Experts preparing for invasion of “dangerous” plant bacteria

Scientists from the University of Stirling are working to tackle the potential introduction and spread of a devastating plant pathogen into the UK as part of a new £4.85 million study.

Described by European Union (EU) officials as “one of the most dangerous plant bacteria worldwide”, Xylella fastidiosa infects 500 species including crops, ornamental plants and trees.

Although it has spread across a number of European countries, the insect-transmitted pathogen has not yet reached the UK. However, Dr Daniel Chapman, of Stirling’s Faculty of Natural Sciences, is now working with nine other research institutions to ensure that the UK Government and industry are prepared to minimise the entry of the pathogen and prevent its spread, should it arrive.

The John Innes Centre in Norwich will lead the consortium, BRIGIT, which forms part of the £17.7 million bacterial plant diseases programme, announced by the Parliamentary Under-Secretary of State, Right Honourable Lord Henley.

The programme – supported by the UK Research and Innovation’s (UKRI) Strategic Priorities Fund – is a collaboration between the Biotechnology and Biological Sciences Research Council (BBSRC) and the Natural Environment Research Council (NERC), together with the Department for Environment, Food and Rural Affairs (DEFRA) and the Scottish Government, which is providing additional funding of £1.1m.

Dr Chapman will work on epidemiological models that test scenarios about how Xylella may spread if introduced to the UK. The simulations will build on existing modelling of the outbreak in Italy, led by Dr Chapman in EU-funded projects. The goal is to use the computer models to test the effectiveness of different surveillance and control strategies.

Dr Chapman said: “This new project will improve the UK’s readiness to deal with a potentially destructive Xylella outbreak. Xylella is Europe’s top plant health concern, so it is hugely important that the UK is building the scientific capacity to inform our response to this threat.”

Xylella is a bacterial pathogen transmitted by insects that feed on xylem tissues, which transport water in vascular plants. These bugs include spittlebugs, also known as froghoppers, which feed on a wide range of plants and are typically found in northern Europe.

If infected plants or insects that carry the pathogen do enter the UK, there may be the potential for the disease to spread through native insects, to many plants, including trees and commercial crops.

Dr Dan Chapman, of the University of Stirling, is working on the £4.85m study.

Professor Saskia Hogenhout, a project leader at the John Innes Centre and one of the principle investigators of BRIGIT, said: “Despite the impact of this disease, we know very little about how the bacteria might spread in Northern Europe, the majority of research on Xylella and its insect vectors has been done in warmer southern climates.

“We believe this consortium is much-needed, bringing a joined-up approach to tackle a potentially damaging plant disease.”

She added: “Thousands of plants are imported into the UK every day and we need to increase knowledge to understand how the disease may spread in the UK if it is introduced.”

The research will focus on how Xylella may spread in the UK either via insect vectors or via transport of plants by humans. A key focus will be introducing and improving best practice in the horticultural trade, to mitigate the impact of any introduction.

Professor Nicola Spence, Chief Plant Health Officer and Deputy Director for plant and bee health at DEFRA, said: “I am delighted that UKRI, together with co-funders DEFRA and the Scottish Government, has agreed to fund this crucial research which will help us to better control bacterial plant diseases in the future. Protecting the UK’s plants from pests and diseases remains one of my Department’s highest priorities, and we need robust science to underpin our actions to combat these threats.

“Xylella fastidiosa is one such bacterial disease and will form the focus of the first phase of the research programme. The knowledge gained through this programme should assist us in further optimising our ongoing surveillance and ensure that our contingency plans are underpinned by the most up-to-date evidence available.”

Professor Melanie Welham, Executive Chair of BBSRC, added: “BBSRC is supporting this important collaborative project to improve the methods of diagnosis and detection of Xylella. Although there hasn’t been a case reported in the UK yet, we can take positive action to understand more, and mitigate the spread of this devastating plant pathogen.”

The BRIGIT consortium involves scientists across the spectrums of genomics and social sciences, plant pathology and entomology, and molecular biology and ecology, and engages stakeholders and policymakers.

Experts at Stirling and the John Innes Centre will work with colleagues at the Amgueddfa Cymru-National Museum Wales; Centre for Ecology and Hydrology; Fera Science Ltd; Forest Research; Royal Horticultural Society; Science and Advice for Scottish Agriculture; The University of Salford; and the University of Sussex. The consortium will also collaborate with international scientists and organisations, including the University of Lisbon on further characterization of the insect vector.