Galls were induced to form on the stems of tomato plants by inoculation with
Agrobacterium tumefaciens
. Free ether-soluble auxins in the galls and in normal tomato stem tissue were extracted and the acidic and neutral fractions of the extracts were examined by paper chromatography. Evidence for the presence of 3-indolylacetie acid (
IAA
), 3-indole-carboxylic acid (
ICA
) and 3-indolyl-acetonitrile (
IAN
) was found in both the crown-gall and normal stem tissue extracts. This evidence was based on
R
f
values, chromogenic reactions, bioassay results and in the case of
ICA
on fluorescence in ultra-violet light. Further confirmation of the presence of
IAN
was obtained by its conversion to
IAA
by alkaline hydrolysis. The auxins in the gall extracts were the same as those in the normal stem extracts, but were present in greater amounts. The amount of free
IAA
in the crown-gall tissue was estimated to be 8 to 12 μg/kg. A transient
IAA
-like colour reaction with Ehrlich reagent was observed in the
IAA
position on chromatograms containing gall or normal stem tissue extracts. The position of the spot corresponded closely with that of
IAA
in all solvents investigated. It was concluded that the reaction was not due to
IAA
but to a compound with properties which enable it to be readily mistaken for
IAA
on chromatograms treated with Ehrlich reagent. Areas were present on chromatograms of both normal stem and gall tissue extracts which corresponded with the ‘inhibitor
β
’ of Bennet-Clark & Kefford (1953). Unknown water-soluble growth promoting substances insoluble in ether were found to be present in the aqueous fluids expressed from both tissues.
The Presence of Both Phage PS8 and Agrobacterium turnefaciens A6 DNA Base Sequences in A6-Induced Sterile Crown-Gall Tissue Cultured in vitro
