Inactivation effects of plasma-activated water against rice blast disease

The prolonged application of synthetic fungicides presents substantial environmental hazards and potential toxicity to non-target organisms, including humans. Plasma-activated water (PAW) has emerged as a promising agent for pathogen inactivation; however, the physiological and biochemical mechanisms underlying its efficacy against the rice blast fungus, Magnaporthe oryzae , remain largely uncharacterized. In this study, we evaluated the antifungal activity of PAW against M. oryzae through in vitro and in vivo assays and characterized the corresponding cellular responses. Seedling rice blast forms spindle-shaped necrotic lesions on young leaves, causing seedling withering and providing fungal spores that trigger severe blast outbreaks in later rice growth stages and drastically cut grain yields. PAW treatment significantly inhibited conidial viability ( P<0.05 ) and markedly reduced disease severity in rice seedlings. Physiological and microscopic analyses indicated that PAW induced cell wall rupture, altered membrane permeability, and triggered mitochondrial dysfunction. These findings were corroborated by transcriptomic profiling, which identified the cell wall, plasma membrane, and mitochondria as the primary organelles targeted by PAW-derived reactive species. Our results elucidate the antifungal mode of action of PAW against M. oryzae and highlight its potential as a sustainable fungicidal alternative or a potent supplement to conventional chemical interventions.