Effect of Seed Freezing and Storage Conditions on Plasma Membrane Properties of Norway Spruce (Piceo abies Karst.) Seedlings

: Norway spruce (Picea abies Karst.) seeds were frozen and stored for 15 months at + 3, − 25, − 75 or − 196°C. After storage, seeds were germinated for 9−14 days to determine viability and plasma membrane protein composition, H+-ATPase activity and fluidity. The results indicate no significant differences in viability of seed 14 days after germination. Biochemical analyses revealed increased plasma membrane fluidity in 9-day-old Norway spruce seedlings raised from seeds pretreated at − 75 °C. and changes in the temperature profile of membrane fluidity in seedlings after pre-treatment of seeds at − 25 °C. On the other hand, the same treatments did not result in changes in plasma membrane protein content, protein composition or ATPase activity. There was also no difference in plasma membrane H+-ATPase activity assayed in the presence of different ATP hydrolysis inhibitors. Based on the presented results, and other experimental data, we suggest that during early seedling growth, adaptation of seeds to − 25 and − 75°C freezing and/or storage temperature results in stability of the plasma membrane protein function and composition and increased fluidity or changes in the temperature-dependent fluidity profile of these membranes.