Alleviation of cadmium and drought stress in wheat by improving growth and chlorophyll contents amended with GA3 enriched deashed biochar

Abstract

Drought and cadmium (Cd) stress are both major issues that significantly affect the growth and development of wheat plants. Both drought stress and Cd toxicity disrupt physiological processes i.e., nutrient uptake, cell expansion, and enzymatic reactions resulting in poor crop growth. To overcome these issues, the use of activated carbon and gibberellic acid (GA3) are considered valuable amendments. However, the current study aimed to add value using GA3-enriched biochar (GA3-BC). That’s why, a lab experiment was conducted on wheat to assess the effectiveness of GA3-BC against Cd and drought stress. For GA3 enrichment in biochar, 10 µg GA3/g biochar was mixed. There were 3 levels of GA3-BC i.e., 0, 0.6 (GA3-BC1), and 0.9% (GA3-BC). All levels were applied in 3 replicates under no stress (0Cd + no drought), drought stress (DS), and 6 mg Cd/ kg soil (6Cd). Results showed that GA3-BC2 caused a significant improvement in shoot length (44.99%), root length (99.73%), seedling length (60.13%) and shoot fresh weight (63.59%) over control at 6Cd + drought stress. A significant improvement in chlorophyll a, chlorophyll b, and total chlorophyll while a decrease in electrolyte leakage and regulation of antioxidants i.e., lipid peroxidation, SOD, CAT, APx, GR, GPx, GST, and DPHH also signified the effectiveness of GA3-BC2 compared to control at 6Cd + drought stress. In conclusion, GA3-BC2 is an efficacious amendment for simultaneously alleviating drought and Cd stress in wheat. More investigations are recommended at the field level on different cereal crops cultivated in different soil textures to declare GA3-BC2 as the best treatment for mitigation of drought stress and Cd toxicity.