Response of potato tubers to hypoxia followed by re-aeration

Potato tubers kept under hypoxia (1%) showed improved viability in comparison to anoxia, which was associated with the maintenance of intermediate adenylate energy charge values (A.E.C. = 0.6) and stable adenylate pools at 50% of the initial levels. Re-admission of oxygen to the tuber resulted in an almost full recovery of adenylate energy charge and total adenylates after up to 3 days of hypoxic pretreatment. Tubers exhibited a mixed fermentation. The high lactate. ethanol and acetaldehyde levels proved to be non toxic. Ethanol was degraded to acetaldehyde during re-aeration. Posthypoxic lipid peroxidation was indicated by malondialdehyde and ethane formation. Both products occurred with a temporary delay and in lower amounts compared to post-anoxia. Ethylene release was also considerably smaller. Severe hypoxia and posthypoxia postponed tissue death compared to anoxia. Survival was correlated with an improved energy supply which stabilized membranes.