Fuente: WIPO "tomato" Compositions of Pseudomonas argentinensis strain SA190 (hereinafter, SA190), alone or in combination with Enterobacter sp. SA187 are provided. The compositions can be used to provide seeds or plants with resistance or tolerance to drought stress. Compositions containing SA190, alone or in combination with SA187 can be used to enhance plant development and yield under environmental stress conditions resulting from drought. Plant substrates for example, soil, peat, compost, vermiculite, perlite, sand, clay and combinations thereof containing effective amounts of SA190 and/or SA187 to confer drought tolerance to the plant following colonization of the plant are also provided.