At present, due to widespread human manipulations in the environment and also due to climate change, plants may face various environmental stresses during their life cycle. Abiotic stresses, especially drought and salinity, can severely affect plant growth and yield and impair human food security. To deal with these stresses, there are various strategies that the use of PGPRs is one of the newest and most useful method. These types of soil bacteria have the ability to change the morphological and biochemical characteristics of plants without permanent changes in the genome of the host plant, so that with these changes, the adaptation of plants to new conditions is increased and stress damage is minimized. Therefore, in this chapter, rhizobacteria and their effects on plants under abiotic stresses, especially drought and salinity, will be introduced.
