The management of soil-borne diseases by microbial antagonists provides an environmental friendly alternative to the use of chemical-based pesticides. The beneficial bacterium Serratia plymuthica HRO-C48 colonizes plant roots preventing the host from fungal attack and is able to promote plant growth. In the present work, the AHL-based quorum sensing system of HRO-C48 was shown to be involved in the population density-dependent expression of beneficial traits including hydrolytic enzymes and antibiotics. Considering plant health and plant growth, the utilization of bio-priming to inoculate oilseed rape seeds and young olive plant by root dipping resulted in effective population densities.
