Influence of the axis on the development of mitochondrial activity in imbibed black gram cotyledons

The respiration rate of mitochondria from detached Vigna mungo L. cotyledons (without the embryonic axis) doubled during the first day after imbibition, whereas that of mitochondria from attached ones increased by only 50%. Contrary to the respiration rate, the respiratory control ratio was higher in attached cotyledons. The activities of enzymes in the mitochondrial fraction from detached cotyledons increased by about 30% during the first day, while those in mitochondria from attached ones changed little. Cycloheximide did not inhibit the development of mitochondrial respiration in either attached or detached cotyledons, although it almost completely inhibited the incorporation of ¹⁴C]-leucine into mitochondrial proteins. Cycloheximide did not retard the increase in the activities of mitochondrial enzymes in detached cotyledons. It is inferred that the development of mitochondria in black gram cotyledons is brought about by repair or activation of mitochondria present in dry seeds and that the axis affects this repair process.