lrx1/2 and fer-4 microbiome sequencing under natural or enriched phosphate levels
Plants establish beneficial associations with microbiota to enhance resilience to biotic and abiotic stresses. FERONIA (FER) kinase shapes the microbiome in response to phosphate stress; despite extensive knowledge on FER interactors that regulate development and immunity, little is known about which FER-interaction partners shape the microbiome. Using a reverse genetic screen of Arabidopsis leucine-rich repeat extensin (LRX) genes, which encode FER-interacting cell wall sensors, we found that loss-of-function of lrx1/2 leads to enriched rhizosphere Pseudomonas fluorescens, similar to fer mutants. Microbiome sequencing further demonstrated that lrx1/2 and fer-4 have similarly altered microbiomes, marked by an overall microbial diversity decrease. Microbiome sequencing under high and low phosphate showed that while the fer-4 mutant exhibits a phosphate-responsive microbiome, the lrx1/2 microbiome remained stable regardless of phosphate status. This indicates that FER and LRX1/2 jointly influence microbiome composition under phosphate scarcity, and work independently when phosphate is sufficient. Collectively these findings suggest that nutrient status sensing by FER and LRX1/2 shape the rhizosphere microbiome.