DNA methylation levels in different tissues in tea plant via an optimized HPLC method

DNA methylation is one of the most important events in epigenetics and significantly influences plant growth and development. In the present study, we established and optimized a high-performance liquid chromatography method for detecting the base composition in DNA in tea plant (Camellia sinensis L.) tissues by using saline buffers-free mobile phases. The DNA methylation level varied with tea plant tissue, cultivar, and growth stage. A relatively higher DNA methylation level was observed in tender leaf (38.34%) and pistil (38.19%) tissues, while a relatively low level was detected in capillary root (19.45%), stamen (19.61%), and old leaf (20.70%) tissues. The pattern of the methylation level formed a saddle curve during the growth of dormant buds in spring; the lowest point appeared at the stage of one leaf and a bud. The methylation level in the adventitious buds regenerated from the branch after pruning seemed to decrease with an increase in the degree of pruning. These DNA methylation levels might be associated with the development of tea plant.