Which specificity in cooperation between phytostimulating rhizobacteria and plants?

Plant growth-promoting rhizobacteria (PGPR) are found in association with a large range of host plants. Although the subject of plant host specificity has been well studied in parasitic and mutualistic interactions, the question of whether phytostimulating rhizobacteria efficiently interact only with a specific host remains poorly discussed. This review presents elements suggesting the existence of specificity in three-step establishment of associative symbiosis between phytostimulating rhizobacteria and plants: bacterial attraction by the host plant, bacterial colonization of roots, and functioning of associative symbiosis.