Polyamine accumulation in aged wheat seeds

Abstract

The present work was conducted to evaluate the content of the main polyamines (Spm, Spd, Put) in a series of naturally aged durum-wheat seeds as well as the activities of the enzymes ODC and ADC involved in their biosynthesis. In dry seeds the content of polyamines, especially that of Spd, rose during ageing till 6 years and then declined sharply. However, an increase of PA content upon imbibition was observed only with the youngest seeds, while a decrease was found in the older ones.The activities of ODC and ADC differed in aged seeds, the ODC activity being constant and lower than the ADC in the course of seed ageing. The ADC increased till the early ageing and decreased then in the very old, ungerminating seeds. Imbibition increased both enzyme activities in the youngest seeds only, in the older ones rather a decrease and changed ADC/ODC ration was found.The obtained results are discussed in relation to the participation of these enzymes in the biosynthesis of polyamines during seed ageing and in the course of plant senescence or stress.