Accelerated and natural ageing processes change the properties of plasma membrane in Norway spruce (Picea abies (L.) Karst.) seeds during storage

The present study examines the mechanism of natural and accelerated ageing processes in Norway spruce (Picea abies [L.] Karst.) seeds stored at low temperature for one (control) and eight years. The analyses of vitality, electrolyte leakage, protein composition and activity of the proton-pump ATPase (P-ATPase, EC.3.6.1.35) in plasma membrane of Norway spruce seeds have been investigated. Seeds collected in 1999 from northeastern Poland have been treated with accelerated ageing method and compared to the seeds of the same provenance, collected in 1992 (control). The vigor and the vitality of the Norway spruce seeds depend on the age of seeds. After 6 days of experiment both samples of seeds (artificially aged seeds and control) expressed the same percentage of germination and similar electrolyte leakage. Analysis of protein composition in the extracts showed an increased amount of some low molecular-weight proteins in artificially and naturally aged seeds compared to the control. Our results indicate similar level of P-ATPase activity in natural, artificially aged and control seeds. This suggests that natural ageing process can involve changes in plasma membrane protein composition but does not affect the P-ATPase activity.