Comparative volatile profiling of Asarum species and MaxEnt-based habitat assessment of Asarum sieboldii: implications for species authentication, geographical origin traceability, and climate-informed conservation.

INTRODUCTION: Asarum sieboldii Miq. (Aristolochiaceae) is an important medicinal plant characterized by substantial chemotypic variation. However, the potential of this variation for species authentication and geographical origin traceability, together with the effects of future climate change on its suitable habitats, remains insufficiently understood. METHODS: We conducted two complementary analyses to evaluate the chemical differentiation and habitat suitability of A. sieboldii. Seventy two wild individuals from 12 populations, comprising seven populations of A. sieboldii and one population from each of five congeneric species, were profiled using HS-SPME/GC-MS and multivariate analyses. An optimized MaxEnt model was further used to identify the principal climatic factors associated with habitat suitability and to project changes in the potential suitable distribution of A. sieboldii under future climate scenarios. RESULTS: A total of 131 volatile metabolites belonging to 11 chemical classes were annotated, revealing pronounced chemotypic differentiation among populations. Five candidate biomarkers, including β-bisabolene, 2-cyclohexen-1-ol acetate, 9H-fluorene derivatives, hexanal, and a putative terpenoid, consistently distinguished A. sieboldii from related species, whereas 12 candidate metabolites differentiated the geographical populations of A. sieboldii and showed potential for geographical origin traceability. The optimized MaxEnt model identified mean diurnal temperature range, annual precipitation, and mean temperature of the coldest quarter as the principal climatic predictors of habitat suitability. Under future climate scenarios, suitable habitats of A. sieboldii were projected to shift northward, with contraction in southern parts of the current range and limited expansion into northern regions. Shaanxi, Hubei, and Henan retained relatively stable suitable areas, whereas substantial habitat losses were projected in Jiangxi and Hunan; newly suitable areas were also projected to emerge in parts of Liaoning and Jilin Provinces. DISCUSSION: Several candidate differential metabolites offer potential chemical markers for species authentication within Asarum and geographical origin traceability of A. sieboldii. In response to projected habitat changes, stable suitable areas should be prioritized for in situ conservation and long-term monitoring, newly suitable northern areas may be considered for future cultivation, and populations in contracting southern habitats should receive greater attention for ex situ germplasm conservation. Together, these findings provide an integrated scientific basis for species authentication, geographical origin traceability, and conservation of A. sieboldii.