Response of growth and antioxidant enzymes to osmotic stress in two different wheat (Triticum aestivum L.) cultivars seedlings

Abstract

To investigate the responses of growth and antioxidant enzymes to osmotic stress in two different wheat cultivars, one drought tolerant (Heshangtou, HST) and the other drought sensitive (Longchun 15, LC15), 15-day-old wheat seedlings were exposed to osmotic stress of -0.25, -0.50, and -0.75 MPa for 2 days. It is found that osmotic stress decreased shoot length in both wheat cultivars, whereas to a lesser degree in HST than in LC15. The contents of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) of shoot in both wheat cultivars were increased by osmotic stress. It is clear that MDA contents increased less in the more drought tolerant cultivar HST than in drought sensitive one LC15. On the contrary, POD and CAT activities increased more in HST than LC15 under osmotic stress. As the activity of SOD, however, no significant differences were found between HST and LC15. These results suggest that wheat cultivar HST has higher activities of antioxidant enzymes such as POD and CAT to cope with oxidative damage caused by osmotic stress compared to sensitive LC15.

Gene expression and activity of antioxidant enzymes in barley (Hordeum vulgareL.) under controlled severe drought

“…In a study on Kentucky bluegrass, progressive drought for 18 days of drought-tolerant genotype and 22 days of the drought-sensitive genotype showed an increase in lipid peroxidation in both genotypes, but the increase was higher in the droughtsensitive genotype (Xu et al 2011). Plants under osmotic stress for 2 days of two wheat genotypes showed an increase in lipid peroxidation compared with the untreated control (Wu et al 2012). The discrepancy in the results of lipid peroxidation can be explained by the different plant species that were tested and the differential severity and duration of drought stress (Reddy et al 2004;Kar 2011).…”

“…Rice seedlings were exposed to mild and severe osmotic stress using PEG-6000; as the severity of osmotic stressthe activity of CAT decreased (Sharma & Dubey 2005). In a study on two wheat genotypes with differential drought tolerance under osmotic stress for 2 days, the two genotypes showed an increase in lipid peroxidation, SOD and CAT activities (Wu et al 2012). Another study on bread wheat under osmotic stress showed a differential change in the activity of SOD, CAT, and APX between the drought-tolerant and drought-sensitive genotypes.…”

Changes in oxidoreductases activity in anthropogenic salty soils

“…CAT is one of the most effective antioxidant enzymes that can degrade H 2 O 2 into water and molecular oxygen in the peroxysomes where H 2 O 2 is produced from β-oxidation of fatty acids and photorespiration (Fazeli et al 2007). Wu et al (2012) reported that CAT activity of shoot in two different cultivar wheat was increased under osmotic stress compared to control. In the soil from the vicinity of Ciech Soda PL there was noted the highest CAT activity in the soil sampled from stand no 1, with the highest value of exchangeable acidity as well as electrical conductivity, as well as the lowest DH activity.…”

Tyrosine-priming modulates phenylpropanoid pathway in maize grown under different pH regimes

“…SOD (superoxide dismutase), APX (ascorbate peroxidase), GPX (glutathione peroxidase), CAT (catalase), (Zobayed et al 2005). Parallelism between these enzymes, stress induced lipid peroxidation and stress tolerance has been previously reported (Zobayed et al 2005;Wu et al 2012).…”