Functionalized Biomass Carbon Dots for Improved Growth of Lettuce and Exocarpium Citri Grandis Saplings

The application of carbon dot (CD) nanomaterials in the agricultural field has shown unique advantages, among which preparing an efficient CD material is the key to its popularization and applications. In this work, a biomass CD material (CDs-gl&al) that can be used for efficient improvement of plant photosynthesis was prepared. Compared with the control, the electron transport rate and actual photosynthetic efficiency of lettuce leaves treated with CDs-gl&al increased by 43.5 and 40.1%, respectively, and the contents of chlorophyll a and chlorophyll b increased by 23.9 and 21.0%, respectively, significantly enhancing the photosynthetic capacity of lettuce. After being absorbed by leaves, CDs-gl&al was mainly transported to other parts through leaf veins. In the assay of superoxide dismutase (SOD) and malondialdehyde (MDA) levels, CDs-gl&al was able to increase the SOD content and decrease the MDA level in the leaves, thus enhancing the lettuce resistance and improving the growth status of lettuce. In experiments with fruit trees, CDs-gl&al had a similar effect in promoting photosynthesis in fruit tree leaves. The coculture experiments with various cells such as mouse small intestine epithelial cells proved that this material had good biosafety. CDs-gl&al would help to further promote the application of CDs in the agricultural field.