Cross-reaction experiments with closely related bacterial species
were performed to rule out relevant cross-reactions. Briefly,
the Agrobacterium sp. TMS1 specific MGB probe was tested with
samples from closely related bacterial species as far as available
to ensure specificity. No relevant (Ct > 40) overlap in the fluorescence
signal was detected using the TMS1 MGB probe. Defined
amounts of DNA from a known species were quantified by realtime
PCR and additionally spiked in a mixture of DNA from other
bacterial strains or DNA extracted from samples. The fluorescence
signal given by the DNA alone was then compared to the signal
obtained from the spiked DNA. No significant differences were
observed, indicating high specificity of the probe used and no relevant
cross-reaction. Moreover, with the primers from the TMS1
region, a fragment is amplified outside the T-DNA which is known
as the part to be inserted in the plant genome during infection
(Citovsky et al., 2007). For this reason, amplification products can
be provided only from the bacteria containing the plasmid, and
not from transformed plant cells. However this has been investigated
in our study and the uses of TMS1 region products from
the Ti plasmid are amplified from the bacterial cells exclusively