Abstract:

To investigate the molecular mechanism of mulberry seedlings responding to cadmium (Cd) stress, and mine the genes closely related to Cd stress, the transcriptomes derived from mulberry seedlings grown under normal and CdCl₂ stress conditions were studied using the Illumina HiSeq method. In this study, 39758 non-redundant transcripts were isolated from mulberry seedlings based on de novo transcriptome assembly. The average length and N50 of these transcripts were 1135 and 1968 bp, respectively, and the average GC content was 41.72%. 15882 differentially expressed genes (DEGs) were identified from different Cd stress periods. KEGG enrichment analysis showed that these DEGs were mainly involved in photosynthesis, secondary metabolism and energy metabolism. In addition, 148 transcription factors (TFs) representing 36 TF families were differentially expressed in different Cd stress periods, including bHLH, MYB, B3, NAC and MYB-related. qRT-PCR showed that the expression profile of DEGs was consistent with RNA-Seq analysis. These results could provide a basis for further understanding of the Cd tolerance mechanism of mulberry.

Key words: mulberry, cadmium stress, transcriptome, bioinformatics, gene expression