Epigenetics: a renewed look at tree adaptability
Trees live longer than many other plants and are exposed to various environmental factors during their lives. Changes in temperature and water availability can cause epigenetic changes, causing trees to adapt.
What is epigenetic change? External influences spontaneously change the chemical structure on a gene. DNA methylation is a well-known example: a methyl group is added to DNA. This allows certain genes to be switched on and off without changing the DNA sequence. Epigenetics studies this phenomenon.
INBO investigated the influence of climate on the epigenome, the operating system of DNA, in the Lombardy poplar. This is a poplar clone that has spread worldwide since the 18th century. Because this poplar has no genetic variation, it is an ideal model for epigenetic research. The Lombardy poplar adapts by switching genes on and off, not by DNA variation.
We studied dozens of Lombardy poplars across Europe for epigenetic changes. We also investigated the heritability of the epigenome and its impact on adaptability.
Although we found no link between climate and epigenome, we discovered that specific DNA methylations are very stable and are passed on over several generations. These DNA methylations can be used to reconstruct the ancestry and recent history of a tree. In addition, we found DNA methylations that varied strongly with the seasons. The Lombardy poplar was also found to have a high adaptability, enabling it to survive in different climates worldwide.
Image above: Lombardy poplar (photo INBO)