Deaf Plants

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As we continue to make advances in the field of genetics, the cost of genome sequencing is getting cheaper and cheaper. We are sequencing entire genomes seemingly overnight. As we learn more about this code that programs every living thing on this planet, the more surprises we uncover. One such surprise came when researchers sequenced the genome of a little mustard known as Arabidopsis thaliana. As it turns out, this lowly little plant has more in common with our own genetic lineage than we ever thought possible. 

One interesting thing that turned up in the genome of Arabidopsis were a handful of genes associated with hearing in humans. For all intents and purposes, plants can't hear. They don't have ears nor do they have a nervous system capable of translating vibrations into what we know as sound. Why, then, were these genes present in a plant? 

Humans contain over 50 genes associated with hearing. A mutation in any of these can cause hearing loss. Arabidopsis shares at least 10 of these genes with us. In humans, one of these shared genes codes for proteins that are involved in forming the microscopic hairs within our inner ear that pick up sound waves. Again, why would a plant need this? When researchers mutated this gene within Arabidopsis, a surprising thing happened. 

Plants produce hair-like structures from their roots. These root hairs vastly increase the amount of surface area the root has for soaking up water and nutrients in the soil. A mutation in one of these hearing genes causes the root hairs to fail to elongate. As a result, the plant then has trouble absorbing things. 

Hearing genes are by no means the only genes we share with plants either. Within the genome of Arabidopsis, researchers have discovered over 100 genes involved in human diseases including breast cancer and cystic fibrosis. Though the differences between humans and plants seem insurmountable, we nonetheless share a common ancestor. The genes that control the development of an organism were laid down long before our lineages became distinct. It would appear that many genes don't change but are simply adopted for different purposes. It is discoveries like these that stand as a stark reminder that so-called "science for the sake of science" is incredibly important. 

Photo Credit: virken (http://bit.ly/1DI50Qz)

Further Reading:

http://www.plantphysiol.org/content/146/3/1109.short

http://nar.oxfordjournals.org/content/31/4/1148.short