Accumulation of a 60-kD dehydrin protein in peach xylem tissues and its relationship to cold acclimation

The seasonal pattern of dehydrin accumulation was characterized during cold acclimation and deacclimation in the xylem tissues of genetically related (sibling) deciduous and evergreen peach (Prunus persica L). Immunological studies indicate that a 60-kD polypeptide in peach xylem tissues is a dehydrin protein. Comparison of its accumulation pattern with seasonal fluctuations in cold hardiness indicate that dehydrin accumulated to high levels during the peak of cold acclimation. However, its accumulation was only weakly associated with cold hardiness during early stages of cold acclimation and during deacclimation. Our results indicate that factors related to supercooling rather than dehydrin accumulation may be primarily responsible for determining levels of cold hardiness during transition periods.