Synthetic communities increase microbial diversity and productivity of Agave tequilana plants in the field

Agaves are plants native to North America that sustain life in arid and semi-arid ecosystems. Previous studies revealed that cultivated plants of Agave tequilana had lower microbial diversity and functionality than wild Agave species. Here, we tested if synthetic communities (syncoms), based on microbial hubs or taxa with enriched microbial functions, could increase microbial diversity, plant health, and productivity in A. tequilana. We applied ten syncoms on the phyllosphere of six-months-old plants of Agave tequilana in the field and monitored their development for two years. Amplicon sequencing of the 16S-rRNA-V4 and ITS2 revealed that the inoculated syncoms played a negligible or minor role in the assembly of the prokaryotic and eukaryotic phyllospheric communities associated with Agave tequilana, respectively. However, syncoms based on microbial hubs, particularly those observed in the phyllosphere associated with the wild A. salmiana (PFCS), promoted microbial communities with higher alpha diversity. Some of these syncoms-derived phyllospheric communities consumed a greater variety of carbon sources; had more complex co-occurrence networks; and increased the content of sugars (oBrix, a measure of productivity in agaves) in the stem and changed the leaf metabolome. Our work demonstrates that the application of syncoms formulated based on predicted microbe-microbe interactions and metagenomic analyses of microbial communities in cultivated and wild plant species represents an effective tool to improve the sustainability and productivity of crops of arid ecosystems.