on disease severity induced by Meloidogyne javanica on cucumber. In addition, changes in some plant defence compounds (such as peroxidase, polyphenol oxidase, catalase, hydrogen peroxide (H2O2) and accumulation of total phenolic compounds) induced by B. megaterium wr101 and M. javanica were also evaluated. Results showed that application of B. megaterium wr101 reduced nematode disease indices compared to non-treated controls. Inoculation of cucumber roots with B. megaterium wr101 increased peroxidase and polyphenol oxidase activities in root tissue from the first day after inoculation (DAI), with maximum levels of these enzymes recorded 4 DAI and then reduced gradually. Catalase activity and H2O2 accumulation showed two peaks on 1 and 5 DAI, respectively, but the presence of nematodes in the plant significantly increased the activity level of catalase enzyme even in the presence of the bacterium. Bacillus megaterium wr101 also stimulated the accumulation of total phenolic compounds in cucumber roots.

scholarly journals GENOTYPIC AND BIOCHEMICAL VARIATION IN THE RESPONSE OF BARLEY TO THE ROOT-KNOT NEMATODE (MELOIDOGYNE JAVANICA) AT SEEDLING STAGE

2019 ◽  
Vol 31 (1) ◽  
pp. 07-17 ◽  
Author(s):  
Majid S. Bajestani ◽  
Esmat M. Moghadam ◽  
Reza Aghnoum ◽  
Hamid Rohani
Keyword(s):  
Superoxide Dismutase ◽  
Polyphenol Oxidase ◽  
Meloidogyne Javanica ◽  
Root Knot Nematode ◽  
Greenhouse Condition ◽  
Breeding Lines ◽  
Resistant Cultivars ◽  
Biochemical Variation ◽  
Moderately Resistant ◽  
Different Levels

The present study was conducted to evaluate 28 commercial cultivars and two promising breeding lines of barley in terms of resistance to Meloidogyne javanica nematode and to investigate the synthesis level of peroxidase, superoxide dismutase, catalase and polyphenol oxidase enzymes in different days after inoculation in greenhouse condition. Based on the results of evaluation, Jolge and Nimrouz cultivars were highly resistant, Rihan and Zarjow were very susceptible. The rest of the cultivars were ranked between these groups in resistant, moderately resistant and moderately susceptible groups. Comparison of the activity of antioxidant enzymes in highly resistance cultivars (Jolge and Nimrouz) and very susceptible cultivars (Rihan and Zarjow) roots showed that the activity of peroxidase, superoxide dismutase and polyphenol oxidase increased in the root of the highly resistant cultivars and decreased or remains unchanged in very susceptible cultivars. Nevertheless, catalase showed a decreasing trend after inoculation by nematodes in highly resistance cultivars, and in general; its level in resistant cultivars was less than susceptible cultivars. Therefore, changes in the activity of these enzymes can be attributed to different levels of resistance among these cultivars.

scholarly journals Mineral composition of beetroot treated with potential elicitors and inoculated with Meloidogyne javanica

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Paula Juliana Grotto Débia ◽  
Beatriz Cervejeira Bolanho ◽  
Claudia Regina Dias-Arieira
Keyword(s):  
Population Density ◽  
Mineral Composition ◽  
Integrated Management ◽  
Meloidogyne Javanica ◽  
Nematode Population ◽  
Root Knot Nematode ◽  
Cu Content ◽  
Manganese Zinc ◽  
Nematode Population Density ◽  
Elicitor Treatments

Abstract Background The root-knot nematode Meloidogyne javanica can infect beetroots, causing extensive damage to this food crop. As chemical and genetic control tactics have shown limited efficacy, new strategies are needed to improve the integrated management of this parasite. This study assessed the influence of potential defence elicitors and M. javanica infection on the mineral composition of beetroot. Plants were treated with acibenzolar-S-methyl (ASM), citrus biomass, or a mannanoligosaccharide-based product (MOS) and inoculated with 1000 eggs and second-stage juveniles of M. javanica. At 60 days after inoculation, beetroot plants were harvested and evaluated for nematode population density, vegetative growth, and mineral content. Results All potential elicitors reduced nematode population density in beetroots (p ≤ 0.10) and improved the vegetative parameters of inoculated plants (p ≤ 0.05), except shoot fresh weight. Some minerals were found to be negatively affected by treatments, particularly calcium, whose levels were consistently lower in treated plants. On the other hand, M. javanica inoculation increased magnesium, iron, manganese, zinc, and copper contents in beetroots. However, the latter mineral (Cu content) of inoculated plants was positively influenced by MOS and ASM. Conclusion Potential elicitor treatments did not improve the mineral composition of beetroot, but were effective in reducing nematode population density. Plants inoculated with M. javanica had higher mineral levels. However, gall formation decreases the commercial value of the crop and might render it unsuitable for commercialisation. M. javanica-infected beetroots may be used for nutrient extraction or sold to food processing industries.

