Glandular trichomes (GT), or leaf hairs, are secretory structures specialized in the production of secondary metabolites. Commonly found on the aerial surfaces of flowering plants, GT are responsible for the aroma of many herbs and the bioactivity of many plant-based medicines.
Cannabis sativa (Cannabis) is among the few crops, where GT have been under intense artificial selection, resulting in GT of modern cultivars being able to produce up to 30% of flower dry weight in secondary metabolites. Because of their abundance, ease of access, extensive phenotypic variation and medicinal value, Cannabis GT have potential as a model system for glandular trichome biology, particularly in the context of complex secondary metabolism of plants.
We developed protocols for the isolation and purifications of GT heads, stalks and subcellular fractions. For quantitative proteomic analysis, we created a trichome-specific sequential window acquisition of all theoretical fragment ion spectra mass spectrometry (SWATH MS) library of >3000 targets. Together they allow for a detailed spatial and temporal dissection of Cannabis GT function.
This presentation will give insights on how Cannabis GT achieve their exceptional productivity, how they change throughout development and how they were shaped through artificial selection.
Cannabis GT are strong sink tissues and their productivity relies on their ability to effectively utilize supplied photoassimilates. Specialized plastids, which generate the bulk of secondary metabolite precursors, are not fully developed until several weeks after GT initiation, resulting in varying metabolite profiles throughout development. Modern cultivars have larger GT characterized by higher abundance of cannabinoid pathway proteins.