Differences in antioxidant activity in response to salinity stress in tolerant and susceptible wheat genotypes

Abstract

Effects of long-term sodium chloride salinity (100 and 200 mM NaCl; ECe = 6.85 and 12.3 dS m -1 ) were studied in tolerant (Kharchia 65, KRL 19) and susceptible (HD 2009, HD 2687) wheat genotypes. NaCl decreased relative water content (RWC), chlorophyll content (Chl), membrane stability index (MSI) and ascorbic acid (AA) content, and increased the contents of hydrogen peroxide, thiobarbituric acid reactive substances (TBARS), and activities of superoxide dismutase (SOD), ascorbate peroxidase (APOX) and glutathione reductase (GR). Kharchia 65 showed lowest decline in RWC, Chl, MSI and AA content, lowest increase in H 2 O 2 and TBARS contents and higher increase in SOD and its isozymes, APOX and GR, while HD2687 showed the highest decrease in AA content, highest increase in H 2 O 2 and TBARS contents and smallest increase in activities of antioxidant enzymes. KRL 19 and HD 2009 showed intermediate response both in terms of oxidative stress and antioxidant activity.

Comparison of an antioxidant system in tolerant and susceptible wheat seedlings in response to salt stress

“…It is clear that high level of endogenous AsA is essential effectively to maintain the antioxidant system that protects plants from oxidative damage due to abiotic and biotic stresses (Shigeoka et al, 2002). Salt induces a decrease in AsA content in wheat at the vegetative stage (Sairam et al, 2005) and at the reproductive stage (Athar et al, 2008). In agreement with this observation, our study showed that salinity induces a decrease in AsA in the two durum wheat cultivars particularly in the cv.…”

“…Parallel to our results, low MDA content is important in terms of salt tolerance as represented in different studies. Salt tolerant barley (Liang et al, 2003), tobacco (Ruiz et al, 2005) and wheat cultivars (Sairam et al, 2002(Sairam et al, , 2005Mandhania et al, 2006) also showed low level of lipid peroxidation which is important sign of higher oxidative damage limiting capacity under salinity.…”

“…APX utilizes AsA as its specific electron donor to reduce H 2 O 2 to water with the generation of monodehydroascorbate (Shigeoka et al, 2002), and plays a crucial role in the management of ROS during stress (Ahmad et al, 2008). It has been reported previously that salinity increases APX activity in many salt tolerant cultivars (Hernández et al, 2001;Sairam et al, 2005;Koca et al, 2007). The susceptibility of the cv.…”

“…It has been demonstrated that NaCl tolerance is closely correlated with the antioxidant capacity in numerous plants, such as bread wheat (Sairam et al, 2002(Sairam et al, , 2005Mandhania et al, 2006;Choudhury et al, 2013;Hossain et al, 2015). However, it has been showed that the increase of the activity of some antioxidant enzymes is concomitantly with salt sensitivity.…”

Drought tolerance in transgenic tropical maize (Zea mays L.) by heterologous expression of peroxiredoxin2 gene-XvPrx2

“…The excessive accumulation of ROS under drought stress might have caused injury to cells in drought sensitive conventional plants. Injuries caused by ROS include lipid peroxidation, degradation of membrane protein and inactivation of enzymes such as those responsible for photorespiration (example RUBiSco, PEP carboxylase) which are important components in the electron transport chain (Sairam et al, 2005;Zlatev and Lidon, 2012).…”