Supplementation of potassium alleviates water stress-induced changes in Sorghum bicolor L.

This report discusses water stress-induced changes and their amelioration by added potassium in Sorghum bicolor L. Chlorophylls, carotenoids, and the activity of nitrogen metabolizing enzymes viz., nitrate reductase, alanine aminotransferase and aspartate aminotransferase were adversely affected under water stress and restricted irrigation. Osmotic as well as water stress trigger ROS production while potassium ameliorated these changes to some extent and increased the activity of SOD, CAT, APX, and GR and the contents of GSH and AsA. Water stress-induced changes ultimately reflecting on growth and yield parameters like plant height, biomass yield, grain yield, days to flowering, and days to maturity. Added potassium affected these parameters positively, both under normal and stress conditions, indicating the use of potassium as a tool for mitigating the water stress induced deleterious changes in sorghum to some extent by enhancing the nitrogen use efficiency and strengthening the enzymatic and non-enzymatic antioxidant components. The results obtained here exhibited similar trends in seedlings and plants raised in sand cultures and field conditions, making them more meaningful and comprehensible.