Isolation of Cold-Regulated Genes from Solanum tuberosum by Reverse Northern Blot Analysis Using cDNA Clones

Changes of expression in cold-regulated mRNA levels in potato (Solanum tuberosum L. cv. Superior) were analyzed. A total of 12,000 cDNAs was subjected to reverse Northern blot analysis using ^(32)P-dCTP- labeled first strand cDNA generated from the total RNA isolated from 25℃- and 4℃-treated potato plants. A total of 245 cDNA clones were sequenced from a cDNA library constructed from the cold treatment. Based on the BLAST results, 103 cDNA clones were found to be redundant. The analyzed genes were classified into 12 groups according to their putative functions, where the 20.2 % of group I was associated with energy metabolism, 13.1％ of group XI with cell rescue and defense, 2.6％ of group Ⅷwith signal transduction. Among the cDNA clones up-regulated by cold treatment from the results of the reverse Northern blot analysis, 32 were used for the Northern blot analysis. Most of the cold-treated clones showed overexpression compared with the control, while some showed down-regulation. In general, it was found that cold stress related genes were overexpressed more than two-folds at 4℃ treatment.