Plant physiological responses of coriander (Coriandrum sativum L.) to Triacontanol (TRIA), in conditions of the toxicity of arsenic

Triacontanol (TRIA), a plant growth regulator that is effective in reducing the effects of abiotic stresses. In order to investigation the effects of interaction between arsenic and TRIA treatment on some physiological indicators of coriander the present study carried out based on a factorial experiment in a completely randomized design with three replications. Factors of experiment include in different concentrations TRIA (0, 5, 10 and 20 &muM) and different levels of oxidative stress induced by arsenic (150 and 300 &muM). Arsenic treatment caused a significant accumulation of hydrogen­peroxide(H2O2), a significant increasing in lipid peroxidation, increasing of proline, soluble sugars and enhancing the activity of antioxidant enzymes, GPX, APX and reduction the content of chlorophyll a, b and total chlorophyll in leaf plant. Simultaneous Treatment of TRIA and arsenic, decreased the amount of hydrogen peroxide and lipid peroxidation , and also reduced the amount of proline and soluble sugars in the plant, while it resulted in increasing the amount of chlorophyll a, b , total chlorophyll and the activity of antioxidant enzymes in the plant and these results showed the significant role of TRIA coriander plant in protection against heavy metal arsenic, which is through the activation of antioxidant enzymes.