The mitochondrial oxidation resistance protein AtOXR2 increases plant biomass and tolerance to oxidative stress

COLOMBATTI, FRANCISCO; MENCIA, REGINA; GARCIA, LUCILA; MANSILLA, NATANAEL; ALEMANO, SERGIO; ANDRADE, ANDREA M; GONZALEZ, DANIEL H; WELCHEN, ELINA

JOURNAL OF EXPERIMENTAL BOTANY

OXFORD UNIV PRESS

Año: 2019

0022-0957

This study demonstrates the existence of the oxidation resistance (OXR) protein family in plants. There are six OXRmembers in Arabidopsis that contain the highly conserved TLDc domain that is characteristic of this eukaryotic protein family. AtOXR2 is a mitochondrial protein able to alleviate the stress sensitivity of a yeast oxr1 mutant. It wasinduced by oxidative stress and its overexpression in Arabidopsis (oeOXR2) increased leaf ascorbate, photosynthesis, biomass, and seed production, as well as conferring tolerance to methyl viologen, antimycin A, and high lightintensities. The oeOXR2 plants also showed higher ABA content, changes in ABA sensitivity, and modified expressionof ABA- and stress-regulated genes. While the oxr2 mutants had a similar shoot phenotype to the wild-type, they exhibited increased sensitivity to stress. We propose that by influencing the levels of reactive oxygen species (ROS),AtOXR2 improves the efficiency of photosynthesis and elicits basal tolerance to environmental challenges that increase oxidative stress, allowing improved plant growth and biomass production.