Biochemical Responses of Wheat Cultivars to PEG-Induced Drought Stress

Resumo

Aim of the present study was to study the biochemical responses of wheat cultivars (Platinum Lok 1, Eagle 135, Prerna Amber, Kisan Farmer 2189 and Ankur Kedar) to polyethylene glycol (PEG-6000—0, 5, 10 and 15%) induced drought stress. Lipid peroxidation, H₂O₂, proline, glycine betaine (GB) and activities of the antioxidant enzymes were evaluated at seedling stage. As the concentration of PEG increased, an increase in free proline and GB accumulation was observed in all the wheat cultivars to different extent. However, the magnitude of reduction of these parameters was more in Prerna Amber and Eagle 135. Platinum Lok 1 showed an increase in free proline and GB contents with low levels of MDA and H₂O₂ contents as compared to rest of the cultivars. The activities of catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) enzymes showed increasing trend with respect to increasing PEG concentration. However, no specific trend was observed for the activity of ascorbate peroxidase (APX). Activities of POX and SOD were significantly high in Plantinum Lok 1. Overall results indicated that Platinum Lok 1 can be considered as drought tolerant which can be associated with higher proline and GB accumulation and lower MDA and H₂O₂ contents. Biochemical parameters such as osmolytes and antioxidant enzymes could provide useful tools for identification of drought tolerant wheat cultivars at seedling stage.