Effect of Cameraria ohridella on accumulation of proteins, peroxidase activity and composition in Aesculus hippocastanum leaves

This study analyzed the dynamics of leaf damage, the content of easily soluble proteins, benzidine-peroxidase activity and the composition of acid enzyme isoforms in the leaves of Aesculus hippocastanum L. under the influence of the chestnut miner Cameraria ohridella Deschka et Dimić (Lepidoptera, Gracillariidae) in plantations in one of the Ukraine’s largest industrial cities Dnipro, located in the steppe zone of Ukraine. During July-August, the destruction of leaves by the pest in relatively stable horse chestnut trees increased to 13.3%, while in unstable trees it increased to 97.5%. The maximum amount of protein was found in horse chestnut leaves in July, which decreased significantly in August and correlated with the level of leaf damage by the pest. The horse chestnut leaves were characterized by a more than twofold increase in cytoplasmic peroxidase activity in cases of high level of damage to the leaves by the phytophage. These observations indicate that consumption of the leaves by C. ohridella causes oxidative stress, which leads to the activation of enzyme. The horse chestnut trees have been shown to respond specifically to the attack of C. ohridella due to changes in the activity of individual peroxidase isozymes, the expression of which varies across the spectrum. In the leaves of the horse chestnut trees with a high level of damage by miner, the expression of enzyme isoforms in the pH range of 4.08–4.15 is significantly activated, which can be considered as a reliable biochemical marker of plant sensitivity of Ae. hippocastanum to phytophagous attack by C. ohridella. However, increase in the degree of phytophage invasion does not change the activity of isoperoxidase 4.21, and isoperoxidase with pI 4.25, 4.42 and 4.58 correspond to a decrease in activity compared with relatively resistant Ae. hippocastanum plants. We noted that the high total activity of peroxidase, as well as active adjustments in the spectrum of the peroxidase system, obviously, contribute to maintaining the functional integrity of the photosynthetic system of leaves of Ae. hippocastanum under the influence of the chestnut miner C. ohridella by neutralizing reactive oxygen species.

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

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).

Evidence of pollen features and peroxidase isozymes in their morphological complexity of ten local cultivars of sweet potato from Indonesia

Suranto, Wahyuni D, Edy Purwanto E. 2019. Evidence of pollen features and peroxidase isozymes in their morphological complexity of ten local cultivars of sweet potato from Indonesia. Biodiversitas 20: 2511-2518. Sweet potato (Ipomoea batatas Lam) has been recorded to have many cultivars and variations in the morphological characters not only for the leaves but also for the tubers. Sweet potatoes had economically significant role, especially as an additional food due to its high content of carbohydrate and other nutrient values. In order to test whether the morphological variation in this species was also expressed at the micro character; such as pollen morphology and enzyme activity, ten sweet potato cultivars were used in this study. The morphological characters such as shape and structure of the pollen features were examined using Scanning Electron Microscopy (SEM). Accordingly, Polyacrylamide Gel Electrophoresis (PAGE) was used to look-at the banding pattern of peroxidase isozymes. Morphological characters of leaves, flowers, and tuber were observed qualitatively both for the typical shape and colors. More detail of flower shapes was drown manually especially their petal edges. The results showed that there was variation among the ten sweet potato cultivars confirmed not only on their morphological characters but also the isozyme banding patterns of ten cultivars tested. At least, two cultivar Antin 3 and Papua Solossa had uniques characters especially the purple stem and yellow tuber and dark skin on the tuber, respectively. In addition, the structural analysis of pollen showed that Beta 1 cultivar has very large pollen; 116,50 μm (axis polar) and the contour surface of exine pollen was concave with the aperture shape and ornamentation were prolate spheroidal and echinate respectively. This unique character was also shown by its peroxidase isozyme bands. Eleven bands of leaf and 13 bands of stem samples were detected respectively. The typical Rf values of 0.31, 0.48 and 0.41 were detected for the leaf, while for stem samples were 0.14, 0.20 and 0.26. The Beta 1 cultivar showed very thick bands in between Rf values of 0.13 and 0.26. Meanwhile, the unique band pattern of Papua Salosa was the absence of band at 0.38.

Effect of aluminium on peroxidase activity in roots of Al-sensitive and Al-resistant barley cultivars

The effect of Al stress on peroxidase activity and peroxidase isozymes was studied in roots of two barley cultivars with contrasting sensitivity to Al. Al treatment induced a tremendous enhancement of guaiacol peroxidase activity especially in roots of Al-sensitive barley cv. Alfor. After 48 h of Al treatment activity of peroxidase in roots of cv. Alfor was up to 5.5 times higher than the control roots. In contrast, activity of peroxidase in the roots of Al-resistant cv. Bavaria was about one half than that in roots of Al-sensitive Alfor. SDS-PAGE analysis revealed that at least five peroxidase isozymes are activated by Al treatment. Using IEF we determined that three of Al-induced peroxidase isozymes are cationic with pI about 8.2, 8.4 and 8.6, while two other are anionic isoperoxidases with pI about 4.0 and 4.5. Al induced increase in the activity of root peroxidases correlated with the extent of Al induced root growth inhibition. The inhibition of root growth in Al-sensitive Alfor represented 44% but in Al-resistant Bavaria only 21% in comparison with control plants. Higher peroxidase activity, as well, as higher inhibition of root growth in Al-sensitive Alfor suggest that enhanced oxidative stress generated by Al treatment is significantly more stressful in Alfor than in the Al-resistant Bavaria.