Abstract
Although cold acclimation process has been studied extensively using Arabidopsis plants, determination of responses to cold at cellular level may be difficult due to the complexity of plant individuals. To study such responses, we characterized cold acclimation process of Arabidopsis T87 suspension cultured cells. Freezing tolerance increased only in cells at the late lag phase after 2 days of cold acclimation. Expression of cold-regulated genes reached maximum at 1 day and subsequently decreased rapidly. Changes in sugar content and osmotic concentration were not associated with freezing tolerance. From these results, we hypothesized that an increase in freezing tolerance both in whole plants and cultured cells from 0 to 2 days is primarily due to the cellular responses to cold and the maintenance of the tolerance in plant individuals after 2 days requires the whole plant responses. To verify this hypothesis, microarray and 2D-PAGE analysis are in progress.
