Altitude-dependent accumulation of gentiopicroside in Gentiana rigescens

Many terpenoids are synthesized by specific plant taxa in response to particular ecological situations. Gentiopicroside is an iridoid glycoside that occurs mainly in plants of the genus Gentiana. It has strong antiviral, anti-inflammatory, and analgesic effects and is used as a standard compound to assess the quality of certain wild or cultivated Gentiana plants for traditional Chinese medicine. A reanalysis of data from a previous study on the variation in gentiopicroside contents in wild Gentiana rigescens Franch. ex Hemsl. was carried out using a linear mixed-effects model with newly added environmental variables. The aim of this study was to explore the factors that may influence the gentiopicroside content in the roots of G. rigescens while taking hierarchical sampling and spatial autocorrelation into consideration. All models with second-order Akaike Information Criterion less than two compared to the best fitted model were selected, and a model-averaging approach was employed to estimate the parameters. Model-averaged coefficient estimates indicated that the content of gentiopicroside in the root increased significantly with increasing altitude (p