Correlation between Changes in Mitochondrial Membranes of Artichoke Tubers and Their Hardening and Dormancy

Spin labeling studies using mitochondrial membranes of Jerusalem artichoke (Helianthus tuberosus L.) showed that the decrease during winter in the temperatures of the upper and lower lipid transitions correlated with the development of freezing hardiness of the tubers. The killing temperature for tuber tissue reached a minimum of −12 C, about 5 C degrees lower than the lower transition. Freeze-hardiness decreased when the lower transition increased at the time of sprouting.