The floral interface: a playground for interactions between insect pollinators, microbes, and plants

Abstract

ABSTRACT Insect pollinators acquire microorganisms when they visit flowers for nutrients. The interactions that occur at the floral interface are complex with three participants – pollinators, plants and microorganisms. The majority of the insect pollinator’s microbiome is shaped by their behaviour, diet and environment. At present the bee (Apidae family) microbiome is the best documented and contributes to our understanding of the bi-directional exchange of microbes between pollinators and flowers. The transferred microorganisms may be mutualistic, commensal or pathogenic. We identify a lack of information due to limited studies concerning the diversity of pollinators and a focus on pathogenic microorganisms and their gut microbiome influence on their health. Each candidate, the insect, plant and microbe, makes their own contribution which aids the interaction, but some participants may benefit more than others. The benefits for pollinators include enhanced acquisition of nutritional resources; for microorganisms dispersal and a ‘new’ habitat to colonise and for plants pollination is the outcome. Finally, we explore a novel concept of whether the fruit acts as a potential vector for insect microorganisms to hibernate and extend their lifecycle in the absence of a pollinator host.