Crown galls induced by octopine-degrading biotype 3 strains of Agrobacterium tumefaciens contain a new form of lysopine dehydrogenase

Extracts of crown gall tumours induced on Kalanchoe daigremontiana by the biotype 3 strains AB-3, AT-6 and Hm-1 were compared with extracts of tumours induced by the wide host range octopine strain B6S3 for their ability to convert lysine, arginine, histidine and methionine into the corresponding opines: lysopine, octopine, histopine and methiopine. In contrast to B6S3 tumour extracts which readily converted all precursors into opines, extracts of tumour tissue induced by biotype 3 strains produced mainly lysopine and octopine. It can therefore be concluded that the enzymes found in tumours induced by AB-3, AT-6 and Hm-1 are different from the well-known lysopine dehydrogenase from B6S3 tumours.