Investigation of the ameliorative effect of N-acetylcysteine on heavy metal toxicity in wheat plant (Triticum aestivum L.)

This study investigated improvement in damage in the shoots and roots of wheat seedlings (Triticum aestivum L. 'Ceyhan-99') exposed to heavy metal stress (Cu, Cd, Hg and Pb) with N-acetylcysteine (NAC) treatment at the physiological (root and shoot length, fresh and dry weight, shoot water potential, etc.) and biochemical levels. Enzymatic (POX, CAT, GR, SOD, APX, MDHAR, DHAR) and non-enzymatic (TPC, phenolic acid, and GSH) antioxidant defense system components, osmolite content (proline, cysteine, sugar, organic acid and heavy metal content) and polyamine levels of the root and shoots of the seedlings were determined for this purpose. N-acetylcysteine alleviated heavy metal-induced decreases in growth parameters and shoot water potential in the wheat seedling. The effects of NAC on the activity of the antioxidant enzymes varied depending on the enzyme and heavy metal species. N-acetylcysteine application resulted in decreased TPC content and PAL activity in the root that increased with heavy metal application. Changes in phenolic acid forms, polyamines, sugar and organic acid contents with heavy metal and NAC application varied depending on heavy metal types. In conclusion, wheat seedlings exhibited high tolerance with NAC application, especially against Cd, Hg and Pb heavy metals.