A majority of seeds, including most agricultural seeds, can remain viable when desiccated. However, some seeds are desiccation-sensitive (recalcitrant) and must be stored moist to remain viable; this is not cost efficient and prevents long-term storage. Although recalcitrant seeds are less common, several economically important plants produce these seeds, including coffee, tea, cocoa, and the ecologically important salt marsh grass, Spartina alterniflora.

To attempt to elucidate the cause of desiccation-sensitivity in recalcitrant seeds, this study examined the impact of oxidative stress on lipids, proteins, and total antioxidant capacity as recalcitrant S. alterniflora and desiccation-tolerant Spartina pectinata seeds were dried. Lipid peroxidation and physical membrane damage indicators did not increase as S. alterniflora was desiccated; therefore, the membranes appear to be undamaged and intact throughout the dry down. Protein carbonyl amounts were measured as an indicator of protein oxidation, and when S. alterniflora seeds were dried, carbonyls increased significantly. Protein carbonyls did not increase when S. pectinata seeds were dried; however, the baseline in S. pectinata was higher than that of S. alterniflora. The total antioxidant capacity also changed significantly when S. alterniflora seeds were dried, decreasing from 35% in fully hydrated seeds, to ca. 15% in seeds with moisture contents <20%. The antioxidant capacity of S. pectinata did not change significantly during drying, yet the baseline antioxidant capacity was lower than that of S. alterniflora seeds. These results suggest that lipid peroxidation and physical membrane damage did not play a role in desiccation-induced death. However, protein oxidation and loss of antioxidant capacity may contribute to loss of viability as S. alterniflora seeds are dried.