Zinc-induced modulation of some biochemical parameters in a high- and a low-zinc-accumulating genotype of Cicer arietinum L. grown under Zn-deficient condition

This study presents a comparative account of biochemical responses evoked by a high-zinc-accumulating (HZnG) and a low-zinc-accumulating (LZnG) genotype of chickpea (Cicer arietinum L.) under conditions of zinc deficiency (0 mg ZnSO4 kg(-1) soil) and on exogenous zinc supply (2.5, 5, and 10 mg ZnSO4 kg(-1) soil), at different growth stages (pre-flowering, flowering, and post-flowering) of the crop. Both the genotypes exhibited significant variation in contents of chlorophyll, protein, nitrate, and leghemoglobin, and in the activity of enzymes (nitrate reductase, superoxide dismutase, and carbonic anhydrase), under zinc-limiting condition. The HZnG maintained a significantly higher level of biochemical parameters at deficient zinc levels, while LZnG was more affected by Zn deficiency (with reduced biochemical attributes), compared to HZnG. However, application of soil zinc alleviated the Zn-induced disturbance and improved the biochemical parameters in both genotypes. The differential biochemical response of plants to Zn deficiency indicated existence of genotypic variation in efficient utilization of the available Zn. The HZnG was more effective in overcoming Zn deficiency than the LZnG. This study suggests that metal-dependent biochemical parameters can be used as reliable indices for selection of genotypes with a better Zn utilization capacity, i.e., the Zn-efficient genotypes.