Plant neighborhood shapes diversity and reduces interspecific variation of the phyllosphere microbiome

This study investigated the role of dispersal from a plant's surrounding neighbors on the assembly of leaf-associated microbiomes. The first part of the study was a manipulative field experiment in which tomato, pepper, or bean plants were grown in a ring of neighbor plants, with all reciprocal combinations of plant species. There were three harvest time points where focal plants were harvested and replaced but the neighbors were left untouched, thus the age/size of neighbors could be assessed over three stages, separated by one month. The second part of the study was a microbiome transplant experiment in which microbiomes harvested from the first study were transplanted onto either the host species from which they came, or the host species by which their previous host was surrounded. In both cases, phyllosphere bacterial communities were assessed by removing the bacteria from the leaf surface, performing DNA extraction, and then performing 16S rRNA gene (region V5-7) community sequencing on the Miseq platform.