Impacts of Carbon Dots on Rice Plants: Boosting the Growth and Improving the Disease Resistance

A series of ∼5 nm sized carbon dots (CDs) with different oxygen contents were fabricated and employed as a model material with which to explore the impacts of carbon nanoparticles on rice-plant growth. We show that CDs can penetrate into all parts of rice plants, including the cell nuclei. Systematic investigations provide insight into the different processes by which seed germination, root elongation, seedling length, enzyme (RuBisCO) activity, and carbohydrate generation are increased. CDs are capable of entering the cell, reaching the nucleus, loosening the DNA structure, and increasing the thionin (Os06g32600) gene expression, which finally enhanced the rice-plant disease-resistance ability. CDs can be degraded by plant to form plant-hormone analogues and CO₂, and then the hormone analogues promote the rice-plant growth, while the CO₂ is converted into carbohydrates through the Calvin cycle of photosynthesis. The outcome of these processes is a 14.8% enhancement of the total rice yield and an increase of the rice-plant resistance to diseases.