Feb 4, 2011

Glossary

Send

Plastid transformation

Inserting genetic information into plant cell plastids

Genetic transformation of plants usually involves inserting the new genetic information into the DNA of the cell nucleus. However, it is also possible to genetically modify plastids – small, self-contained units within the plant cell. Plastids, e.g. chloroplasts, have their own ring-shaped DNA, the plastome, and their own ribosomes (protein factories) for turning the DNA into proteins.

Plastid transformation has been successful in tobacco, potatoes, tomatoes, thale cress and other plants. Attempts are being made to apply the technology in the most important agricultural crops like maize and wheat.

One benefit of plastid transformation is the high expression rate, i.e. the productivity of the inserted genes is particularly high and a lot of protein is produced. In addition, it is easier to insert several genes into the plant at once. These advantages are particularly relevant when the aim is to develop plants that will produce large quantities of new substances.

In terms of the safety of genetically modified plants, another advantage is that the genetic information in the plastids is not normally passed on via pollen, since plastids are inherited through the maternal side. This means that introduced genes are biologically contained and cannot spread.

In rare cases, however, plastid DNA is passed on via pollen or ‘strays’ from the plastome to the nuclear genome. Several biosafety research projects are therefore investigating how ‘leak-proof’ plastid transformation is as a containment method.