The chances in the redox priming of nondormant recalcitrant seeds by spermidine

The problems posed by seed sensitivity to desiccation and aging have motivated the development of various techniques for mitigating their detrimental effects. The redox priming of seeds in antioxidant solution to improve their postharvest performance is one of the approaches. Spermidine (Spd) was tested as an invigorating solution on nondormant recalcitrant (desiccation-sensitive) seeds of the silver maple (Acer saccharinum L.). The treatment resulted in an 8-10% increase in germination capacity in seeds subjected to mild and severe desiccation, while in aged seeds stored for 6 months, no significant change was observed. The cellular redox milieu, genetic stability, mitochondrial structure and function were investigated to provide information about the cellular targets of Spd activity. Spermidine improved the antioxidative capacity, especially the activity of catalase, and cellular membrane stability, protected genome integrity from oxidative damage and increased the efficiency of mitochondria. However, it also elicited a hydrogen peroxide burst. Therefore, it seems that redox priming in nondormant seeds that are highly sensitive to desiccation, although it positively affected desiccated seed performance, may not be a simple solution to reinvigorate stored seeds with a low-efficiency antioxidant system.

Automated summary

The use of antioxidant solutions for redox priming of seeds is a method to improve their postharvest performance. Testing spermidine solution on silver maple seeds showed an increase in germination capacity for desiccated seeds, but not for aged seeds. Spermidine improved antioxidative capacity, cellular membrane stability, genome integrity, and mitochondria efficiency, but also led to a hydrogen peroxide burst. Therefore, redox priming may not be a simple solution for reinvigorating stored seeds with a low-efficiency antioxidant system.