Isolated DNA sequence capable of serving as regulatory element in a chimeric gene which can be used for the transformation of plants

Abstract

An isolated DNA sequence capable of serving as regulatory element in a chimeric gene which can be used for the transformation of plants is disclosed. A chimeric gene for the transformation of plants is also disclosed. The gene comprises at least, in the direction of transcription, a promoter sequence, a transgene and a regulatory element, characterized in that the regulatory element consists of at least one intron 1 in the noncoding 5′ region of a plant histone gene allowing the expression of the protein in the zones undergoing rapid growth. The production of transgenic plants is also disclosed.

1 . An isolated DNA sequence capable of serving as a regulatory element in a chimeric gene which can be used for the transformation of plants and allowing the expression of the product of translation of the chimeric gene in particular in the regions of the plant undergoing rapid growth, characterized in that it comprises at least one intron such as the first intron (intron 1) of the noncoding 5′ region of a plant histone gene.  
     
     
         2 . DNA sequence according to  claim 1 , characterized in that histone intron comes from a plant histone gene of the “H3.3-like” type.  
     
     
         3 . DNA sequence according to either of claims  1  and  2 , characterized in that histone intron 1 comes from a dicotyledonous plant.  
     
     
         4 . DNA sequence according to  claim 3 , characterized in that histone intron 1 comes from  Arabidopsis thaliana.    
     
     
         5 . DNA sequence according to either of claims  1  and  2 , characterized in that histone intron 1 comes from a monocotyledonous plant.  
     
     
         6 . DNA sequence according to  claim 5 , characterized in that histone intron 1 comes from  Zea mays.    
     
     
         7 . DNA sequence according to any one of  claims 1  to  6 , characterized in that intron 1 is oriented, in the direction of transcription of the chimeric gene, in a direct or reversed manner relative to its initial orientation in the direction of transcription of the gene from which it is derived.  
     
     
         8 . DNA sequence according to any one of  claims 1  to  7 , characterized in that the regulatory element comprises two introns 1, identical or different, which are combined.  
     
     
         9 . Chimeric gene for the transformation of plants comprising at least, in the direction of transcription, one regulatory element comprising a promoter sequence, a sequence of a herbicide tolerance gene and a regulatory element, characterized in that the regulatory element comprises, in addition, an intron 1 according to any one of  claims 1  to  8 .  
     
     
         10 . Chimeric gene according to  claim 9 , characterized in that the promoter sequence comes from a promoter of a plant histone gene.  
     
     
         11 . Chimeric gene according to either of claims  9  and  10 , characterized in that the promoter zone comes from the same plant histone gene as intron 1.  
     
     
         12 . Chimeric gene according to any one of  claims 9  to  11 , characterized in that the promoter sequence comprises a promoter for a duplicated plant histone.  
     
     
         13 . Chimeric gene according to any one of  claims 9  to  12 , characterized in that the promoter sequence contains at least one promoter of a plant histone gene combined with a different promoter derived from a gene which can be naturally expressed in plants.  
     
     
         14 . Chimeric gene according to one of  claims 9  to  13 , characterized in that the coding gene makes it possible to confer on plants an enhanced tolerance to a herbicide.  
     
     
         15 . Chimeric gene according to  claim 14 , characterized in that the herbicide tolerance gene is fused with a DNA sequence encoding a signal peptide allowing the accumulation of the product of translation of the herbicide tolerance gene in a subcellular compartment.  
     
     
         16 . Chimeric gene according to  claim 15 , characterized in that the signal peptide zone allows the accumulation of the product of translation of the herbicide tolerance gene in the plastid compartment.  
     
     
         17 . Chimeric gene according to  claim 16 , characterized in that the signal peptide sequence comprises, in the direction of transcription, at least one signal peptide sequence of a plant gene encoding a signal peptide directing transport of a polypeptide to a plastid, optionally a portion of the sequence of the mature N-terminal part of a plant gene produced when the first signal peptide is cleaved by proteolytic enzymes, and then optionally a second signal peptide of a plant gene encoding a signal peptide directing transport of the polypeptide to a sub-compartment of the plastid.  
     
     
         18 . Chimeric gene according to any one of  claims 9  to  17 , characterized in that the herbicide tolerance gene encodes an enzyme which is active towards herbicides whose target is EPSPS.  
     
     
         19 . Chimeric gene according to  claim 18 , characterized in that the herbicide tolerance gene encodes an enzyme which is active towards glyphosate.  
     
     
         20 . Vector for the transformation of plants, characterized in that it comprises a chimeric gene according to any one of  claims 9  to  19 .  
     
     
         21 . Strain of Agrobacterium sp., characterized in that it contains a vector according to  claim 20 .  
     
     
         22 . Transformed plant cells, characterized in that it contains a chimeric gene according to any one of  claims 9  to  19 .  
     
     
         23 . Transformed plant or plant portion obtained from a cell according to  claim 22 .  
     
     
         24 . Process for the construction of a chimeric gene according to any one of  claims 9  to  23 , which comprises isolating an intron 1 from a plant histons gene as defined in any one of  claims 1  to  8 , a promoter sequence, a signal peptide, and at least one transgene, and assembling them, in that order in the direction of transcription of the transgene.