Raffinose Priming Improves Seed Vigor by ROS Scavenging, RAFS, and α-GAL Activity in Aged Waxy Corn

Raffinose family oligosaccharides (RFOs) are known to benefit plants under stress conditions; however, the role of exogenous raffinose in seed germination remains poorly understood. In this study, we investigated the potential role of raffinose in promoting seed germination and elucidated the underlying mechanisms. The results showed that artificial aging significantly reduced the germination rate and vigor of waxy corn seeds. Conversely, exogenous raffinose significantly enhanced the germination of these artificially aged seeds. Exogenous raffinose significantly reduced the levels of reactive oxygen species (O2− and H2O2) and enhanced the activity of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Additionally, the levels of α-galactosidase (α-GAL) and raffinose synthase (RAFS) were significantly elevated in raffinose-treated aged seeds. These findings suggest that exogenous raffinose induces the expression of α-GAL and RAFS, thereby providing energy and reducing excessive reactive oxygen species (ROS), which in turn promotes the germination of artificially aged seeds. This study provides a theoretical foundation for enhancing seed vigor and extending seed longevity in crop management.