Enhancing Germination of Wheat Seeds under Drought Conditions by Bacillus cereus DS1 Isolated from the Rhizospheric Soil of Celosia argentea

Drought is a prolonged period of insufficient rainfall, leading to water scarcity that adversely affects both the natural environment and human endeavours. Water scarcity disrupts photosynthesis, resulting in underdeveloped, smaller plants, wilting leaves, reduced root growth, and, under severe conditions, plant death. Drought remains one of the most significant challenges to global food security, causing crop failures, rising food prices, and widespread malnutrition. The key objective of the present investigation was to isolate bacterial species capable of surviving drought conditions and to evaluate their plant growth-promoting potential. The Bacillus cereus DS1 strain was isolated from a soil sample collected from the rhizospheric region of the drought-tolerant plant Celosia argentea. Among the various tested osmotic pressure conditions, Bacillus cereus DS1 not only significantly tolerated 5% PEG 8000 (−0.47 MPa osmotic pressure) but also exhibited promising plant growth-promoting properties. The in vitro plant growth-promoting activity of the isolate was evaluated using various tests, including hydrogen cyanide, indole acetic acid, ammonia, and siderophore production; ACC deaminase activity; and phosphate solubilization and nitrogen fixation under both stress and non-stress conditions. Additionally, the effect of Bacillus cereus DS1 on seed germination was assessed, and a notable enhancement of 88% seed germination was observed in bioprimed seeds compared to the control (seeds primed with distilled water). Overall, the local isolate Bacillus cereus DS1 has the potential to withstand various levels of drought stress and enhance seed germination under drought conditions, indicating that it could serve as a valuable bioinoculant for improving crop yield in arid and semi-arid regions.