Investigating the role of bacterial endosymbionts in aphid transmission of Barley yellow dwarf virus

This is one of the funded projects for our 2025 Undergraduate vacation bursary, click here to return to the list of 15 projects.

This project is going to be…	Experimental (lab/field based)
Institute	Keele University
Project supervisor	Dr. Trisna Tungadi
Title of Project	Investigating the role of bacterial endosymbionts in aphid transmission of Barley yellow dwarf virus
Date of Project Commencement	07 July 2025
Duration (weeks)	8
Brief Description of Project	Majority of plant viruses are transmitted (vectored) by Hemipteran insects such as aphids. More than 80 species of aphids vector approximately 30 % of known plant viruses. Most aphid species form lifelong mutualistic symbiosis relationship with bacterial endosymbionts. These endosymbionts live inside the aphid’s body and are categorised into primary and secondary endosymbionts. Primary endosymbiont such as Buchnera aphidicola, are vital for aphid survival. Secondary endosymbionts confer various fitness benefits to aphids such as protection against predators and increased tolerance against harsh environmental conditions. The bird cherry oat aphid (Rhopalosiphum padi) is a major insect pest. Aphids damage cereal crops from their feeding activities and vector Barley yellow dwarf virus (BYDV). BYDV cause significant yield loss by reducing root and shoot growth of the plant. BYDV is vectored by aphids in a persistent way. The virus circulates in the aphids’ body and prolonged feeding are required for aphids to take up and transmit BYDV. Bacterial endosymbionts living in the aphids can affect aphid fitness and aphid-vectored transmission of plant viruses. In our lab, we have fully characterised and genotyped R. padi aphid colonies. The student will utilise three R. padi aphid colonies, each aphid colony is harbouring a particular bacterial endosymbiont : Hamiltonella defensa, Regiella insectiola, and Rickettsia viridis respectively. The student will use these aphid colonies to conduct BYDV transmission experiments on barley plants. The project aim is to compare whether aphid colonies harbouring certain bacterial endosymbiont species exhibit different efficiencies to transmit a plant virus (BYDV).The experimental project is lab based. The student will join the plant virology lab at the School of Life Sciences, Keele University, UK. The experimental project is lab based. The student will join the plant virology lab at the School of Life Sciences, Keele University, UK. Day-to-day laboratory supervision will be provided by Trisna Tungadi (group leader). The student will be trained in molecular biology and entomology experiment, involving i) aphid and plant handling, ii) molecular biology techniques such as DNA and RNA extraction, iii) PCR and RT-PCR to detect the presence of specific bacterial endosymbiont species and BYDV, and iv) virus transmission experiments. The student will participate in lab meetings, trained in data collection, presentation, and statistical analysis. The student will meet regularly with Trisna to discuss progress. Overall, this project will provide the student an experience working in a research lab, whilst simultaneously contributing to a larger research project in the group focusing on aphids as plant virus vector. Recommended reading for the projectCarr, J. P; Murphy, A. M; Tungadi, T.; and Yoon, J-.Y. (2019). Plant defense signals : Players and pawns in plant-virus-vector interactions. Plant Science 279 : 87-95. Available at : https://doi.org/10.1016/j.plantsci.2018.04.011 Chirgwin, E., Yang, Q., Umina, P.A., et al. Barley yellow dwarf virus influences its vector’s endosymbionts but not its thermotolerance. (2023) Microorganisms 12 : 1. Available at https://doi.org/10.3390/microorganisms12010010Leybourne D. J., Whitehead, M.A., and Will, T. (2024). Genetic diversity in vector population influences transmission efficiency of an important plant virus. Biol. Lett. 22 :5. Available at : https://doi.org/10.1098/rsbl.2024.0095