Increase In Guaiacol Peroxidase Activity Research Articles

Morpho-physiological effects of irrigation with saline water in ex vitro plants of Juglans regia ‘Sorrento’

Soil salinization is a global problem limiting growth and economical yield in fruit species including walnut. Knowledge of the response of varieties and cultivars to salinity can represent an important contribution to future walnut plantation in areas affected by soil salinization. Juglans regia ‘Sorrento’ is a commercially important Italian variety. The present work aimed to explore the morpho-physiological response to NaCl-induced stress in ‘Sorrento’ plants using clonally propagated ex vitro plantlets to reduce the impact of genetic variation. Ex vitro acclimatized plants were exposed to salinity conditions by irrigating pot soil with half-strength Hoagland solution containing 100 mM NaCl for 20 days. Salt-induced effects on plant growth, chlorophyll and carotenoid content, osmolality, membrane injury and on activities of antioxidant enzymes catalase and guaiacol peroxidase (G-POD) in leaves were evaluated. Morphological and growth parameters were not significantly altered by salt stress with respect to the control. Slight differences in leaf necrosis and absence of injury in the membranes, stable content of photosynthetic pigments, and an increase in G-POD activity were also found in salt-treated plants. These results collectively suggest that ‘Sorrento’ has potential for the cultivation in salinized environments.

Hydroponic phytoremediation of antimony by Tamarix smyrnensis and Nerium oleander

AbstractBackgroundAntimony (Sb) is considered a priority pollutant and its removal from the environment is of great importance. Among the various treatments, phytoremediation is considered an efficient method when the accumulation of this metalloid in plant tissues is sufficiently high. This work focused on removal of Sb(III) from aqueous solution at two Sb concentrations (5 and 10 ppm) and using salt as stressor (100 mmol L−1) only at the lowest Sb concentration (5 ppm). The response of two salt‐tolerant plant species – Tamarix smyrnensis and Nerium oleander – was monitored when subjected to Sb‐contaminated hydroponic solutions.ResultsPlant growth and water content remained unaltered within the 15‐day experimental period, while the chlorophyll content declined significantly at the higher Sb level (10 ppm) only for N. oleander. The antioxidant enzymatic activity in T. smyrnensis with respect to guaiacol peroxidase (GPOD) and catalase (CAT) was significantly increased in the treatment under Sb and salt stress. In N. oleander there was a strong increase in GPOD activity by the exposure to Sb, whereas the CAT activity was increased considerably with the presence of salinity. Sb concentration was detected on the surface of the leaves, indicating that excretion occurred in both plants. Increased accumulation was observed in N. oleander in the absence of salinity whereas, under salt stress, Sb accumulation was considerably higher (60%) in T. smyrnensis. Notably, both plants could accumulate a high amount of Sb, preferentially in the roots, with the concentrations in the leaves being significantly lower.ConclusionThe experimental results from this study demonstrate that both plants are suitable for phytoremediation due to substantial Sb accumulation without visible Sb toxicity. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).

Assessment of adaptive capacity of native and adventive species of trees and shrubs in Dnipro region

