Protective enzymes against reactive oxygen species during ripening of tomato (Lycopersicon esculentum) fruits in response to low amounts of UV-C

2001 ◽  
Vol 28 (8) ◽  
pp. 785 ◽  
Author(s):  
Essaid Ait Barka

In previous studies with tomato (Lycopersicon esculentum L.) exposed to a low level (3.7 kJ m –2) of UV-C (λ: 254 nm) radiation, which is defined as a beneficial level, we report a delay in fruit ripening by at least 1 week for treated fruit. In the present study, we investigate the changes in the activities of different enzymes involved in defense mechanisms, such as guaiacol peroxidase, ascorbate peroxidase, catalase, superoxide dismutase, ascorbate oxidase, lipoxygenase and phenylalanine ammonia lyase in tomato fruit in response to a beneficial level of UV-C. The irradiation leads to an increase in the guaiacol peroxidase and ascorbate peroxidase activities, whereas catalase activity remains similar to the control. The activities of superoxide dismutase and ascorbate oxidase were significantly reduced after UV-C exposure. In UV-C-treated fruit, an increase of lipoxygenase and phenylalanine ammonia lyase activities occurred within the first 5 d, followed by a second period in which these activities were below those of the control. Our study suggests that the level of UV-C used induced a rapid but moderate accumulation of photooxidation products, to which plants react by stimulating their defence mechanisms against oxidation. This activation may explain the delay observed in ripening and senescence of irradiated tomato fruit.

2013 ◽  
Vol 49 (1-2) ◽  
pp. 115-121 ◽  
Author(s):  
Jacek Patykowski ◽  
Elżbieta Kuźniak ◽  
Henryk Urbaniak

Defence reactions: O<sub>2<sub> - generation, superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase activities after <em>B. cinerea</em> infection in tomato plants propagated <em>in vitro</em> and grown <em>in vivo</em> have been compared. Infection resulted in rapid O<sub>2<sub> - generation. Superoxide dismutase activity increase was slower than O<sub>2<sub> - response. In plants propagated <em>in vitro</em> catalase and guaiacol peroxidase activities after infection were induced less strongly than in plants grown <em>in vivo</em>. K<sub>2<sub>HPO<sub>4<sub> pretreatment of plants grown <em>in vitro</em> enhanced significantly the activities of catalase and guaiacol peroxidase after infection. Slight restriction of <em>B. cinerea</em> infection development in <em>in vitro</em> propagated plants pretreated with K<sub>2<sub>HP0<sub>4<sub> was observed.


1995 ◽  
Vol 50 (7-8) ◽  
pp. 543-551
Author(s):  
Bernhard Epping ◽  
Alexander P. Hansen ◽  
Peter Martin

Abstract Nodules of Rhizobium leguminosarum bv. phaseoli in symbiosis with Phaseolus vulgaris were compared with regard to their nitrogenase activity and activities of enzymes involved in the removal of O2·- and H2O2 as well as total ascorbate content. Activities of catalase (EC 1.11.1.6), ascorbate peroxidase (EC 1.11.1.11), and total ascorbate content were consist­ently higher in nodules inhabited by bacterial strains with higher nitrogenase activity. Values for superoxide dismutase (EC 1.15.11), and guaiacol peroxidase activity did not differ for the bacterial strains compared. On the other hand, when different plant cultivars were inoculated with the same bacterial strain, high nitrogenase activity did not correlate with a higher activ­ity of the oxygen scavenging enzyms or a higher content of total ascorbate. In this case, values for guaiacol peroxidase activity were greatly enhanced in nodules with lower nitrogen­ ase activity. This may be part of a hypersensitive reaction of the plant cultivar against the bacterial symbiotic partner. Inhibition of catalase activity in the nodules by addition of triazole to the nutrient solution did not alter nitrogenase activity within the first nine hours after addition. It can be concluded that the activity of catalase, ascorbate peroxidase, and superoxide dismutase is not generally coupled to nitrogenase activity in root nodules of P. vulgaris.


Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 413 ◽  
Author(s):  
Katarzyna Głowacka ◽  
Anna Źróbek-Sokolnik ◽  
Adam Okorski ◽  
Janusz Najdzion

The analysis of the effects of cadmium (Cd) on plant cells is crucial to understand defense mechanisms and adaptation strategies of plants against Cd toxicity. In this study, we examined stress-related enzyme activities after one and seven days of Cd application and the ultrastructure of roots of Pisum sativum L. after seven days of Cd treatment (10, 50, 100, and 200 μM CdSO4). Our results showed that phenylalanine ammonia-lyase (PAL) activity and the amount of Cd accumulated in the roots were significantly positively correlated with the Cd concentration used in our experiment. However, Cd caused a decrease of all studied antioxidative enzyme activities (i.e., catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX)). The analysis of the ultrastructure (TEM) showed various responses to Cd, depending on Cd concentrations. In general, lower Cd concentrations (50 and 100 μM CdSO4) mostly resulted in increased amounts of oil bodies, plastolysomes and the accumulation of starch granules in plastids. Meanwhile, roots treated with a higher concentration of Cd (200 μM CdSO4) additionally triggered protective responses such as an increased deposition of suberin lamellae in the endodermal cell walls. This indicates that Cd induces a complex defense response in root tissues.


2013 ◽  
Vol 72 (1) ◽  
pp. 145-156 ◽  
Author(s):  
Zamin S. Siddiqui

Abstract The effects of double stress environment i.e. lead (heavy metal) and NaCl (saline) on the activity of antioxidant enzymes in Vigna radiata seedling were studied. The antioxidant activities of enzymes, i.e of superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, glutathione reductase and their activity proportions were examined. Superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase and glutathione reductase activities were substantially increased in a combined stress environment as compared to catalase. Further, in comparison with catalase and ascorbate peroxidase, glutathione reductase showed increased activities together with superoxide dismutase in a combined stress environment. Superoxide dismutase and glutathione reductase showed higher activity proportion in combined treatment. Physiological role of these enzymes in stress tolerance mechanism is discussed.


Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Danúbia Aparecida Costa Nobre ◽  
Adriene Aparecida Silva ◽  
Gisele Machado Fernandes ◽  
Geraldo Humberto Silva ◽  
Willian Rodrigues Macedo

Abstract During seed germination there is production of reactive oxygen species, which, in a controlled way, are important to cell signaling and protection against pathogens, but, in excess, impair germination. Therefore, the objective of this study was to assess the action of different compounds on antioxidant mechanisms and enzymatic activation in cabbage seeds. Compounds like kojic acid, thymol and tyrosol were used to imbibe the cabbage seeds together with distilled water, and a control treatment without imbibition was used as well, with subsequent assessment by means of germination test, endosperm rupture, vigor, radicle protrusion, and assessment of seedling biochemical analyses by the activity of enzymes ascorbate peroxidase, catalase, superoxide dismutase and α-amylase. Data were subjected to analysis of variance and to the LSD means comparison test. Seeds treated with tyrosol presented higher results on the rupture of the endosperm, germination and vigor, and root development increased with use antioxidants. For the activity of antioxidant enzymes in seedlings, only kojic acid showed increase in the superoxide dismutase activity. There was also a reduction in the catalase activity with the use of thymol and tyrosol compounds compared to dry-seed assessments. After tyrosol treatment, ascorbate peroxidase enzyme was not detected, and water-imbibed seeds showed higher α-amylase activity. The use of antioxidant compounds has beneficial effects on cabbage seeds, and soaking with tyrosol led to better physiological quality, with activation of antioxidant defense mechanisms during germination.


Author(s):  
Roumiana Dimova Vassilevska-Ivanova ◽  
Lydia Shtereva ◽  
Ira Stancheva ◽  
Maria Geneva

Response of sunflower germplasms viz. cultivated sunflower H. annuus and two breeding lines H. annuus x T. rotundifolia and H. annuus x V. encelioides developed after wide hybridization were used for identification of drought tolerant sunflower genotypes at the seedling growth stage. Three water stress levels of zero (control), -0.4, and -0.8 MPa were developed using polyethyleneglycol-6000 (PEG-6000). Physiological and biochemical stress determining parameters such as root and shoots length, fresh weight, antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPO), ascorbate peroxidase (APX) and antioxidant metabolite content (total antioxidant capacity, total phenols and total flavonoids content) were compared between seedlings of all three genotypes. Results revealed that sunflower genotypes have similar responses at two osmotic potentials for shoot and root length and fresh weight. The data also showed that drought stresss could induce oxidative stress, as indicated by the increase level of ascorbate peroxidase and guaiacol peroxidase at -04 MPa in H. annuus cv 1114. Although the activity of ascorbate peroxidase and guaiacol peroxidase was differentially influenced by drought, the changes of antioxidant enzyme activities such as catalase, superoxide dismutase, guaiacol peroxidase, and ascorbate peroxidase subjected to drought stress follow a similar pattern in both breeding lines, indicating that similar defense systems might be involved in the oxidative stress injury in sunflowers. Increase in content of phenols and flavonoids were detected for all three genotypes under stress, which showed that these were major antioxidant metabolites in scavenging cellular H2O2.


2016 ◽  
Vol 73 (2) ◽  
pp. 159-164 ◽  
Author(s):  
Salma Kloula Ben Ghorbal ◽  
Lobna Maalej ◽  
Kalthoum Chourabi ◽  
Sana Khefacha ◽  
Hadda-Imene Ouzari ◽  
...  

Author(s):  
O. I. Horielova ◽  
◽  
N. I. Ryabchun ◽  
M. A. Shkliarevskyi ◽  
A. M. Reznik ◽  
...  

Along with specific adaptive reactions, universal defense reactions, in particular activation of antioxidant system, are of great importance for plant survival under cold conditions. We have studied a relationship among the content of low-molecular-weight protective compounds with antioxidant properties (proline, soluble carbohydrates, flavonoids), the activity of antioxidant enzymes (superoxide dismutase, catalase, and guaiacol peroxidase) in seedlings of winter wheat, rye and triticale, and frost resistance of etiolated seedlings and adult plants at tillering stage. It was found that there was a fairly close correlation between the frost resistance of seedlings and adult cereal plants (r = 0,78). It was shown that a pronounced relationship between individual indicators of antioxidant system functioning in unhardened seedlings and their frost resistance was not found. After 6-day hardening of seedlings at 2-4°C, there was a high correlation between the total indicator of the enzymatic antioxidant system (the sum of normalized indicators of superoxide dismutase, peroxidase, and catalase activity) and their frost resistance (r = 0,86), but the correlation coefficient of this index with frost resistance of plants in tillering phase was significantly lower (r = 0,47). At the same time, a high correlation was found between the content of low-molecular-weight protectors in hardened seedlings and frost resistance of tillering adult plants (r = 0.89). The closest correlation was observed between the integral normalized indicator, comprising the sum of normalized values of antioxidant enzymes activity and the content of low-molecular-weight protectors in hardened seedlings, and frost resistance of seedlings (r = 0,94) and plants in tillering phase (r = 0,89). A presence of specific features in the functioning of antioxidant system during cold adaptation of cereal seedlings was established. Rye is characterized by a high content of low-molecular-weight protective compounds; at the same time, increased activity of antioxidant enzymes - superoxide dismutase and catalase - was noted in wheat seedlings. In triticale, depending on the genotype, the values of both enzymatic antioxidant activity and the content of low-molecular-weight protectors varied.


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