Speaker
Description
The Common Symbiosis Signalling Pathway (CSSP) plays a pivotal role in orchestrating symbiotic relationships between plants and arbuscular mycorrhiza fungi, as well as between leguminuos plants and nitrogen-fixing bacteria. These symbioses are vital for optimal plant nutrient acquisition, particularly nitrogen and phosphorous. While the functions of CSSP genes in arbuscular mycorrhizal symbiosis in cereals are well- documented, their impact on other root microbiota, such as free-living nitrogen-fixing bacteria, remains unknown. Understanding interactions between cereals and other potentially beneficial soil microbes is crucial for addressing contemporary environmental challenges related to crop nutrient limitations and organic fertiliser development. In our approach, we employed barley CSSP mutants and combined microbiome profiling and metabolomics to unravel the effect of symbiosis signalling on bacterial assembly, and to identify CSSP-dependent root metabolites that navigate plant-microbe interactions. Our findings reveal that CSSP genes exert distinct effects on various rhizosphere bacteria, including Rhizobiales, which host a broad variety of nitrogen-fixing species. We identified that CSSP genes are involved in the biosynthesis of several signalling molecules, such as flavonoids, known in legumes for attracting nitrogen-fixing bacterial symbionts. These results provide a foundation for future research and engineering efforts to enhance cereal interactions with beneficial soil bacteria, addressing current agricultural challenges.
