Programmed accumulation of LEA-like proteins during desiccation and cold acclimation of overwintering grape buds

Molecular investigation of the process of cold acclimation in woody plants has been limited by the superimposition of dormancy-related events on the process of cold tolerance development. To address this limitation, we have used the grape Vitis labruscana L. ev. Concord to develop a system in which the developmental programme of dormancy can be induced seperately from cold acclimation. Using this system we have characterized differential accumulation of several proteins in grape buds during the normally superimposed endodormancy and cold acclimation programmes, and in buds which have entered only the endodormancy programme. A set of 47 kD proteins accumulated during endodormancy without cold acclimation to a level similar to that found in endodormant and cold-acclimated buds, but without any associated increase in bud cold-acclimation level. However, a 27 kD LEA-like protein accumulated only in cold acclimated buds. We conclude that expression of the 47 kD glycoprotein is endodormancy-related, but is not strictly related to the development of cold acclimation, while the 27 kD protein appears to be more specific to cold acclimation. In addition to strengthening the association of LEA-like proteins with cold acclimation, this system allows more specific assessment of cold acclimation-associated phenomena in overwintering buds.