secondary metabolite metabolism opine metabolism Crown gall tumors and hairy roots are plant neoplasias induced by pathogenic members of the genus Agrobacterium. The transformed plant cells are characterized by low MW compounds called opines. The biosynthesis of these compounds is mediated by specific enzymes encoded by genes contained in a small segment of DNA (known as the T-DNA, for 'transfer DNA') inserted by the pathogen bacterium in the plant genome during infection. The opines produced by plant tumors serve as nutrient sources for the pathogenic agrobacteria. Each strain of Agrobacterium induces and catabolizes a specific set of opines. UPa:UPA00735 pathway