[Nucleic acids during tumorous transformation in plants].

Crown-gall, one of the "plant cancer" is induced in the presence of a soil bacterium Agrobacterium tumefaciens which elaborates a Tumor inducing principle (T.I.P.), the nature of which is unknown. Several informations suggest that some DNA sequences of bacterial origin are included in tumorous cells of tissue cultures. A ribonuclease inhibits induction. An RNA extracted from Agrobacterium induces some hyperplasia transplantable by graft.