Prion-inhibition-like protein (PiP) governs Aspergillus flavus spore dormancy under postharvest drying stress: A...

Aflatoxin contamination in postharvest grains, primarily caused by Aspergillus flavus, poses a significant threat to global food security and public health. Current drying strategies, while effective in temporarily suppressing fungal activity through desiccation stress, are limited by the remarkable dormancy capacity of A. flavus spores, which enables post-stress reactivation. Here, we identify the prion-inhibition like protein (PiP) as a key regulator of the dormancy-germination switch in A. flavus. Targeted deletion of PiP (Δpip) resulted in premature spore germination under suboptimal hydration (aw<0.78), leading to a 48.19 % increase in mortality due to desiccation vulnerability. RNA sequencing revealed that PiP regulates 1440 differentially expressed genes, primarily involved in RNA and protein synthesis pathways. Among these, several proteins with prion-like domains (PrLDs), including DAO, SOS, POA1, TPK2, and GAR1, were identified as PiP-regulated. Storage experiments with peanuts and corn demonstrated that the absence of PiP significantly enhanced the efficacy of drying treatments, reducing fungal growth and AFB₁ production even under conditions favorable for mold growth. Our findings highlight three major advancements: (1) Molecular elucidation of fungal dormancy through prion-mediated stress memory; (2) Experimental validation of PiP as a novel target for anti-germination strategies; (3) Proof-of-concept for energy-efficient drying optimization, reducing processing time while maintaining the 0.78 aw threshold efficacy. This dual mechanistic and technological breakthrough offers a blueprint for next-generation postharvest management, addressing both food safety imperatives and sustainable agriculture goals by reducing energy consumption in grain storage systems.