Silica nanoparticles improve growth, chemical bioactive, and antioxidant enzyme activity of Dianthus caryophyllus L., plant

Nanotechnology has provided innovative use of various materials with unique properties. These substances may react positively in plants, and the induction of bioactive compounds and antioxidant activity is particularly remarkable. Ornamental plant production is a positive economic activity of great interest, especially Carnation (Dianthus caryophyllus L.). This plant is more attractive for its various colors, but the flower quality and its longevity can diminish very fast. Thus, examining methods capable of improving flower quality and vase life is crucial. Additionally, carnation can be used to treat coronary and nervous disorders. Carnation contains compounds that calm the nervous system and minimize swelling and inflammation. This research aimed to evaluate the effect of silica nanoparticles (SiO2 NPs) on the growth, bioactive chemical analysis, enzyme activity, and antioxidant accumulation. The different rates of SiO2 NPs (0, 150, and 300 ppm) were used in two ways: foliar spray and soil drench; it was applied 3 times. The first application was after 3 weeks of transplanting and repeated with 21-day intervals. The results showed that foliar application of SiO2 NPs increased all morphological and flowering traits compared with drench and the control, higher levels of photosynthetic pigments and anthocyanin, greater total phenols, total sugars, and total free amino acids were obtained from plants treated with foliar spray 300 ppm followed than 150 ppm. In addition, the greatest levels of enzyme activity were recorded with plants treated with foliar spray of SiO2 NPs at a rate of 300 ppm, as well as improved anatomical structure of the stem and stomata properties compared with the drench method and control. Similarly, SiO2 NPs application method is more critical than their concentration. Therefore, it is recommended that foliar spraying of SiO2 NPs at 300 ppm can enhance plant growth, flowering, bioactive compounds, enzyme activity, and anatomical structure of the stem of carnation plants while adding SiO2 NPs drench at a rate of 150 ppm had rather acceptable findings.