Alleviation of Salt Stress in Eggplant (Solanum melongena L.) by Plant-Growth-Promoting Rhizobacteria

This study was conducted to elucidate the effects of inoculation with plant-growth-promoting rhizobacteria (PGPR) on eggplant growth, yield, and mineral content under salt stress [0, 25, and 50 mM sodium chloride (NaCl)]. The PGPR strains Xanthobacter autotrophicus BM13, Enterobacter aerogenes BM10, and Bacillus brevis FK2 were isolated from the salt-affected maize and kidney bean fields. The increase in salinity decreased the growth and yield and increased the sodium (Na+) uptake of eggplant. However, inoculation with PGPR strains reduced the negative effects at each level of salinity tested. The E. aerogenes strain was capable of promoting eggplant growth and yield when compared to an uninoculated control. The B. brevis was the most effective strain for reducing the negative effects of salinity, and its effects occurred through increasing the potassium (K+)/Na+ ratio and K+-Na+ selectivity in the eggplant shoots. Inoculation of the eggplant seedlings with PGPR could alleviate the negative effects of salt stress.