Recent CO2 levels promote increased production of the toxin parthenin in an invasive Parthenium hysterophorus biotype

Recent carbon dioxide (CO2) concentrations promoted higher parthenin concentrations in an invasive Parthenium hysterophorus biotype. Mean concentrations of parthenin, an allelopathic and defensive sesquiterpene lactone, were 49% higher at recent (similar to 400 ppm) than at mid-twentieth-century (similar to 300 ppm) CO2 concentrations, but did not vary in a non-invasive biotype, suggesting that recent increases in atmospheric CO2 may have already altered the chemistry of this destructive weed, potentially contributing to its invasive success.

Automated summary

Recent increases in atmospheric CO2 concentrations may have already altered the chemistry of an invasive plant species, potentially contributing to its invasive success.