فهرست نشریات علمی دسترسی آزاد ایران

In order to study effects of salt stress on activities of hydrogen peroxide scavenging enzymes, glutathione S-transferase, some oxidative stress markers and Na+ and K+ distribution patterns in sensitive (Koohdasht) and tolerant (Gaskogen) wheat varieties were selected and grown in aeroponics culture. The seedlings were fed by nutrition solution till 3-4 leaf stage then the medium was added 200 mM NaCl. The plants were hold at this condition for 14 days. The results indicated that Gaskogen had always more shoot dry matter than Koohdasht. Also, dry matter production rate in control condition was higher than salinity. The enzyme activity of catalase, ascorbate peroxidase and glutathione S-transferase, was significantly decreased under salinity condition compared to the control condition in Koohdasht variety. However guaiacol peroxidase activity in this variety did not change significantly compared to the control. The activities of guaiacol peroxidase and glutathione S-transferase in Gaskogen significantly was increased under salinity whereas ascorbate peroxidase and catalase did not have any significant variation. Further results showed that sodium was readily absorbed and transported to the shoot in both varieties. Among various parts of cultivars there was no difference regarding the level of accumulated sodium. As a result, the ratio of potassium and sodium in various parts of the seedlings was decreased. Results obtained from this study showed that activity of scavenging enzyme like hydrogen peroxide together with glutation S-transferase caused controlling of toxic compounds in the Gaskogen variety and suppressed oxidative stress affects in compared to Kouhdasht that could refer to lower rate of hydrogen peroxidase and less lipid peroxidation in Koohdasht. As a final result, it could be stated that H2O2-scavenging enzymes and glutathione S-transferase had special roles in detoxification of toxic compounds leading to keep stable conditions inside the plant cells in salinity conditions. In addition, it is suggested that for better evaluation of salt tolerance in wheat genotypes or varieties and optimum utilization of genetic resources, addition to sodium rate and its allocation in various parts of the plant, defense mechanisms should be considered against oxidative stress induced salinity.