Bacillus subtilis ameliorates water stress tolerance in maize and common bean

Water stress is one important abiotic stress with negative impacts on plant productivity. In order to ameliorate abiotic stress, plant growth-promoting rhizobacteria (PGPR), such as Bacillus subtilis, can be used due to their positive effects on plant physiology. The present study aimed to evaluate the effects of B. subtilis on the performance of maize and common bean under water deficit conditions. The study was performed in a plant growth chamber and the growth, gas exchange parameters and antioxidant activity were evaluated. B. subtilis promoted the growth of common bean and maize, and also increased the water use efficiency. The inoculation with B. subtilis increased leaf water content and the regulation of stomata, without damaging photosynthetic rates. Overall, B. subtilis decreased antioxidant activities in both plants. The results suggest that B. subtilis could be used as inoculants for common bean and maize to protect against water stress.