POD) And Polyphenoloxidase Activities Research Articles

Effect of storage temperature and time on potato cv. Innovator industrial quality

Reducing the storage temperature delays sprouting and increases the storage period, prolonging the supply to the industry. However, it may cause enzymatic browning before frying and non-enzymatic browning over frying. Therefore, the objective of this study was to determine the effects of a reduction in the temperature and storage time on the quality of cv. Innovator intended for frying. Potato tubers were stored at 6, 7 and 8 °C for 150 days. This study analyzed the total soluble sugars (TSS), non-reducing sugars (NRS), reducing sugars (RS), post-frying coloring, fresh mass loss (FML), sprouting onset, peroxidase (POD) and polyphenoloxidase (PPO) activity. The TSS, NRS and RS contents were higher in tubers stored at 6 °C, classified in category 3, while at 7 and 8 °C, it was classified in category 2. Storage time affected sugar concentrations only in tubers at 6 °C. Also at 6 °C, the FML was lower and sprouting was delayed by 30 days. Regardless of temperature and storage time, there was no enzymatic darkening due to POD and PPO activity. It is concluded that reducing the storage temperature to 6 °C prolongs the dormancy period, reduces fresh mass loss, increases reducing sugar content and non-enzymatic browning.

Changes in bioactive compounds in spiny coriander leaves in response to inflorescence pruning at different growth stages

The objective of the study was to evaluate the effect of inflorescence pruning on spiny coriander and determine the levels of antioxidants at different growth stages. Inflorescence pruning increased leaf biomass by 188%, although total biomass did not vary among treatments. Pruning altered the biomass partition, induced the earmarking of a higher percentage of photosynthates for the production of new leaves, and increased the leaf contents of reducing sugars, sucrose and soluble proteins. The contents of bioactive compounds and antioxidant activity were not affected by inflorescence pruning. Regarding the growth stages, the polyphenol and flavonoid contents were high during the juvenile stage, and highest levels of carotenoids, chlorophyll a and chlorophyll b were produced at the beginning of plant maturation. From the full maturity stage onwards, peroxidase (POD) and polyphenoloxidase (PPO) were highest, coinciding with a decrease in bioactive compounds. Considering the production of bioactive compounds and antioxidant, POD and PPO activities, the ideal harvesting time would be in the late juvenile and early maturation stages of spiny coriander, between 90 and 120 days after germination. Moreover, inflorescence pruning is recommendable for spiny coriander cultivation, for increasing the leaf biomass without affecting the leaf levels of bioactive compounds and antioxidant activity. Our results highlight the relevance of the growth stages for the production of bioactive compounds of this crop, contributing to improve the cultivation practices, with higher yields and an optimized use of the therapeutic properties of the leaves.

Antioxidative responses of Nostoc ellipsosporum and Nostoc piscinale to salt stress

The responses of the cyanobacteria Nostoc ellipsosporum and Nostoc piscinale to salt stress during various growth stages were studied. Nostoc ellipsosporum was more NaCl tolerant and attained more biomass under salinity than N. piscinale. Accumulation of proline was detected in N. ellipsosporum under salinity stress. Malondialdehyde content decreased in both species on day 9 (mid log phase) under salt stress. A similar trend was detected in hydrogen peroxide (H2O2) content in N. ellipsosporum. Strong induction in catalase (CAT) activity was observed in N. ellipsosporum on day 9 in the presence of salt. The increase in CAT activity of N. piscinale was observed only at higher concentrations of NaCl. In contrast to N. ellipsosporum, induction in peroxidase and polyphenol oxidase (PPO) activities on day 9 was stronger in N. piscinale. Salinity enhanced superoxide dismutase (SOD) and PPO activity in N. ellipsosporum at all growth stages. Moreover, different isoforms of CAT and SOD were detected in these cyanobacteria. Apparently, selection pressure in these cyanobacteria has led to the evolution of SODs and CATs as the main antioxidant enzymes against reactive oxygen species. Phycobiliprotein content in N. ellipsosporum under all conditions was significantly higher than that in N. piscinale. NaCl at moderate concentrations significantly increased phycobiliprotein content in the middle of the log phase in both species. Moreover, contrary to N. piscinale, the size of phycobilisomes [phycoerythrin + phycocyanin / allophycocyanin] in N. ellipsosporum increased significantly under salt stress at the mid of log phase and later. The increase in size of phycobilisomes in N. ellipsosporum could help this species to withstand salt stress by enhancing energy transfer capacity. These results suggest that N. ellipsosporum cells could be better protected against salinity-induced oxidative damage by maintaining higher levels of antioxidative enzymes, proline, and phycobiliproteins than the cells of N. piscinale.

