Mitochondria, organelles of bacterial origin, contain their own DNA, which is essential for cellular respiration. In plants, several enzymes required for its maintenance have been lost over the course of evolution.
In a study published in The Plant Cell, José Gualberto’s team describes the fundamental role of the OEX1 protein in maintaining mitochondrial DNA in Arabidopsis thaliana. OEX1 compensates for the absence of key enzymatic activities by removing potentially harmful DNA structures and contributing to DNA repair.
In mutant plants lacking this protein, the researchers observed genomic rearrangements, sterility, and developmental defects. Two OEX1 isoforms, generated by alternative splicing, may have distinct roles depending on the tissue or developmental stage.
This work highlights a central player in mitochondrial genome stability and its impact on plant growth and fertility.
