2019/11/11 by Anne‐Laure Jacquemart, Christel Buyens, Marie‐France Hérent +4 · 1 citation
Agricultural and Biological Sciences · Pharmacology, Toxicology and Pharmaceutics · Chemistry · #Plant and animal studies #Plant-based Medicinal Research #Chemical synthesis and alkaloids
paper · pdf · doi:10.1038/s41598-019-53355-3
openalex publication_date 2019/11/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Many plants require animal pollinators for successful reproduction; these plants provide pollinator resources in pollen and nectar (rewards) and attract pollinators by specific cues (signals). In a seeming contradiction, some plants produce toxins such as alkaloids in their pollen and nectar, protecting their resources from ineffective pollinators. We investigated signals and rewards in the toxic, protandrous bee-pollinated plant Aconitum napellus, hypothesizing that male-phase flower reproductive success is pollinator-limited, which should favour higher levels of signals (odours) and rewards (nectar and pollen) compared with female-phase flowers. Furthermore, we expected insect visitors to forage only for nectar, due to the toxicity of pollen. We demonstrated that male-phase flowers emitted more volatile molecules and produced higher volumes of nectar than female-phase flowers. Alkaloids in pollen functioned as chemical defences, and were more diverse and more concentrated compared to the alkaloids in nectar. Visitors actively collected little pollen for larval food but consumed more of the less-toxic nectar. Toxic pollen remaining on the bee bodies promoted pollen transfer efficiency, facilitating pollination.