Study Shows Natural Genetic Engineering in Grafted Plants

Rutgers University researchers led by Pal Maliga reported that grafted plants exchange mitochondria, the powerhouse of the cells which contain their own genomes. Furthermore, when the whole mitochondria from one plant get into the cells of another, they combine their DNA with that of the existing mitochondria. These findings, published in PNAS, show that farmers from all over the world who graft plants have been doing unintentional genetic engineering.

Maliga and team grafted one tobacco species onto another. One species had a mutation in the mitochondria that inhibits the normal development of male flower parts. Then the researchers took slices of the sterile-male portion of the plant and grew whole plants from them. Some of these plants produced flowers with normal male parts indicating successful mitochondrial transfer between the two species. Swapping of genomes was found to occur in areas close to the graft, but new shoots usually form in this region. These new shoots grow into new plants with mixed genomes.

Get more details from PNAS and New Scientist.