Abstract
When tubers of Helianthus tuberosus L. (Jerusalem artichoke) were frozen at -10℃ by equilibrium freezing, the tubers were injured lethally after thawing. In plasma membrane fraction prepared from sublethally frozen tubers, the levels of some plasma membrane proteins, named frost-susceptible proteins (FSPs), decreased as compared with that from unfrozen tubers. Response of FSP120, one of the major FSPs with a molecular mass of 120 kDa, to freezing treatment were characterized using the antibody to FSP120 in this study. The total amount of FSP120 in the crude extract scarcely declined after sublethal freezing treatment of tubers although the levels of FSP120 in the crude microsomes decreased after freezing treatment. These results suggest that FSP120 might be released from plasma membranes during freezing treatment of the tubers of Jerusalem artichoke.