Cultivar differences in cold acclimation/freezing tolerance and Cor gene expression in common wheat.

摘要

The cold acclimation process in plants is primarily regulated through induction and/or enhancement of expression of different sets of cold-responsive (Cor) genes. Cold acclimation increased dramatically the level of freezing tolerance in two wheat cultivars, Mironovskaya 808 (M808) and Chinese Spring (CS). M808 showed much higher levels of freezing tolerance than CS. To understand molecular basis of this phenotypic difference, we compared expression profiles of 13 Cor genes and two wheat DREB/CBF homologues, which are the candidate genes for transcription factors of the Cor genes. Expression profiles of several Cor genes during the short-term (within 10 days) and long-term acclimation (until 63 days) seemed to explain the observed cultivar difference. Expression of the two DREB/CBF homologues was enhanced at significantly higher levels in M808 than in CS. These results suggest that the cultivar difference of the freezing tolerance is based on the enhanced level of the predicted COR-signaling pathways through cold acclimation.