Quercetin and Rutin as Tools to Enhance Antioxidant Profiles and Post-Priming Seed Storability in Medicago truncatula

Seed priming is routinely applied to improve germination rates and seedling establishment, but the decrease in longevity observed in primed seeds constitutes a major drawback that compromises long-term storability. The optimization of priming protocols able to preserve primed seeds from aging processes represents a promising route to expand the scope of seed priming. The present work explores this possibility in the model legume Medicago truncatula by testing the effectiveness of quercetin- and rutin-supplemented seed priming at improving the response to subsequent artificial aging. In comparison with a non-supplemented hydropriming protocol, supplementation with quercetin or rutin was able to mitigate the effects of post-priming aging by increasing germination percentage and speed, improving seed viability and seedling phenotype, with consistent correlations with a decrease in the levels of reactive oxygen species and an increase in antioxidant potential. The results suggest that quercetin and rutin can reduce the effects of post-priming aging by improving the seed antioxidant profiles. The present work provides novel information to explore the physiological changes associated with seed priming and aging, with possible outcomes for the development of tailored vigorization protocols able to overcome the storability constrains associated with post-priming aging processes.