DNA replication errors and DNA damages due to reactive oxygen species, UV, radiation and so on have occurred throughout life span. Most of DNA damages and replication errors can be repaired, but some damages and errors cannot be repaired and result in mutations. Most of mutations are deleterious, and the accumulation of somatic mutations causes cellular dysfunction, resulting in less viability. Although trees, which generally have long life span, are exposed to many risks of occurring and accumulating mutations caused by DNA damages or replication errors, they can maintain to live long time. In this study, we focused on the DNA repair ability as a mechanism to suppress the occurrence of mutations, and examined whether trees have high DNA repair ability. We compared copy number of genes within gene family associated with DNA repair across plant species using database. Using PLAZA database, we collected data on the copy number of genes in 144 gene family associated with DNA repair across 45 plants species including trees, perennial herbs and annual herbs. Then, we clustered species based on the copy number of genes, and compared the copy number of DNA repair genes between trees and herbs for each gene family.
Results/Conclusions
As a result of clustering, 31 species were divided into a cluster with high copy number and 5 species were divided into a cluster with low copy number. In the cluster with high copy number, there were no significant difference in the number of species of each life form. In contrast, in the cluster with low copy number, no tree species were included. As a result of comparison analysis for the copy number of DNA repair genes between trees and herbs for each gene family, trees had significantly higher copy number of genes within a gene family associated with repair of base lesions, DNA single strand breaks and double strand breaks and a gene family associated with DNA damage response and epigenetic regulations than herbs. Assuming that species with high copy number of DNA repair genes has high DNA repair ability, trees would have high DNA repair ability to response to DNA damages and to repair of DNA damages including base lesions, DNA single strand breaks and double strand breaks.