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Infection mechanisms of ash dieback unravelled

Copyright: James Brown, JIC
News from: National Institute of Agricultural Botany

UK scientists are a step closer to understanding the mechanisms of natural fungal infections that cause the ash dieback disease affecting European Ash (Fraxinus excelsior) trees across the UK and continental Europe.

The research, funded by BBSRC, has shed light on the fungal infection process, by which the fungal pathogen first infects the host via ascospores, the sexual reproduction spores of the pathogen. The work, carried out at the horticultural research organisation NIAB EMR, in Kent, and Imperial College London, enables scientists to mimic the natural infection pathway of the fungus. The next step is to develop rapid screening methods to identify ash trees, with resistance to the pathogen, which could be used to repopulate lost woodland.

“We now have a far greater understanding of the interactions between the fungus and the host tree during the infection phase,” commented Dr Robert Saville, plant pathologist at NIAB EMR.

He continued, “Our work, published in the journal Plant Pathology, has identified a biotrophic phase (in which the fungus attacks and keeps the host cell alive whilst preventing the host’s normal ‘cell death’ defence response) in the early stages of the infection pathway, providing hope that major genes for resistance can be discovered.”

NIAB EMR hosts a nationally important collection of ash, a legacy of DEFRA-funded work for the genetic improvement of broad-leaved forest species. In collaboration with the John Innes Centre this collection has been complemented with resistant germplasm collected from ancient woodland around Norfolk. The population, consisting of 328 diverse ash lines, is now to be used as a resource for the study of dieback resistance and other traits in a recently awarded BBSRC project led by JIC in collaboration with NIAB EMR and The University of Warwick.

Although there will be many mechanisms by which plants will resist a disease like ash dieback, an in-depth understanding of the infection phase is seen as critical in identifying naturally-occurring resistance.


Notes to editors

The ash dieback research project, ‘Nornex’ (BBS/E/J/000CA523), funded jointly by the Biotechnology and Biological Sciences Research Council (BBSRC) and the Department of Environment Food and Rural Affairs (Defra), helped support ash dieback research at NIAB EMR. The project results are published in the journal Plant Pathology in the paper: John Mansfield, Nikoleta Galambos and Robert Saville. The use of ascospores of the dieback fungus Hymenoscyphus fraxineus for infection assays reveals a significant period of biotrophic interaction in penetrated ash cells. doi: 10.1111/ppa.12844.


Based at East Malling in Kent, National Institute of Agricultural Botany (NIAB) EMR is an internationally renowned plant science organisation conducting research on horticultural crops and their interactions with the environment, with particular emphasis on perennial and clonally propagated fruit crops. NIAB EMR is part of the NIAB Group, the UK’s fastest growing crop science organisation, with rapidly expanding research capabilities in plant genetics, agronomy, farming systems and data science, the largest national field trials capability, and strong research links with industry, Government and academia. NIAB’s headquarters are in Cambridge, with regional offices across the country, the largest of which is NIAB EMR in Kent. NIAB employs more than 400 people across the UK and provides scientific research, technical services and practical advice to improve the yield, efficiency and resilience of crop production across the arable, horticulture and top and soft fruit sectors.


UK Research and Innovation Media Office

Tags: fundamental bioscience botany plants trees fungus ash dieback Defra NIAB EMR BBSRC press release