| This project going to be… | Experimental (lab/field based) |
| Email | lawrence.bramham@rothamsted.ac.uk |
| Position held | Postdoctoral Research Scientist |
| Title of Project | Exploring Barley yellow dwarf virus strain infection dynamics in wheat and viral reacquisition by aphids |
| Institution Department and Address | Protecting Crops and the Environment, Rothamsted Research, West Common |
| Harpenden, Hertfordshire AL5 2JQ |
| United Kingdom |
| Full Name of Supervisor | Lawrence Bramham |
| Date of Project Commencement | 03/07/2023 |
| Duration (weeks) | 10 |
| Brief Description of Project | The core aims of work to be undertaken in this project are to: 1. Use established Rothamsted aphid cultures (Sitobion avenae and Rhopalosiphum padi), each carrying distinct UK strains of Barley yellow dwarf virus (BYDV, strains MAV, PAV and PAS) to challenge wheat plants then monitor these for strain-associated disease. This will take the form of visual assessments and sampling of various plant tissues at key time stages post-challenging for molecular BYDV diagnostics/detection. 2. Explore how mixed BYDV infections impact disease symptoms/progression (using similar techniques to those highlighted above). 3. Explore if/how virus reacquisition from BYDV-infected plants is impacted by aphid feeding time and tissue site, aphid species (R. padi vs S. avenae) and/or the presence of multiple BYDV strains. Specific project-related training to be provided are: – Handling of aphids and wheat plants for efficiently challenging plants with key BYDV strains. – Experimental design (specifically how to start to answer questions on the theme of virus reacquisition by aphids and impacts of mixed strain infection), the need for appropriate controls and an overall appreciation for scientific rigour. – Training in molecular biology, chiefly viral disease diagnostics; this will involve the generation of BYDV-specific complementary DNA from viral RNA extractions (from both plant and aphid samples), various PCR-based techniques (qualitative and quantitative) and gel electrophoresis. Through our weekly Wheat Pathogenomics lab meetings, the student will also interact with colleagues and other visiting UG students. Towards the end of their placement, students will have the opportunity to present during these lab meetings with time allocated for questions from the wider team. This project will ultimately equip the student with the experience of collecting data following robust experimental design, analysis of outputs, the drawing of valid conclusions and presenting their work to peers. Outputs will also prove valuable for greater knowledge of BYDV dynamics and how the impacts of this disease can be better managed. Barley yellow dwarf virus (BYDV) is spread from an affected plant to new hosts by sap-feeding aphid vector species and is considered the most important viral pathogen infecting cereal crops worldwide. Historically, insecticides (primarily neonicotinoid-based agrochemicals) have been used to indirectly target BYDV and other viral pathogens through the nonspecific removal of aphids. Aside from the detrimental impacts associated with misuse of such chemistry, resistances are evolving across key aphid populations to these and other insecticides. Legislative restrictions are also being placed on the use of some pesticides. These and other considerations generate an increasingly urgent need for alternative integrated pest management (IPM) approaches. Any such IPM strategies are fundamentally reliant, however, on improved knowledge of both the pathogen threat (i.e. BYDV and associated strains/variants) and how these are spread (UK aphid vector species, most notably Sitobion avenae and Rhopalosiphum padi). Previous work undertaken at Rothamsted, including valuable contributions from a previous BSPP undergraduate vacation student (2021), has identified key BYDV strains of interest distributed across the UK. Aphid cultures carrying these strains have now been established at Rothamsted as a scientific resource. An improved understanding of UK BYDV variation has also enabled the development of refined disease diagnostics, although significant knowledge gaps still remain. It is unknown specifically how these UK strains vary in pathogenicity on current commercial crop cultivars, how mixed infection of these strains within a single host plant may influence disease progression, and/or if any impacts exist in how BYDV is reacquired by aphids from hosts where multiple strains are present. Do certain UK BYDV strains take precedence in being more readily acquired and transmitted? Such questions are the foundation for this project and which we aim to start to answer. Valuable applied research outputs from this work will contribute to more informed decisions to be made on how to effectively deploy genetic resistance(s) to BYDV. This 10-week studentship provides the opportunity to be equipped with diverse skill sets relating to plant science, virology and entomology at one of the oldest agricultural research institutions in the world with access to our active labs. In addition to being equipped with an improved general scientific skill set, you will receive all necessary training for relevant lab work. This will include molecular BYDV detection using the newly developed diagnostic tools (sample preparation, RNA isolation, cDNA synthesis, and various PCR-based techniques), and various training for handling aphids and wheat plants. Presentation skills will also be refined through weekly lab meetings with colleagues culminating in the opportunity to share your project findings with scientists working in similar areas. |
| Attach the recommended reading for the project | Ng, J. C., & Perry, K. L. (2004). Transmission of plant viruses by aphid vectors. Molecular plant pathology, 5(5), 505-511. DOI: 10.1111/j.1364-3703.2004.00240.x |
| Aradottir, G. I., & Crespo-Herrera, L. (2021). Host plant resistance in wheat to barley yellow dwarf viruses and their aphid vectors: a review. Current Opinion in Insect Science, 45, 59-68. DOI: 10.1016/j.cois.2021.01.002 |
| More references available should the candidate student wish to get in touch. |
