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

The study described here demonstrates the existence of the OXidation Resistance (OXR) protein family in plants. There are six OXR members 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. AtOXR2 is induced by oxidative stress. AtOXR2 overexpression in Arabidopsis (oeOXR2) increases leaf ascorbate, photosynthesis, biomass and seed production, as well as conferring tolerance to methyl viologen, antimycin A and high light intensities. The oeOXR2 plants also show higher ABA content, changes in ABA sensitivity and modified expression of ABA- and stress-regulated genes. While the oxr2 mutants have a similar shoot phenotype to the wild type, they exhibit 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.