Role of specific ions on growth and metabolic patterns in moth bean (C₃) and pearl millet (C₄) of Indian desert

Iso-osmotic solution (−4 bar) of various salts (NaCl, KCl, CaCl₂ and MgCl₂) were applied to study the role of specific ions on seedlings of Vigna aconitifolia (Moth bean) and Pennisetum typhoides (Pearl millet). Following salt treatment seedling growth, pigment biosynthesis, level of various osmo-regulatory solutes and activity of peroxidase and superoxide dismutase was altered differently in both the plants. MgCl₂ reduced the growth of the seedlings in both the plants more drastically as compared to other salts. KCI was least effective in depressing the growth of the seedlings. Overall growth reduction was more pronounced in Vigna as compared to Pennisetum. Sucrose and proline contents were significantly increased in both the plants by all the salts. Activity of peroxidase (POX) and superoxide dismutase (SOD) was greatly enhanced by all the salts with difference in their magnitude of response. Addition of CaCl₂ salt with NaCl partially counteracted the ill effect of NaCl on growth of seedlings in both the plants. The role of specific ions on growth and metabolic patterns in Vigna (C-3) and Pennisetum (C-4) has been discussed.