ZnO NPs Enhanced Photosynthetic Capacity, Promoted New Shoot Development, and Improved the Community Composition of Phyllosphere Epiphytic and Endophytic Microorganisms in Tea Plants

Abstract

Background Nanotechnology holds revolutionary potential in the field of agriculture, with zinc oxide nanoparticles (ZnO NPs) demonstrating advantages in promoting crop growth. Photosynthesis is a key process in the growth and quality formation of tea plants, and phyllosphere microorganisms also have a significant impact on plant growth and health. However, the effects of ZnO NPs on the photosynthesis of tea plants, the sprouting of new shoots, and the community of phyllosphere microorganisms are not yet clear. Results This study investigated the photosynthetic physiological parameters of tea plants under the influence of ZnO NPs, the content of key photosynthetic enzymes such as RubisCO, chlorophyll content, chlorophyll fluorescence parameters, transcriptomes (leaves and new shoots), extensively targeted metabolomes (leaves and new shoots), mineral element content (leaves and new shoots), and the communities of epiphytic and endophytic microorganisms in the phyllosphere. The results indicated that ZnO NPs could enhance the photosynthesis of tea plants, upregulate the expression of some genes related to photosynthesis, increase the accumulation of photosynthetic products, promote the development of new shoots, and alter the content of various mineral elements in the leaves and new shoots of tea plants. Additionally, ZnO NPs improved the community composition of epiphytic and endophytic microorganisms in the phyllosphere of tea plants, inhibited potential pathogenic microorganisms, and allowed various beneficial microorganisms with potential growth-promoting properties to become dominant species. Conclusion This study demonstrates that ZnO NPs have a positive impact on the photosynthesis of tea plants, the sprouting of new shoots, and the community of phyllosphere microorganisms, which can improve the growth condition of tea plants. These findings provide new scientific evidence for the application of ZnO NPs in sustainable agricultural development and contribute to advancing research in nanobiotechnology aimed at enhancing crop yield and quality.