Silver nanoparticles enhance the vase life of cut roses by regulating antioxidant defense systems and inhibiting microbial clogging

• 2.5 μg/mL AgNPs provides optimal preservation effects for fresh-cut roses. • Optimal concentration of AgNPs enhanced the antioxidant capacity of cut flowers. • AgNPs reduced bacterial proliferation at stem ends and prevented bacterial secretions. • 2.5 μg/mL AgNPs reduced ethylene yield by suppressing ethylene-related genes’ expression. • PCA and cluster analysis further validated a significant difference between 2.5 μg/mL AgNPs group and control. Despite the well-documented antioxidant and antimicrobial properties of silver nanoparticles (SNP), their application research in prolonging the vase life of cut flowers has remained limited. This study investigated the effects of various concentrations of SNP on the morphology, water balance, cell viability, antioxidant capacity, antimicrobial characteristics, ethylene contents, and expression level of several genes in fresh roses. The results demonstrated that 2.5 μg/mL SNP treatment significantly prolonged vase life by 6 days while minimizing the reduction in crimson pigment content. This optimal concentration enhanced the antioxidant capacity of cut flowers through reducing reactive oxygen species accumulation, increasing antioxidant enzyme activities, and activating glutathione reductase. Fourier transform infrared (FTIR) spectroscopy analysis further validated the antioxidant results. SNP exhibited significant antimicrobial effects, reducing bacterial proliferation at stem ends and preventing bacterial secretions from clogging xylem vessels, as confirmed by colony culture, stereo microscopy, scanning electron microscopy observation, and FTIR peak area analysis in the 2300–2100 and 2100–1800 cm -1 ranges. Although higher concentrations of SNP displayed stronger antimicrobial effects, they were less effective overall. Meanwhile, 2.5 μg/mL SNP treatment effectively suppressed ethylene production and the expression levels of ethylene relative genes. Principal component analysis and cluster analysis also showed significant differences between 2.5 μg/mL SNP treatment and the control group. Therefore, 2.5 μg/mL SNP emerged as the optimal preservation concentration, significantly extending vase life, owing to their superior antioxidant and antibacterial properties, and suppressed ethylene production. This study provided novel insights into the application of SNP for extending the longevity of cut flowers.