Abstract
Arabidopsis thaliana increases its freezing tolerance upon exposure to chilling temperature (a.k.a. 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, we characterized a T-DNA insertion mutant of DRP1E in the CA process. CA increased freezing tolerance in both wild type and drp1e plants but the extent was greater in wild type. Furthermore, the increase occurred faster in younger leaves than in older (and mature) leaves. Western blot analysis with anti-DRP1E antibody confirmed an accumulation of DRP1E in the plasma membrane during CA. These results suggest that DRP1E have critical roles in freezing tolerance in young leaves. To further understand the role of DRP1E in plant freezing tolerance, effect of CA on DRP1E accumulation profiles and proteomic analysis of the plasma membrane in young and old leaves will be presented.
