OXR2 proteins from arabidopsis and sunflower improve tolerance to uv-b damage in Arabidopsis

TORTI, PABLO; MENCIA, REGINA; WELCHEN, ELINA

online

Congreso; RAFV 2021; 2021

Oxidation resistance (OXR) proteins are members of a protein family present in Eukaryotic organisms involved in alleviating stress, ageing, inflammatory responses and DNA damage in mammals. We previously demonstrated that increased expression of the OXR2 gene from Arabidopsis (AtOXR2) or their sunflower homologous (HaOXR2) confers tolerance to oxidative stress in Arabidopsis and maize. Here, we show that AtOXR2 transcript levels increased after UV-B exposure. Moreover, the rosette diameter and leaf area of Arabidopsis AtOXR2 and HaOXR2 overexpressor (OE) plants were not affected after repeated plant exposition to UV-B, related to the phenotype observed in Wild-type (WT) plants. We evaluated the effect of UV-B on the primary root development and demonstrated that AtOXR2 and HaOXR2 OE plants were less affected in the root growth parameters compared to WT, showing reduced levels of cell dead per root meristem. Molecular analysis of the AtOXR2 and HaOXR2 OE plants showed a differential expression of enzymes that participate in the DNA damage repair produced by UV-B and enzymes responsible for the ROS homeostasis control after UV-B exposure. These OXR2 OE plants produce lower levels of anthocyanins than WT plants after UV-B challenges. In sum, our results suggest the existence of a protective role performed by the OXR2 proteins against DNA damage in plants, exerting a positive effect, possibly regulating the cellular redox balance.