Plant virus

Abstract

The invention relates to the field of virology. The invention provides an isolated plant virus (ToTV) named Tomato torrado virus (ToTV), and components thereof. The invention further relates to methods of producing a ToTV-resistant plant comprising the steps of identifying a ToTV-resistant donor plant, crossing said ToTV-resistant donor plant with a recipient plant, and selecting from an offspring plant a resistant plant.

1 . A plant virus named Tomato torrado virus (ToTV), deposited with the Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH on 24 Nov. 2004 under depositors reference number ToTV-E01 (DSM 16999).  
     
     
         2 . A plant virus named Tomato Marchitez virus (TMarV), to be deposited with a depository under the Budapest Treaty under depositors reference number PRI-TMarV0601.  
     
     
         3 . A virus comprising at least one nucleic acid sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:15, SEQ ID NO:16 and sequences having a nucleotide sequence homology of at least 50% thereof.  
     
     
         4 . The virus according to  claim 3 , wherein said virus is associated with one or more tomato diseases selected from the group consisting of “Torrado,” “Marchitez” and “Chocolate spot disease,” or wherein said virus, based on numerical taxonomic analysis of taxonomic descriptors essentially as defined in Table 1, shows to be more closely related to the virus as defined in  claim 1  than to any other virus, and wherein said virus is associated with a disease that causes necrotic lesions in tomato.  
     
     
         5 . An isolated or recombinant nucleic acid or ToTV-specific fragment thereof comprising a nucleic acid sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:15, SEQ ID NO:16, sequences having a nucleotide sequence homology of at least 50% to SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:15 or SEQ ID NO:16 or their complementary strands and ToTV-specific fragments thereof.  
     
     
         6 . An expression vector comprising a nucleic acid according to  claim 5 .  
     
     
         7 . A polynucleotide capable of hybridizing under stringent conditions to a nucleic acid according to  claim 5 .  
     
     
         8 . An isolated or recombinant polypeptide obtainable from a virus according to  claim 1  or a ToTV-specific fragment thereof.  
     
     
         9 . The polypeptide according to  claim 8 , wherein said polypeptide is selected from the group consisting of 23 kDa capsid protein, 26 kDa capsid protein, 35 kDa capsid protein, helicase, RNA-dependent RNA polymerase and putative movement protein (MP) of ToTV or ToTV-specific fragments thereof.  
     
     
         10 . An antigen comprising a polypeptide according to  claim 8 .  
     
     
         11 . An antibody specifically directed against the antigen according to  claim 10 .  
     
     
         12 . A method for producing an antibody against ToTV comprising the steps of: 
 a) providing a ToTV virus, or a protein or peptide fragment thereof;    b) immunizing an appropriate vertebrate host with said virus, said protein or said peptide fragment; and    c) harvesting from blood or splenocytes of said vertebrate host antibodies against said virus, said protein or said peptide fragment.    
     
     
         13 . The method according to  claim 12 , further comprising the steps of selecting one antibody-producing splenocyte, fusing said splenocyte to an immortalized hybridoma cell line to create a hybridoma fusion and allowing said hybridoma fusion to produce monoclonal antibodies.  
     
     
         14 . An antibody obtainable by a method according to  claim 12 .  
     
     
         15 . A method for identifying a viral isolate as a ToTV virus comprising reacting said viral isolate or a component thereof with an antibody according to  claim 11 .  
     
     
         16 . A method for identifying a viral isolate as a ToTV virus comprising reacting a viral isolate or a component thereof with a polynucleotide according to  claim 7 .  
     
     
         17 . A method for detecting the presence of ToTV in a sample comprising determining in said sample the presence of a ToTV virus or component thereof by reacting said sample with a polynucleotide according to  claim 6 .  
     
     
         18 . A method for identifying a ToTV-resistant plant, comprising the steps of: 
 a) exposing a plant or plant part to an infective dosage of ToTV; and    b) identifying said plant as a ToTV-resistant plant when, after said exposure, either    disease-symptoms in said plant or plant part remain absent or are delayed in expression or are at least reduced in severity or are localized relative to a susceptible control plant, or    ToTV virus or ToTV genomic sequences are not present in said plant or plant part or the presence of ToTV virus is at least quantitatively reduced relative to a susceptible control plant.    
     
     
         19 . The method according to  claim 18 , wherein in step b) the presence of ToTV in said plant or plant part is determined by performing a method according to  claim 17 .  
     
