<p>Plants harbor a huge diversity of the microbes in their rhizosphere, internal tissues and aerial parts. The beneficial interactions between the plants and their microbes occur by direct and indirect mechanisms which impact growth and overall health of the plants. These mechanisms include production of phytohormones, solubilization and availability of nutrients for plant uptake, production of hydrolytic enzymes and other compounds for protecting them against the pathogens. These microbes offer benefits of combating the abiotic stresses to which plants are exposed. Looking at the importance of beneficial plant-microbe interactions and need for economical solutions for meeting global healthy food demands, the beneficial microbes could be developed as bio-inoculants for sustainable agricultural biotechnology under changing climate. Depending on their mode of action, inoculants could be used as biofertilizers, biopesticides, and stress alleviators. There is a strong growing market for bio-inoculants so that the application of the chemical fertilizers could be reduced. The present review highlights the functional diversity of the plant associated microbes in major crops, their mechanisms of action and role as biofertilizers, biocontrol agents, in stress mitigation and bioremediation. Overall, exploration of the beneficial plant associated microbes and their use as bio-inoculants holds a potential for sustainable growth.</p>