Isozymes of antioxidative enzymes during ripening and storage of ber (Ziziphus mauritiana Lamk.)

Abstract

Isozyme profile of antioxidative enzymes viz. superoxide dismutase (SOD), peroxidase (POX), catalase (CAT) and ascorbate peroxidase (APX) was studied during ripening and storage of two cultivars of ber fruit (Ziziphus mauritiana Lamk.) differing in their shelf-lives viz. Umran (shelf-life, 8-9 d) and Kaithali (shelf-life, 4-5 d). The profile revealed that Umran variety exhibited three bands each of SOD and POX while in Kaithali, these enzymes had two isoenzymes throughout ripening. CAT and APX, however, showed two isozymes each during ripening of both the varieties and the pattern remained the same at all the stages of ripening except at the initial stage i.e immature green stage where single CAT isozyme was visible. During storage, one extra band each of SOD and POX present only in Umran got disappeared at later stages of storage, whereas in Kaithali, the pattern remained unchanged. Also, there was no change in the pattern of CAT and APX isozymes during storage of both the varieties. One isozyme of CAT could be considered as ripening related while one isozyme each of SOD and POX could be related to higher shelf life of fruits.

Preharvest salicylic acid and acetylsalicylic acid treatments preserve quality and enhance antioxidant systems during postharvest storage of sweet cherry cultivars

“…CAT, POD, APX and SOD are the main antioxidant enzymes involved in the radical scavenging of ROS species and thus are considered as a mechanism for repairing cell oxidative damage . Preharvest application of SA or ASA induced a greater activity of CAT and POD at the time of harvest compared to control cherries for the three cultivars (Fig.…”

Methyl salicylate treatments of sweet cherry trees increase antioxidant systems in fruit at harvest and during storage

“…SOD, CAT, POD and APX have been implicated in senescence and stress responses in vegetable tissues, since efficient activity of these antioxidant enzymes is essential for avoiding ROS caused damages (Hodges et al, 2004;Kumar et al, 2014). The present results show a general trend in those antioxidant enzymes, that is, decreases along storage, although important differences existed between control and treated cherries, among cultivars and growing seasons.…”

“…However, in spite of the presence of these efficient antioxidant systems, oxidative damages still occur in plant cells either due to uncontrolled production or inefficient scavenging of ROS. Thus, since the overall process of fruit ripening is considered as a functionally modified protracted form of senescence, associated with ROS accumulation (Hodges et al, 2004), the presence of high content of antioxidant compounds and high activity of antioxidant enzymes could lead to a delay of the fruit postharvest ripening process and to maintain fruit quality attributes for longer periods (Mondal et al, 2009;Kumar et al, 2014). In this sense, in fruits such as mango and sugar apple, it has been shown that postharvest salicylic acid (SA) treatments led to lower superoxide free radical production and lipoxygenase activity and increases in the activity of SOD, CAT, and APX antioxidant enzymes during storage as compared with control fruit (Ding et al, 2007;Mo et al, 2008).…”

Enhancement of Antioxidant Systems and Storability of Two Plum Cultivars by Preharvest Treatments with Salicylates

“…The increased activity of these antioxidant enzymes would lead to a more efficient cleaning of ROS species, such as O 2 – OH, or 1 O 2 , since they contribute to peroxidation of membrane lipids, damage to DNA and proteins, and acceleration of senescence processes [ 2 , 3 , 43 , 44 ]. Oxidative stress, involving ROS accumulation, has been associated with fruit ripening process, which is considered as a functionally-modified protracted form of senescence [ 2 ].…”