The Effect of Cold Stress on the Expression of Several Genes Associated with Cold Signal Transduction System Pathway in Cultivars of Canola (Brassica napus)

The identification of genes that are involved in the adaptation and tolerance to cold stress especially the regulatory genes is essential. In this study the expression patterns of four cold induced-genes was investigated in two Zarfam (Resistant) and Sarigol (Susceptible) Brssica napus cultivars using real-time PCR technique. After RNA extraction and cDNA synthesis, expression of four genes, including, CBF17, Bn115, COR25 and NAC5–11 were studied in the seedling stage of Sarigol and Zarfam cultivars under controlled and cold stress (−4°C) condition for 0, 3, 6, 12 and 24 hours after cold treatments. The results indicated that in Zarfam the cold induced-genes generally had higher expression than Sarigol. Also, the CBF17 and NAC5-11genes which considered as the genes induced at the early stages of plant response to cold, were highly expressed in the early hours of cold stress in the Zarfam (especially when treated for 6 hours) and then the expression levels of these genes gradually decreased, on the other hand the Bn115 and COR25 as genes involved in homeostasis process and improvement resistance to stress effects were induced after transcription factors. It is observed that the Bn115 and COR25 genes had the maximum expression in 24 hours after treatment under cold stress.