Abstract
Winter wheat plants can develop freezing tolerance after a period of exposure to low but nonfreezing temperature. To analyze this process we have undertaken a large-scale analysis of the wheat transcriptome. For cold treatment the wheat plants (cv. Valuevskaya, highly freezing tolerant) were exposed to 2/0.5oC for 7 weeks. Total RNA was isolated from control and cold-acclimated leaves. The RNA samples were labeled with Cy3- or Cy5-dCTP and hybridized to 22k wheat oligo microarrays. In the comparison between control and cold-acclimated leaves, 2,435 genes (15.5% of the 15,679 genes) were significantly regulated by long-term cold acclimation. In addition to the using of winter wheat cv. Valuevskaya, we also used spring wheat cv. Haruyutaka (very low freezing tolerant) for comparing gene expression patterns of both cultivars. As a result, 1,571 genes (9.0% of the 17,503 genes) including 900 genes showing cold-dependent expression were differentially expressed between the two cultivars.
