Recent discoveries in the field of epigenetics, the study of inheritance of traits that occur without changing the DNA sequence, have shown that chronological age in mammals correlates with epigenetic changes that accumulate during the lifetime of an individual.
In humans, this observation has led to the development of epigenetic clocks, which are now extensively used as biomarkers of aging. While these clocks work accurately from birth until death, they are set back to zero in each new generation.
Now, an international team co-led by the University of Georgia, the GEOMAR Helmholtz Centre for Ocean Research Kiel and the Technical University of Munich, shows that epigenetic clocks not only exist in plants, but that these clocks keep ticking accurately over many generations. In a new study published in the journal Science, the team describes how this clock can tell time with a resolution from decades to centuries, an accuracy that cannot be achieved with traditional DNA mutation-based clocks.
The research sheds new light on microevolutionary questions that have been challenging to resolve, such as the timing of introduction of invasive species and the consequences of human activities since the emergence of modern industrialization.
“Our first hint that an epigenetic clock exists in plants was revealed when we studied how DNA methylation, a chemical modification to DNA sequence underlying many epigenetic processes, varied across numerous branches in a 300-year-old poplar tree,” said Frank Johannes, professor of plant epigenomics at the Technical University of Munich and co-author of the study. “We combined DNA methylation data with branch diameter and coring data to count tree rings, which reflects branch age. We were unable to core one branch, but we accurately estimated its age using only DNA methylation data, which provided the first clues there exists an epigenetic clock in plants.”
2023-09-30 06:48:02
Link from phys.org