Dose-Dependent Effect of ZnO Quantum Dots for Lettuce Growth

Abstract

As the cadmium-free semiconductor quantum dots, ZnO quantum dots (ZnO QDs) have wide potential applications in agriculture. However, the effects of ZnO quantum dots on crop growth and nutritional quality have not been fully studied. In this work, the lettuce was sprayed with different concentrations of ZnO QDs from 50 to 500 mg·L –1 to evaluate their influence on lettuce antioxidant, biomass, and nutritional quality. The results showed that ZnO QDs existed in the lettuce in the form of Zn 2+ . Lettuce treated with 500 mg·L –1 ZnO QDs would produce a large amount of reactive oxygen species (ROS), which adversely affected the absorption of nutrients, soluble protein content, and chlorophyll content, thus reducing plant biomass. When the concentrations range from 50 to 200 mg·L –1 , the antioxidant enzyme systems of lettuce were triggered to counteract the damage caused by excessive ROS. Moreover, ZnO QDs at this level promoted Ca, Mg, Fe, Mn, Zn, and B absorption and accumulation; increased soluble sugar content; and improved the lettuce biomass and nutritional quality.

In vitro ZnO Nanoparticles Enhanced Pea (Pisum sativum L.) Seedlings Growth

“…However, after 1.8 ppm ZnO NPs, two ecotypes revealed higher dosages promptly declined the content of MDA. This result is in accordance with those published by Liang et al (2021) in the study of high concentration ZnO-Quantum dot for lettuce growth. Their results demonstrate that high dosages (500 mg L −1 ) of ZnO QDs can strongly promote the value of MDA, which revealed that high dosage of ZnO QDs stimulated stress in lettuce, outcoming in MDA.…”

Visible-Light-Driven Zinc Oxide Quantum Dots for the Management of Bacterial Fruit Blotch Disease and the Improvement of Melon Seedlings Growth

“…Thus, the development and application of zinc-based quantum dot materials in agriculture have received extensive attention. Previous studies suggested that ZnO QDs have excellent antibacterial properties for Escherichia coli and Staphylococcus aureus, which may be attributed to the excessive generation of reactive oxygen species and the dissolution of zinc ions. , A recent study indicated that foliar spraying of 50–200 mg/L ZnO QDs could also enhance the growth of lettuce by activating the antioxidant system and promoting the uptake of trace elements . However, ZnO QDs as a bactericidal agent applied in controlling plant disease has not been reported.…”

Large-Scale Preparation of Peanut-Bran-Derived Carbon Dots and Their Promoting Effect on Italian Lettuce

“…From the HRTEM image shown in Figure b, it is observed that the lattice spacing of the CDs is 0.23 nm. It can be seen that the uniform spherical CD particles have lattice planes, which also illustrate the order of the CD particles. , The Fourier transform infrared spectroscopy (FTIR) shown in Figure d was used to characterize the surface functional groups of the CDs. The wide absorption band of 3340 cm –1 is due to the vibration of the O–H bond.…”

“…It can be seen that the uniform spherical CD particles have lattice planes, which also illustrate the order of the CD particles. 28,29 The Fourier transform infrared spectroscopy indicate that CDs are rich in hydrophilic groups, including hydroxyl and carboxyl groups. This is consistent with the excellent water solubility of CDs.…”