Respiration of potato tissue as influenced by previous storage temperature of the tubers

Abstract

Discs of 1 mm or more in thickness from potato tubers stored at 0 C showed a higher rate of oxygen uptake both in water and in 0.25 M sucrose than corresponding discs from tubers stored at 12.8 C. Tissue from tubers stored at O C was more susceptible to injury from cutting and hypotonicity than tissue from tubers stored at 12.8 C. The enhanced respiratory activity of tissue from cold-stored tubers could not be explained by a greater supply of respiratory substrate or by qualitative differences in respiration. Dinitrophenol induced a marked increase in oxygen uptake in tissue from tubers stored at 12.8 C both in water and in 0.25 M sucrose, but induced no increase in oxygen uptake in tissue from tubers stored at 0 C when incubated in water and only a limited increase when this tissue was incubated in 0.25 M sucrose. Similar to dinitrophenol, incubation at 35 C revealed the structural weakness and susceptibility to damage from hypotonicity of the tissue from tubers stored at O C. After overnight aerobic incubation, discs from tubers stored at O C were not capable of developing the high state of metabolic activity attained by the discs from tubers stored at 12.8 C. Salt leakage from tissue of tubers stored at 0 C was several-fold greater both in water and in 0.25 M sucrose than leakage from tissue from tubers stored at 12.8 C. Salt leakage from tissue from cold-stored tubers was markedly lower in 0.25 M sucrose than in water, but the leakage was still greater than that from tissue from tubers stored at 12.8 C. The different behavior of the tissue from cold-stored tubers may result from physiological changes in the tuber which enable it to withstand prolonged cold storage.