Unveiling diversity and adaptations of the wild tomato microbiome in their center of origin in the Ecuadorian Andes

Microbiome assembly has been studied for many plant species and is recognized as a key driver of plant growth and plant tolerance to (a)biotic stresses. To date, assembly of the tomato rhizosphere microbiome has been investigated primarily for commercial varieties and field soils subjected to agricultural management practices, whereas the microbiome of wild tomato genotypes in their native habitats remains largely unexplored. This research focused on distinct populations of Solanum pimpinellifolium in three natural habitats in the Ecuadorian Andes to identify the taxonomic and functional diversity of their rhizosphere microbiome. The results showed that, despite genotypic differences among the wild tomato populations, different soil types and soil microbiome compositions, the rhizosphere microbiome showed strikingly compositional similarity across the three habitats. Proteobacteria, in particular taxa classified as Enterobacteriaceae, and specific unclassified fungal taxa were highly represented in the rhizosphere of S. pimpinellifolum. Metagenomic analyses suggested that the prevalence of Enterobacteriaceae on wild tomato roots may be explained by several traits, in particular nutrient competition, motility, iron acquisition, membrane transport, stress response, and plant hormone biosynthesis. These results reveal a conserved microbiome signature associated with wild tomato rhizosphere in their center of origin. Alike genomes of wild crop ancestors provide a valuable source of beneficial traits for breeding cultivated varieties, exploring their microbiome in native environments could uncover microbial taxa and traits that contribute to crop growth and health.