Estimation of hyperauxinity during tumour formation in castor bean hypocotyls

摘要

The hyperauxinity of tumourous tissues of castor bean plants (Ricinus communisL. variety Pacific 6), infected byAgrobacterium tumefaciens(Smith and Town) Conn, strain B6, was quantitatively estimated. The auxin extracted was found to be indole-acetic acid (IAA), which gave a typical Ehrlich's reaction, an equal R.f. value and a characteristic indole UV spectrum which were similar to those of authentic IAA. TheAvenacoleoptile straight growth test revealed a higher auxin concentration in the typical R.f. region (0.2–0.4) in the tumourous tissues than in the control. Colorimetric estimation of the auxin concentration in developing tumourous tissues revealed fluctuating hyperauxinities throughout the test period. The possible nature of this fluctuation is discussed but it is still unexplaine