Transient interactions and influence among bacteria in field-grown Arabidopsis thaliana tissues

Abstract

Interactions between bacteria are thought to play an important role in the assembly of plant microbial communities (1), yet the extent of temporal variation in these interactions is unclear. We inferred interactions from sequence-based counts of bacteria in a series of Arabidopsis thaliana tissue samples spanning major developmental transitions in the plant life cycle (2). Bacterial interactions were transient, even among variants found together at consecutive developmental stages. The overwhelming majority of these interactions were positive, indicating that competition for the plant niche might be a less important driver of bacterial abundances than cooperation or common responses to host and environmental factors. Over time, interaction networks diverged from an initial scale-free structure and became increasingly modular. In all networks, we found evidence of a hierarchical structure in which hub bacteria bridged network modules. However, the identities of bacteria in these influential roles also varied during plant growth.

Host genotype controls ecological change in the leaf fungal microbiome

“…Early-arriving species are typically those with effective long-range dispersal, while the climax community is dominated by species that can more effectively use resources under competition [6]. While these broad patterns are generalizable, the composition of any particular successional community depends greatly on both the habitat colonized and interspecific interactions such as priority effects, where the order of arrival of taxa governs the success of later arrivals [7,8]. While most successional theory is based on studies in macroscale organisms, the principles of succession are evident in microbial communities as well, but on a more rapid timescale [9][10][11].…”