Scientists Finally Record Successful Mitochondrial DNA Editing in Plants

July 10, 2019

Researchers from the University of Tokyo were able to edit the mitochondrial DNA of the plant for the first time. The scientists turned their attention to the cytoplasmic male sterility (CMS) of the plant, which is a type of rare plant male infertility caused by genes in the mitochondria. CMS is attributed to certain mitochondrial genes.

Using rice and rapeseed (canola), the research team used the technique called mitoTALENs, or the mitochondria localization signals transcription activator-like effector nucleases. This technique was previously used to edit mitochondrial genomes of animal cells. To sum up, the technique uses a single protein to locate the mitochondrial genome, then cut the DNA at the desired gene to delete it. By deleting the CMS gene, the plants became fertile again. The Japanese scientists likened the plants used in the experiment as "more polite," noting how the plants bowed deeply under the weight of heavy seeds.

Further investigation through sequencing showed that double-strand breaks induced by mitoTALENs were repaired by homologous recombination. This proved that the target genes and surrounding sequences were deleted, showing that mitoTALENs can be used to stably and heritably modify the mitochondrial genome in plants. This is the first time that the editing of a mitochondrial plant DNA was documented.

The mitochondria is the powerhouse of the cell. Plants get a significant portion of their energy through the mitochondria. Quoting the scientists, "without it, there is no life." Currently, there is a lack of mitochondrial genetic diversity in crops, which is a weak point in the global food production. The result of this study is an important first step towards plant mitochondrial research that could lead to a more secure food supply.

Read more from Science Daily, and see the abstract in Nature.