Methylation systems have been conserved during the divergence of plants and animals, although they are regulated by different pathways and enzymes. However, studies on the interactions of the epigenomes among evolutionarily distant organisms are lacking. To address this, we studied the epigenetic modification and gene expression of plant chromosome fragments (~30 Mb) in a human-Arabidopsis hybrid cell line. The whole-genome bisulfite sequencing results demonstrated that recombinant Arabidopsis DNA could retain its plant CG methylation levels even without functional plant methyltransferases, indicating that plant DNA methylation states can be maintained even in a different genomic background. The differential methylation analysis showed that the Arabidopsis DNA was undermethylated in the centromeric region and repetitive elements. Several Arabidopsis genes were still expressed, whereas the expression patterns were not related to the gene function. We concluded that the plant DNA did not maintain the original plant epigenomic landscapes and was under the control of the human genome. This study showed how two diverging genomes can coexist and provided insights into epigenetic modifications and their impact on the regulation of gene expressions between plant and animal genomes.

• Klíčová slova
• Arabidopsis genome, DNA methylation, epigenome, gene expression, human–plant hybrid cell line, whole-genome bisulfite sequencing (WGBS),
• MeSH
• Arabidopsis genetika   MeSH
• buněčné linie MeSH
• chromozomy rostlin genetika   MeSH
• DNA rostlinná genetika   MeSH
• epigeneze genetická genetika   MeSH
• epigenom genetika   MeSH
• epigenomika metody   MeSH
• genom rostlinný genetika   MeSH
• hybridní buňky fyziologie   MeSH
• lidé MeSH
• methyltransferasy genetika   MeSH
• metylace DNA genetika   MeSH
• repetitivní sekvence nukleových kyselin genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA rostlinná MeSH
• methyltransferasy MeSH

Telomere homeostasis is regulated at multiple levels, including the local chromatin structure of telomeres and subtelomeres. Recent reports demonstrated that a decrease in repressive chromatin marks, such as levels of cytosine methylation in subtelomeric regions, results in telomere elongation in mouse cells. Here we show that a considerable fraction of cytosines is methylated not only in subtelomeric, but also in telomeric DNA of tobacco BY-2 cells. Drug-induced hypomethylation (demonstrated at subtelomeric, telomeric, and global DNA levels) results in activation of telomerase. However, in contrast to mouse cells, the decrease in 5-methylcytosine levels and upregulation of telomerase do not result in any changes of telomere lengths. These results demonstrate the involvement of epigenetic mechanisms in the multilevel process of regulation of telomerase activity in plant cells and, at the same time, they indicate that changes in telomerase activity can be overridden by other factors governing telomere length stability.

• MeSH
• adenin analogy a deriváty   farmakologie   MeSH
• aktivace enzymů účinky léků   MeSH
• cytidin analogy a deriváty   farmakologie   MeSH
• DNA rostlinná chemie   účinky léků   MeSH
• epigeneze genetická MeSH
• genetická transkripce účinky léků   MeSH
• kultivované buňky MeSH
• metylace DNA účinky léků   MeSH
• nukleozomy účinky léků   fyziologie   MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• tabák cytologie   účinky léků   genetika   metabolismus   MeSH
• telomerasa metabolismus   MeSH
• telomery chemie   účinky léků   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 9-(2,3-dihydroxypropyl)adenine MeSH Prohlížeč
• adenin MeSH
• cytidin MeSH
• DNA rostlinná MeSH
• nukleozomy MeSH
• pyrimidin-2-one beta-ribofuranoside MeSH Prohlížeč
• rostlinné proteiny MeSH
• telomerasa MeSH

Developmental processes are closely connected to certain states of epigenetic information which, among others, rely on methylation of chromatin. S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) are key cofactors of enzymes catalyzing DNA and histone methylation. To study the consequences of altered SAH/SAM levels on plant development we applied 9-(S)-(2,3-dihydroxypropyl)-adenine (DHPA), an inhibitor of SAH-hydrolase, on tobacco seeds during a short phase of germination period (6 days). The transient drug treatment induced: (1) dosage-dependent global DNA hypomethylation mitotically transmitted to adult plants; (2) pleiotropic developmental defects including decreased apical dominance, altered leaf and flower symmetry, flower whorl malformations and reduced fertility; (3) dramatic upregulation of floral organ identity genes NTDEF, NTGLO and NAG1 in leaves. We conclude that temporal SAH-hydrolase inhibition deregulated floral genes expression probably via chromatin methylation changes. The data further show that plants might be particularly sensitive to accurate setting of SAH/SAM levels during critical developmental periods.

• MeSH
• adenin analogy a deriváty   toxicita   MeSH
• adenosylhomocysteinasa antagonisté a inhibitory   metabolismus   MeSH
• DNA primery genetika   MeSH
• epigeneze genetická účinky léků   fyziologie   MeSH
• klíčení účinky léků   fyziologie   MeSH
• komplementární DNA genetika   MeSH
• květy anatomie a histologie   fyziologie   MeSH
• metylace DNA MeSH
• neparametrická statistika MeSH
• pyl fyziologie   MeSH
• regulace genové exprese u rostlin účinky léků   genetika   fyziologie   MeSH
• rostlinné proteiny metabolismus   MeSH
• Southernův blotting MeSH
• tabák enzymologie   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 9-(2,3-dihydroxypropyl)adenine MeSH Prohlížeč
• adenin MeSH
• adenosylhomocysteinasa MeSH
• DNA primery MeSH
• GLO protein, Nicotiana tabacum MeSH Prohlížeč
• komplementární DNA MeSH
• rostlinné proteiny MeSH

The widespread occurrence of epigenetic alterations in allopolyploid species deserves scrutiny that DNA methylation systems may be perturbed by interspecies hybridization and polyploidization. Here we studied the genes involved in DNA methylation in Nicotiana tabacum (tobacco) allotetraploid containing S and T genomes inherited from Nicotiana sylvestris and Nicotiana tomentosiformis progenitors. To determine the inheritance of DNA methyltransferase genes and their expression patterns we examined three major DNA methyltransferase families (MET1, CMT3 and DRM) from tobacco and the progenitor species. Using Southern blot hybridization and PCR-based methods (genomic CAPS), we found that the parental loci of these gene families are retained in tobacco. Homoeologous expression was found in all tissues examined (leaf, root, flower) suggesting that DNA methyltransferase genes were probably not themselves targets of uniparental epigenetic silencing for over thousands of generations of allotetraploid evolution. The level of CG and CHG methylation of selected high-copy repeated sequences was similar and high in tobacco and its diploid progenitors. We speculate that natural selection might favor additive expression of parental DNA methyltransferase genes maintaining high levels of DNA methylation in tobacco, which has a repeat-rich heterochromatic genome.

• MeSH
• diploidie MeSH
• DNA rostlinná genetika   MeSH
• DNA-(cytosin-5-)methyltransferasa klasifikace   genetika   metabolismus   MeSH
• epigeneze genetická MeSH
• exprese genu MeSH
• fylogeneze MeSH
• genom rostlinný MeSH
• klonování DNA MeSH
• metylace DNA genetika   MeSH
• molekulární sekvence - údaje MeSH
• multigenová rodina * MeSH
• polyploidie MeSH
• repetitivní sekvence nukleových kyselin MeSH
• rostlinné geny * MeSH
• sekvence nukleotidů MeSH
• selekce (genetika) MeSH
• tabák enzymologie   genetika   MeSH
• tkáňová distribuce MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA rostlinná MeSH
• DNA-(cytosin-5-)methyltransferasa MeSH