Scientists Have Decoded The Genetic Sequence Of The Ash Tree: Hope To Stop Dieback And Emerald Ash Borer That Are Wiping Out Trees

Alicia Bayer

Scientists have successfully decoded the genetic sequence of the ash tree to help fight ash dieback and the Emerald Ash Borer beetle, which are killing hundreds of millions of ash trees in Europe and North America, Nature has reported.

In a paper published in the scientific journal Nature today, a team of scientists led by Richard Buggs of Royal Botanic Gardens in Kew reported that they had assembled a reference genome and analyzed the diversity of ash trees throughout Europe.

The scientists are hoping to use the genetic information to fight ash dieback, a debilitating fungal disease that is devastating the population of ash trees in Europe, in addition to fighting the Emerald Ash Borer, a beetle that has killed hundreds of millions of ash trees in North America.

Their collaborators have used the information to identify genes that may be associated with low susceptibility to ash dieback. From there, they used these to predict the effect that ash dieback will have on ash trees all over Britain. Dieback has affected 90% of Denmark's ash trees, and Britain faces a similar threat, according to the Guardian.

"This is the first time a plant genome has been rapidly sequenced in response to an emerging disease threat, leading to an assessment of the susceptibility of as yet uninfected populations," said Project Leader Dr Richard Buggs, Senior Research Leader of Plant Health at RBG Kew, who conducted the work at Queen Mary University of London's School of Biological and Chemical Sciences. "Kew is continuing to work with the latest genomic technologies to increase the armoury of methods that can be deployed against plant pests and pathogens."

There are 520 specimens of the Ash tree at Kew and its Sussex site, Wakehurst. At Kew's Millennium Seed bank scientists are also involved in gathering seed of different ash populations around Britain to help inform broader efforts to control disease spread and drive plant health policy.

The British Ash Tree Genome Project reports that it's goal is sequencing, assembling and annotating the genome of a British Ash Tree. "This will assist scientists in the search for genes that may confer resistance to ash dieback (Chalara fraxinea)," they say.

In North America, it is the Emerald ash borer, an Asian insect first identified in Detroit in 2002, that is decimating ash trees. The beetle has become the most destructive forest insect to ever invade the U.S., according to American Forests. Populations of emerald ash borer, have been found in at least 18 states, along with Ontario and Quebec.

Scientists around the world have been working to protect ash trees. In April, UK scientists announced that they had identified the country's first ash tree that shows tolerance to ash dieback, raising the possibility of using selective breeding to develop strains of trees that are tolerant to the disease, the Biotechnology and Biological Sciences Research Council reported. The scientists identified a tree they nicknamed "Betty," as having a strong tolerance to Ash dieback, even though it was in a woodland area where a large number of other Ash trees were infected with the devastating fungus. "Betty" demonstrated low levels of infection by the ash dieback fungus and may help scientists develop a strain of Ash tree that can resist infection by Ash dieback.

A spokesperson for Defra, which co-funded that research with the Biotechnology and Biological Sciences Research Council, said that the UK has invested more than any other country in research on ash dieback. The breakthrough is "an excellent example of how the UK's cutting-edge science is leading the way to help support tree health," he said.

"We want to guarantee the graceful ash tree continues to have a place in our environment for centuries to come and this vital work is a major step towards ensuring just that."

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