Production of virus resistant plants

Claim 1

A method of producing a transformed plant cell with a reduced capacity to support the expression of a plus-sense RNA virus gene relative to an untransformed plant cell, the method comprising transforming the plant cell with a nucleic acid molecule wherein the nucleic acid molecule comprises a coding sequence operably linked to a promoter sequence, and wherein the coding sequence encodes an untranslatable plus-sense transcript that shares at least 80% nucleotide sequence similarity with a transcript of the plus-sense RNA virus gene.

Claim 2

A method of producing a transformed plant cell with a reduced capacity to support the expression of a plus-sense RNA virus gene relative to an untransformed plant cell, the method comprising transforming the plant cell with a nucleic acid molecule wherein the nucleic acid molecule comprises a coding sequence operably linked to a promoter sequence, and wherein the coding sequence encodes an untranslatable plus-sense transcript that shares at least 80% nucleotide sequence similarity with a transcript of the plus-sense RNA virus gene.

Claim 9

A method of producing a transformed plant cell with a reduced capacity to support the expression of a potyvirus gene relative to an untransformed plant cell, the method comprising transforming the plant cell with a nucleic acid molecule wherein the nucleic acid molecule comprises a coding sequence operably linked to a promoter sequence, the coding sequence comprising a premature stop codon within 50 nucleotides of a translation initiation codon and encoding an untranslatable plus-sense transcript that shares at least 85% nucleotide sequence similarity with a transcript of the potyvirus gene.

Claim 10

A method of producing a transformed plant cell with a reduced capacity to support the expression of a potyvirus gene relative to an untransformed plant cell, the method comprising transforming the plant cell with a nucleic acid molecule wherein the nucleic acid molecule comprises a coding sequence operably linked to a promoter sequence, the coding sequence comprising a premature stop codon within 50 nucleotides of a translation initiation codon and encoding an untranslatable plus-sense transcript that shares at least 85% nucleotide sequence similarity with a transcript of the potyvirus gene.

Claim 11

A method of producing a plant with a reduced susceptibility to a plus-sense RNA virus comprising the steps of: providing a nucleic acid sequence that shares at least 80% nucleotide sequence similarity with a plus-sense RNA virus gene sequence over a length of at least 100 nucleotides and wherein the nucleic acid sequence encodes a plus-sense RNA molecule; modifying the nucleic acid sequence by introducing at least one stop codon or at least one frameshift mutation such that the plus-sense RNA encoded by the modified nucleic acid molecule is untranslatable; transforming at least one plant cell with the modified nucleic acid sequence; regenerating at least one differentiated plant from the transformed plant cells; and selecting a regenerated transformed plant that exhibits reduced susceptibility to the plus-sense RNA virus.

Claim 12

A method of producing a plant with a reduced susceptibility to a plus-sense RNA virus comprising the steps of: providing a nucleic acid sequence that shares at least 80% nucleotide sequence similarity with a plus-sense RNA virus gene sequence over a length of at least 100 nucleotides and wherein the nucleic acid sequence encodes a plus-sense RNA molecule; modifying the nucleic acid sequence by introducing at least one stop codon or at least one frameshift mutation such that the plus-sense RNA encoded by the modified nucleic acid molecule is untranslatable; transforming at least one plant cell with the modified nucleic acid sequence; regenerating at least one differentiated plant from the transformed plant cells; and selecting a regenerated transformed plant that exhibits reduced susceptibility to the plus-sense RNA virus.

Claim 13

A method of producing a plant with a reduced susceptibility to infection by a target plus-sense RNA virus comprising the steps of: providing nucleic acid molecules comprising a coding sequence operably linked to a promoter sequence, wherein the coding sequence encodes an untranslatable plus-sense transcript that shares at least 80% nucleotide sequence similarity with a transcript of a gene of the target plus-sense RNA virus; transforming plant cells with the nucleic acid molecules; growing plants from the transformed plant cells; and selecting a transformed plant that shows a reduced susceptibility to infection by the target plus-sense RNA virus.

Claim 14

A method of producing a plant with a reduced susceptibility to infection by a target plus-sense RNA virus comprising the steps of: providing nucleic acid molecules comprising a coding sequence operably linked to a promoter sequence, wherein the coding sequence encodes an untranslatable plus-sense transcript that shares at least 80% nucleotide sequence similarity with a transcript of a gene of the target plus-sense RNA virus; transforming plant cells with the nucleic acid molecules; growing plants from the transformed plant cells; and selecting a transformed plant that shows a reduced susceptibility to infection by the target plus-sense RNA virus.