*2.7. Expression Profiling of the M. sativa HSF Gene in Different Tissues*

To determine the expression patterns of individual *MsHSF* genes in various tissues, a hierarchical clustering heat map was also constructed from public RNA-seq data obtained from NCBI for exploring the transcriptional patterns of *MsHSF* genes in this study (Figure 9). The blue color in the graph indicates low transcript abundance and the red color indicates high transcript abundance. The analysis showed that there were different *HSF* genes showing a trend of high expression in six tissues of *M. sativa*. *MsHSF06* and *MsHSF15* were highly expressed in the roots. The expression of each gene was not significant in the root nodules. In pre-elongating stems, *MsHSF05*, *MsHSF09* and *MsHSF14* showed higher expression. However, the gene with higher expression in elongating stems was *MsHSF03*. In *M. sativa* leaves, *MsHSF07*, *MsHSF08* and *MsHSF16* showed higher expression. Interestingly, *MsHSF10* was not expressed in any other tissue parts of alfalfa but was expressed in the flowers, a phenomenon that suggests that different *MsHSF* genes have more obvious specificity in different tissues.

**Figure 8.** A schematic representation of the cis-acting elements identified in the 2000 bp promoter region upstream of the *MsHSF* gene. The different colors represent the number of cis-acting elements contained (**A**). The number of *MsHSF* genes corresponding to the cis-acting element (**B**).
