Antioxidative defence mechanisms in two grapevine (Vitis vinifera L.) cultivars grown under boron excess in the irrigation water
Keywords:ascorbate, glutathione, oxidative stress, phenolic acids, reactive oxygen species
The aim of this study was to investigate the impact of B excess on the antioxidative defence system in two grapevine cultivars differently sensitive to B, in order to evaluate in which way the different sensitivity was correlated to the activation of defence mechanisms. Two-year-old Vitis vinifera L. plants (‘Merlot’ and ‘Sangiovese’), grafted on the same rootstock, were subjected to B treatment as potted vines, and biochemical determinations were employed to evaluate the antioxidative response. Compared to ‘Sangiovese’, ‘Merlot’ showed a much higher B accumulation and both leaf and peroxidative damages. In B-treated ‘Sangiovese’ the activity of superoxide dismutase did not change compared to control leaves, whereas in ‘Merlot’ a dramatic decrease in the enzyme activity was observed. B increased reduced ascorbate pools in both cultivars, but ascorbate peroxidase activity was enhanced only in ‘Merlot’. In this latter cv. an enhancement of total phenols was also observed. ‘Merlot’ showed a lower ability to contrast B accumulation in leaves than ‘Sangiovese’ evidencing a higher oxidative stress. Even if defence mechanisms were generally activated in ‘Merlot’, they did not counteract efficiently metabolic damages likely due to the dramatic decrease in superoxide dismutase, the first enzyme involved in the detoxification of oxygen radicals.
The content of VITIS is published under a Creative Commons Attribution 4.0 license. Any user is free to share and adapt (remix, transform, build upon) the content as long as the original publication is attributed (authors, title, year, journal, issue, pages) and any changes to the original are clearly labeled. We do not prohibit or charge a fee for reuse of published content. The use of general descriptive names, trade names, trademarks, and so forth in any publication herein, even if not specifically indicated, does not imply that these names are not protected by the relevant laws and regulations. The submitting author agrees to these terms on behalf of all co-authors when submitting a manuscript. Please be aware that this license cannot be revoked. All authors retain the copyright on their work and are able to enter into separate, additional contractual arrangements.