Transcriptomic Analysis of Antimony Response in Tall Fescue (Festuca arundinacea)

Antimony (Sb) is a toxic trace element for plants and animals. With the development of industrial applications and mining, Sb pollution is becoming more serious. Phytoremediation is regarded as an eco-friendly technique to reduce the threat of Sb to the environment and human health, and tall fescue that is highly adaptable to heavy metal stress can be a candidate species for Sb-contaminated soil phytoremediation. However, the mechanism of the Sb stress response in tall fescue is not clear. Therefore, transcriptomic analysis was used in this study to reveal the molecular mechanisms of Sb stress response regulation in tall fescue. The results suggested that the roots and leaves of tall fescue responded to Sb stress in different ways. In roots, the lignin and flavonoids might reduce the toxicity of Sb by anti-oxidation and Sb chelation. At the same time, the DEGs in leaves were mainly enriched in the pathways of glutathione metabolism, β-alanine metabolism, and glycine, serine, and threonine metabolism. Additionally, genes related to the pathways, such as 4CL, GST, AGXT2, and ALDH7A1, especially cytochrome P450 family genes (e.g., CYP73A, CYP75A, and CYP98A), might play key roles in the regulation of the Sb stress response in tall fescue. These findings provided a theoretical reference for the efficient use of tall fescue to control Sb-contaminated soil in the future.