Root metabolites regulated by FERONIA promote phosphorus-solubilizing rhizobacteria enrichment induced by Arabidopsis thaliana coping with phosphorus deficiency.

The recruitment of the phosphorus-solubilizing rhizobacteria plays an important role in response to phosphorus deficiency. Through the treatments of Arabidopsis thaliana (Col-0) and the FERONIA (FER) functional deficient mutants (fer-4 and fer-5) with the soil suspension in various phosphorus conditions, we discovered that FER could promote phosphorus-solubilizing rhizobacteria enrichment to rescue the defective plant during phosphorus deficiency. The amplicon sequencing data reflected that the phosphorus-solubilizing rhizobacterial genus Alcaligenes was significantly enriched of Col-0 than fer-4 in low phosphorus conditions. Metabolomics analysis revealed that there were more α-D-Glucose (α-D-Glc) and L-Leucine (L-Leu) in Col-0 roots than those in fer-4 roots. The alterations of α-D-Glc and L-Leu mediated by FER had high-positive correlations to the enrichment of Alcaligenes. We successfully isolated a phosphorus-solubilizing rhizobacteria strain identified as Alcaligenes faecalis PSB15. The α-D-Glc and L-Leu could promote the strain PSB15 growth on LB agar plates and assist fer-4 in recovering from phosphorus starvation in the low phosphorus (LP) liquid medium vermiculite with tricalcium phosphate (TCP). The α-D-Glc and L-Leu could be considered as promising compounds to enrich beneficial phosphorus-solubilizing rhizobacteria, such as Alcaligenes, and provide a reference for overcoming the plight of phosphorus deficiency in crops in the field of agricultural production in the future.