Bacillus sp. and Pseudacidovorax intermedius colonization effect on biochemical and metabolites expression in drought-stressed Sorghum bicolor (L.) Moench

Drought stress severely affects the physiology and metabolism of plants. Fortunately, using plant growthpromoting bacteria can provide an environmentally friendly solution. Hence, the present experiment was conducted on the sorghum plant for drought amelioration by utilizing Bacillus sp. and Pseudacidovorax intermedius bacterization to the sorghum seeds under greenhouse conditions. Drought stress was induced by the withholding of water after 52 days of emergence (flowering stage). However, the inoculation of Bacillus sp. and Pseudacidovorax intermedius could significantly improve the drought tolerance capacity through the production of different antioxidant enzymes and metabolites in sorghum plants under drought and recovery conditions. The results declared that the inoculation of Bacillus sp. significantly reduced the membrane leakage by 37 % by minimizing the production of malondialdehyde (49 & 47 %) and hydrogen peroxide (32 & 36 %) content. In addition to protecting membrane leakage, bacterial inoculation positively modulates the antioxidant enzymes namely catalase, ascorbate peroxidase, glutathione peroxidase, superoxide dismutase, and phenol content in the plant system. Metabolomic results revealed that inoculation of Bacillus sp. and consortia of Bacillus sp. and Pseudacidovorax intermedius up regulate the carboxylic acid, organic, and amino acids biomolecules expression inside the inoculated plants. The study concluded that inoculation of Bacillus sp. is an assured technology for mitigating the drought effect through the expression of antioxidant compounds, and expression of leaf metabolites in sorghum during drought conditions. Further, the research needs to comprehend the underlying molecular mechanism of bacterial-induced drought-tolerant in sorghum plants. It will also create a road map to develop a bestselling bioinoculant for climate-smart agriculture.