Transposable elements in plants

Article By:

Lisch, Damon Department of Plant and Microbial Biology, University of California, Berkeley, California.

Last reviewed:2014

DOI:https://doi.org/10.1036/1097-8542.YB140306

A genome (the genetic endowment of a species) is often thought to be composed of genes (the basic units of inheritance in the form of DNA sequences) whose function is to provide a selective advantage to an organism. However, these DNA sequences actually only represent a small portion of most eukaryotic genomes. Instead, in the case of plants, the dominant part of the average plant genome is made up of endogenous parasites known as transposable elements (TEs). TEs are stretches of DNA that are able to replicate themselves within a genome. The DNA of TEs does not have to provide a benefit for the organism in order to persist. It has only to outreplicate the rest of the genome. In plants, TEs have been wildly successful at doing this. Indeed, the average stretch of plant DNA is almost certainly a TE whose function is to make more of itself. Ongoing replication and subsequent deletion of these molecular parasites largely explain the enormous variation in DNA content that is observed in plants.

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