The effect of NaCl on antioxidant enzyme activities in potato seedlings

Abstract

The effect of NaCl on the growth and activity of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were investigated in the seedlings of four potato cultivars (Agria, Kennebec; relatively salt tolerant, Diamant and Ajax; relatively salt sensitive). The shoot fresh mass of Agria and Kennebec did not changed at 50 mM NaCl, whereas in Diamant and Ajax it decreased to 50 % of that in the controls. In Agria and Kennebec, SOD activity increased at 50 mM NaCl, but no significant changes observed in Diamant and Ajax. At higher NaCl concentration, SOD activity reduced in all cultivars. CAT and POD activities increased in all cultivars under salt stress. Unlike the other cultivars, in Ajax seedlings, APX activity increased in response to NaCl stress. We also observed new POD and SOD isoenzyme activities and changes in isoenzyme compositions under salt stress. These results suggest that salt-tolerant potato cultivars may have a better protection against reactive oxygen species (ROS) by increasing the activity of antioxidant enzymes (especially SOD) under salt stress.

Antioxidant Enzyme Activities as a Tool to Discriminate Ecotypes of Crithmum maritimum L. Differing in Their Capacity to Withstand Salinity

“…In the present study, the activity of this enzyme increased in the leaves of the more tolerant ecotype (Tabarka), in the presence of NaCl, but no significant change in SOD activity was detected in the more sensitive ecotype (Korbous). Such a differential response to salt stress was reported between cultivars of potato (Rahnama and Ebrahimzadeh, 2005), rice (Dionisio-Sese and Tobita 1998), millet (Srenivasulu et al, 2000), wheat (Sairam et al, 2002), tomato (Shalata and Tal, 1998), strawberry (Turhan and Gulen Erics, 2008), cotton (Gossett et al,1994) and beet (Bor et al, 2003). In plants, scavenging of superoxides occurs by differential regulation of SOD isoforms (Wang et al, 2004).…”

Oxidative Stress Studies in Plant Tissue Culture

“…Shri et al, (2009) observed that during the As-stress Cu/Zn-SOD isoenzyme band induced. NaCl stress induced new SOD isoenzyme bands in Agria and Kennebec potato cultivar (50 mM) and in Jatropha curcas callus (40, 60, and 80 mM), respectively (Rahnama and Ebrahimzadeh, 2005;Kumar et al, 2008). (CAT,EC 1.11.7.6) CAT is a tetrameric heme-containing enzyme that catalyzes dismutation reactions of H2O2 into H2O and O2 and is indispensable for ROS detoxification during stress conditions.…”

Proline, Sugars, and Antioxidant Enzymes Respond to Drought Stress in the Leaves of Strawberry Plants

“…ROS, superoxide anion radical (O 2 ･ -), and hydrogen peroxide (H 2 O 2 ), seriously disturb the normal metabolism by making oxidative damage to lipids, proteins, nucleic acids, and membrane function (Meloni et al, 2003). Plants have developed several antioxidant systems which counteract the cytotoxic effects of oxidative damage (Rahnama and Ebrahimzadeh, 2005), including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). These enzymes react with ROS to keep them at a low-level, and subsequently regenerate cellular antioxidants including glutathione reductase and ascorbate peroxidase.…”