Abstract
Although graphene oxide (GO) has extensive recognized application prospects in slow-release fertilizer, plant pest control, and plant growth regulation, the incorporation of GO into nano herbicides is still in its early stages of development. This study selected a pair of sweet corn sister lines, nicosulfuron (NIF)-resistant HK301 and NIF-sensitive HK320, and sprayed them both with 80 mg kg(-1) of GO-NIF, with clean water as a control, to study the effect of GO-NIF on sweet corn seedling growth, photosynthesis, chlorophyll fluorescence, and antioxidant system enzyme activity. Compared to spraying water and GO alone, spraying GO-NIF was able to effectively reduce the toxic effect of NIF on sweet corn seedlings. Compared with NIF treatment, 10 days after of spraying GO-NIF, the net photosynthetic rate (A), stomatal conductance (G(s)), transpiration rate (E), photosystem II photochemical maximum quantum yield (F(v)/F(m)), photochemical quenching coefficient (q(P)), and photosynthetic electron transfer rate (ETR) of GO-NIF treatment were significantly increased by 328.31%, 132.44%, 574.39%, 73.53%, 152.41%, and 140.72%, respectively, compared to HK320. Compared to the imbalance of redox reactions continuously induced by NIF in HK320, GO-NIF effectively alleviated the observed oxidative pressure. Furthermore, compared to NIF treatment alone, GO-NIF treatment effectively increased the activities of superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) in both lines, indicating GO induced resistance to the damage caused by NIF to sweet corn seedlings. This study will provides an empirical basis for understanding the detoxification promoting effect of GO in NIF and analyzing the mechanism of GO induced allogeneic detoxification in cells.