Zinc Oxide Nanoparticles Enhanced Growth of Tea Trees via Modulating Antioxidant Activity and Secondary Metabolites

Abstract

Nano-fertilizer has been dubbed ‘the fertilizer of the 21st century’, and it is already being used extensively in agriculture. Zinc oxide nanoparticles (ZnO-NPs) have excellent biological properties and are expected to be an ideal choice for plant zinc fertilizer. Tea is one of the top three beverages in the world, and improving the quality of tea is a priority in its research field. In this study, different concentrations (0, 10, 50, 100, 150, and 200 mg·L−1) of ZnO-NPs were sprayed on tea leaves to investigate their effects on volatile aroma substances and biochemical aspects of tea leaves. The results revealed that various concentrations of ZnO-NPs had different effects on physiological indexes. The concentration of 150 mg·L−1 of ZnO-NPs enhanced chlorophyll content, while the 100 mg·L−1 concentration of ZnO-NPs promoted the accumulation of soluble proteins and the activity of antioxidant enzymes, including a decrease in the content of malondialdehyde. In addition, the ZnO-NPs spray reduced the content of tea polyphenols. A total of 27 volatiles were identified under six treatments, with benzene being the common compound with an average content of 45.97%. Ethanolamine and cis-3-hexenyl acetate were the other two major compounds. It was concluded that the presence of ZnO-NPs improved the antioxidant system of teas, increased soluble protein content and provided better reactive oxygen species protection for plants, especially in the case of ZnO-NPs at 100 mg·L−1. We highlighted that ZnO-NPs application was a favorable way to improve tea trees growth.

Heat Waves Coupled with Nanoparticles Induce Yield and Nutritional Losses in Rice by Regulating Stomatal Closure

“…Rice, a staple food with global significance in the context of the world’s food supply, also serves as a valuable model plant for assessing plant responses to NPs. , We hypothesized that HWs combined with CeO 2 NPs may influence rice production by altering stomatal movement. Thus, the main aims of this study were to (1) assess the yield and nutritional quality of rice in response to HWs and CeO 2 NPs, (2) elucidate the stomatal movements regulated by HWs and CeO 2 NPs, and (3) explore the molecular mechanisms underlying the regulation of stomatal movements and rice production using omics and regular analysis methods.…”