Telomeres in Plants with Hypomethylated Genomes

Telomeres, nucleoprotein structures located at the ends of linear eukaryotic chromosomes, are essential for the maintenance of genome integrity and proper cell function. Traditionally, telomeres have been considered as heterochromatic regions but in light of recent results, the view on the epigenetic nature of telomeric chromatin in both plant and mammalian models is being re-examined. Relevant studies have been done using animals, while in plants data at this field are rather scarce.

We analyze methylation of telomeric cytosines and length of telomeres in hypomethylated plants; in Nicotiana tabacum culture cells cultivated in the presence of hypomethylating drugs, and in Arabidopsis thaliana plants (i) with loss of function of enzymes crucial for the maintenance of stable methylation pattern and (ii) germinated in the presence of the hypomethylating drugs. Our data demonstrate that similarly to the other repetitive sequences in the plant genome, telomeres are under epigenetic control and suggest distinctions in pathways of epigenetic regulation of telomeres and telomerase, even between different model plants.