@Article{phyton.2026.075656,
AUTHOR = {Xiao Wang, E Liang, Xiaohui Song, Deyan Li},
TITLE = {Moderate CO<sub>2</sub> Enrichment Enhances Saponin Accumulation in <i>Panax japonicus</i> by Activating Sugar Metabolism},
JOURNAL = {Phyton-International Journal of Experimental Botany},
VOLUME = {95},
YEAR = {2026},
NUMBER = {3},
PAGES = {--},
URL = {http://www.techscience.com/phyton/v95n3/66763},
ISSN = {1851-5657},
ABSTRACT = {Three-year-old <i>Panax japonicus</i> was exposed to elevated CO<sub>2</sub> concentrations using open-top chambers: ambient CO<sub>2</sub> (aCO<sub>2</sub>), moderately elevated (e1CO<sub>2</sub>, 550 μmol/mol), and highly elevated (e2CO<sub>2</sub>, 750 μmol/mol). Gas exchange parameters, photosynthetic pigments, sugar accumulation, and total saponin content were measured to assess the effects of CO<sub>2</sub> enrichment on photosynthesis, sugar metabolism, and saponin biosynthesis. The e1CO<sub>2</sub> treatment significantly increased net photosynthetic rate (by 17.22% at 36 days and 69.62% at 92 days), chlorophyll a content, and soluble sugar, sucrose, and starch accumulation. Key sugar metabolism enzymes, including sucrose phosphate synthase (SPS), also showed enhanced activity. Consequently, underground rhizome total saponins rose significantly by 15.16%. In contrast, e2CO<sub>2</sub> initially (36 days) stimulated photosynthesis but lost this effect over prolonged exposure (92 days), with no significant impact on photosynthetic parameters, pigments, or sugar levels. Correlation analysis indicated that rhizome saponin content was positively associated with leaf sucrose levels and sucrose synthase (synthetic direction) activity. These findings suggest that moderate CO<sub>2</sub> elevation (e1CO<sub>2</sub>) enhances <i>P. japonicus</i> photosynthesis and sugar metabolism, driving greater saponin accumulation. However, high CO<sub>2</sub> (e2CO<sub>2</sub>) has transient benefits, with stimulatory effects diminishing over time.},
DOI = {10.32604/phyton.2026.075656}
}