Involved in the secretion of root-derived phenolics upon iron ions (Fe) depletion. Promotes disease resistance toward B.cinerea, H.arabidopsidis and P.syringae pv. tomato DC3000. Required during rhizobacteria-mediated (e.g. P.fluorescens WCS417r) broad-spectrum induced systemic resistance (ISR) against several pathogens. Hydrolysis of terminal, non-reducing beta-D-glucosyl residues with release of beta-D-glucose. Expressed at low levels predominantly in root epidermal cells. Accumulates upon rhizobacteria-mediated (e.g. P.fluorescens WCS417r) induced systemic resistance (ISR) in root trichoblasts and, to a lesser extent, in cortical cells. Reduced secretion of root-derived phenolics upon iron ions (Fe) depletion, thus leading to their accumulation in the root interior. Impaired P.fluorescens WCS417r-mediated broad-spectrum induced systemic resistance (ISR) against several pathogens. Belongs to the glycosyl hydrolase 1 family.