Abstract
Some plants are able to induce freezing tolerance by cold acclimation. In this process, abscisic acid (ABA) has an important role in stress signaling. Previous studies using Arabidopsis thaliana suspension-cultured cells reported that induction of freezing tolerance after ABA treatment depended on growth phase of the cells (lag and log phases): ABA-induced increase in freezing tolerance was detected only cells at the lag phase, but not the log phase. To understand the ABA responses at cellular level associated with freezing tolerance induction, gene expression and protein accumulation of dehydrins, stress responsible proteins belonging to LEA (late embryo abundant protein) family, are determined using RT-PCR, 2D-PAGE, and Western blotting with anti-dehydrin antibody. We found that the accumulation of two dehydrins occur only in ABA-treated lag phase cells. These results suggest that these dehydrins may play a role in regulation of freezing tolerance at cellular levels.
