Freshly-cut slices of mature tubers liberated little 14CO2 from [2–3 14C] succinate even when sprouting after 9 months storage at 5° C. Output from 24-hour washed slices was considerable; it increased in amount with increasing length of storage period and was enhanced when light was excluded during washing and incubation in succinate.
A comparison was made between non-tuberizing stolon tips and young tubers taken within a day or so of tuber initiation. The fresh stolon tips released an appreciable quantity of CO2 from succinate, much less after washing. Fresh young tubers liberated much less 14CO2, slightly more after washing. Although this indicated that the tricarboxylic acid- (TCA-) cycle block might arise soon after initiation, the qualitative distribution of the label in tissue extracts showed stolon tips and young tubers to be similar to each other and distinct from mature tuber tissue.