Circadian Rhythms of Fungi in Plant Disease Interactions and Management

Abstract

Fungal diseases remain a persistent threat to global crop production, yet for a long time their effects on host plants were studied without accounting for the daily rhythms that govern fungal biology. It is now clear that many fungi do not behave uniformly throughout the day. Processes such as growth, sporulation, metabolism, and the production of virulence factors follow predictable daily cycles, enabling fungal pathogens to time their activity in ways that coincide with favourable environmental conditions and periods of reduced host resistance. Light, temperature, and humidity all contribute to shaping these rhythms, and the resulting patterns have meaningful consequences for how infection unfolds in the field. Strong molecular evidence for functional circadian clocks exists in well studied fungi such as Neurospora crassa and Botrytis cinerea, but comparable understanding at the gene and protein level is still lacking for many crop pathogens of economic importance. In these organisms, separating genuine clock-driven rhythms from simple environmental responses remains a genuine difficulty. Despite this, the growing body of evidence points toward practical possibilities in disease management particularly in timing fungicide applications, irrigation, and other interventions to coincide with windows of pathogen vulnerability or stronger host immunity. Most of what we know, however, still comes from controlled laboratory settings, and field level confirmation remains limited. Bridging that gap will be essential if circadian biology is to move from an area of scientific interest into a reliable tool for sustainable crop protection.