Effects of increased concentrations of chloride on the expression of Mn-SODenzyme in tobacco

摘要

Chlorine is one of the ions contributing to salinity, despite being an essential micronutrient. CI" absorption takes place more easily than other nutrients so, the toxic effects of chlorine on the growth has considered rather than its scarcity. Salt stress can ultimately leads to oxidative stress through ROS increase and antioxidant defense system is induced. Therefore, in this study the effect of different concentration of chlorine in irrigation water on the expression of manganese superoxide dismutase was investigated as an indicator of antioxidant defense system activation. Seedlings of tobacco were treated with different concentrations, i.e. 2, 4, 8 mM of CaCl2. Evaluation of Mn-SOD isoenzyme gene expression was performed using RT-qPCR (quantitative reverse transcription PCR) at 0, 3, 6 and 12 hours after treatment. The results showed Mn-SOD gene transcription increased after 3 h treatment with 8 mM CaCl2 and peaked at 6 hours. Based on the observed changes, concentrations of calcium chloride greater than 8 mM in water used for irrigation of tobacco causes stress that results in activation of antioxidant response.