Abstract:

DNA methylation is an important way to regulate gene expression，which is a main content of epigenetic research field. The way to determinating DNA methylation rate of a gene is mainly by bisulfite conversion，then amplifying the converted DNA sequence by PCR，and cloning and sequencing the PCR production to measure the rate of cytosine converted into the thymine in the sequence. Based on this method，we developed anenzyme linked immunosorbent assays（ELISA）instead of cloning and sequencing to measure the rate of cytosine converted into the thymine in DNA sequence. We used this improved method to detecting the methylation rate of promotor region sequence of recessive SP11 in the heterozygote plants containing one dominate SP11 and one recessive SP11 of Brassica rapa L. ssp. rapiferu Metzg. Compared with the original method，the method reported here is more economical and time saving.

Key words: Brassica rapa, DNA methylation, SP11 gene, bisulfite conversion, ELISA