DNA mutagenesis in 2- and 20-yr-old Panax ginseng cell cultures
- 281 Downloads
Previously, Panax ginseng var. Mimaki C.A. Meyer had been shown to accumulate genetic mutations during long-term propagation of a callus culture over a period of 20 yr. In this study, we analyzed the mutation types and frequency in a 2-yr-old P. ginseng callus culture and compared it with the 20-yr-old callus culture, and leaves of cultivated plants. We analyzed the sequence variability between the Actin genes, which are a family of housekeeping genes; phenylalanine ammonia-lyase (PAL) and dammarenediol synthase (DDS), which actively participate in the biosynthesis of ginsenosides; and the somatic embryogenesis receptor kinases (SERK), which control plant development. The frequency of point mutations in the Actin, PAL, DDS, and SERK genes in the 2-yr-old P. ginseng callus culture was markedly higher than in cultivated plants, but lower than in the 20-yr-old callus culture. Most of the mutations in the 2-yr-old P. ginseng calli were A↔G and T↔C transitions, as in the 20-yr-old calli and intact P. ginseng plants. The number of nonsynonymous mutations was higher in the 2- and 20-yr-old callus cultures than the number of nonsynonymous mutations in cultivated P. ginseng. Interestingly, the total number of N→G or N→C substitutions in the analyzed genes was 1.6 times higher than the total number of N→A or N→T substitutions. Using a methylation-sensitive DNA fragmentation assay, we showed the level of methylcytosine to be higher in the DNA of the 20-yr-old P. ginseng calli that than in the DNA of the 2-yr-old cultures.
KeywordsPanax ginseng Cell cultures Mutagenesis Nucleotide substitutions
This work was supported by grants from the Russian Foundation for Basic Research (10-04-00189-а) and from the Far East Division of the Russian Academy of Sciences (12-III-А-06-072).
- Lauve LS, Burundukova OL, Muzarok TI, Zhuravlev YN (2008) Chromosome numbers of Panax ginseng (Araliaceae). Bot J 93:158–161Google Scholar
- Tyunin AP, Kiselev KV, Zhuravlev YN (2012) Effects of 5-azacytidine induced DNA demethylation on methyltransferase gene expression and resveratrol production in cell cultures of Vitis amurensis. Plant Cell Tiss Organ Cult. doi: 10.1007/s11240-012-0125-x