Fluorescent g-C₃N₄ nanosheets enhanced photosynthetic efficiency in maize

Nano-enabled agriculture becomes a new and rapidly evolving area of research, particularly, nanomaterials (NMs) with light-harvesting capacities for enhancing photosynthesis. However, mechanisms for the interactions between these NMs and plants are not fully understood. Herein, fluorescent and water-soluble graphitic carbon nitride (g-C₃N₄) nanosheets were prepared and used as artificial antenna to amplify light harvesting ability and enhance photosynthesis in maize. Upon root exposure to 10 mg·L^-1 g-C₃N₄ nanosheets, the g-C₃N₄ can be taken up and distributed in leaves. Also, the nutrients (Mg, P, Fe, and Mn), chlorophyll content, electron transfer rate, net photosynthetic rate, and carbohydrates content in maize were increased significantly by 1.1%, 51.8%, 44.6%, 121.8%, 12.1%, 44.5%, 30.0% and 32.3%, respectively. In addition, the gene expressions of psbA (photosystem II reaction center protein A) and psaA (photosystem I P700 chlorophyll A apoprotein A1) were up-regulated by 56.3% and 26.8%, respectively. Moreover, the activities of phosphoenolpyruvate carboxylase (PEPC) and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) were significantly increased by 242.3% and 156.3%, respectively. This study provides a new perspective on the use of g-C₃N₄ nanosheets to promote plant growth and develop nano-enabled agricultural technology.