Acyl-CoA dehydrogenase activity in pea cotyledon tissue during germinationand initial growth

Acyl-CoA dehydrogenase activity has been measured in homogenates of post-im bibition to 14-day-old hydroponically grown pea seeds at daily intervals, u sing C-4, C-12 and C-16 acyl-CoA substrates. The activity peaks of the diff erent chain-length acyl-CoA dehydrogenases did not transpose at all points and the ratios of the chain-length activities were not constant. It therefo re has to be concluded that more than one dehydrogenase is present in pea m itochondria. There was a post-imbibition initial surge of activity with sho rt- and mid-chain-length substrates. The C-16-handling enzyme first peaked at 3-4 days, which coincided with the onset of plumule unfurling and greeni ng. Further peaks were observed with all three substrates, coinciding with secondary root formation and leaf enlargement and later with cotyledon dege neration. Overall activity showed that the long-chain acyl-CoA dehydrogenas e was much more active than the short-chain acyl-CoA dehydrogenase.