Fig. 5.

Expression profile of cystatin family genes in tobacco, which was constructed based on the relative expression level of each cystatin gene in different tissues. The expression level was normalized to the average expression level of GAPDH (AJ133422), polyubiquitin (GQ281244), and elongation factor 1α (AF120093). A blue box indicates a higher expression level of the cystatin family genes, whereas a white box indicates a lower expression level of the cystatin family genes. Anthers at stages 1–4 correspond to anthers containing microspore mother cells, tetrads, single-nucleated pollen, and bi-nucleated pollen, respectively. The scale bar represents the fold change (log2 value).