Some activities of mitochondria, isolated from an embryogenic cell line of Abies alba, during
proliferation and maturation stages of somatic embryogenesis (SE), were studied. After the transfer of
A. alba embryogenic cell masses (ECMs) from proliferation to maturation media, an increase in cellular
ATP and glucose-6-phosphate content was observed. Mitochondria obtained from ECMs during
proliferation showed a low activity of alternative pathways, such as the alternative oxidase (AO) and
external NADH dehydrogenases, and a high level of potassium fluxes mediated by the K+
ATP channel.
Conversely, when the same parameters were evaluated in mitochondria isolated from ECMs, after 6 and
9 week lasting maturation, a different pattern was observed. In fact, the oxidation of exogenous NADH,
the AO capacity and expression were increased, while the K+ transport through the inner membrane was
decreased. These results indicate that there is a correlation between some mitochondrial activities and
the development of somatic embryos. In particular, the K+
ATP channel was more active during the
proliferation of ECMs, whereas the alternative pathways were activated during maturation of somatic
embryos.
