Drought is one of the major constraints on agricultural productivity worldwide and is likely to further
increase. Several adaptations and mitigation strategies are required to cope with drought stress. Plant
growth promoting rhizobacteria (PGPR) could play a significant role in alleviation of drought stress in
plants. These beneficial microorganisms colonize the rhizosphere/endo-rhizosphere of plants and impart
drought tolerance by producing exopolysaccharides (EPS), phytohormones, 1-aminocyclopropane- 1-
carboxylate (ACC) deaminase, volatile compounds, inducing accumulation of osmolytes, antioxidants,
upregulation or down regulation of stress responsive genes and alteration in root morphology in acquisition
of droughttolerance. The termInduced Systemic Tolerance (IST) was coined for physical and chemical
changes induced by microorganisms in plants which results in enhanced tolerance to drought stresses.
In the present review we elaborate on the role of PGPR in helping plants to cope with drought stress.
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