Fusion protein and transgenic plant expressing said protein

Abstract

The present invention concerns a nucleic acid molecule capable of expressing, in at least one plant tissue, a chimeric protein comprising a polygalacturonase (PG) of fungal, bacterial or insect origin and a plant polygalacturonase inhibitor protein (PGIP) plant capable of inhibiting said PG. The present invention also relates to transgenic plants that express said chimeric protein.

The invention claimed is: 
     
       1. A nucleic acid molecule coding for a chimeric protein comprising: an amino acid sequence with polygalacturonase inhibitor (PGIP) activity of plant origin; and an amino acid sequence with polygalacturonase (PG) activity of fungal, bacterial or insect origin;
 wherein expression of the chimeric protein is under control of a non-constitutive promoter; and 
 wherein the amino acid sequence with the PGIP activity is separated from the amino acid sequence with the PG activity by a linker configured to prevent intramolecular interactions, 
 wherein the nucleic acid molecule comprises a nucleotide sequence consisting essentially of SEQ ID NO: 5, SEQ ID NO: 7 or SEQ ID NO: 9. 
 
     
     
       2. The nucleic acid molecule according to  claim 1 , wherein said chimeric protein comprises the amino acid sequence with the polygalacturonase inhibitor (PGIP) activity of plant origin at the N-terminal portion of the chimeric protein, and the amino acid sequence with the polygalacturonase (PG) activity of fungal, bacterial or insect origin at the C-terminal portion of the chimeric protein. 
     
     
       3. The nucleic acid molecule according to  claim 1 , comprising a region coding for a signal peptide. 
     
     
       4. The nucleic acid molecule according to  claim 1 , wherein the promoter regulates the expression of PR-1 gene of  Arabidopsis  (PPR-1). 
     
     
       5. The nucleic acid molecule of  claim 1 , incorporated in an expression vector. 
     
     
       6. The expression vector according to  claim 5 , wherein the nucleic acid molecule is under the control of the promoter which is active in plants. 
     
     
       7. The expression vector according to  claim 6 , wherein the promoter is pathogen inducible. 
     
     
       8. A method for producing at least one transgenic plant cell, comprising: introducing the expression vector of  claim 5  into at least one plant cell. 
     
     
       9. The nucleic acid molecule according to  claim 1 , wherein the promoter is pathogen inducible. 
     
     
       10. The nucleic acid of  claim 1  incorporated in at least one host cell. 
     
     
       11. The host cell of  claim 10 , wherein the host cell is a plant cell.