PhD Studentship: Harnessing Symbionts for Control of Vector Borne Disease in Agriculture

Supervisor

Dr Lee Henry, l.henry@qmul.ac.uk, Reader (Associate Professor) in Molecular Microbial Ecology, Queen Mary University of London

Project Details

Insects vector globally important diseases in agriculture, posing significant economic burdens and threatening food security. Virus transmission by sap-sucking insects account for nearly half of all plant pathogens, leading to >£24 billion in global annual costs. Since the 2018 ban on neonicotinoid pesticides, Europe has seen a rise in insect vectored viruses threatening crop industries. The UK’s sugar beet industry lost 25% of its crop in 2020 due to Virus Yellows (VY), at a loss of £67M, and Potato Leafroll Virus (PLRV), which causes >20M tonnes of annual yield loss globally, is rising. Climate change is increasing insect-vectored diseases in temperate regions, as milder winters boost disease-carrying insect populations. Insecticides are the primary method of control sap-feeding insects, but these are becoming ineffective and undesirable due to insecticide resistance and pollution.

Heritable bacterial symbionts offer promising solutions to control insect-vectored disease by making insects less susceptible to transmitting diseases, while also spreading through insect populations via maternal transmission. For example, the introduction of the Wolbachia symbiont into A. aegypti mosquitoes has reduced dengue virus incidence by 77% in field trials. Heritable symbionts are also common in sap-sucking insect pests, but symbiont-based control strategies have yet to be developed for virus transmission in agriculture. Recent studies show the symbiont Regiella insecticola LSR can eliminate viruses of pea aphids, suggesting that symbionts may also suppress plant viruses in aphid pests, but this remains to be tested. 

Aim: The aim of this project is to develop aphids as a model for understanding symbiont-plant virus interactions with the goal of identifying symbiotic microbes and anti-pathogen factors that can be used to reduce virus transmission by hemipteran pests in agriculture. 

System and Objectives: The project will focus on two destructive crop viruses on the rise in the UK: Virus Yellows (VY) in sugar beets (Beta vulgaris) and Potato Leafroll Virus (PLRV) in potatoes (Solanum tuberosum). Both are vectored by the world’s most destructive agricultural pests, the green-peach aphid, Myzus persicae. Microinjections will be used to establish clonal aphid lines carrying different symbiont lineages and the culturable gut symbiont Serratia symbiotica CWBI. The study will address the following objectives:

• Assess whether facultative symbionts influence plant viral titre or vectoring capacity in aphids, or whether they generate aphid phenotypes that affect virus transmission, e.g., reducing fecundity or inducing dispersal morphs.
• Identify gene regulatory networks in bacteria that suppress plant virus transmission in aphids. 
• Create transgenic symbiont lines that express anti-pathogen factors to suppress virus replication and transmission in Myzus persicae.

Benefits to the student: The project is a collaboration between a world-leading academic institute (Biology at QMUL) and an international centre of excellence in industrial research (Fera Science), thus providing students with training and professional development in diverse areas. At QMUL, the student will gain skills in molecular biology (e.g., DNA/RNA extraction, qPCR, RNA-seq libraries), synthetic microbiology (bacteria culturing and transformations), and computational biology (e.g., programming, genomic data analysis). The student will also receive ongoing training in transferable skills such as project management, communication (via seminars, lab meetings), problem-solving, and teamwork to maximise their professional development. At Fera, the student will gain industry experience while running crop disease vectoring experiments within their greenhouse quarantine cubicles. The student will also focus on learning about molecular interactions underlying insect vectoring of crop viruses, learn about biopesticide development from industry experts at Fera, and develop analytical pipelines to study virus-insect-bacteria molecular interactions emerging from the transcriptomic data.

Research Environment: The successful applicant will join a vibrant research environment under the supervision of Dr. Lee Henry. His lab offers world-class facilities in genomics, synthetic microbiology, and molecular biology, providing the student with comprehensive training and professional development. The student will have access to ample funds to facilitate the research through Prof. Henry's external funding. He currently supervises 4 PhD students, 1 PDRA, and a technician, with an outstanding track record of guiding students toward high-impact first-author publications (e.g., Wu et al. 2022, Proc Soc B; Jackson et al. 2022, ISME Journal).

Impact: The project will identify symbiotic microbes and anti-viral factors to suppress VY and PLRV in agriculture. It will also develop novel transgenic symbiont strains for integrated pest management, thereby reducing the need for pesticides and offering a sustainable solution for controlling a wide range of insect pests.

For more research details, visit: https://www.henry-lab.co.uk

Find out more about the School of Biological and Behavioural Sciences on our website.

Informal enquiries about the project can be sent to Dr. Henry at l.henry@qmul.ac.uk