“Plants often produce a cocktail of active substances,” said Prof. Jakob Franke of the LUH Institute of Botany. This is no different for the plants investigated in the study. Some have anti-inflammatory properties, others are calming, and others display insecticidal qualities and can even repel pests. For example, winter cherry is known in traditional Ayurvedic medicine as ashwagandha and is believed to reduce stress and improve sleep.
To enable the more targeted application of the plants’ properties for specific uses, the researchers first decoded the gene sequence using methods from bioinformatics, which then allowed them to obtain information about the plants’ metabolic pathways. “To do this, we compared the gene sequences of the withanolide-producing plants with those of other nightshade plants which do not produce withanolides,” said Prof. Boas Pucker of the Institute for Cellular and Molecular Botany at the University of Bonn. The researchers identified an area of the genome that is responsible for the formation of these substances.
Building on this foundation, the researchers successfully replicated the first steps of the metabolic pathway in model organisms – in this case in baking yeast and in Nicotiana benthamiana, an Australian tobacco plant which is frequently used as a model plant in plant science. “Similarly to using a Lego set, we use simple building blocks to replicate complex molecules in a step-by-step way,” explained Professor Franke. “This enables us to produce simple withanolide compounds in the model organisms.”
The findings represent a milestone on the path to the further medicinal application of nightshade plants. They will now be incorporated into the project and are intended to form the basis for the complete identification of withanolides’ metabolic pathways.