Surface dielectric barrier discharge plasma priming enhances salt-tolerant wheat germination through predicted AMY1.1 redox stabilization

Soil salinity severely constrains wheat ( Triticum aestivum ) germination, the developmental stage most dependent on redox-sensitive starch hydrolysis. Surface dielectric barrier discharge (SDBD) cold atmospheric plasma is a chemical-free seed-priming technology, yet the molecular basis of its transition from beneficial low-dose priming to inhibitory overexposure is unresolved. We combined a systematic SDBD dose-response (ten exposure durations, 0–180 s) under 4000 ppm NaCl with comprehensive agrophysiological profiling — germination, photosynthetic pigments, antioxidant enzymes, osmolytes, gas exchange, membrane stability, mineral nutrition and multivariate analysis — and with in silico molecular docking and protein-flexibility analysis of the high-pI germination α-amylase (AMY1.1) against three plasma-generated redox species (GSH, GSNO, ONOO⁻). Germination and salt tolerance peaked at 140 s (66.67% germination; salt-tolerance index 88%) within a statistically indistinguishable 120–160 s optimum, declining sharply at 180 s. We propose an integrated hormetic model in which moderate doses act through three hierarchical tiers — seed-surface remodelling, antioxidant and osmolyte priming, and predicted AMY1.1 stabilization by GSH and GSNO — whereas excessive doses shift the chemistry toward ONOO⁻-associated distress. The docking analyses generate testable molecular hypotheses rather than proof. SDBD priming at ~ 140 s is a scalable, chemical-free strategy for salt-tolerant wheat establishment.