Fig. 4

Heat shock protein and transcription factor analyses under different elevated temperature treatments. Expression levels of (a) ascorbate peroxidase 2 (APX2), (b) heat shock protein 70–3 (HSP70–3), (c) HSP70–9, (d) HSP70–14, (e) HSP90–2, (f) HSP90–3, (g) HSP90–4, (h) HSP22.0, (i) heat shock factor A 1A (HSFA1A), and (j) HSFA2. Each bar represents mean ± SD; n = 3. k Heatmap of 34 differentially expressed transcription factors under control, prolonged warming and heat shock treatments, grouped into 4 main categories. Red rectangles mean up-regulation of expression and blue means down-regulation. l–p The expression levels of several selected transcription factors: (l) HSFA4A, (m) HSFA6A, (n) HSFA6B, (o) DREB2A, and (p) DREB2C were determined using quantitative RT-PCR analyses. Pink bars: results from deep sequencing; blue bars: results from qRT-PCR. Each bar represents mean ± SD; n = 3. CK: control; PW: prolonged warming; HS: heat shock