The effect of seedling chilling on glutathione content, catalase and peroxidase activity in Brassica oleracea L. var. italica

Abstract

IntroductionProper growth and development of plants depends on an efficient defense system, mainly against reactive oxygen species. Studies on how plant genotypes respond to all kind of stresses indicate a similar mechanism of adaptation to unfavorable environmental conditions. These reactions are mostly connected with neutralizing free radicals, particularly reactive oxygen species (ROS) which frequently appear as the effect of different stress factors [1][2][3]. Many experiments indicate significance changes in the enzymatic and non-enzymatic antioxidant system during environmental stresses in plant tissues. The most active in this respect are usually the classified enzymes: catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) as well as chemical compounds such as glutathione, ascorbic acid or different polyphenols [4,5]. It is well established that the mechanisms of tolerance to chilling, freezing, drought or high salinity include the action of common genes. For this reason chilling transplants before planting might result in a better adaptation of plants cultivated from such transplants to various stresses via a well-defined increase in the antioxidant activity system in particular plant organs [6,7]. In recently carried out investigations that were focused on the reaction of wild species or cultivated plant cultivars to abiotic stresses, only early vegetative stages of development in the studied genotypes were applied [7,8]. Moreover, these experiments were mainly carried out in strictly controlled conditions. As a rule, neither the natural environment of plant growth nor the stage of full generative development was considered.The Brassica oleracea L. var. italica that was used in the presented experiment is a vegetable of great economical value, and in Europe it is grown on a large scale that could be compared to that of the cauliflower. Broccoli flower buds contain an elevated level of health-promoting substances, which are active during the neutralization of free radicals [9,10]. A crucial example of such is glutathione, a non-enzymatic hydrophilic antioxidant that commonly occurs in plants belonging to the Brassicaceae family. This thiol compound is an important substrate of the enzymatic defense system in the cytoplasm and in the chloroplasts of plant cells. Because of its anticarcinogenic functions it is very important in the human diet. In some cultivars of broccoli the glutathione content may exceed 200 nmol g −1 of fresh weight [11]. The cultivar italica of B. oleracea can optionally be planted from transplanted seedlings in spring, summer or autumn, but this practice sometimes requires storage of the transplant material. The storage may be necessary because of unfavorable weather conditions. For that reason offering an efficient way AbstractThe study was designed to determine the possible relationship between Brassica oleracea var. italica seedlings stored at 2°C in the dark for seven and fourteen days, respectively, and the level of certain antioxidant parameters in particular organs. ...

Effect of Temperature Stress on Antioxidant Defenses in Brassica oleracea

“…A significant increase in the level of glutathione was observed in the seedlings of broccoli subjected to cold conditions. 10 The content of glutathione increased significantly after heat stress in the seedlings of B. juncea . 5…”

“…The most active enzymes in response to environmental stressful conditions are CAT and SOD. 10 SOD is usually considered as the first line of defense against oxidative stress. 11 This enzyme catalyzes the partitioning of O 2 – into either an ordinary molecular O 2 or into H 2 O 2 , which is also damaging, but less so, and is degraded by other enzymes such as APX or CAT.…”

“…An increment in the CAT and SOD activities compared to the control temperatures was also observed in different species of the Brassica genus subjected to cold conditions. The activity of these enzymes has been associated to the resilience to low temperatures in canola ( Brassica napus L.) cultivars, 10 , 13 especially in the cold-adapted ones. 14 However, although we recently reported that cabbage showed a higher stability under cold conditions than kale based on the physiological parameters, 2 we did not observe any differences between the two crops under cold conditions for any of the three enzymatic activities measured.…”

“…Cold and heat produced a significant increase of enzymatic activities compared to the values observed under the control temperature, confirming that the plants under stressful conditions undergo oxidative stress (Figure ). The most active enzymes in response to environmental stressful conditions are CAT and SOD . SOD is usually considered as the first line of defense against oxidative stress .…”

Evaluation of expression changes, proteins interaction network, and microRNAs targeting catalase and superoxide dismutase genes under cold stress in rapeseed (Brassica napus L.)

“…Considering the substrate for CAT activity is H 2 O 2 , a by-product of SOD action, their functions should be coupled to achieve a synergistic effect on stress tolerance (Xu et al, 2014). Published studies also confirmed that cold stress increased catalase and superoxide dismutase activity in B. oleracea (Soengas et al, 2018;Wojciechowska et al, 2013). Another study on sweet potato (Ipomoea batatas) indicated Overexpression of IbCAT2 gave salt and drought tolerance in Escherichia coli and Saccharomyces cerevisiae.…”