CHEMISTRY AND BIOCHEMISTRY OF OPINES, CHEMICAL MEDIATORS OF PARASITISM

Opines consititute a class of substances that are characteristic of cr own gall and hairy root, two proliferative plant diseases caused by Ag robacterium tumefaciens and A. rhizogenes. About 20 of these compounds have been described. Being produced by plant cells and used by the pa thogen as growth substrates, they can be described as chemical mediato rs of parasitism. This plant-bacteria interaction is a natural instanc e of genetic manipulation since the genes encoding opine synthesis in plant cells are transferred from a bacterial plasmid into the plant ge nome. The current knowledge on opines is presented, as well as some bi ological aspects of this unique system.