Effect of honey and calcium dips on quality of fresh-cut nectarine (Prunus persica L. Batsch)

The effects of calcium chloride (CaCl2) and honey dips were investigated on the quality of fresh-cut nectarines. Nectarine fruit samples at the commercially ripe stage were wedged and then dipped in distilled water, 50% honey, 1% CaCl2 or 1% CaCl2 combined with 50% honey solutions, followed by storage at 4 ± 0.5 °C and 90 ± 2% relative humidity for 7 d. The following parameters were investigated during storage: firmness, total soluble solids (TSS), superficial color, color darkening score and index, total phenols content and the enzyme activities of peroxidase and polyphenol oxidase (PPO). CaCl2 and CaCl2 + honey solution dips improved the texture and maintained the TSS content. Honey and CaCl2 + honey suppressed an increase in the color difference. Minor changes were found in color attributes (lightness (L*), hue and chroma values), color darkening, total phenols content and PPO activity during storage. CaCl2 + honey maintained the quality of the nectarines by delaying color change and firmness loss.

Evaluation of some Chemical Substances as Inducers forTomato Resistance Against Root-Knot Nematode, Meloidogyne incognita

The potency of the some chemicals from different groups known as inducersof systemic acquired resistance (SAR) viz., acetylsalicylic acid (ASA), DL-3-aminobutyric acid (BABA), 2,6-dichloroisonicotinic acid (INA), 5-chlorosalicylic acid(CSA), nitrosalicylic acid (NSA),salicylic acid (SA),ascorbic acid (AS), and selenium(SE) in reducing reproduction Meloidogyne incognita in tomato plants cv. Castelrock was investigated under greenhouse conditions. Supplying chemicals threedays-before nematode inoculation showed maximum efficacy in reducing nematodegalls, egg-masses and eggs numbers followed by synchronized addition withinoculation, while post-inoculation treatment was less effective. Reiterative dosespost-inoculation were improved the efficacy of single dose, also three doses usedwere more effective than one or two, while, differences between two or three doseswere insignificant. On the other hand, plant fitness was slightly impaired with thirddose than second one. INA and SE showed pronounced effect in inhibitionnematode population after third dose compared with the rest chemicals, whichshowed mild increase in their efficacy from second to third doses. Unfortunately,three doses of SE were reduced plant fitness after enhanced by double doses,while INA was showed obvious phytotoxicity gradually increased by repeatingdoses. Gathering between the most effective application time (before inoculation)and the proper activated dose after inoculation was studies for emphasized theiraction and comparing with pre-inoculation only in suppressing M. incognitapopulation. Chemical activators showed enhancing in peroxidase andpolyphenoloxidase activities. In conclusion, CSA, NSA, BABA and SA were showedhighest efficacy as resistance inducers. This collectively showed reduction of totalpopulation with pre-inoculation time application and pre plus post-inoculationapplication, 57.6&83.8%, 56.5&81.6%, 55.4&79.2% and 54.5&78.1%, respectively.Also the fecundity of nematode was taking similar trend as total population. Theresults suggest that tested chemicals especially CSA, NSA, BABA and SA havepotential to suppress root-knot nematode infection in tomato plants through inducedsystemic resistance.

Impact of different washing procedures on quality of fresh-cut iceberg lettuce (Lactuca sativa var. capitata L.) and endive (Cichorium endivia L.)