Nowadays, deterioration and loss of ecological functions of urban tree and shrub plantations take place in Europe and, in particular, in Ukraine; it was noted that their number is insufficient to counteract the negative impact of global climate change and protect the population against industrial pollution effects. The issue of resistance of native and adventitious tree species used in the plantations of industrial cities remains relevant; it necessitates the assessment of physiological and biochemical aspects of their adaptation to extreme environmental factors, such as moisture limit in the steppe zone, periodic dangerously low winter temperatures and anthropo-technogenic load (in large urban agglomerations). In order to optimize the assortment of tree species of large megalopolises of the steppe zone of Ukraine and determine their potential resistance to anthropogenic pressures the study was conducted in conditionally clean forest biogeocenoses of the Samara River levee zone and in artificial plantations on the territories located in the coastal zone of the Dnipro River within 1500 m from the Prydneprovskaya thermal electric station (PTES, Dnipro city). It well known that the TPP is the source of atmospheric air pollution by such heavy metals as lead and cadmium. A study of the activity of antioxidant protection enzymes in leaves of native and adventive tree species showed that in the zone of Prydneprovskaya TES impact there was an increase of guaiacol peroxidase activity in Acer platanoides, Ulmus minor, Morus alba; benzidine peroxidase in Acer negundo, Ulmus laevis, Acer platanoides; catalase in A. platanoides, A. negundo, U. laevis, Ulmus pumila and Robinia pseudoasasia. High peroxidase activity, which is complemented by higher catalase activity, indicates the relative resistance of these species to atropo-technogenic pressures supported by antioxidant defense mechanisms. Total chlorophyll content (Chla + Chlb) in leaves of native species Ulmus laevis, Acer platanoides and adventive Morus alba decreased in the zone of TPP impact in relation to conditionally clean areas. The ratio of chlorophyll a to chlorophyll b in contaminated areas significantly increased in leaves of native species Ulmus laevis, Ulmus minor, Acer platanoides compared with control. The invasive species Acer negundo, Morus alba, Ulmus pumila had no significant changes in this indicator. In invasive species such as Ulmus pumila, Acer negundo there was an increase in leaf mass, which may indicate adaptation of these species to anthropogenically altered growth conditions.

Evaluation of antioxidant bioindicators and growth responses in Malva parviflora L. exposed to cadmium.

In this study, the effect of cadmium (Cd) uptake and concentration on some growth and biochemical responses were investigated in Malva parviflora under Cd treatments including 0, 10, 50 and 100µM. The shoots and roots were able to accumulate Cd. However, increased Cd dose led to a considerable Cd content in the roots. Cd stress decreased growth, increased lipid peroxidation and also enhanced proline and ascorbic acid contents in both shoots and roots. Chlorophyll and carotenoid contents decreased in the plants with the increasing Cd concentration. While the activities of catalase (CAT) and superoxide dismutase (SOD) increased in the shoots under different Cd doses, these activities decreased in the roots as compared to the control. Both shoots and roots demonstrated a significant increase in guaiacol peroxidase activity in response to Cd stress. Contrary to the aboveground parts, the roots subjected to Cd doses showed a rise in protein content. Despite higher Cd content in the roots, it seems that CAT and SOD do not play a key role in detoxification of Cd-induced oxidative stress. These findings confirm that reduced biomass and growth under Cd stress can be due to an increase in oxidative stress and a decrease in photosynthetic pigment content. The present study clearly indicates that the shoots and roots exploit different tolerance behaviors to alleviate Cd-induced oxidative stress in M. parviflora.

Effect of ethylene on total phenolics, antioxidant activity, and the activity of metabolic enzymes in mung bean sprouts

Mung bean sprouts are a well-known healthy food and their nutritional enhancement has become an important area of research due to the rapid expansion of the industry and their importance to human health. The purpose of this study was to investigate the effect of ethephon treatment at different concentrations on total phenolics metabolism and free radical scavenging-linked antioxidant activity. Mung bean sprouts treated with 100 mg/L of ethephon gave the highest total phenolics content of 0.594 mg/g FW, which was approximately 31 % higher than that of the control on the second day of germination. Total phenolics content in mung bean sprouts increased significantly by increasing glucose-6-phosphate dehydrogenase activity to resist oxidative stress caused by ethylene during early-stage germination. Total phenolics synthesis was greater than polymerization at this time. In contrast, polymerization of total phenolics gradually increased with the decrease in oxidative stress during late-stage germination. Total phenolics were polymerized to lignin because of the increase in guaiacol peroxidase activity. These results indicated that ethylene could improve the nutritional value of mung bean sprouts, and harmless stress factors could be used to enhance health-promoting compounds in the sprouts.

