Effects of three graphene-based materials on the growth and photosynthesis of Brassica napus L

Xiaolu Xiao; Xiuping Wang; Lixin Liu; Chang Chen; Aihua Sha; Jun Li

doi:10.1016/j.ecoenv.2022.113383

Effects of three graphene-based materials on the growth and photosynthesis of Brassica napus L

Ecotoxicol Environ Saf. 2022 Apr 1:234:113383. doi: 10.1016/j.ecoenv.2022.113383. Epub 2022 Mar 9.

Authors

Xiaolu Xiao¹, Xiuping Wang², Lixin Liu¹, Chang Chen¹, Aihua Sha³, Jun Li⁴

Affiliations

¹ Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute, Chinese Academy of Agricultural Science, Wuhan 430062, China.
² Analysis and Testing Center, Hebei Normal University of Science and Technology, Qinhuangdao 066000, China.
³ Hubei Collaborative Innovation Center for Grain Industry, Yangtze University, Jingzhou 434023, China.
⁴ Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute, Chinese Academy of Agricultural Science, Wuhan 430062, China. Electronic address: junli1999@126.com.

PMID: 35276609
DOI: 10.1016/j.ecoenv.2022.113383

Abstract

The environmental safety and threats of graphene-based materials (GBMs) to the agroecosystem have attracted increasing attention in recent years. However, the mechanisms underlying the effects of GBMs on plants remain unclear. Here, we investigated the phytotoxicity of reduced graphene oxide (RGO), graphene oxide (GO) and amine-functionalized graphene (G-NH₂) on Brassica napus L. The results revealed that RGO impaired photosynthesis mainly by decreasing the chlorophyll content and Rubisco activity. A further gene-level analysis suggested that this effect of RGO might be due to its toxicity on sulfate transmembrane transporter and nitrogen metabolism, which ultimately led to nutrient imbalance. However, GO directly damaged the photosystem by disrupting the chloroplast structure, and a decrease in Rubisco activity indicated that GO also inhibits carbon fixation. Further gene-level analysis demonstrated that GO has toxicity on the chloroplast membrane, photosystem, photosynthethic electron transport and F-type ATPase. In addition, G-NH₂ at 10-1000 mg L^-1 showed no significant toxicity. These findings shed light on the potential mechanism for the toxicity of GBMs on plants for risk assessment.

Keywords: Amine-functionalized graphene; Graphene oxide; Photosynthesis; Phytotoxicity; Reduced graphene oxide.