The objective of this study was to determine the effects of alternative washing procedures on fresh-cut iceberg lettuce and endive, applying warm water (45 °C), warm water with CaCl2 (1 g/L), and chlorinated water (4 °C, 120 ppm), respectively. Processing was conducted on pre-industrial scale, and the produce was subsequently stored in consumer-sized bags (4 °C, 10 days). O2 and CO2 levels in the modified atmosphere, and activities of phenylalanine ammonia-lyase (PAL), peroxidase (POD) and polyphenoloxidase (PPO) of the samples were analyzed. Counts of total aerobic bacteria and pseudomonades were determined on the produce and in the process water. In both commodities, wound-induced PAL activities were significantly reduced by warm water treatment. In iceberg lettuce, adding CaCl2 to warm water resulted in a further reduction of PAL activities. Chlorinated water was less effective than warm water in suppressing wound-induced PAL activity in endive, but proved to be most effective in reducing total microbial cell counts by 1.1 and 2.1 log10 cfu/g in iceberg lettuce and endive, respectively. Warm water treatment exhibited reduction rates of similar magnitudes. For process water, chlorine proved to be the most efficient sanitizer. PPO and POD activities were only marginally affected by the different washing procedures. As indicated by respiration of the fresh-cut produce, warm water treatments applied retained the vitality of both plant species. The results suggest that warm water treatments are suitable measures to improve the quality of iceberg lettuce and endive, but were less efficient in sanitizing the process water.

Changes in Antioxidant Enzymes Activity and Oxidative Damage in Four Argania spinosa Ecotypes Under Water Stress Conditions

AbstractArgania spinosa L. Skell, a tree endemic of Morocco, grows in semiarid and arid areas. Biochemical response to drought in four ecotypes of the A. spinosa was compared. Choice of ecotypes was based on evident differences in geographical features in south-west Morocco: two coastal ecotypes (Essaouira and Agadir) and two paralittorale ecotypes (Aoulouz and Lakhssas). Lipid peroxidation (malonyldialdehyde (MDA)), content of endogenous hydrogen peroxide (H2O2) and antioxidant enzyme system (Catalase (CAT), Ascorbate peroxidase (APX), Total peroxidase (POD) and Polyphenoloxidase (PPO) were measured in control (100% relative humidity (RH) at field capacity (FC)) and water-stressed plants (50 and 25% RH at FC). For all ecotypes, drought stress significantly increased the contents of MDA and H2O2 and an ecotype effect was noted. According Two-way ANOVA analysis, the ecotype x watering regime interaction was highly significant. We found an increase in the activities of the four ROS-scavenging enzymes and an ecotype effect was noted. Ecotype x watering regime interaction shows that only the CAT and APX activities were significant. Highest values of POD and PPO activities were found in both paralittorale ecotypes. Increase in antioxidant enzyme activities appears to be an adaptive response to restore the reactive oxygen species in their homeostasis. The four study ecotypes were separated by two discriminant functions obtained by canonical discriminant analysis. Coastal ecotypes are separated from the paralittorale ecotypes mainly by POD and PPO activities and MDA content.

Peroxidase and Polyphenoloxidase Activities and Phenol Content in Fruit of Eggplant and Their Relationship to Infestation by Shoot and Fruit Borer

The shoot and fruit borer (Leucinodes orbonalis Guen.) does severe damage to eggplant (Solanum melongena L.). In order to predict the level of fruit infestation and perhaps correlate it to specific biochemical characteristics, the basis of resistance against the shoot and fruit borer in eggplant was investigated. Seven cultivars of eggplant were sampled at 10, 15, 20, and 25 days after flowering (DAF) for peroxidase (PO) and polyphenoloxidase (PPO) activity and at 15, 20, and 25 DAF for phenol content. Stepwise multiple regression analysis revealed that there was a lack of correlation between fruit infestation and PO activity. However, a correlation between fruit infestation; PPO activity at 15, 20, and 25 DAF; and phenol content at 15 and 20 DAF was observed. Principal components analysis indicated that BCB-38 was the best performing cultivar and can likely be used as improved genetic material in future breeding programs.

Palmito de pupunha (Bactris gasipaes Kunth.) composição mineral e cinética de enzimas oxidativas

A análise da presença de enzimas oxidativas como a peroxidase (POD) e a polifenoloxidase (PPO) e o controle da atividade destas enzimas são importantes na preservação e no processamento de alimentos. Este trabalho teve por objetivo determinar a atividade enzimática da polifenoloxidase (PPO) e da peroxidase (POD) do palmito de pupunha, bem como avaliar o comportamento destas enzimas frente ao tratamento térmico e assim calcular a cinética de inativação térmica das mesmas para suas porções termorresistente e termolábil. Para a extração de peroxidase (POD) e polifenoloxidase (PPO) de palmito, utilizou-se solução tampão fosfato de sódio 100 mM com diferentes pHs (5,5; 6,0; 6,5 e 7,0). O melhor pH de extração da POD foi 5,5 e da PPO, 6,5. Estes extratos foram tratados em diferentes temperaturas (65, 70, 75 e 80 °C) por períodos de 1 a 10 minutos. A POD e a PPO sofreram um decréscimo de 70 e 80%, respectivamente, em relação às suas atividades iniciais. As energias de ativação, nas temperaturas estudadas, para a porção termolábil e termorresistente da peroxidase foram 154,0 e 153,0 kJ.mol-1, respectivamente, enquanto que para a polifenoloxidase foram 26,3 e 27,0 kJ.mol-1, respectivamente. Resultados apresentaram valores que estão dentro da faixa de energia de ativação reportada para o processo de inativação térmica de enzimas.

