Antioxidant status and their enhancements strategies for water stress tolerance in chickpea

Water stress executes severe influences on the plant growth and development through modifying physio-chemical properties. Therefore, a field experiment was designed to evaluate the antioxidant status and their enhancements strategies for water stress tolerance in chickpea on loam and clay loam soils under agro-ecological conditions of Arid Zone Research Institute, Bahawalpur (29.3871 °N, 71.653 °E) and Cholistan farm near Derawer (28.19°N, 71.80°E) of Southern Punjab, Pakistan during winter 2014-15. Experimental treatments comprised of two chickpea cultivars i.e. Bhakhar 2011 (drought tolerant) and DUSHT (drought sensitive), two water stress levels i.e. water stress at flowering stage and water stress at flowering + pod formation + grain filling stage including well watered (control) and two exogenous application of osmoprotectants i.e. glycine betaine (GB) 20 ppm and proline 10 uM including distilled water (control). Results indicated that water stress at various growth stages adversely affects the growth, yield and quality attributes of both chickpea cultivars. Exogenous application of GB and proline improved the growth, yield and quality parameters of both chickpea cultivars even under water stress conditions. However, superior results were obtained with exogenously applied GB on Bhakhar 2011 under well-watered conditions. Similarly, foliar spray of GB on chickpea cultivar Bhakhar 2011 under stress at flowering + pod formation + grain filling stage produced maximum superoxide dismutase, peroxidase and catalase contents. These results suggested that application of GB mitigates the adverse effects of water stress and enhanced tolerance in chickpea mainly due to higher antioxidant enzymes activity, demonstrating the protective measures of plant cells in stress condition. Hence, antioxidants status might be a suitable method for illustrating water stress tolerance in chickpea.