Strigolactones shape the assembly of root-associated microbiota in response to phosphorus availability

Plants rely on strigolactones (SLs) to regulate their development and form symbiotic relationships with microbes as part of the adaptive strategies to phosphorus (P) efficiency. However, the impact of SLs on root-associated microbial community in response to phosphorus availability remains unknown.Here, root microbiota of SL biosynthesis (max3-11), perception (d14-1) and P-relevant (phr1) mutants were compared to wild type Col-0 plants under different P concentrations. Based on high-throughput sequencing, the relationship between SLs, P concentrations and the root-associated microbiota were investigated to reveal the variation in microbial diversity, composition and interaction.Plant genotypes and P availability played important but different roles in shaping the root-associated microbial community, while P had a stronger effect on the root-associated microbial community than SL genotypes. The biomarker of Massilia and Bacillus recruited by SLs, which were considered as plant growth-promoting rhizobacteria . Importantly, isolated CP-2 (Acinetobacter soli) could promote plant growth in cocultivation experiments. Moreover, SLs could change the topologic structure within co-occurrence networks and increased the number of keystone taxa (e.g., Rhizobiaceae and Acidobacteriaceae) to enhance microbial community stability.This study uncovers the keystone taxa recruiting by SLs and reveal the key role of SLs in mediating root-associated microbiota interactions.