Harnessing plant-to-plant signalling via common mycorrhizal networks for enhanced community-level resistance in crops.

Inter-plant signals can be transmitted via plant volatiles or exudates as well as through biological connections such as parasitic plants and common mycorrhizal networks (CMNs), formed by mycorrhizal fungi. The molecular mechanisms underlying mycorrhiza-mediated inter-plant signals and their functional significance in plant defence against pathogens represent an emerging area of research, expanding our understanding of inter-plant communication beyond well-studied intra-plant systemic signals and responses such as systemic acquired resistance and induced systemic resistance. By examining mechanistic bases and evolutionary perspectives from both phyto- and mycocentric viewpoints, we aim to clarify how CMNs may contribute to inter-plant information exchange and resulting plant community-level defence against pests and pathogens. Ongoing investigations into cross-kingdom crosstalk offer novel insights into candidate molecular mechanisms, such as small RNA trafficking, potentially involved in CMN-mediated inter-plant signalling. We further highlight the significance of conceptualizing crops as interconnected plant systems, a framework that will be critical in shaping future research directions. Finally, we address the challenges and future perspectives for the development of microbiological plant growth supplements and utilizing CMNs to mediate inter-plant danger signals for sustainable agroecosystem designs.