Bacteria isolated from dried tobacco to enhance drought tolerance in wheat

Drought poses a major threat to global food security, reducing yields of staple crops such as wheat. Sustainable solutions to improve plant resilience are urgently needed. Tobacco is widely cultivated for cigarette production, but its dried leaves can also harbor thermotolerant bacterial strains with potential plant growth-promoting properties. This study aimed to evaluate the biostimulatory potential of endophytic bacteria isolated from dried tobacco leaves in enhancing drought tolerance in winter wheat (Triticum aestivum L.). Five bacterial strains were characterized for key PGP (plant growth-promoting) traits, including auxin production, phosphate solubilization, siderophore production, and salt tolerance. In greenhouse experiments under controlled drought stress (100%, 75%, and 50% field capacity), selected strains were applied to wheat seedlings, and their effects on plant growth, biomass accumulation, and oxidative stress markers (malondialdehyde and hydrogen peroxide) were assessed. The effects of bacterial inoculation varied by strain and irrigation level, with the most beneficial responses generally observed under moderate drought stress. Certain strains significantly reduced oxidative damage and enhanced shoot biomass compared to noninoculated controls These findings demonstrate the untapped potential of tobacco leaf-derived PGP bacteria as sustainable bioinoculants to improve drought resilience in wheat, contributing to climate-resilient agriculture and reduced reliance on chemical inputs. KEY POINTS: • Tobacco leaf bacteria improve wheat growth under drought stress • Isolated strains show biostimulant and drought tolerance effects • Bacterial application may support sustainable wheat farming in dry conditions.