OXR2: A MITOCHONDRIAL PROTEIN INVOLVED IN GROWTH AND DEFENSE IN ARABIDOPSIS

JUTTA LUDWIG-MÜLLER; ELINA WELCHEN; REGINA MENCIA

Simposio; Simposio Fronteras en Biociencia 3; 2018

OXR2 is an Arabidopsis mitochondrial protein that belongs to the eukaryotic OXR (OXidation Resistance) protein family. The main characteristic of this family is the presence of a TLDc domain at the C-terminal half and their role in preventing cell damage from oxidative stress in mammals. In order to study the function of the OXR2 protein we analyzed plants that constitutively overexpress OXR2 (oeOXR2), which exhibited larger size, higher biomass and prolonged vegetative stage that render in higher plant production. Also, we face plants with altered levels of OXR2 to two different pathogens: Pseudomonas syringae and Plasmodiophora brassicae, the causal agent for the clubroot disease of economic importance worldwide. Interestingly, oeOXR2 plants showed increased resistance to both (hemi)biotrophic pathogens compared to wild type (WT) plants and the opposite behavior was observed in a knockout T-DNA oxr2 mutant that was clearly more sensitive. In agreement, plants with altered expression of OXR2 have different levels of hormones like cytokinins and salicylic acid that support the responses against pathogens observed. We concluded that OXR2 constitutes another example of the interplay between mitochondrial proteins that fulfill a role connecting the organelle activity with the hormonal control of growth and defenses in plants.