Fighting Microbes with Microbes to Protect Our Native Trees

2017 | Rachael Antwis, PhD, University of Salford, U.K. and Co-Investigator Andrea Harper, PhD, University of York, U.K.  

Trees constitute the foundation of our natural ecosystems and contribute considerable value to the economy. Emerging infectious diseases, such as the chalara fungus (Hymenoscyphus fraxineus) that infects ash (Fraxineus excelsior), are destroying tree populations, and novel and effective control strategies are urgently needed. Natural microbial communities of trees regulate health and pathogenic invasion, and present a unique opportunity to develop such strategies. Here we aim to identify microbial (bacterial and fungal) signatures of ash resistance to chalara. We will also correlate these microbial signatures of resistance with markers of host gene expression. We predict that combining these two approaches (microbiomes and host gene expression) will identify a much larger cohort of resistant trees, which will provide a wider range of genetically diverse trees for cultivation and reforestation. This information can then be used by nurseries and other facilities to select trees that are resistant to the fungus. This project will result in a management strategy to enhance the resilience of ash trees to chalara, as well as maps of chalara susceptibility across the UK, identifying resistant and vulnerable individuals based on a combination of biological traits. Based on the data collected, we will publish two peer-reviewed journal articles, as well as non-technical reports for all project partners. This project aligns with two of TREE’s Research Priorities: Plant Health Care, and Tree Planting and Establishment.

Study Results

Our published research showed that the diversity, composition and interactions of ash leaf microbial communities are associated with the severity of infection from ash dieback disease. We also provided evidence that ash dieback may disrupt the natural communities living on the leaves, which then allows other pathogens to proliferate. We also show that the genetics of the host influences leaf fungal community composition, but does not directly influence ash dieback infection. These findings help us to understand the relationships between host genetics, the microbiome, and ash dieback, highlighting potential resistance mechanisms and possible co-infection concerns that could inform ash tree management and selection.

Year: 2017

Funding Duration: 1 Year

Grant Program: Jack Kimmel International Grant

Grant Title: Fighting Microbes with Microbes to Protect Our Native Trees

Researcher: Rachel Antwis, PhD

Key words: Microbes, ash trees

Peer Reviewed Publications from Grant:

General Audience/Trade Publications:

“Complex associations between cross‐kingdom microbial endophytes and host genotype in ash dieback disease dynamics,” Sarah M. Griffiths, Marciana Galambao, Jennifer Rowntree, Ian Goodhead, Jeanette Hall, David O’Brien, Nick Atkinson and Rachael E. Antwis, Journal of Ecology. 2019;00:1–19


Presentation to City of Trees –a Manchester (UK) based charity involved in regional tree planting –January 2020.

For more information on this project, contact the researcher via TREE Fund at