Pulse plasma treatment inhibits storage pest of rice seeds during storage and promotes subsequent seed germination and seedling establishment

The vigor of rice seeds inevitably declines during prolonged storage due to physiological degradation, and effective, environmentally friendly methods to mitigate this deterioration remain limited. Pulse plasma treatment (PPT), which generates reactive species such as ozone (O₃), hydroxyl radical(・OH), and atomic oxygen (·O) through narrow pulse discharge, has been widely used for gas purification and pathogen elimination, but its potential for seed storage applications has been largely unexplored. This study evaluated the effects of PPT on pest control and seed vigor maintenance in rice seeds during a 60-day room temperature storage, comparing PPT with conventional fumigation treatment (FT) and an untreated control. PPT significantly inhibited storage pests, although to a lesser extent than FT. Both PPT and FT improved seed germination rate and seedling establishment from stored seeds; however, PPT resulted in significantly higher seedling dry weight compared to FT. Mechanistically, PPT reduced the accumulation of H₂O₂ and malondialdehyde (MDA), enhanced antioxidant enzyme activities, and increased soluble sugar, glucose, and ATP levels by upregulating α-amylase and α-glucosidase activities during early germination. Additionally, PPT elevated the GA/ABA ratio by modulating enzymes and gene expression involved in GA/ABA metabolism. Collectively, the PPT-mediated enhancement of germination and seedling emergence in stored rice seeds is associated with pest suppression, alleviation of oxidative stress, promotion of starch hydrolysis, and hormonal regulation. These findings highlight PPT as a promising, environmentally friendly alternative to chemical fumigation for maintaining rice seed vigor during storage.