PARP proteins, NAD, epigenetics, and antioxidative response in abiotic stress

In higher eukaryotes and plants poly ADP-ribose polymerases (PARPs) are involved in chemical and oxidative damage. PARP proteins are shown to confer resistance to Reactive Oxygen Species and to oxidative stress. In addition, PARP activity regulates NAD pool. Synthesis and stability of PAR polymer seems to influence cell survival or death. PARP enzymes and plant PARP-domain proteins showed to exert a control of chromatin, nucleosomes, gene silencing and epigenetic regulation by transcription factor complexes. Plant PARP proteins have been shown able to regulate transcription factor complexes involved in the activation of flavonoid late biosynthesis genes, sustaining the accumulation of antioxidant anthocyanins in stressed and non stressed plants.