Figure 4

Expression profiles of Populus Hsfs and Hsps across different tissues. Heatmap showing expression of Hsf and Hsp genes across various tissues and different stem development/growth stages. The Affymetrix microarray data (GSE13990) and the NimbleGen microarray data (GSE13043) were obtained from NCBI Gene Expression Omnibus (GEO) database. CL, continuous light-grown seedling; DL, etiolated dark-grown seedling transferred to light for 3 h; DS, dark-grown seedlings; YL, young leaf; ML, mature leaf; R, root; DX, differentiating xylem; FC, female catkins; MC, male catkins; IN2-IN5, and IN9, stem internode 2 to internode 5, and internode 9. Background corrected expression intensities were log transformed and visualized as heatmaps (see Methods). Color scale represents log2 expression values, green represents low level and red indicates high level of transcript abundance. Blank represents a gene has no corresponding probe sets in the microarray data.