Abstract
Trachycarpus fortunei is probably most cold-hardy palm species. They tolerate -14C and can grow up to Sendai. NMR micro-imaging non-invasively visualized freezing behavior of Trachycarpus leaves. Epidermis and water in the vascular bundles froze around -10C while the mesophyll cells remained deep-supercooled until -14 to -22C. The results suggest that most live tissues employ deep supercooling as the mechanism of cold hardiness in this plant, which makes it a good model system to study mechanisms of deep supercooling. DTA revealed that Trachycarpus leaves had a HTE starting around -10C, unusually low compared to other cold-hardy plants. To elucidate factors involved in deep supercooling and low HTE, we are currently analyzing substances extracted from the leaves. The extract has the ability to stabilize deep-supercooling of water and also work as anti-ice nucleating agents. The extract can inhibit the ice nucleation by several known ice nucleators such as ice nucleating bacteria.
