A1258690256lAwmc

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Testing of transgenic plant lines for detection
of transgenic VVTL-1 protein ELISA was used to
test plant lines for constitutive expression of
transgenic VVTL-1 protein. The presence of the
transgenic protein was detected in significantly
higher levels in four transgenic plant lines
compared to the negative control as indicated by
absorbance values at 405nm wavelength (Figure 3).
Greenhouse testing of transgenic plant lines for
resistance to powdery mildew incidence Susceptible
control plants developed severe disease symptoms
7 days after onset of first visible lesions
(Figure 4), receiving an average score of 5.0
(Figure 5). Six percent of transgenic plant lines
exhibited a 7-10 day delay in symptom development
compared to the susceptible controls and received
an average score ranging from 2.7 to 3.5 (Figure
5). The level of VVTL-1 expression in transgenic
plants was found to be positively co-related with
disease resistance. High disease pressure in the
greenhouse was demonstrated by the resistant
control, Vitis hybrid Tampa, which began to
exhibit disease symptoms 17 days after the
susceptible controls (Figure 5). Selected
transgenic lines are being propagated, repeatedly
re-screened and will be tested under field
conditions. In addition, transgenic VVTL-1 lines
of V. vinifera Merlot and Vitis hybrid Seyval
Blanc have been regenerated and are currently
being screened.