Abstract
Arabidopsis thaliana increases its freezing tolerance upon exposure to chilling temperature (e.g., cold acclimation, CA). CA results in changes of lipid and protein compositions in the plasma membrane. We recently found that one of the dynamin-related proteins (DRP1E) that are associated with endocytosis pathway accumulated in the plasma membrane during CA. Thus, we hypothesize that DRP1E involves in CA-induced modification of the plasma membrane. To address this question, we characterized a T-DNA insertion mutant of DRP1E (drp1e) in the CA process. CA increased freezing tolerance in both wild type and drp1e plants but the extent was much less in drp1e mutant. Furthermore, the effect of DRP1E knockout on the extent of cold acclimation was more apparent in younger leaves than in older (and mature) leaves and considerable differences in cold-responsive proteins were found in the plasma membrane of younger leaves between the wild type and drp1e plants. These results suggest that DRP1E have critical roles in freezing tolerance in young leaves.
