From Weed to Cereal Crop: Corn’s Self-Mutation Brought it to Where it is Today

About 10,000 years ago, a mutation in the teosinte plant occurred, causing the protective husks surrounding the golden grains to disappear, giving us what we now know as corn.  Despite being well known, the story has left some question unanswered until now.  Researchers have recently discovered where the mutation that turned the teosinte plant into corn  occurred at a molecular level.

A single letter in the plant’s DNA was found to have caused the mutation.  Nucleotides, which are four types of molecules found in DNA that dictate how living organisms look and function.  One of those letters caused a change that made the protective green husks fall off.  What the researchers found was, while there were plenty of mutations that occurred in the plant’s history, one small mutation has made the plant from an insignificant looking weed, to one of the most produced cereal crops in the world.

The plant started to look like how it does today after the mutation affected essential proteins in the plant.  Scientists were able to find the gene responsible by simply reenacting the mutation.  The scientists analyzed genomes of generations of teosinte plants to set up molecular markers.  This allowed them to find clues to which gene controls which physical trait.  They were eventually able to find the exact nucleotide that, when changed, resulted in the plant to lose the husks.