Fig. 1

Characterization of differentially expressed genes before and after cold treatment in TT or YT. A Principal Component Analysis (PCA) of gene expression profiles in TT and YT before and after cold treatment. Each point represents one treatment for gene expression profiling. B, C Heatmaps showing genes differentially expressed at each time point in YT (B) or TT (C) before (0 h) and after cold treatment (0.5, 1, 2, 4, 8 h). 5602 DEGs in YT and 6774 DEGs in TT were analyzed by using k-means clustering. Each heatmap was generated through k-means clustering algorithm with the Z-score result of gene expression in Cluster 3.0 software. The color key representing the standardized gene expression levels from high (red) to low (blue). D Venn plots showing comparisons of genes that were up-regulated or down-regulated after cold treatment between YT and TT