About 98 percent of the human genome is said to be noncoding DNA or "junk DNA". A new study has found that this junk DNA, which is abundant in many organisms, has no role of play in the life cycle of a carnivorous plant.

The study was based on the genome of bladderwort plant, Utricularia gibba. Researchers from Laboratorio Nacional de Genómica para la Biodiversidad (LANGEBIO) in Mexico and the University at Buffalo say that the plant has been trying to remove the junk DNA from its genome since many generations.

The carnivorous plant has a complex life. It lives in freshwater ponds and lakes and captures insects by removing water from bladders, turning them into vacuums.

The plant, however, has a "lean genome", with about 80 million DNA base pairs compared to its relatives such as tomato that has 780 million base pairs; although both have about 28,500 genes. Interestingly, U. gibba has undergone three complete genome doublings since the time it deviated from the tomato lineage.

"This surprisingly rich history of duplication, paired with the current small size of the bladderwort genome, is further evidence that the plant has been prolific at deleting nonessential DNA, but at the same time maintaining a functional set of genes similar to those of other plant species," said Luis Herrera-Estrella from LANGEBIO and one of the study authors, according to a news release.

Previous studies have shown that the genes present in this noncoding DNA have some biological functions. However, whether these genes had some important activity in the genome wasn't clear.

Researchers in the present study said that organisms don't just keep these noncoding DNA for benefit, but rather to obey a certain mechanistic bias that makes them either store this DNA or remove it from the genome.

"The big story is that only 3 percent of the bladderwort's genetic material is so-called 'junk' DNA. Somehow, this plant has purged most of what makes up plant genomes. What that says is that you can have a perfectly good multicellular plant with lots of different cells, organs, tissue types and flowers, and you can do it without the junk. Junk is not needed," said Victor Albert, Professor of Biological Sciences, University at Buffalo.

The study is published in the journal Nature.