conference schedule and program with abstracts - Horticulture ...

O-41
Gene silencing as strategy to induce grapevine fan leaf virus (GFLV) resistance in
grapevine rootstocks
E. Torres, A. Cadavid, C. Santibáñez, F. Godoy, C. Medina, P. Arce-Johnson*
P. Universidad Catholica de Chile, Fac. de Ciencias Biologicas, Santiago, Chile
*Corresponding author: parce@bio.puc.cl
Viral infections in grapevines cause physiological disorders that lead to foliar deformations,
alterations in the berry color and finally reductions in productivity. Most viral infections in
grapevine are disseminated by biological vectors and then by the vegetative propagation of
infected material. More than ten viruses commonly infect the grapevine, and it is not rare to find
two or three different viruses in one infected plant. There are not efficient chemical treatments
against virus infections. A molecular strategy to induce virus resistance in plants is gene
silencing. This strategy requires the transformation of plants with a short sequence of the
pathogen in a way that a double-strand RNA structure is formed during transcription, initiating
gene silencing in the host. The objective of this work is the induction of virus silencing in
grapevine rootstocks plants in order to use it for grafting. It is hoped that the mobile silencing
signal induces virus silencing in the scion. We have transformed rootstocks plants (110 Richter
and Harmony) by co-culture of embryogenic and organogenic tissues with Agrobacterium
tumefaciens carrying a silencing vector containing a sequence of the coat protein of grapevine
fanleaf virus (GFLV). Twenty-three transgenic plants of the 110 Richter rootstock have been
recovered, analyzed by PCR against the GFLV sequence, and propagated to obtain several plants
of each line. The transgenic rootstocks have been grafted with GFLV infected plants that were
positive for virus presence by RT-PCR analysis. Once the grafts were set, the RT-PCR analysis
was repeated in the scion. After one month the detection of the virus has been abolished in the
scion, in four of ten analyzed rootstocks lines and the same result was maintained after six
months.
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