From Seed to Tree: The Functioning and Evolution of DNA Repair in Plants

Abstract

In order to alleviate harmful effects of DNA damage and maintain genome integrity, all living organisms have developed a complex network of DNA repair mechanisms. However, the biochemical and genetic studies of DNA repair pathways have hitherto focused mostly on bacterial, yeast and mammalian systems ... Plants are sessile organisms, which are continuously exposed to a wide variety of biotic and abiotic stresses, which can cause DNA damages directly or indirectly via the generation of reactive oxygen species (ROS) (Roldán-Arjona & Ariza, 2009). In plants, mutations, which initially arise in somatic cells, may also be present in gametes because plants lack a reserved germline and produce meiotic cells late in development (Walbot and Evans, 2003). However, the mutation rate in long-lived coniferous forest trees, such as pines, is not unexpectedly high, which indicates that the activities responsible for maintaining genome integrity must be efficient in somatic cells (Willyard et al., 2007). This chapter gives an overview of the special requirement of DNA repair in plants particularly from the point of view of longevity and the lifestyle of plants. We introduce the sequences of the Scots pine (Pinus sylvestris L.) putative RAD51 and KU80 genes which are involved in the repair of double-strand breaks (DSBs) by homologous recombination (HR) and non-homologous end-joining (NHEJ), respectively.