Exogenous spermidine differentially alters activities of some scavenging system enzymes, H 2O 2 and superoxide radical levels in water-stressed cucumber leaves

In order to examine whether polyamines (PAs) modify the functioning of the scavenging system and oxidative stress levels in water-stressed plants, cucumber (Cucumis sativus L.) seedlings were treated with spermidine (Spd) prior to dehydration, and stress-evoked changes in superoxide dismutase (SOD) (EC 1.15.1.1), catalase (EC 1.11.1.6), guaiacol peroxidase (EC 1.11.1.7) activities, H(2)O(2) and superoxide radical levels were determined. Free PA content during Spd treatment and during the stress period were also determined. Exogenous application of Spd differentially influenced enzymes of the antioxidative system under stress conditions; we observed an increase of guaiacol peroxidase activity, and, to a lesser degree, a reduction of SOD and catalase activities in Spd-treated plants in comparison to untreated stressed plants. Hydrogen peroxide and superoxide radical contents were also reduced in stressed plants after Spd pretreatment. These positive effects were observed in the case of 1mM Spd concentration. A higher concentration (3mM) influenced negative, more significant stress-induced changes, but a lower concentration (0.1mM) had a very limited effect. In summary, PAs are able to moderate the activities of scavenging system enzymes and to influence oxidative stress intensity.

Cell wall immobilisation and antioxidant status of Xanthoria parietina thalli exposed to cadmium.

Total and cell wall-bound cadmium and the major antioxidants were measured in thalli of the lichen Xanthoria parietina (L.) Th. Fr. exposed to two Cd concentrations, namely 4.5 or 9.0 μm, in liquid medium during exposure periods of either 24 or 48 h. Total Cd in the thalli was within the range of previous field measurements and was proportional to the exposure concentration, but less than proportional with respect to exposure duration. More than half of the total Cd was immobilised by the cell wall. The adopted conditions of Cd stress caused: (i) no changes in dry weight and protein concentration; (ii) an increase in the level of ascorbic acid and a decrease in that of reduced glutathione, as well as an increase in guaiacol peroxidase activity; (iii) no changes or moderate decreases in the activities of superoxide dismutase, catalase, dehydroascorbate-, NADPH-dependent glutathione disulfide-, and monodehydroascorbate reductases and of ascorbate peroxidase; (iv) an increase of the level of thiobarbituric acid-reactive substances, assumed to reflect malondialdehyde formation arising from membrane lipid peroxidation. Thus, X. parietina might withstand realistic levels of Cd stress by: (1) intercepting the heavy metal at cell wall level, (2) the intervention of antioxidant metabolites, and (3) a moderate increase in guaiacol peroxidase activity.

Responses of Xanthoria parietina thalli to environmentally relevant concentrations of hexavalent chromium.

Thalli of the lichen Xanthoria parietina (L.) Th. Fr. were soaked for either 24 or 48 h in a buffered medium in the presence of environmentally relevant concentrations (4.8 and 9.6 μM) of hexavalent chromium [Cr(VI)]. Treatment effects on the antioxidant status, differential distribution and fate of Cr(VI) among the mycobiont and the photobiont cells, and potential damage to cell ultrastructure in the two bionts, were evaluated. The adopted conditions of low Cr(VI) stress caused: (i) an increase in the level of ascorbic acid and a decrease in that of reduced glutathione, as well as a moderate increase in guaiacol peroxidase activity, only observed after treatment with 9.6 μM Cr(VI); (ii) no changes in malondialdehyde content; (iii) a remarkable Cr accumulation in the mycobiont cytosol and compartmentalisation in the mycobiont vacuoles;(iv) a modest apoplastic Cr immobilisation by the outer part of the cell walls, of both the mycobiont and the photobiont. The response of X.parietina to low concentrations of Cr(VI) appears to be a complex phenomenon, which might reflect maintenance of cellular homeostatic equilibria, rather than specific response pathways.

Polyamines and ”scavenging system”: influence of exogenous spermidine on catalase and guaiacol peroxidase activities, and free polyamine level in barley leaves under water deficit

Barley (Hordeum vulgare) seedlings were treated with spermidine prior to water deficit treatment to determine whether this polyamine is able to influence the activity of catalase (EC 1.11.1.6) and guaiacol peroxidase (EC 1.11.1.7). The content of endogenous polyamines was determined as well. This stress caused a visible increase of catalase activity and a much higher increase of guaiacol peroxidase activity. Treatment with exogenous spermidine induced a significant decrease in the activity of the both enzymes, whereas the polyamine level was enhanced, suggesting that polyamines are able to influence the activity of hydrogen peroxide scavenging enzymes and to moderate in that way this signal molecule level.

