False smut of rice: integrating molecular pathogenicity and epidemiology for next-generation disease management

Abstract

False smut of rice, caused by Ustilaginoidea virens, has emerged as a serious threat to global rice production, resulting in substantial yield and grain quality losses. This review summarizes recent advances in understanding the pathogen’s life cycle, infection biology, and epidemiological factors, while highlighting the limitations of current management strategies that rely predominantly on fungicide applications. U. virens exhibits a unique biotrophic infection strategy, colonizing floral tissues without specialized infection structures and manipulating host physiology through a diverse repertoire of effectors that suppress immunity, alter hormonal signaling, and hijack sugar transport systems to facilitate nutrient diversion and smut ball formation. Integrating molecular mechanisms with epidemiological factors such as climate variability and inoculum dynamics provides important insights into disease development and spread. Recent progress in artificial intelligence has enabled the development of predictive modeling frameworks, while advances in spectral imaging and molecular diagnostics offer promising tools for early detection and disease forecasting. In the absence of identified resistance rice cultivars, genome editing and microbiome-based strategies are viable alternative approaches for durable disease control. These advances together provide a basis for a transition to an integrated management framework incorporating forecasting models, genome editing, and microbiome-informed interventions for more sustainable and effective control of rice false smut.