*2.5. Analysis of the Potential Mechanism of IlAP2 under Cd Stress*

To further explore the mechanism by which *IlAP2* regulates Cd tolerance, RNA-seq analysis was performed on transgenic *A. thaliana* seedlings. The comparison between the transgenic *A. thaliana* and the WT identified 2210 genes as DEGs: 1340 up-regulated and 870 down-regulated (Figure 6a). The GO enrichment analysis showed that the enrichment degree of transferase activity was the highest in molecular function, indicating that ion signal transduction played an important role in *I. lactea*'s response after 24 h of Cd stress (Figure 6b). The KEGG enrichment analysis showed that plant hormone signal transduction was significantly enriched (Figure 6c), suggesting that plant hormones also played an important role in response to Cd stress. In addition, we found that bHLH, WRKY, NAC, MYB, GRAS, AP2/ERF and other transcription factors were all affected by *IlAP2* after 24 h of Cd stress (Figure 6d). We randomly chose six differentially expressed transcription factors and analyzed the relative changes in expression using qRT-PCR (Figure S1). The results showed that the expression patterns of most of the transcription factors tested with qRT-PCR were similar to those obtained from the sequencing data. Additionally, it was proven again that the transcription factors were affected by *IlAP2*.

**Figure 6.** RNA-seq analysis of WT and transgenic *A. thaliana*. (**a**) DEG analysis results, (**b**) GO enrichment results, (**c**) KEGG enrichment results and (**d**) gene families possibly affected by *IlAP2*.
