Correlation analysis between artemisinin and its derivative contents and trichome characteristics from different Artemisia species

Artemisia species have significant commercial, medical, and economic value and are widely used in the traditional medicine and pharmaceutical industries. Artemisinin, a powerful antimalarial agent, is an important pharmaceutical metabolite that primarily accumulates within the glandular trichomes (GTs) on the leaf surface of Artemisia plants. Trichomes arising from the elongation of epidermal cells can be classified into GTs and non-glandular trichomes (NGTs) based on their morphology. GTs and NGTs are present in Artemisia species, and the relationship between GTs and artemisinin has been extensively studied; however, the correlation between NGTs and artemisinin remains relatively unexplored. In this study, we inferred artemisinin derivatives and trichome characteristics based on the type of species, developmental stage, and leaf age and conducted correlation analyses to investigate the factors influencing artemisinin content across different Artemisia species. Artemisinin and its derivatives exhibited variations in distribution based on species and leaf age, with a decreasing trend observed across most species as the developmental stage progressed. Noticeable differences among Artemisia species were observed in leaf shape, morphology, and trichome distribution. Although the observed data did not evidently differentiate between species, developmental stage, and leaf age groups, principal component analysis revealed that artemisinin was positively associated with the NGTs density, indicating a correlation coefficient of 0.56 (p < 0.0001). Therefore, the number of NGTs may affect the artemisinin content in different Artemisia species.