Genetic and Epigenetic Mechanisms of Longevity in Forest Trees.

Trees are unique in terms of development, sustainability and longevity. Some species have a record lifespan in the living world, reaching several millennia. The aim of this review is to summarize the available data on the genetic and epigenetic mechanisms of longevity in forest trees. In this review, we have focused on the genetic aspects of longevity of a few well-studied forest tree species, such as , , and , , and , as well as on interspecific genetic traits associated with plant longevity. A key trait associated with plant longevity is the enhanced immune defense, with the increase in gene families such as , and in the expansion of the disease resistance families in species and the steady expression of R-genes in . A high copy number ratio of the family genes involved in DNA repair and defense response was found in , and . An increase in the number of copies of the epigenetic regulators (maintenance of meristems and genome integrity) and (antiviral protection) was also found in long-lived trees. CHG methylation gradually declines in the gene in , a conservative age biomarker in conifers, as the age increases. It was shown in that grafting, cutting and pruning change the expression of age-related genes and rejuvenate plants. Thus, the main genetic and epigenetic mechanisms of longevity in forest trees were considered, among which there are both general and individual processes.