Grapevine leafroll virus (type 2) proteins and their uses

Abstract

The present invention relates to isolated proteins or polypeptides of grapevine leafroll virus (type 2). The encoding DNA molecules either alone in isolated form or in an expression system, a host cell, or a transgenic grape plant are also disclosed. Other aspects of the present invention relates to a method of imparting grapevine leafroll resistance to grape and tobacco plants by transforming them with the DNA molecules of the present invention, a method of imparting beet yellows virus resistance to a beet plant, a method of imparting tristeza virus resistance to a citrus plant, and a method of detecting the presence of a grapevine leafroll virus, such as GRLaV-2, in a sample.

1 . An isolated RNA molecule encoding protein or polypeptide of a grapevine leafroll virus (type 2).  
     
     
         2 . The isolated RNA molecule according to  claim 1 , wherein the protein or polypeptide is selected from a group consisting of a polyprotein, an RNA-dependent RNA polymerase, a heat shock 70 protein, a heat shock 90 protein, a diverged coat protein, and a coat protein.  
     
     
         3 . An isolated DNA molecule encoding a protein or polypeptide of a grapevine leafroll virus (type 2).  
     
     
         4 . The isolated DNA molecule according to  claim 3 , wherein the protein or polypeptide is selected from a group consisting of a polyprotein, an RNA-dependent RNA polymerase, a heat shock 70 protein, a heat shock 90 protein, a diverged coat protein, and a coat protein.  
     
     
         5 . An expression system comprising a DNA molecule according to  claim 3  in a-vector heterologous to the DNA molecule.  
     
     
         6 . The expression system according to  claim 5 , wherein the protein or polypeptide is selected from a group consisting of a polyprotein, an RNA-dependent RNA polymerase, a heat shock 70 protein, a heat shock 90 protein, a diverged coat protein, and a coat protein.  
     
     
         7 . A host cell transformed with a heterologous DNA molecule according to  claim 3 .  
     
     
         8 . The host cell according to  claim 7 , wherein the host cell is selected from the group consisting of  Agrobacterium vitis  and  Agrobacterium tumefaciens.    
     
     
         9 . The host cell according to  claim 7 , wherein the host cell is selected from a group consisting of a grape cell, a citrus cell, a beet cell, and a tobacco cell.  
     
     
         10 . The host cell according to  claim 7 , wherein the protein or polypeptide is selected from a group consisting of a polyprotein, an RNA-dependent RNA-polymerase, a heat shock 70 protein, a heat shock 90 protein, a diverged coat protein, and a coat protein.  
     
     
         11 . A transgenic plant cultivar comprising the DNA molecule according to  claim 3 .  
     
     
         12 . The transgenic plant cultivar according to  claim 11 , wherein the plant cultivar is selected from a group consisting of a grape plant cultivar, a citrus plant cultivar, a beet plant cultivar, and a tobacco plant cultivar.  
     
     
         13 . The transgenic plant cultivar according to  claim 11 , wherein the protein or polypeptide is selected from a group consisting of a polyprotein, an RNA-dependent RNA polymerase, a heat shock 70 protein, a heat shock 90 protein, a diverged coat protein, and a coat protein.  
     
     
         14 . A method of imparting grapevine leafroll virus resistance to a  Vitis  scion or rootstock cultivar or a  Nicotiana  cultivar comprising the steps of: 
 (a) transforming of cells of a  Vitis  scion or rootstock cultivar or cells of a  Nicotiana  cultivar with an isolated DNA molecule encoding a protein or polypeptide of a grapevine leafroll virus (type 2); and    (b) regenerating a  Vitis  scion or rootstock cultivar or a  Nicotiana  cultivar from said transformed cells.    
     
     
         15 . The method according to  claim 14 , wherein the protein or polypeptide is selected from a group consisting of a polyprotein, an RNA-dependent RNA polymerase, a heat shock 70 protein, a heat shock 90 protein, and a coat protein.  
     
     
         16 . The method according to  claim 14 , wherein the protein or polypeptide is a grapevine leafroll virus (type 2) coat protein.  
     
     
         17 . The method according to  claim 14 , wherein the protein or polypeptide is a grapevine leafroll virus (type 2) heat shock 70 protein.  
     
     
         18 . The method according to  claim 14 , wherein the grapevine leafroll virus is GLRaV-2.  
     
     
         19 . The method according to  claim 14 , wherein said transforming is  Agrobacterium  mediated.  
     
     
         20 . The method according to  claim 14 , wherein said transforming comprises: 
 propelling particles at grape or tobacco plant cells under conditions effective for the particles to penetrate into the cell interior; and    introducing an expression vector comprising the DNA molecule into the cell interior.