Plant growth promotion is bacteria and plant species-specific
To assess the changes in growth of Arabidopsis (model plant), Artemisia (medicinal plant) and Broccoli (crop) induced by strains of three specific rhizobacterial genera (Figure 1a ), we expressed fresh root and shoot biomass as a percentage relative to the non-treated control plants. Two-way ANOVA showed that the impact of the three rhizobacterial strains on plant growth was dependent on the interacting partners (Supplementary Material, Table S1 ). In the following sections, we refer to these interactions as ‘effective partnerships’ when the rhizobacterial strain promotes growth whereas ‘ineffective partnerships’ result in no growth promotion or reduced growth.