The present invention relates to improved promoters and utilization
thereof, in particular to promoters which are improved so as not to
undergo methylation in the course of constructing transformants, and
utilization thereof. The improved promoters of the present invention are
represented by the following (1) and (2): (1) a DNA comprising the
nucleotide sequences shown in SEQ ID NOS: 1 to 4; (2) a DNA comprising a
nucleotide sequence consisting of the nucleotide sequences shown in SEQ
ID NOS 1 to 4, wherein one to several nucleotides are deleted, added or
inserted and the deleted, added or inserted sequence is free from any
consecutive sequences represented by CG, CAG, CTG, CCG or CGG; the DNA
having promoter activity. According to the present invention, the
expression efficiency of a structural gene can be enhanced even in a
plant, e.g. chrysanthemum, which has weak expression of the structural
gene by a cauliflower mosaic virus 35S promoter which has been considered
a high expression promoter for plants.