AsianScientist (Jul. 25, 2019) – Researchers in Japan have edited plant mitochondrial DNA for the first time, which could lead to a more secure food supply. They published their findings in Nature Plants.
Nuclear DNA was first edited in the early 1970s, chloroplast DNA was first edited in 1988, and animal mitochondrial DNA was edited in 2008. However, successfully editing plant mitochondrial DNA has remained extremely challenging, and only now have researchers devised a suitable molecular tool.
In the present study, scientists led by Associate Professor Shin-ichi Arimura of the University of Tokyo, Japan, found a way to manipulate the complex plant mitochondrial genome. The team adapted a technique that had previously edited mitochondrial genomes of animal cells that were grown in a dish. The technique, called mitoTALENs, uses a single protein to locate the mitochondrial genome, cut the DNA at the desired gene and delete it.
They used the mitoTALENs system to delete the cytoplasmic male sterility (CMS) gene which is found inside the mitochondria of plant cells.
“Without the CMS gene, plants are fertile again,” said Arimura.
Hence, the researchers were able to create four new and fully fertile lines of rice, as well as three new lines of rapeseed (canola).
“We knew we were successful when we saw that the rice plant was more polite—it bowed deeply,” said Arimura, joking about how a fertile rice plant bends under the weight of heavy seeds.
His team hopes to use the technique to address the current lack of mitochondrial genetic diversity in crops, a potentially devastating weak point in our food supply. For example, in 1970, a fungal infection that took hold in Texas corn farms was exacerbated by a gene in the corn’s mitochondria. All corn on the farms had the same gene, so none were resistant to the infection. Fifteen percent of the entire American corn crop was killed that year. Corn with that specific mitochondrial gene has not been planted since.
“This is an important first step for plant mitochondrial research,” Arimura concluded.
The researchers plan to study the mitochondrial genes responsible for plant male infertility in more detail and identify potential mutations that could add much-needed diversity.
The article can be found at: Kazama et al. (2019) Curing Cytoplasmic Male Sterility via TALEN-mediated Mitochondrial Genome Editing.
———
Source: University of Tokyo; Photo: Tomohiko Kazama/Shin-ichi Arimura.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.
