Ice nucleation, propagation and deep supercooling: the lost tribes of freezing studies.

Prior to the emphasis on the molecular biology of cold acclimatization, considerable research was conducted on the processes of ice nucleation and deep supercooling. In many species, these two processes are critical to winter hardiness or surviving episodes of frost. Over the past two decades, however, research on these topics has diminished drastically. The objectives of the current report are to review these topics and identify critical questions that still need answers, and to indicate how a greater understanding of these topics may lead to new strategies for improving cold hardiness in plants or new technologies for improving frost protection. The ideas and concepts presented have been developed over the past two decades through experimentation and conversations with a host of plant physiologists, horticulturists and microbiologists who have devoted significant time and thought to the process of ice formation in plants.