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Genetic material of plants and animals are well protected in the nucleus of each cell and store all the information that forms an organism. In addition, cells contain small organelles that contain their own genetic material. These include chloroplasts in plants, which play a key role in photosynthesis, and mitochondria, which are found in all living organisms and represent the power plants of every cell. Scientists at the Max Planck Institute of Molecular Plant Physiology in Potsdam have shown, through experimental approaches, (Science Advances) how the genetic material is not actually permanently stored within one cell but can migrate from cell to cell.
They conducted experiments with tobacco plants using grafting. Two different tobacco plants were grafted on to each other and the cells of the junction were observed microscopically in real time. They could observe that genome transfer from cell to cell occurs in both directions with high frequency at this site.
The researchers were able to observe structural changes in the cell walls in the wound tissue of the graft site. Protrusions formed on the cell walls, thus creating junctions between the two partners. The size of the created pores allowed the migration of an entire plastid. “Therefore, the genome does not migrate freely, but encapsulated from cell to cell,” Dr. Alexander Hertle says in a release. However, to actually make this possible, the plastids have to shrink and become mobile. These rod-shaped plastids grow back to normal size after transfer into the target tissue. It now remains to be studied if mitochondria and the nuclear genome also use similar transfer mechanisms.
