The impact of UV-B irradiation applied at different phases of somatic embryo development in Norway spruce on polyamine metabolism
Higher polyamine levels of fully developed embryos had positive effects on their ability to tolerate UV-B irradiation when compared with induced response s of early embryos. The aim of this work was to test the hypothesis that the higher levels of polyamines (PAs) might be involved in the response of Norway spruce somatic embryos to UV-B irradiation. We compare here the effects of 0.1, 0.6 and 6 W m-2 h-1 UV-B irradiation on polyamine metabolism in early and fully developed Norway spruce somatic embryos.