Induction and mechanism of cucumber resistance to anthracnose induced by Pieris rapae extract

Pieris rapae extract was sprayed on the surface of cucumber leaf to determine the induction of resistance to anthracnose. The enzyme activities of peroxidase (POD) and polyphenoloxidase (PPO) were detected on cucumber leaves after P. rapae extract induction and pathogen challenge. The results showed that the disease index of cucumber anthracnose was significantly decreased after the cucumber was induced with the P. rapae extract at a concentration of 5.0 mg·mL−1. The POD and PPO activities in foliar-applied P. rapae extract without pathogen inoculation (PETO) or with pathogen inoculation (PETI) were relatively higher than those with no-P. rapae extract treatment and without pathogen inoculation (CONO) or with pathogen inoculation (CONI), respectively. The results suggested that the increased levels of POD and PPO activities in PETO and PETI play an important role in the induction of resistance to cucumber anthracnose.

Minerais e enzimas oxidativas em brócolos (Brassica oleracea L. Cv. Italica) minimamente processado

The aim of this research was to determine the action of peroxidase (POD) and polyphenoloxidase (PPO) as well as mineral contents into natural and blanched broccoli, Brassica oleracea L. (Brassicaceae), - the latter was submitted to thermal treatment at 95,0 o C during 10 to 12 minutes. Extracts containing POD and PPO were prepared using sodium phosphate buffer 100mmol/L in different pH (5.0, 5.5, 6.0, 6.5, 7.0 and 7.5). The procedure was followed in order to extract the soluble fraction and the fraction ionically linked to the cellular wall. Among the extracted fractions from both natural and blanched broccoli a strong distinction on the soluble fraction was noticed, being POD and PPO activity more intense on natural broccoli. The same variation, however, was not detected in ionically linked fractions. The thermal treatment used in the blanching process did not affect mineral contents: Fe (152.3ppm e 149.0ppm); Cu (15.5ppm e 9.6ppm); Zn (104.3ppm e 104.3ppm); Mn (59.8ppm e 59.6ppm); Ca (0.69% e 0.59%); Mg (0.29% e 0.29%); K (2.58% e 3.04%) - for natural and blanched broccoli, respectively.

Antimicrobial and antioxidant activities of edible coatings enriched with natural plant extracts: In vitro and in vivo studies

Consumers demand less use of chemicals on minimally processed fruits and vegetables so more attention has been paid to the search for naturally occurring substances able to act as alternative antimicrobials and antioxidants. The susceptibility of the native microflora of butternut squash and Listeria monocytogenes was analyzed by in vitro assays using (a) film-forming solutions (chitosan, carboxymethyl cellulose and casein), (b) oleoresins (olive, rosemary, onion, capsicum, cranberry, garlic, oreganum and oreganum + carvacrol 5%) and (c) film-forming solutions enriched with oleoresins. Film-forming solutions did not show significant antimicrobial properties. The oleoresins with meaningful antimicrobial activity against both squash native microflora and L. monocytogenes were olive and rosemary. In general, film-solutions containing 1% of different oleoresins showed limited antimicrobial effects against these indicator microorganisms. In vitro antioxidant properties were measured on different crude vegetable extracts. The enzyme source proved to affect peroxidase (POD) and polyphenoloxidase (PPO) susceptibility to the film-forming solutions. Most oleoresins significantly affected POD activity, regardless of the enzyme source. When the film-forming solutions were enriched with oleoresins, the latter lost, or retained their potential to reduce POD and PPO activities. In vivo experiments were focused on the treatments offering potential antibacterial and antioxidant benefits. The use of chitosan coatings enriched with rosemary and olive oleoresins applied to butternut squash did not produce a significant antimicrobial effect, however antioxidant effects were observed during the first day, exerting POD inhibition for up to 5 d of storage. Both oleoresins and chitosan enriched with them exerted significant antioxidant activities over PPO throughout 5 d of storage. The use of chitosan enriched with rosemary and olive did not introduce deleterious effects on the sensorial acceptability of squash. Chitosan enriched with rosemary and olive improved the antioxidant protection of the minimally processed squash offering a great advantage in the prevention of browning reactions which typically result in quality loss in fruits and vegetables.

