Preparation of Siraitia grosvenorii Leaf-Derived Carbon Dots and Its Effect on Tissue Culture Seedlings of Siraitia grosvenorii

In order to investigate the effects of carbon dots on Siraitia grosvenorii tissue culture, fluorescent carbon dots (L-CDs) were prepared via a one-step hydrothermal method using S. grosvenorii leaves as a novel carbon source. The synthesized L-CDs exhibited blue fluorescence under UV irradiation, with an optimal excitation wavelength of 379 nm and an optimal emission wavelength of 451 nm. The L-CDs demonstrated excellent biocompatibility, superior anti-photobleaching and salt-tolerance properties, and high stability across a wide pH range of 1–12, making them highly suitable for plant tissue culture. Notably, 0.6 mg·L−1 L-CDs significantly promoted the growth of S. grosvenorii tissue-cultured seedlings and increased their propagation coefficient. Further studies revealed that 0.6 mg·L−1 L-CDs significantly enhanced antioxidant enzyme activities, with SOD, POD, and CAT activities increasing by 82.61%, 33.33%, and 58.82%, respectively, compared to the control group. This study highlights the potential of L-CDs as highly efficient and non-toxic growth promoters in plant tissue culture, providing a sustainable and effective strategy for their application in plant biotechnology.