Transcriptome analyses reveal the toxicity of graphene oxide with different diameters on buckwheat root growth

Abstract

Graphene-based materials (GBMs) have become potential soil pollutants due to their wide applications in agricultural environments. Although physiological mechanisms of plant responses to GBMs have been previously explored, the underlying molecular mechanisms remain unclear. In this paper, we analysed the physiological and transcriptomic changes of buckwheat (Fagopyrum spp.) roots exposed to 100 mg/L graphene oxide (GO) with different diameter. GO negatively affected root growth and higher diameters of GO caused more adverse effects on the root. In total 3 724 GO-responsive genes were identified in root by transcriptome analysis. 70 differentially expressed genes (DEGs) were involved in ROS detoxification, and 37 transporter-encoding genes were found to be involved in GO response. These transporters may regulate the uptake and transport of GO in buckwheat. The gene expression of 84 transcription factors (TFs) showed a response to GO stress in the root, which may regulate the transporters and reactive oxygen species (ROS) detoxification-related genes. Finally, the difference in the transcriptomic response of the root to the three GO materials with different diameters was investigated. 49 GO-responsive genes may be involved in the difference in the toxicity of GO with different diameters. This study provides new insights into the molecular mechanisms of plant roots to GBMs.

Keywords

• buckwheat
• graphene oxide
• phytotoxicity
• transcriptome analysis