A scaffold protein manages the biosynthesis of steroidal defense metabolites in plants

plants produce two major classes of valuable sterol derived natural products-steroidal glycoalkaloids and steroidal saponins-from a common cholesterol precursor. Attempts to heterologously produce these molecules have consistently failed, although the genes responsible for each biosynthetic step have been identified. Here we identify a cellulose synthase like protein, an unexpected biosynthetic component that interacts with the early pathway enzymes, enabling steroidal scaffolds production in plants. Moreover, knockout of this gene in black nightshade,