Importance of pathobiomes to the success of microbial weed biocontrol agents

The role of microbial communities in the establishment of plant pathogens introduced to new environments as weed biocontrol agents is relatively unexplored. Substantial evidence from crop protection research shows how bulk microbial communities influence the establishment, survival, and success of pathogens. Just as mismatches between biocontrol agents, host genotypes, and climate can lead to establishment failure, we propose that mismatches between microbial biocontrol agents and resident microbiomes may be a cause of apparent weed biocontrol failures. From this perspective, we discuss recent progress in research on plant-associated microbial communities whose interactions influence disease development, or “pathobiomes,” and consider the implications for biocontrol agent evaluation and release. Open questions about how weed pathobiomes develop and influence agent success rates provide ample opportunity for researchers to adapt new methods and analytical frameworks that will enhance biocontrol programs. We conclude by prioritizing the development of standard methods to include microbiomes as a component of release studies. Developing a pathobiome-aware agent selection and release process will improve agent establishment rates and biocontrol outcomes.