DNA damage response in plants: conserved and variable response compared to animals

Abstract

The genome of an organism is under constant attack from endogenous and exogenous DNA damaging factors, such as reactive radicals, radiation, and genotoxins. Therefore, DNA damage response systems to sense DNA damage, arrest cell cycle, repair DNA lesions, and/or induce programmed cell death are crucial for maintenance of genomic integrity and survival of the organism. Genome sequences revealed that, although plants possess many of the DNA damage response factors that are present in the animal systems, they are missing some of the important regulators, such as the p53 tumor suppressor. These observations suggest differences in the DNA damage response mechanisms between plants and animals. In this review the DNA damage responses in plants and animals are compared and contrasted. In addition, the function of SUPPRESSOR OF GAMMA RESPONSE 1 (SOG1), a plant-specific transcription factor that governs the robust response to DNA damage, is discussed.

Figure 1

DNA damage response pathways in animals.Double-strand DNA break (DSB) and single-stranded DNA signal through the sensors shown in green, signal transducing kinases shown in red, mediators shown in gray, and effectors shown in blue, leading to DNA repair, cell-cycle checkpoint, apoptosis, or senescence.

Figure 2

DNA damage response pathways in plants. DNA damage signal through the sensors shown in green, signal transducing kinases shown in red, mediators shown in gray, and effectors shown in blue, leading to DNA repair, cell-cycle checkpoint, programmed cell death, and endoreduplication. Dashed lines denote hypothetical situations.