Addressing agricultural challenges through biomimetic surfaces: Reframing foliar fungal disease as a biointerface...

Foliar fungal diseases are major threats to global grain production, which is integral to food security and agricultural economies. Current management relies on broadacre fungicides applied after infection, which are costly, environmentally problematic, and promote the emergence of chemically resilient phytopathogens. Prophylactic strategies remain limited, but a shared requirement of foliar disease may be a key target for intervention: the pathogen must successfully detect and recognize the surface of their host. The initial point of contact in plant-fungi interactions can hence be reframed as a biointerface problem governed by the physicochemical properties of the leaf surface. Leaf surfaces are coated in a waxy layer called the cuticle, a biocomposite comprised of a cutin matrix embedded and coated with compounds called cuticular waxes. Increasing evidence shows that these waxes can signal recognition to pathogenic fungi to promote infection. However, studying these interactions is challenging due to their complexity, with whole-leaf models masking the contributions of individual surface variables. To address this, we propose a biomimetic model system using fabricated wax films to replicate native leaf chemistries on inert substrates. These systems allow for precise tuning of surface physicochemical properties, enabling systematic investigation of fungal responses to defined surface chemistries. These systems can then be used to develop prophylactic strategies that alter leaf surface properties, disrupting host-recognition in fungal pathogens to reduce foliar fungal disease incidence in agriculture globally. By reframing fungal disease as a biointerface problem, this research offers a path toward more sustainable and targeted fungal disease management.