qRT-PCR analysis of selected
in different tissues. The relative mRNA abundance of selected seven Hsfs, three sHsps, three Hsp60s, three Hsp70s and three Hsp100s was normalized with respect to two reference genes PtActin and PtTubulin in five different tissues. Bars represent standard deviations (SD) of three technical replicates. YL, young leaves; ML, mature leaves; PS, primary stem; SS, secondary stem; R, roots. Bars with the same letter are not significantly different according to Duncan test and Fisher’s protected LSD test (P < 0.05).