Ash tree genome aids fight against disease

Tens of millions of ash trees across Europe are dying from the Hymenoscyphus fraxinea fungus -- the most visible signs that a tree is infected with ash dieback fungus are cankers on the bark and dying leaves.

Project leader Dr Richard Buggs from QMUL's School of Biological and Chemical Sciences said: "This ash tree genome sequence lays the foundations for accelerated breeding of ash trees with resistance to ash dieback.

A small percentage of ash trees in Denmark show some resistance to the fungus and the reference genome is the first step towards identifying the genes that confer this resistance.

The ash tree genome also contains some surprises. Up to quarter of its genes are unique to ash. Known as orphan genes, they were not found in ten other plants whose genomes have been sequenced.

Dr Buggs added: "Orphan genes present a fascinating evolutionary conundrum as we have no idea how they evolved."

This research is published today in the journal Nature. It involved a collaboration between scientists at: QMUL, the Earlham Institute, Royal Botanic Gardens Kew, University of York, University of Exeter, University of Warwick, Earth Trust, University of Oxford, Forest Research, Teagasc, John Innes Centre, and National Institute of Agricultural Botany.

The reference genome from QMUL was used by scientists at University of York who discovered genes that are associated with greater resistance to ash dieback. They have used these to predict the occurrence of more resistant trees in parts of the UK not yet affected by the disease, which is spreading rapidly.

The genome sequence will also help efforts to combat the beetle Emerald Ash Borer, which has killed hundreds of millions of ash trees in North America.

Ash trees have a huge significance in culture and society -- they are one of the most common trees in Britain and over 1,000 species, from wildflowers to butterflies, rely on its ecosystem for shelter or sustenance. Ash timber has been used for years for making tools and sport handles, for example hammers and hockey sticks, and is used often for furniture.

The work was funded by NERC, BBSRC, Defra, ESRC, the Forestry Commission, the Scottish Government, Marie Sklodowska-Curie Actions, Teagasc -- the Agriculture and Food Development Authority.