Figure 5.

Differential expression of Populus Hsfs and Hsps under different abiotic stresses. Heatmap showing expression of Hsf and Hsp genes across various tissues and genotypes analyzed. Microarray data under the series accession number GSE16786 (for low N, wounding, and MeJ treatment) and GSE17230 (for drought treatment) was obtained from NCBI GEO database. Genotypes analyzed included: P. fremontii × P. angustifolia clones 1979, 3200, and RM5, P. tremuloides clones L4, and P. deltoids clones Soligo and Carpaccio. Tissues analyzed included: YL, young leaves; EL, expanding leaves; R, root tips; C, suspension cell cultures. Stress treatments included: low N, nitrogen limitation; wounding, sampled either one week or 90 hours after wounding; MeJ, Methyl Jasmonate elicitation; EAR, early response (EAR) to water deficit by 36 hours; LMI, long-term (10-day) response to mild stress with soil relative extractable water (REW) at 20–35%; LMO, long-term (10-day) response to moderate stress with soil REW at 10–20%. 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 abundances.