*3.5. Analysis of HhMYB Gene Expression Patterns under Salt and Drought Stress*

In order to gain insight into the potential function of *HhMYB*s in response to saline and drought stress, we analyzed the expression patterns of *HhMYB*s using transcriptomic data obtained from *H. hamabo* subjected to these conditions (Figure 2) [22]. *HhMYB* genes in subfamilies XIX, XVIII, XVII, and I were not detected in any sample, whereas other subfamilies showed significant differences in expression patterns in response to the stress treatments. Several *HhMYB*s showed similar response trends to the two stresses. For example, the expression levels of *HhMYB46* of XXIII and *HhMYB117* of XXIV were upregulated under both stresses, while the expression levels of *HhMYB140* of the XXI subgroup was down-regulated under both stresses, suggesting that these genes may play roles in both drought and salt stress. However, some genes, such as *HhMYB96* of the subgroup XIII, displayed different expression patterns under the two stresses. The expression level of *HhMYB96* increased under drought stress but decreased under salt stress, suggesting the differential deployment of this gene in response to temperature and drought stresses in *H. hamabo*. In addition, *HhMYB* genes in the same evolutionary branch showed different expression characteristics, indicating their functional differentiation.

**Figure 2.** Expression pattern of *MYB* genes in *H. hamabo* under salt and drought stress as determined from RNA-Seq data. The expression level was represented by color: red, higher expression; white, lower expression. HhMYBs with a dot were specifically mentioned in the manuscript. P0, P6, P24, CL0, CL6, and CL24 represent treatments for 0 h, 6 h, and 24 h under PEG treatment and 0 h, 6 h, and 24 h under NaCl treatment, respectively.
