Dynamic change of DNA methylation and cell redox state at different micropropagation phases in birch
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Phase change-related epigenetic and physiological changes in the micropropagation process of Betula platyphylla.
To evaluate the epigenetic regulation and the cell redox state during micropropagation, Betula platyphylla was used to regenerate plants from callus. Axillary bud, callus (20 days after induction), aged callus (40 days after induction), budding callus, regenerating shoots and regenerated root were estimated for the cell redox state using 18 biochemical parameters, such as the steady-state levels of reactive oxygen, content of peroxidation products and enzymatic or non-enzymatic protective systems. These biochemical parameters at different developmental phases were found to be significantly different. DNA methylation and corresponding enzyme activities were also investigated at different phases. The average percentage of methylated CCGG sites in the three birch lines varied from 11.92 to 17.03 % at different phases. The level of DNA methylation in the axillary bud and young callus was 13.84 and 11.92 %, respectively. It increased to 12.36 % at budding callus phase and to 15.24 % in the regenerated bud. At rooting phase, DNA methylation was observed to be the highest (17.03 %). When compared between different phases, younger callus was found to have a lower level of DNA methylation (11.92 %) than that of the older callus (14.50 %), indicating that DNA methylation took place as the callus aged. The results also showed that CCGG site methylation patterns (hemi-methylation of external C sites and full methylation of internal C sites) were different at various differentiation phases. The results of principal component analysis clearly demonstrated that there were phase change-related epigenetic and physiological changes in the micropropagation process. These data lead to the identification of biochemical parameters during the process of micropropagation and demonstrate a dynamic connection between plant micropropagation in vitro, cell redox state and DNA methylation.
KeywordsBetula platyphylla DNA methylation Micropropagation Differentiation
Reactive oxygen species
- Chl a and b
Chlorophylls a and b
Author contribution statement
Conceived and designed the experiments: ZHAN YG and ZENG FS. Performed the experiments: ZENG FS, SUN FK and LUO W. Analyzed the data: ZENG FS and ZHAO XT. Contributed reagents/materials/analysis tools: ZHAN YG, ZENG FS and LIANG NS. Wrote the paper: ZENG FS and ZHAN YG.
This work was financially supported by the Fundamental Research Funds for the Central Universities (NO: 2572014DA04) and the National Natural Science Foundation of China (NO: J1210053, 31070531 and 31200463). We also thank the editor and two anonymous reviewers for many detailed and helpful comments that improved the quality of this manuscript.
Conflict of interest
The authors declare that they have no conflict of interest.
- Amako K, Chen G-X, Asada K (1994) Separate assays specific for ascorbate peroxidase and guaiacol peroxidase and for the chloroplastic and cytosolic isozymes of ascorbate peroxidase in plants. Plant Cell Physiol 35:497–504Google Scholar
- De Tullio MC, De Gara L, Paciolla C, Arrigoni O (1998) Dehydroascorbate-reducing proteins in maize are induced by the ascorbate biosynthesis inhibitor lycorine. Plant Physiol Biochem 36:433–440Google Scholar
- Giannino D, Mele G, Cozza R, Bruno L, Testone G, Ticconi C, Frugis G, Bitonti MB, Innocenti AM, Mariotti D (2003) Isolation and characterization of a maintenance DNA-methyltransferase gene from peach (Prunus persica [L.] Batsch): transcript localization in vegetative and reproductive meristems of triple buds. J Exp Bot 54:2623–2633CrossRefPubMedGoogle Scholar
- Lloyd GB, McCown BH (1980) Commercially feasible micropropagation of mountain laurel, Kalmia latifolia, by use of shoot-tip culture. Proc Int Plant Prop Soc 30:421–427Google Scholar
- Xu L, Han L, Huang B (2011) Antioxidant enzyme activities and gene expression in drought-stressed Kentucky bluegrass. J Am Soc Hortic Sci 136:247–255Google Scholar
- Zaefyzadeh M, Quliyev RA, Babayeva SM, Abbasov MA (2009) The effect of the interaction between genotypes and drought stress on the superoxide dismutase and chlorophyll content in durum wheat landraces. Turk J Biol 33:1–7Google Scholar