Across generations, humans adapt to a changing environment by passing down knowledge. Corn plants have their own strategy for adaptation, using “jumping genes” to maintain genetic diversity.
Jumping genes, which are known as transposons, were discovered in the 1940s by Nobel Prize-winning Cold Spring Harbor Laboratory (CSHL) geneticist Barbara McClintock.
In a new study, CSHL Professor Doreen Ware and colleagues have published genome sequences from 26 different strains of corn.
The researchers analyzed the genetic diversity found in the genomes of these modern corn plants, including transposons and genes that regulate desired crop traits. This genetic diversity was established as corn plants were bred in different climates throughout the world.
“Humans have brains. Our main adaptive component is our ability to transfer culture and knowledge, right? And that’s how we deal with our environment. A plant’s strategy is to have a fluid genome. They have a very intimate relationship with these transposons, where they use them to bring in new genetic diversity so that they can deal with these events because they can’t run away. They’re not going to go into the house, and they’re not going to move water to them,” explained Professor Ware.
The CSHL team mapped the first corn genome in 2009, and has continued the research ever since. Recent technology made it possible for the experts to locate and study both important crop genes and the nearby regions that regulate their use.
“We had little access to the regulatory architecture of corn before,” said Professor Ware. The most recent analysis reveals how the corn genome was shuffled over time.
“These genomes provide us a footprint of that life history. Different strains have experienced different environments. For example, some came from tropical environments, others experienced particular diseases, and all those selective pressures leave a footprint of that history,” said Professor Ware.
More than 366 million metric tons of corn was grown in the United States from 2018 to 2019. With the new detailed maps of the corn genome, scientists are now equipped to develop crops for a rapidly changing climate.
“The Midwest is not going to have the same temperature profile twenty years from now,” said Professor Ware. “The genomes provide broader insights into corn genetics, and this, in turn, can be used to start optimizing corn to grow in future environments.”
The study is published in the journal Science.
By Chrissy Sexton, Earth.com Staff Writer