How pollinators mediate microbiome assembly in flowers is a major unresolved question of theoretical and applied importance in the face of anthropogenic disturbance and climate change.
Microbiomes can profoundly influence plant fitness in natural and agricultural settings. Relative to rhizosphere (root) and phyllosphere (leaf), the anthosphere (floral) microbiome is least well studied but has the most direct impact on plant reproductive success. Our understanding of what governs microbiome assembly in flowers – a highly dynamic niche – has advanced only recently. The identified drivers include, for instance, microbial dispersal mediated by pollinators, floral traits that can influence niche availability and microbial source pool, anthropogenic changes in mutualistic and antagonistic interactions, and disturbance imposed by agrochemicals. Yet, as these different drivers have often been studied independently, we lack a clear view as to how they act together and thus their relative importance in shaping the floral microbiome.
To address this question, we are using crop–wild relative systems in strawberries (Fragaria) and apples (Malus). This line of research involves a series of related projects: (1) What influences plant–pollinator interactions? (2) How do plant–pollinator interactions govern floral microbial diversity and network? (3) How do plant mutualistic (e.g. mycorrhizae) and antagonistic interactions (e.g. herbivory) at the rhizosphere and phyllosphere influence the floral microbiome? (4) How does phenology change influence plant–pollinator interactions and in turn the floral microbiome? We address these questions using field observations of pollinators, manipulative experiments (e.g. agrochemicals, mycorrhizae, herbivory), floral trait measurements (e.g. flower abundance, size, pollen production, color, volatiles), and microbiome sequencing.
community assembly, crabapple, NCEP plot, microbiome, mycorrhizae, pollinators, phenology, strawberry