FIGURE 1.

Illustration of salt tolerance mechanisms induced by plant growth promoting rhizobacteria (PGPR). Root surfaces are colonized by PGPR and extracellular polysaccharide matrix acts as a protective barrier against salt stress. Some extracellular molecules function as signaling cues that manipulate phytohormonal status in plants. Enhanced root-to-shoot communication improves water and nutritional balance, source-sink relations and stomatal conductance. Stimulating osmolyte accumulation, carbohydrate metabolism and antioxidant activity delay leaf senescence, which inturn contribute to photosynthesis. Regulation of physiological processes are indicated by black arrows and signaling pathways are indicated by purple arrows.