Effect of K and Si Applications on Plant Development, Na and K Content and Some Antioxidant (SOD, CAT, APX) Activities of Wheat (Triticum aestivum L.) Plant Exposed to Salt Stress

The problem of salinity in our soils is increasing day by day. This problem has become even more important with global climate change. It is the plants that are most affected by this problem. Salinity affects many metabolic activities in a very complex way by causing stress in plants. Reactive oxygen species, especially formed by salt stress, cause serious damage to plant cells. They use antioxidative enzymes such as catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) to protect the plant from this stress. The aim of this research is to determine the effects of potassium and silicon applications on some antioxidant enzyme activities in wheat plant in salty conditions. In the experiment conducted under potted conditions, increasing doses of salt (0 and 100 mM NaCl), potassium (0, 150 and 300 mg/kg K) and silicon (0, 75 and 150 mg/kg Si) were applied to the wheat plant. According to the results obtained, SOD activity increased in 100 mM NaCl, 150 mg/kg K 0 mg/kg and 300 mg/kg Si applications. The effect of salt application on CAT activity was not found to be significant compared to control. APX activity was generally increased with the addition of salt. However, the increase in APX activity due to 100 mM NaCl administration decreased significantly with increasing silicon doses when 150 mg/kg potassium administration was kept constant. This situation shows that K and Si applications can be beneficial in reducing salt stress.