New mechanism of transposon activation discovered in plants

Vanja Cavrak and other members of the Mittelsten Scheid group at the GMI have discovered how a transposon applies a “wolf in sheep´s clothing” strategy to gain an advantage over its plant host. Transposons are among the most reduced or simplified parasites that a host organism can accommodate. They are stretches of DNA that are programmed to amplify and consequently spread to other locations in the genomes of their hosts. In return, hosts fight transposons by inactivating them, an evolutionary arms race.

When plants are exposed to heat stress, they turn on a set of protective genes that help to survive. One transposon has copied the corresponding switch from the plant genes and integrated it into its own control element, thereby masking itself as part of this heat stress response. The transposon is inevitably activated in heat-stressed plants and amplifies its DNA sequence. This makes it impossible for the plant to respond appropriately to stress without losing control over the transposon. However, the plants seem to have built up their defense at the time of reintegration of the new copies.

Cavrak VC, Lettner N, Jamge S, Kosarewicz A, Bayer LM, Mittelsten Scheid 0 (2014) How a Retrotransposon Exploits the Plant's Heat Stress Response for Its Activation. Plos Genetics, Published: January 30, 2014DOI: 10.1371/journal.pgen.1004115

Press release (German)