Abstract
Chromosomal double-strand DNA breaks (DSBs) are produced by ionizing radiation, oxygen free radicals, DNA cross-linking reagents, and DNA replication failure. There are two major repair pathways for DSBs: non-homologous end joining (NHEJ) and homologous recombination (HR). HR is also involved in meiotic recombination process.
Although plants have long played a key role in building our understanding of genetics, relatively little is known at the molecular level of HR processes of plants.
The completion of the Arabidopsis genome sequence has greatly facilitated the search for genes involved in HR in this model plant. In addition, the huge collection of T-DNA /transposon tagging mutant lines in Arabidopsis has helped identify the function of some of these genes in plants. Several Arabidopsis mutants involved in HR show hypersensitivity to DSBs-inducing agents. However, in contrast to the case in vertebrates, with a few exceptions these mutants do not show embryonic lethality or severe growth defects. This could represent a distinct advantage of plant systems for the study of DSB repair and recombination. In addition, several genes involved in HR that are unique in plants have been identified by forward genetic approaches.
In this presentation, we focus on recent advances in our knowledge of the process of HR, in higher plants
