Rhizobacteria-mediated induced systemic resistance (ISR) in Arabidopsis: involvement of jasmonate and ethylene

Abstract

The capacity of a plant to express a broad-spectrum systemic acquired resistance (SAR) after primary infection is well known and extensively studied. A relatively unknown form of induced disease resistance is triggered by nonpathogenic, root-colonizing rhizobacteria and is commonly referred to as rhizobacteria-mediated induced systemic resistance (ISR). Rhizosphere bacteria are present in large numbers on the root. Certain strains stimulate plant growth and are therefore called plant growth-promoting rhizobacteria (PGPR). Selected strains with biological control activity, mainly fluorescent Pseudomonas spp., reduce plant diseases by suppressing soil-borne pathogens through competition for nutrients, siderophore-mediated competition for iron or antibiosis.