Fig. 4

Heat map of RNA-seq expression of PbWRKY gene in response to drought stress. Color scale of the dendrogram represents log2 ratio value of treated sample to control sample. D1, D3, D6 and D24, dehydrated for 1, 3 and 6 h in an ambient environment and recovered for 24 h in water, respectively. The colors of genes in Cluster 1–4 represent their groups in the phylogenetic tree in Fig. 2