Production of the monoterpenoid acid moiety of pyrethrins, trans-chrysanthemol, in the moss Physcomitrium patens

Biopesticides are gaining attention as eco-friendly alternatives to synthetic pesticides, driven by growing concerns about health and environmental impacts. Pyrethrins, a natural class of insecticides derived from the flowers of Tanacetum cinerariifolium, are highly valued for their efficiency and minimal environmental and animal toxicity. Their biosynthetic route involves the biosynthesis of two moieties, a monoterpenoid acid and an alcohol moiety, which fuse to form the esters responsible for their insecticidal activity. In this study, we investigated Physcomitrium patens, a model bryophyte, as a potential biological chassis for pyrethrin biosynthesis. By expressing the essential enzyme chrysanthemyl diphosphate synthase (TcCDS), we successfully produced trans-chrysanthemol at levels comparable to those observed in angiosperm hosts. However, trans-chrysanthemic acid yields were lower than reported for other biotechnological experiments, highlighting that further optimization is needed. The results position P. patens as a promising platform for the sustainable production of small molecules and pyrethrins, offering new avenues for future biotechnological applications.