Evidence for the existence of a universal crown-gall tumor initiation enhancer

摘要

Tumor initiation of different dicotyledonous plant species inoculated withAgrobacterium tumefaciensB6has been studied in vivo and in vitro. The tumor formation in weakly susceptible plants can be strongly enhanced by exogenously applied active extract fractions derived from highly susceptibleHelianthuscotyledons. It is found that highly susceptible plants (Kalanchoë, Lycopersiconand Pinto beans) contain an active tumor initiation enhancer which is clearly similar to the compound(s) found inHelianthuscotyledons. No activity can be detected in extracts derived from weakly susceptible plants (Coleus, Phaseolus) or in those obtained from crown-gall tumor tissues