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 containing the DNA sequence as a regulatory element 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 comprises an intron from 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.