Epigenetic diversity variation characteristics of Flaveria bidentis genome DNA of different organs at different developmental stages

As one of the epigenetic modifications, DNA methylation has become ubiquitous in plant genome DNA. It not only plays an important role in rapid adaptation to new environments but also participates in the process of plant growth and organ differentiation. In this study, we constructed an optimized MSAP system to analyze the methylation variation characteristics of different organs at different developmental stages of the same organs of Flaveria bidentis. The results showed that the organ-specific MSAP system amplified 536 bands by using 13 pairs of primers, in which the primer EhHM7 made the greatest contribution to epigenetic diversity, and the percentage of polymorphism was 92.45%. The developmental stage-specific MSAP system amplified 407 bands by using 14 pairs of primers, in which EcHM1 had the greatest contribution to epigenetic diversity, and the percentage of polymorphism was 80.56%. The results of varying themethylation type showed that there were significant differences in methylation levels among the different organs (roots, stems, and leaves)at different developmental stages of the same organs (old leaves and young leaves), among the three methylation variants of hemi-methylation, full methylation, and overall methylation, the methylation rate of the stem tissue was the highest, reaching 30.28%, 19.37% and 49.66%, respectively.The full-methylated and overall methylated rate of the old leaf tissue were significantly higher than those of the young leaf tissue, reaching 33.29% and 52.77%, respectively.The principal component analysis showed that the individual distribution of leaves of Flaveria bidentis were more intensive than that of roots and stem organs, and the young leaves were denser than the old leaves, which indicated that there were larger differences between individual roots and stems. This individual difference was greater than that of the leaves of Flaveria bidentis, and the individual difference of old leaves were greater than that of young leaves, which could not be ignored during sample collection. Therefore, during the studies on the invasiveness of Flaveria bidentis by using epigenetic methods, it is necessary to formulate a scientific sampling plan and consider plant organ and growth stage specificity as important factors.