One single enzyme induces the chemical defense of a mushroom against larvae
(PHYSorg.com Chemistry)

Some mushrooms produce long-chain unsaturated carboxylic acids as their chemical defense against insect larvae. The biosynthesis of these polyenes relies on only one enzyme, as German scientists have now discovered. In the journal Angewandte Chemie, they report the unprecedented multiple double-bond-shifting activity by the enzyme, which is representative of a yet uncharacterized phylogenetic clade of polyketide synthases.