Accumulation of raffinose during cold acclimation in Lonicera caerulea L. plantlets cultured in vitro

The development of freezing resistance and soluble sugar contents were exam ined using Lonicera caerulea plantlets grown in vitro. The plantlets were c old-acclimated at 5 degrees C for 1 week, then acclimated at 0 degrees C. B oth nodal and internodal segments developed freezing resistance after 12 da ys of acclimation Nodal and internodal segments from the 2-week cold-acclim ated plantlets survived at a rate greater than 67% at -7.5 degrees C accord ing to a regrowth test, and more than 55% at -7 degrees C according to a TT C reduction test. The concentration of raffinose in these tissues increased significantly during cold acclimation. These results suggest that raffinos e is closely related to the development of freezing resistance in L. caerul ea plantlets grown in vitro.