Graphene oxide modulates root growth of Brassica napus L. and regulates ABA and IAA concentration

Researchers have proven that nanomaterials have a significant effect on plant growth and development. To better understand the effects of nanomaterials on plants, Zhongshuang 11 was treated with different concentrations of graphene oxide. The results indicated that 25–100 mg/l graphene oxide treatment resulted in shorter seminal root length compared with the control samples. The fresh root weight decreased when treated with 50–100 mg/l graphene oxide. The graphene oxide treatment had no significant effect on the Malondialdehyde (MDA) content. Treatment with 50 mg/l graphene oxide increased the transcript abundance of genes involved in ABA biosynthesis (NCED, AAO, and ZEP) and some genes involved in IAA biosynthesis (ARF2, ARF8, IAA2, and IAA3), but inhibited the transcript levels of IAA4 and IAA7. The graphene oxide treatment also resulted in a higher ABA content, but a lower IAA content compared with the control samples. The results indicated that graphene oxide modulated the root growth of Brassica napus L. and affected ABA and IAA biosynthesis and concentration.