RNA-sequencing analysis reveals transcriptional changes in the roots of low-cadmium-accumulating winter wheat under cadmium stress

Wheat is the second most important food crop worldwide, and thus, it is important to protect both its yield and quality. Cadmium (Cd) is a heavy metal with strong soil–plant mobility and biological toxicity. Thus, screening low-Cd-accumulating genotypes to elucidate the underlying molecular regulatory mechanisms and gene networks related to Cd stress may be useful to reduce dietary exposure to this heavy metal. Here, the root transcriptomes of the low-Cd-accumulating genotype YM16 treated (YT) or not treated (YC) with Cd were analyzed using the Illumina Hiseq4000 data. The gene expression analysis of YT and YC revealed 1427 differentially expressed genes (DEGs; 429 upregulated and 998 downregulated). Of these, 298 upregulated DEGs were assigned to 41 gene ontology (GO) terms, whereas 537 downregulated DEGs were assigned to 61 GO terms. The pathway enrichment analysis showed that phenylpropanoid biosynthesis, glutathione metabolism, sulfur metabolism, and nitrogen metabolism were significantly enriched in upregulated DEGs, which are involved in defense and detoxification in response to Cd stress. The expression pattern of eight selected DEGs was also analyzed by quantitative real-time polymerase chain reaction, and the results were consistent with those obtained by RNA-sequencing, confirming data reliability. Overall, our study might increase the understanding of complex molecular mechanisms that regulate the responses of plants to Cd stress, and help develop new improved wheat varieties with low Cd content in the grain.