Ses Europe N.v./s.a.

Sesvanderhave Nv

Emmanuelle Lauber

Hubert Guilley

Ken Richards

Elodie Klein

David Gilmer

Gerard Jonard

G&eacute;rard Jonard

The present invention concerns a method of genetic modification of a TGB-3 wild type viral sequence for reducing or suppressing the possible deleterious effects of the agronomic properties of a transformed plant or plant cell by said TGB-3 viral sequence. The invention further relates to genetically modified TGB-3 viral sequences suitable to induce gene silencing. In particular hairpin constructs based on such sequences proved highly efficient to induce a PTGS mechanism and degradation of the whole of RNA2 thereby. When plants are transformed accordingly the spread of the virus in the plant is significantly reduced or blocked.

P15 hairpin constructs and use

The present invention concerns a method of genetic modification of a TGB-3 wild type viral sequence for reducing or suppressing the possible deleterious effects of the agronomic properties of a transformed plant or plant cell by the TGB-3 viral sequence, comprising the following successive steps: submitting the sequence to point mutation(s) which allow the substitution of at least one amino-acid into a different amino-acid, selecting genetically modified TGB-3 wild type viral sequences having the point mutation(s) and which are not able to promote cell-to-cell movement of a mutant virus having a dysfunctional TGB-3 wild type viral sequence, when expressed in trans from a replicon, further selecting among the genetically modified TGB-3 viral sequences, the specifically genetically modified sequence which inhibits infection with a co-inoculated wild type virus when the mutant form was expressed from a replicon, and recovering the specifically genetically modified TGB-3 viral sequence.

Method of genetic modification of a wild type viral sequence

Growing community of inventors

Castanet-Tolosan, France

Emmanuelle Lauber