Characteristics of cytosine methylation status and methyltransferase genes in the early development stage of cauliflower (Brassica oleracea L. var. botrytis)
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DNA methylation is one of the most important epigenetic modifications involved in the development and differentiation in plants. Hypocotyl and cotyledon are the two major tissues of cauliflower (Brassica oleracea L. var. botrytis) seedlings. Both tissues show significantly different tissue specificity and regenerative abilities in vitro. However, the characteristics of DNA methylation modification and its roles in regulating the organ development in cauliflower remain largely unknown. In the present study, the DNA methylation status between the hypocotyl and cotyledon of cauliflower seedlings were analyzed. The results indicated that although the hypocotyl and cotyledon of cauliflower seedlings share the same genome, the genomic DNA methylation levels and patterns at CCGG sites were different. Compared with the cotyledon, the hypocotyl showed higher DNA methylation level, and more loci showing methylation pattern adjustments were also discovered. Twelve loci with changes of DNA methylation patterns were further explored. The quantitative expression analysis indicated that eight out of twelve sequenced fragments showed differential expression between the hypocotyl and cotyledon, of which the expression of six sequences was identified to be negative correlation with their DNA methylation status. In addition, three main DNA methyltransferase genes MET1, CMT3 and DRM were first explored in cauliflower. The results indicated that the expression of these three genes was closely associated with the different DNA methylation status in the hypocotyl and cotyledon. These findings provided more information to further explore the roles of DNA methylation modification in tissue differentiation and development of cauliflower.
KeywordsDNA methylation DNA methyltransferase genes Cauliflower (Brassica oleracea L. var. botrytis) Hypocotyl Cotyledon
We greatly thank Dr. Deling Sun at Tianjin Kernel Vegetable Research Institute, China for kindly providing the cauliflower seeds. This work was performed with financial support from The Natural Science Foundation from The National Natural Science Foundation of China (No. 31100234) and Tianjin (No. 10JCZDJC17900).
Conflict of interest
The authors declare that they have no conflict of interest.
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