Gene from wild barley helps explain sea to land evolution

Genetic mutation growing in Judean Desert shows how the transition of aquatic to land plants created life on the terra firma as we know it today.

By JUDY SIEGEL-ITZKOVICH
Barley (photo credit: Courtesy)
Barley
(photo credit: Courtesy)
A genetic mutation in wild barley growing in the Judean Desert – discovered by an international team based on a Haifa University doctoral student’s thesis – has shown how the transition of aquatic to land plants created life on the terra firma as we know it today.
The work by Guoxiong Chen, the Chinese doctoral student working under the supervision of Prof. Eviatar Nevo of Haifa University’s Institute of Evolution in 2000, made the chance discovery.
The doctoral student’s finding of the genetic mutation led to an international study, of which Nevo is a member, deciphering evolution of life on land.
After some eight years of research, the team has discovered a new gene that contributes to the production of cutin, which is found in all land plants but is either nonexistent or present in tiny amounts in aquatic plants. Chen called this new gene Eibi1, in honor of his supervisor, Nevo, who is nicknamed Eibi.
“This is one of the genes that contributed to the actual eventuality of life on land as we know it today. It is a key element in the adaptation process that aquatic plants underwent in order to live on land,” Nevo said.
Chen found a mutation of wild barley that was significantly smaller than regular wild barley. It was found that this mutation causes an abnormal increase in water loss because of a disruption in the production of the plant’s cutin, which is secreted from the epidermal cells and is a component in the plant’s cuticle; this reduces water loss and prevents the plant from dehydrating.
“Life on Earth began in the water, and in order for plants to rise above water to live on land, they had to develop a cuticle membrane that would protect them from uncontrolled evaporation and dehydration,” Nevo explained. “In our study, we discovered a completely new gene that, along with other genes, contributes to the formation of this cuticle.”
The study has been published in the prestigious journal Proceedings of the National Academy of Sciences.
Besides the evolutionary importance of this new gene, it is also of value in fighting world hunger.
According to the Haifa professor, “Once we can fully understand the mechanism behind the production of cutin and discover genetic variants of the Eibi1 gene, we will have the ability to enhance the cuticle formation of wheat and barley species so as to make them more resistant to water loss and more durable in the dryer conditions on land,” he said.
“Genetic enhancement of cultivated plants to make them durable in dry and saline conditions can increase food production around the world.”
The international team of scholars comes from China, Japan, Switzerland and Israel.
Chen has since returned to China and achieved full professorship, while continuing his study of the Judean Desert’s wild barley.


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