Chimeric gene for the transformation of plants

Abstract

Chimeric gene for conferring to plants an increased tolerance to a herbicide having as its target EPSPS comprises, in the direction of transcription, a promoter region, a transit peptide region, a coding sequence for glyphosate tolerance and a polyadenylation signal region, wherein the transit peptide region comprises, in the direction of translation, at least one transit peptide of a plant gene encoding a plastid-localised enzyme, a partial sequence of the N-terminal mature part of a plant gene encoding a plastid-localised enzyme and then a second transit peptide of a plant gene encoding a plastid-localised enzyme. Production of glyphosate-tolerant plants is disclosed.

We claim: 
     
       1. A nucleic acid construct which codes for a polypeptide sufficient for localization of a gene product in a chloroplast of a plant cell which polypeptide comprises a fusion which in the direction of translation comprises a first chloroplast transit peptide from a ribulose-1,5-biphosphate carboxylate small subunit, an N-terminal domain of a mature ribulose-1,5-bisphosphate carboxylate small and subunit protein and a second chloroplast transit peptide from a ribulose-1,5-bisphosphate carboxylate small subunit. 
     
     
       2. The nucleic acid construct of claim 1 wherein said first chloroplast transit peptide and said second chloroplast transit peptide have identical amino acid sequences. 
     
     
       3. The nucleic acid construct of claim 1 wherein said first chloroplast transit peptide and said second chloroplastic transit peptides each have different amino acid sequences. 
     
     
       4. The nucleic acid construct of claim 1 wherein said first or second transit peptide is a transit peptide of a maize ribulose-1,5-bisphosphate carboxylate small subunit. 
     
     
       5. The nucleic acid construct of claim 1 wherein said N-terminal domain is an N-terminal domain of a mature maize ribulose-1,5-bisphosphate carboxylate small subunit. 
     
     
       6. The nucleic acid construct of claim 1 wherein said first or second transit peptide and said N-terminal domain are from the same 1,5-bisphosphate carboxylase small subunit protein. 
     
     
       7. The nucleic acid construct of claim 1 wherein said first or second transit peptide is a transit peptide of a sunflower ribulose-1,5-bisphosphate carboxylate small subunit. 
     
     
       8. The nucleic acid construct of claim 1 wherein said N-terminal domain is an N-terminal domain of mature sunflower ribulose-1,5-bisphosphate carboxylase small subunit. 
     
     
       9. The nucleic acid construct .[.of any.]. of claim.[.s.]. 1, .[.5, 6 or 8.]. wherein said N-terminal domain comprises about 10 to about 40 amino acids. 
     
     
       10. The nucleic acid construct .[.of any.]. of claim .[.1,.]. 5, .[.6 or 8.]. wherein said N-terminal domain comprises about 18 to about 33 amino acids. 
     
     
       11. A nucleic acid construct which codes for a polypeptide sufficient for localization of a gene product in a chloroplast of a plant cell which polypeptide comprises a fusion which in the direction of translation comprises a first chloroplast transit peptide from a sunflower ribulose-1,5-bisphosphate carboxylase small subunit, approximately 22 amino acids from the N-terminal region of a mature maize ribulose-1,5-bisphosphate carboxylate small subunit and a second chloroplast transmit peptide from a maize ribulose-1,5-bisphosphate carboxylate small subunit. .Iadd. 
     
     
       12.  A plant which comprises in its genome a nucleic acid sequence encoding a transit peptide region, wherein the nucleic acid sequence encoding the transit peptide region comprises, in the direction of transcription, a) a transit peptide sequence of a ribulose-1,5-bisphosphate carboxylase oxygenase small subunit,   b) a sequence encoding an N-terminal domain from a nature ribulose-1,5-bisphosphate carboxylase oxygenase small subunit, and   c) a transit peptide sequence of a ribulose-1,5-bisphosphate carboxylase oxygenase small subunit. .Iaddend..Iadd.   
     
     
       13.  A plant as claimed in claim 12, wherein the N-terminal domain comprises 10-40 amino acids. .Iaddend..Iadd.14. A plant as claimed in claim 13, wherein the N-terminal domain is from maize, sunflower, pea or tobacco. .Iaddend..Iadd.15. A plant which contains in its genome a nucleic acid sequence encoding a transit peptide region, wherein the nucleic acid sequence encoding the transit peptide region comprises in the direction of transcription, a) a transit peptide sequence of sunflower ribulose-1,5-bisphosphate carboxylase oxygenase small subunit,   b) a sequence encoding an N-terminal domain of a mature maize ribulose-1,5-bisphosphate carboxylase oxygenase small subunit, and   c) a transit peptide sequence of maize ribulose-1,5-bisphosphate carboxylase oxygenase small subunit. .Iaddend..Iadd.16. A plant transformation vector comprising nucleic acid sequence encoding a transit peptide region, wherein the nucleic acid sequence encoding the transit peptide region comprises, in the direction of transcription,   a) a transit peptide sequence of a ribulose-1,5-bisphosphate carboxylase oxygenase small subunit,   b) a sequence encoding an N-terminal domain from a mature ribulose-1,5-bisphosphate carboxylase oxygenase, and   c) a transit peptide sequence of a ribulose-1,5-bisphosphate carboxylase oxygenase small subunit. .Iaddend..Iadd.17. A plant transformation vector as claimed in claim 16, wherein the transit peptide sequence a) is a sunflower transit peptide sequence, the N-terminal domain comprises 10-40 amino acids from a mature ribulose-1,5-bisphosphate carboxylase oxygenase, and the transit peptide sequence c) is a maize transit peptide sequence. .Iaddend.