Expression of two-cold regulated genes of canola responding to cold acclimation

Cold acclimation increases freezing tolerance and the changes of gene expression may involve in the enhancement of freezing tolerance during cold acclimation. This study was conducted to determine the responses of two cold-regulated genes in canola (Brassica napus L.), BN28 and BN115, to cold acclimation and find out correlation between increasing of freezing tolerance and the expression of the genes. Six winter cultivars and one spring cultivar that had previously exhibited a broad range of winter survival were examined in a controlled environment chamber. Southern blot analysis revealed that the seven cultivars examined had the same copy number of BN28 and BN115. Northern blot analysis indicated that these genes were induced within one day by cold temperature and turned off immediately by deacclimation. Though time-course increase of transcript in one of the genes was highly correlated with the time-course increase of freezing tolerance, no correlation was found at the cultivar lever at specific time of measurement. However, this does not rule out the possible role of cold-regulated genes in freezing tolerance of canola.