Isolation of Protoplasts from Tissues of Mexican Prickly Poppy (Argemone mexicana L.): An Alkaloid-Producing Medicinal Plant.

Protoplasts are plant cells from which the pectocellulosic cell wall has been removed, thus keeping the plasma membrane intact. For plant secondary metabolites research, this system is a powerful tool to study the metabolites' dynamics inside the cells, such as the subcellular localization of proteins, characterization of gene function, transcription factors involved in metabolite pathways, protein transport machinery, and to perform single-cell omics studies. Due to its lack of a cell wall, better images of the interior of the cell can be obtained compared to the whole tissue. This allows the identification of specific cell types involved in the accumulation of specialized metabolites, such as alkaloids, given their autofluorescence properties. Here is a simplified protocol to obtain protoplasts from leaves and in vitro cell cultures from Argemone mexicana, which produces the pharmacologically important alkaloids berberine and sanguinarine.