Plant–Rhizobacteria Interaction and Drought Stress Tolerance in Plants

Abstract

Agricultural productivity is threatened mainly by climate changes and excessive use of agrochemicals resulting in continuous environmental degradation. In the following decades, warmer temperatures, high dioxide carbon levels and an increase in the frequency and duration of drought are expected. Moreover, water shortage is considered one of the major environmental factors that has adverse effects on yield and quality in agricultural crops worldwide. Therefore, alternative eco-friendly approaches need to be considered. Rhizobacteria are symbiotic, free-living, or endophytic microorganisms that colonize the roots of plants system. Numerous studies indicate that plant growth-promoting rhizobacteria (PGPR) have an important role in the metabolism, growth, and development of plants. The use of PGPR as biofertilizers is proposed as an alternative solution for the sustainability of agro-ecosystems. The beneficial effects of PGPRs have been demonstrated in many agricultural crops and several rhizobacteria strains are responsible for alleviating plants from biotic and/or abiotic stresses. Production of plant growth regulators by PGPR is one of the principal mechanisms used to explain the improvement of plant growth and development. This chapter is focused on plant–rhizobacteria interaction and its effect on regulation abscisic acid (ABA) metabolism in plants submitted to drought stress.