Biological control of Fusarium wilt of cucumber with nonpathogenic isolates of Fusarium oxysporum

1987 ◽  
Vol 33 (5) ◽  
pp. 349-353 ◽  
Author(s):  
T. C. Paulitz ◽  
C. S. Park ◽  
R. Baker
Keyword(s):  
Biological Control ◽  
Fusarium Oxysporum ◽  
Infection Rate ◽  
Fusarium Wilt ◽  
Disease Incidence ◽  
Infection Rates ◽  
Control Activity ◽  
Significant Difference ◽  
Cucumber Roots ◽  
Linear Regressions

Nonpathogenic isolates of Fusarium oxysporum were obtained from surface-disinfested, symptomless cucumber roots grown in two raw (nonautoclaved) soils. These isolates were screened for pathogenicity and biological control activity against Fusarium wilt of cucumber in raw soil infested with Fusarium oxysporum f. sp. cucumerinum (F.o.c.). The influence of three isolates effective in inducing suppressiveness and three ineffective isolates on disease incidence over time was tested. The effective isolates reduced the infection rate (R), based on linear regressions of data transformed to loge (1/1 – y). Effective isolate C5 was added to raw soil infested with various inoculum densities of F.o.c. In treatments without C5, the increase in inoculum densities of F.o.c. decreased the incubation period of wilt disease, but there was no significant difference in infection rate among the inoculum density treatments. Isolate C5 reduced the infection rate at all inoculum densities of F.o.c. Various inoculum densities of C5 were added to raw soils infested with 1000 cfu/g of F.o.c. In the first trial, infection rates were reduced only in the treatment with 10 000 cfu/g of C5; in the second trial, infection rates were reduced in treatments with 10 000 and 30 000 cfu/g of C5.

The effect of organic compost of Caryocar brasiliense waste against Meloidogyne javanica in two vegetable crops

Nematology ◽  
2021 ◽  
pp. 1-8
Author(s):  
Fabíola de J. Silva ◽  
Regina C.F. Ribeiro ◽  
Adelica A. Xavier ◽  
Vanessa A. Gomes ◽  
Paulo V.M. Pacheco ◽  
...  
Keyword(s):  
Integrated Control ◽  
Meloidogyne Javanica ◽  
Control Measures ◽  
Vegetable Crops ◽  
Root Knot Nematode ◽  
Second Stage ◽  
Tomato Roots ◽  
Crop Development ◽  
Caryocar Brasiliense ◽  
Organic Compost

Summary Root-knot nematodes (Meloidogyne spp.) are responsible for various significant crop losses, which require taking integrated control measures. The present study aimed to identify a possible sustainable approach to the management of Meloidogyne javanica in vegetable crops using an organic compound based on pequi (Caryocar brasiliense) fruit residues. A pot experiment was conducted using cultivars of tomato and lettuce susceptible to M. javanica, with three amendments including inorganic fertiliser, cattle manure and five doses of organic compost with pequi residues. All treatments were inoculated with second-stage juveniles of M. javanica to simulate the root-knot nematode disease in field conditions. Increasing doses of organic compost with pequi residues from 5 kg m−3 to 30 kg m−3 promoted a significant decrease in the nematode population in both cultures evaluated. Organic compost (30 kg m−3) reduced the numbers of galls and eggs of M. javanica by 41.6 and 46.5% in tomato roots, and by 80.3 and 59.2% in lettuce roots, respectively, compared with non-treated control. Organic compost also increased crop development considerably. In general, there was a 43.0% increase in plant development compared to non-treated control. Hence, organic compost of pequi residues could be an alternative to toxic chemical nematicides and recommended as eco-friendly management of M. javanica in vegetable crops.

scholarly journals Effect of Frozen Storage on Polyphenol Oxidase, Antioxidant Content, and Color of Pawpaw (Asimina Triloba [L.] Dunal) Fruit Pulp

2017 ◽  
Vol 6 (3) ◽  
pp. 93 ◽  
Author(s):  
Robert G Brannan ◽  
Gai Wang
Keyword(s):  
Ascorbic Acid ◽  
Polyphenol Oxidase ◽  
Frozen Storage ◽  
Color Difference ◽  
Browning Index ◽  
Air Samples ◽  
Significant Difference ◽  
Main Effect ◽  
Effect Of Treatment ◽  
Main Effects

Polyphenol oxidase (PPO) activity values for pawpaw pulp during frozen storage were measured for the main effect of month of storage at three levels (0, 4, 8 months) and treatment at four levels (vacuum, air, ascorbic acid or n-acetylcysteine). A significant effect of treatment was observed in PPO activity (p<0.001). Post hoc analysis revealed no significant difference between samples that were vacuum packaged and those for which no attempt to exclude air was made. The addition of the two chemical browning inhibitors significantly lowered PPO activity. Ascorbic acid exhibited a significant 69% reduction in PPO activity compared to vacuum and air samples and n-acetylcysteine was significantly more effective than ascorbic acid and almost completely inhibited PPO activity compared to the vacuum and air samples. CIELAB tristimulous color values (L*, a*, b*) were used to generate the applied color values total color difference (DE), browning index, hue and chroma in pawpaw pulp for the two main effects. Analysis of variance for the main effects showed significance for all seven color attributes at p<0.001. For the main effect of storage time, ANOVA showed significance during storage for all seven color attributes at p<0.001, indicating that there were color changes during storage. Pawpaw pulp samples at 8 months of storage were significantly darker (lower L*), more yellow (higher b*), more vivid (higher chroma), and had a higher browning index than the samples at 0 or 4 months of storage. For the main effect of treatment, ascorbic acid and n-acetylcysteine treatment produced pawpaw pulp that was significantly different than samples to which air was not excluded for all seven dependent color variables. Specifically, n-acetylcysteine and ascorbic acid produced pulp that was lighter (higher L*), less red (lower a*), and more yellow (higher b* and hue), more vivid (higher chroma), and exhibited more color difference (higher DE). A strategy to inhibit enzymatic browning during frozen storage would be useful for the nascent pawpaw industry.

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