CHANGES OF SOLUBLE PROTEIN, PEROXIDASE AND POLYPHENOL OXIDASE IN LEAVES AND BUDS OF RIPENING OLIVE

ABSTRACT Changes in the protein profile of total soluble protein (TSP)/peroxidase (PO) and polyphenoloxidase (PPO) activities in leaves and buds of olive trees (cv. Zard) from the Gilvan region were studied. An increase in TSP content for leaves and buds during fruit ripening was highest at full fruit ripening and decreased or remained relatively high throughout fruit softening. However, the protein profile showed the appearance of new bands while the intensity of some bands also occurred during ripening. PO and PPO activities in leaves and buds were low at early fruit development, increased at full fruit development and then decreased at softening stages. Therefore, there is a close relationship between these enzymes, specific protein and the process of fruit development. Finally, in all cases, protein content and both enzyme activities in buds were higher than leaves during the growth and development of olive. PRACTICAL APPLICATIONS In a recent project, we found changes in the content and profile of proteins and oxidative enzymes during ripening period in leaves and buds. Differences of expression of these proteins and enzymes are going to guide ours to the gene or genes of corresponding to this process. Then, we are going to reach greater yield by using the genes of expression in the future.

Effects of compressed carbon dioxide treatment on the specificity of oxidase enzymatic complexes from mate tea leaves

This work evaluates the enzymatic activity of peroxidase (POD) and polyphenoloxidase (PPO) present in the crude extract of mate tea leaves ( Ilex paraguariensis St. Hill) submitted to compressed CO 2. The effects of temperature, exposure time, solvent reduced density, pressure, and depressurization rate on the activity of peroxidase and polyphenoloxidase were evaluated through a fractionated factorial experimental planning. Results show that temperature of 30 °C, pressure of 70.5 bar, exposure time of 1 h, depressurization rate of 10 kg m −3 min −1 and carbon dioxide reduced density of 0.60 led to an enhancement of around 25% in the peroxidase activity and a polyphenoloxidase activity loss of 50%. Using this experimental condition, thermal stability at low temperature (−4 °C) and the influence of successive pressurization/depressurization cycles were determined. Results suggest that it is possible to increase the specificity of the enzymatic extract towards enhancing POD or PPO activity depending on the experimental condition employed, and that the processing of enzymatic complexes with compressed CO 2 may be a promising route to increase the specificity of enzymatic extracts.

1-Methylcyclopropene Interactions with Diphenylamine on Diphenylamine Degradation, α-Farnesene and Conjugated Trienol Concentrations, and Polyphenol Oxidase and Peroxidase Activities in Apple Fruit

1-Methylcyclopropene (1-MCP) is a new technology that is applied commercially to inhibit ethylene action in apple fruit, but its interactions with existing technologies such as diphenylamine (DPA) for control of superficial scald development in fruit during and after storage is unknown. To investigate possible interactions between 1-MCP and DPA, Delicious apples were untreated or treated with 2 g L(-1) DPA, and then with or without 1 microL L(-1) 1-MCP. Ethylene production and respiration rates of fruit were measured immediately following treatment, and fruit was stored at 0.5 degrees C for 12 weeks. Internal ethylene concentrations (IEC), alpha-farnesene and conjugated trienol (CTol) concentrations, activities of peroxidase and polyphenol oxidase (PPO), and DPA levels in the skin of the fruit were measured at intervals during storage. 1-MCP reduced the rate of DPA loss from peel tissue so that by 12 weeks of storage concentrations of the chemical were 25% higher than in untreated fruit. 1-MCP, with and without DPA, markedly inhibited ethylene production and respiration rates, maintained low IEC and alpha-farnesene and CTol concentrations, while DPA had little effect on these factors except inhibition of CTol accumulation. Treatment effects on peroxidase and PPO activities were inconsistent.

