Scientists have identified 53 genes that allow Asian ash trees to fight emerald infestation. This dangerous pest was introduced to Europe and North America and threatens the existence of native species of ash trees. The authors of the publication in Nature Ecology and Evolution hope that their discovery will form the basis of methods of breeding or gene editing, which will help to keep the European and North American ash trees.
The development of international trade erases biogeographic boundaries and contributes to the rapid spread of pests and parasites. This often leads to environmental problems. For example, imported Asian fungus Cryphonectria parasitica , almost completely destroyed the population of the American chestnut (Castanea dentata) in the early twentieth century. And the people of well-known sad story of Colchis box tree (Buxus colchica), which became a victim of introduced pest, the box tree moth (Cydalima perspectalis).
In recent decades, experts are seriously concerned about the fate of the American and European species of ash trees (Fraxinus sp.). These trees are considered key for temperate forests, but over them hangs the threat of invasive beetle the emerald ash borer. (Agrilus planipennis). The birthplace of this insect East Asia. Native species of ash trees have adapted to coexist with infestation, however, the American and the European types are defenseless in front of her. It is not surprising that the appearance of this insect in Europe and North America threatens the ash mass destruction. Buprestids in the United States has killed hundreds of millions of trees and billions may follow them in the coming years.
The researchers hope that, having studied Asian ash, is able to resist the emerald slutcam, it will be possible to find a way to protect from extinction the American and European types. This took scientists under the leadership of Laura Kelly (Laura J. Kelly) of London’s Queen Mary University. They reconstructed the phylogenetic relationships of 26 species and subspecies of the ash-trees and compared their resistance to the defeat sladami evaluated experimentally.
It turned out that the ability to resist the emerald Zlatko occurred three times independently in the genus Fraxinus. The researchers found six resistant to the pest species. They all come from East Asia. Interestingly, some of them were the closest relatives of the vulnerable species from Europe and North America. This gives hope for the creation of hybrid ash trees that can save the population of these trees.
In addition, the team identified 53 candidate genes that may help Asian ash trees to defend themselves from the beetles. 48 of them have independently arisen in three evolutionary lines. Seven genes involved in the synthesis of protective substances phenylpropanoids, and another seventeen are associated with the recognition of herbivores, the transfer protective signals and programmed cell death. The analysis showed that among the vulnerable species, some of these genes also occur, but they are often damaged by mutations.
The authors note that the discovered genes can become targets for breeding or genetic editing of the American and European ash trees. Using these methods, you can try to prevent the extinction of these trees and restore their population in areas that have already suffered from the invasion of the invasive beetles.
Emerald planipennis is not the only dangerous form, moved to a new place of residence with a person and became a problem for local ecosystems. Scientists call these types of exotic species. To learn more about these types can be found in our test, “Immigrants or invaders?”.