Sustainable agriculture is vitally important in today’s world because it offers the potential to meet our future agricultural needs, something that conventional agriculture will not be able to do. Soil microorganisms with beneficial activity on plant growth and health represent an attractive alternative to conventional agricultural practice. Plant Growth-Promoting Rhizobacteria (PGPR) are naturally occurring soil bacteria that aggressively colonize plant roots and benefit plants by providing growth promotion. PGPR are associated with plant roots and augment plant productivity and immunity; however, recent work by several groups shows that PGPR also elicit so-called ‘induced systemic tolerance’ to salt and drought. PGPR might also increase nutrient uptake from soils, thus reducing the need for fertilizers and preventing the accumulation of nitrates and phosphates in agricultural soils. Scientific researches involve multidisciplinary approaches to understand adaptation of PGPR, effects on plant physiology and growth, induced systemic resistance, biocontrol of plant pathogens, bio fertilization, and potential green alternative for plant productivity, viability of co inoculating, plant microorganism interactions, and mechanisms of root colonization.