Evolution of robusta green coffee redox enzymatic activities with maturation.

Oxidation reactions in coffee involve redox-sensitive polyphenols and appear to control the fragmentation of coffee storage proteins both in solution and during roasting. Coffee-specific nitrogenous flavor precursors may derive from this process. Accordingly, data converge to suggest that the redox status of the green bean before roasting might control the development of subsequent redox reactions during roasting. Consequently, we decided to identify biological events that may trigger or prevent oxidation during maturation of the coffee cherry and set the final redox status of the green bean. In a previous study, we observed that the sensitivity of green coffee to oxidative processes decreased along maturation. By using the very same samples originating from open-pollinated Robusta clones, we followed the activity of three essential redox enzymes: catalase (CAT), peroxidase (POD) and polyphenoloxidase (PPO). While CAT and POD activities increased with maturation, PPO activities decreased. Thanks to the identification of an atypical immature subclass, it appeared that CAT might be an essential factor in setting the final redox status of the green bean before the roasting event.

Enzymatic activities in the varieties of hazelnuts ( Corylus avellana L.) grown in Tarragona, Spain

Enzymatic activities of lipase, esterase, lipoxygenase (LOX), peroxidase (POD) and polyphenoloxidase (PPO) of the main local, Italian and Turkish varieties of hazelnuts grown in Tarragona, with and without irrigation, were determined. Enzymatic extract protein was estimated by calculating Δ Abs/min.mg of protein with spectrophotometry. Oleic (C 18:1) and linoleic (C 18:2) acid percentages were determined using high resolution gas chromatography (HRGC). Data were statistically analysed using General Linear Models and Duncan's multiple test. It is observed that variety is a determining factor for all enzymatic activities, especially lipase and peroxidase activity. Negret (Negret and Pauetet varieties), the most cultivated variety in Tarragona, has a high C 18.2 content and high enzymatic activities. Italian varieties have lower lipase, POD and PPO activities. All varieties show minimum activity of esterase and lipoxygenase.

Peroxidase and Polyphenoloxidase Activities in Papaya During Postharvest Ripening and After Freezing/Thawing

ABSTRACTChanges in peroxidase (POD) and polyphenoloxidase (PPO) activities of papaya (Caricu papava), cv Sunrise, during ripening, freezing and short frozen storage were studied. Fruits were stored at 14°C and 85 90 % RH until maturity for processing was reached (about 21 days). Fruit were frozen cryogenically and frozen slices were stored at — 18°C. POD activity increased in pulp tissue up to the ripe stage, showing a maximum value after 7 days cold storage. Similarly, PPO activity showed an important increase (4 × initial value) on the same date. The quantity of extractable proteins was at a maximum after 15 days storage at 14°C. Freezing and frozen storage (‐18°C) produced an increase of POD activity while EPO activity was only slightly affected.

Variations of Phenoloxidase Activities as a Consequence of Stresses that Induce Resistance to Fusarium Wilt of Tomato

AbstractThe variations over 7–8 day of peroxidase (PO) and polyphenoloxidase (PPO) activity have been investigated in tomato plants the roots of which had been subjected to stresses (heat, chloroform and a non‐pathogenic form of Fusarium oxysporum) that induce resistance to Fusarium oxysporum f. sp. lycopersici.All treatments induced increase of PO and PPO activity that reached a maximum 3 days after the treatments in leaves, 4 days in stem and roots and were higher in leaves than in other parts. Activity decreased to levels for the control plants after 8 days.Inoculation with Fusarium oxysporum f. sp. lycopersici further stimulated PO and PPO activity in all treated plants over that caused by the treatments alone. Again, activity of treated plants was lower than in controls 7 days after inoculation.It is concluded that 1. increased PO and PPO activity in tomato is a systemic response to cellular injury caused in the root by heat, chloroform and non‐pathogenic Fusarium oxysporum, 2. these treatments do no prevent the pathogen from interacting with the plants and inducing further enzyme increase, 3. treated plants react more strongly to the challenge inoculation than untreated plants.

Increases in peroxidase-and polyphenoloxidase-activities and production of antifungal substances in mulberry shoots following wounding or infection by pathogenic fungi.

Increases in peroxidase-and polyphenoloxidase-activities and production of antifungal substances in mulberry shoots following wounding or infection by pathogenic fungi.