How tomatoes make cholesterol

Abstract

People often turn to a plant-rich diet when they want to reduce their cholesterol intake. But plants often make the complicated sterol too, albeit at a level that’s at least two orders of magnitude less than that made by animals: Cholesterol can be found in leaf lipids, can be used to make a precursor for vitamin D-3, and can be turned into herbivore-deterrents and pathogen poisons, such as α-solanine in potatoes and α-tomatine in tomatoes. Now, more than two centuries after French chemists first discovered cholesterol in human gallstones, scientists have figured out how plants make the useful molecule. A team of scientists led by Asaph Aharoni at the Weizmann Institute of Science identified the 12 enzymes and 10 chemical conversions used by the tomato plant to convert 2,3-oxidosqualene to cholesterol (Nat. Plants 2016, DOI: 10.1038/nplants.2016.205). They found that the biosynthetic pathway for cholesterol overlaps with the metabolic pathway for