The Effect of Carbon Nanomaterials on Senescence of Cut Flowers in Carnation (Dianthus caryophyllus L.)

Carbon nanomaterials (CNMs) have remarkable chemical, physical, electrical, and structural properties and favorable biocompatibility. This study used carnation (Dianthus caryophyllus L.) cut flowers as a model to evaluate the protective effects of 3 kinds of CNMs (single-walled carbon nanotubes [SWCNT], graphene quantum dots [GQD], and fullerenes [C60]) on the antioxidant activity and senescence of plant cells. We found that 1 mg·L -1 C60 and 25 mg·L -1 GQD extended the vase life (VL) of carnation by approximately 10%. SWCNT cannot be absorbed and transported by plant vascular tissue, and higher concentrations of SWCNT can block vascular tissue, leading to decreased VL. Physiological tests have shown that theThe malondialdehyde (MDA) and hydroxyl radical (OH·) levels significantly decreased after the GQD and C60 treatments, and the main factors that cause cell damage changed from H2O2 to OH·. The in vitro Fenton reaction and 2,2-diphenyl1-picrylhydrazyl (DPPH) free radical scavenging assay indicated that both C60 and GQD may inhibit OH· generation by approximately 10% to 15%, and GQD had higher DPPH free radical scavenging activity. Accordingly, a suitable concentration of C60 and GQD can influence reactive oxygen species metabolism and downstream biological events, including the cell redox state, the antioxidant system, and membrane lipid peroxidation, effectively delaying senescence and abscission of plant tissue. Additional key words: antioxidant system, fullerene, graphene quantum dots, reactive oxygen species, vase life