Transcription Factors and Retained Intron Act Vital Roles in Cadmium Stress Response of Medicinal Model Plant Salvia miltiorrhiza

Cadmium (Cd) has seriously affected the quality of traditional Chinese medicinal material Salvia miltiorrhiza in recent years, threatening human health. The physiological and metabolic profiles of S. miltiorrhiza in response to Cd stress have been revealed in previous studies. However, transcriptional and post-transcriptional regulation in response to different degrees of Cd (0, 25, 50, and 100 mg/kg) stress in S. miltiorrhiza remains unclear. Here, transcriptome atlas in S. miltiorrhiza under different degrees of Cd Stress was unveiled using RNA sequencing (RNA-seq). These results showed that the profiles of gene expression were different in the response to Cd treatment. Defense response-related biological processes were involved in differentially expressed genes (DEGs). In total, 1966 genes were identified as transcription factors (TFs) with seven expressed trends. Retained intron (RI) was the major phenomenon. Targeted genes of intron splicing factors were identified via weighted gene co-expression network analysis (WGCNA). All of these indicated that transcriptional and post-transcriptional regulations were involved in response to Cd stress in S. miltiorrhiza. Our study will provide the most comprehensive resource for studying heavy metals in traditional Chinese medicine plants.