Lead toxicity induces lipid peroxidation and alters the activities of antioxidant enzymes in growing rice plants

When seedlings of two rice ( Oryza sativa L .) cultivars were raised in sand cultures under 500 and 1000 μM Pb(NO 3) 2 in the medium, lengths as well as weights of roots and shoots decreased with increase in Pb concentration. Pb-treated seedlings showed elevated levels of lipid peroxides with a concomitant increase in the activities of the enzymes superoxide dismutase (SOD), guaiacol peroxidase, ascorbate peroxidase and glutathione reductase compared to controls. Though Pb was readily absorbed by growing seedlings, its localization was greater in roots than shoots. The level of Pb accumulation in seedlings was far higher than the supplied one. Seedlings grown for 5–20 days in presence of 1000 μM Pb(NO 3) 2 showed about 21–177% increase in the level of thiobarbituric acid reacting substances (TBARS) in shoots indicating enhanced lipid peroxidation compared to controls. With increase in the level of Pb treatment in situ peroxidases showed more increase in activity than SOD. Under both controls as well as Pb treatments roots maintained higher activity of these enzymes than shoots. About 87–100% increase in SOD activity, 1.2–5.6 times increase in guaiacol peroxidase activity and 1.2–1.9 times increase in ascorbate peroxidase activity was observed in the roots of seedlings grown for 15 days in presence of 1000 μM Pb in the medium. Under similar treatment conditions about 128–196% increase in glutathione reductase activity was recorded in roots and 69–196% increase in shoots compared to control grown seedlings. Pb treatment resulted in a decline in catalase activity in roots whereas in shoots catalase activity increased in seedlings grown at moderately toxic Pb (500 μM) level whereas a highly toxic Pb (1000 μM) level led to a marked inhibition in enzyme activity. Two catalase isoforms were detected in roots and three in shoots of the seedlings. A highly toxic Pb (1000 μM) level led to decrease in the intensity of two pre-existing catalase isoforms in shoots. Results suggest that Pb induces oxidative stress in growing rice plants and that SOD, peroxidases and GR could serve as important components of antioxidative defense mechanism against Pb induced oxidative injury in rice.

Ozone tolerance and antioxidant enzyme activity in soybean cultivars.

The current study confirmed earlier conclusions regarding differential ozone (O(3)) tolerances of two soybean cultivars, Essex and Forrest, and evaluated antioxidant enzyme activities of these two varieties based on their performance under environmentally relevant, elevated O(3) conditions. The experiment was conducted in open-top chambers in the field during the 1994 and 1995 growing seasons. Exposure of plants to moderately high O(3) levels (62.9 nl l(-1) air, 2-year seasonal average) caused chlorophyll loss and increased membrane permeability when compared to control plants grown in charcoal filtered air (24.2 nl l(-1) air). The other effects of O(3) treatment were decrease in seed yield, loss of total sulfhydryl groups, reduction of soluble protein content, and increase in guaiacol peroxidase activity in leaves of both cultivars. The O(3)-induced increase in guaiacol peroxidase activity was much smaller in cv. Essex leaflets. Cv. Essex had less leaf oxidative damage and smaller reduction in seed yield than cv. Forrest under elevated O(3) conditions. During ozonation, mature leaflets of the more O(3) tolerant cv. Essex had higher levels of glutathione reductase (30%), ascorbate peroxidase (13%), and superoxide dismutase (45%) activity than did mature leaflets of cv. Forrest. Cu,Zn-superoxide dismutase, which represented 95% of total superoxide dismutase activity in the two cultivars, appeared to be increased by O(3) exposure in the leaflets of O(3) tolerant cv. Essex but not in those of cv. Forrest. Cytosolic ascorbate peroxidase activity was also higher in leaflets of cv. Essex than in cv. Forrest regardless of O(3) level. Stromal ascorbate peroxidase and Mn-superoxide dismutase activity did not appear to be involved in the O(3) tolerance of the two soybean cultivars.