FERONIA Kinase Interacting Cell Wall Sensors LRX1/2 Regulate the Plant Rhizosphere Microbiome.

Plants establish beneficial associations with microbiota, enhancing their resilience to environmental challenges. FERONIA (FER) kinase shapes the microbiome; despite extensive knowledge on FER interactors that regulate development and immunity against pathogens, the specific partners involved in microbiome modulation remain underexplored. Through 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, similar to fer mutants. When grown in natural soil, 16S rRNA sequencing revealed that lrx1/2 and fer-4 have similarly altered rhizosphere microbiomes with decreased bacterial diversity. Notably, lrx1/2 and fer-4 mutants both exhibit growth defects in high pH natural soil that could be rescued by lowering soil pH and increasing phosphate. Microbiome sequencing under conditions that rescued fer-4 and lrx1/2 stunting showed that the altered microbiome of lrx1/2 and fer-4 persists independently of changes in plant growth. This indicates that FER and LRX1/2 play an integral role in shaping the rhizosphere microbiome.