     
         20 . A method of producing a ToTV-resistant plant comprising the steps of: 
 a) identifying a ToTV-resistant donor plant by performing a method according to  claim 18;     b) crossing said ToTV-resistant donor plant with a recipient plant; and    c) selecting from offspring plants a resistant plant by performing a method according to  claim 18 .    
     
     
         21 . The method according to  claim 20 , wherein said donor plant is a plant of the family Solanaceae or Cucurbitaceae.  
     
     
         22 . The method according to  claim 20 , wherein said donor plant is a tomato plant, an eggplant plant, a pepper plant, a melon plant, a watermelon plant or a cucumber plant.  
     
     
         23 . The method according to  claim 20 , wherein said recipient plant is a plant of the family Solanaceae or Cucurbitaceae.  
     
     
         24 . The method according to  claim 20 , wherein said recipient plant is a tomato plant, an eggplant plant, a pepper plant, a melon plant, a watermelon plant or a cucumber plant.  
     
     
         25 . The method according to  claim 20 , wherein said recipient plant is a tomato plant of the species  Solanum lycopersicum , more preferably an  S. lycopersicum  line that possess commercially desirable characteristics.  
     
     
         26 . A ToTV-resistant plant, or part thereof, obtainable by a method according to  claim 20 .  
     
     
         27 . A diagnostic kit for performing the method according to  claim 16 , comprising at least one component selected from the group consisting of a virus according to  claim 1 , a virus according to  claim 2 , a virus according to  claim 3 , a virus according to  claim 4 , a polynucleotide according to  claim 7 , a polypeptide according to  claim 8 , a polypeptide according to  claim 9 , an antigen according to  claim 10 , an antibody according to  claim 11 , an antibody according to  claim 12 , an antibody according to  claim 13  and an antibody according to  claim 14 .  
     
     
         28 . Use of at least one component selected from the group consisting of a virus according to  claim 1 , a virus according to  claim 2 , a virus according to  claim 3 , a virus according to  claim 4 , a polynucleotide according to  claim 7 , a polypeptide according to  claim 8 , a polypeptide according to  claim 9 , an antigen according to  claim 10 , an antibody according to  claim 11  and an antibody according to  claim 14  for the production of a diagnostic composition.  
     
     
         29 . A diagnostic composition comprising at least one component selected from the group consisting of a virus according to  claim 1 , a virus according to  claim 2 , a virus according to  claim 3 , a virus according to  claim 4 , a polypeptide according to  claim 8 , a polypeptide according to  claim 9 , an antigen according to  claim 10 , an antibody according to  claim 11  and an antibody according to  claim 14 .  
     
     
         30 . Use of a virus according to  claim 1 , its genome, or resistance-conferring parts thereof as antiviral agent.  
     
     
         31 . Use of a virus according to of  claim 1 , or its genome, or parts thereof as expression vector.  
     
     
         32 . Use of an attenuated form of a virus according to  claim 1 , or its genome, or parts thereof, for premunition of a plant.  
     
     
         33 . An isolated or recombinant polypeptide obtainable from a virus according to  claim 2  or a ToTV-specific fragment thereof.  
     
     
         34 . An isolated or recombinant polypeptide obtainable from a virus according to  claim 3  or a ToTV-specific fragment thereof.  
     
     
         35 . A method for identifying a viral isolate as a ToTV virus comprising reacting said viral isolate or a component thereof with an antibody according to  claim 14 .  
     
     
         36 . A method for detecting the presence of ToTV in a sample comprising determining in said sample the presence of a ToTV virus or component thereof by reacting said sample with an antibody according to  claim 11 .  
     
     
         37 . A method for detecting the presence of ToTV in a sample comprising determining in said sample the presence of a ToTV virus or component thereof by reacting said sample with an antibody according to  claim 14 .  
     
     
         38 . Use of a virus according to  claim 2 , its genome, or resistance-conferring parts thereof as antiviral agent.  
     
     
         39 . Use of a virus according to  claim 3 , its genome, or resistance-conferring parts thereof as antiviral agent.  
     
     
         40 . Use of a virus according to  claim 2 , or its genome, or parts thereof as expression vector.  
     
     
         41 . Use of a virus according to  claim 3 , or its genome, or parts thereof as expression vector.  
     
     
         42 . Use of an attenuated form of a virus according to  claim 2 , or its genome, or parts thereof, for premunition of a plant.  
     
     
         43 . Use of an attenuated form of a virus according to  claim 3 , or its genome, or parts thereof, for premunition of a plant.  
     
     
         44 . The method according to  claim 25 , wherein said  Solanum lycopersicum  is an  S. lycopersicum  line that possesses one or more commercially desirable characteristics.