Relative concentration of (-)-antofine in Vincetoxicum rossicum invaded soil

Background/Question/Methods

Secondary metabolites may directly inhibit the growth of native plants or act indirectly by altering soil microbial communities. Vincetoxicum rossicum is an invasive vine known to exudate such a metabolite, (-)-antofine. Although (-)-antofine has been shown to exhibit antimicrobial properties, whether the chemical is ecologically relevant is unclear. The objective of this study was to assess how (-)-antofine production relates to the abundance of V. rossicum in different habitats. Soil cores were collected across twelve meadow and nine understory sites covering replicated gradients (n=8) of V. rossicum at Rouge National Urban Park, Canada. In total 1344 soil samples were analyzed using Liquid Chromatography – Mass Spectrometry to measure the (-)-antofine concentration. V. rossicum and (-)-antofine patterns were compared using linear-mixed effect models with site as a random effect to control for site level differences in (-)-antofine.

Results/Conclusions

Our results show that (-)-antofine concentration was higher in areas where V. rossicum is more abundant (P < 0.05). The same held true in both meadow (P = 0.049) and understory (P < 0.05) habitats. As site was used as a random effect, this suggests that the abundance of (-)-antofine is not dependant on site but on the density of V. rossicum. This may suggest that V. rossicum ability to invade a wide range of habitats is due to (-)-antofine exudation. As (-)-antofine has anti-microbial properties, V. rossicum invasion success may involve changes in plant-soil interactions. Our research indicates that (-)-antofine may be an important factor in the invasive success of V. rossicum.