Drought-Stress Tolerance in Wheat Seedlings Conferred by Phenazine-Producing Rhizobacteria.

The specific role of phenazines produced by rhizosphere-colonizing in mediating wheat seedling drought-stress tolerance and recovery from water deficit was investigated using 30-84 and isogenic derivatives deficient or enhanced in phenazine production compared to wild type. Following a 7-day water deficit, seedlings that received no-inoculum or were colonized by the phenazine mutant wilted to collapse, whereas seedlings colonized by phenazine producers displayed less severe symptoms. After a 7-day recovery period, survival of seedlings colonized by phenazine-producing strains exceeded 80%, but was less than 60% for no-inoculum controls.