Investigation and characterisation of diamide insecticide resistance conferred by target-site mutations in the ryanodine receptor of lepidopteran pest

Lead Research Organisation: Cardiff University
Department Name: School of Medicine

Abstract

Diamide insecticides, such as flubendiamide and chlorantraniliprole, act as conformation sensitive activators of insect ryanodine receptors (RyR), releasing calcium from intracellular stores in insect muscle, and causing an irreversible paralysis. These compounds are the main active ingredients in diamide formulations used to control a diverse range of herbivorous insects, particularly lepidopterans such as the diamondback moth, Plutella xylostella, a notorious global pest on cruciferous crops. This common pest has recently developed widespread resistance to diamides through specific mutations in the trans-membrane domain of the RyR. Additional diamide insecticides such as cyclaniliprole, broflanilide and tetraniliprole are currently under development and will further increase the selection pressure on a number of target pests. It is therefore a key priority to investigate these resistance mechanisms by means of detailed biochemical and molecular studies. This project will characterise their impact on diamide insecticide action and RyR function, using state of the art approaches including cell-line expression of recombinant proteins, radioligand binding studies, electrophysiological recordings, calcium imaging and CRISPR/Cas9 guided drosophila transgenesis, and will be key to providing a fundamental understanding of diamide insecticide binding to allelic RyR variants. This knowledge will further impact future resistance management strategies for diamides and the discovery pipeline for novel insecticidal RyR modulators. You will be trained in standard biochemical, molecular and genetic techniques that are widely applicable and will also benefit from learning more specialised techniques such as insect transgenesis. You will also be required to spend 3 months on placement with the industry partner Bayer CropScience in Monheim, Germany.

Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/N504075/1 26/10/2015 25/10/2019
1653661 Studentship BB/N504075/1 02/11/2015 01/11/2019 Ewan Richardson
 
Description The stated purpose of the studentship was to determine the impact of ryanodine receptor mutations upon diamide efficacy. To that end, candidate mutations identified in the field were inserted into the ryanodine receptor of an otherwise diamide-susceptible moth, species Plutella xylostella.

The biology of mutated ryanodine receptors was investigated both in-vitro and in-vivo.

Key outcomes of the work:
- Creation of a resistance-model fly strain which expresses the ryanodine receptor (and mutants there-of) of a moth in place of its own.
- Quantitative and qualitative characterisation of two field-derived mutations, in terms of their impact upon diamide efficacy, in moth cell lines.
Additionally, characterisation of one of these mutations in vivo, by use of the afore-mentioned fly model.
Exploitation Route Findings may be used by manufacturers and farmers to predict diamide control failures in the field

Additionally, the developed fly model may vastly accelerate repeated investigations of this kind.
Sectors Agriculture, Food and Drink,Chemicals,Environment,Pharmaceuticals and Medical Biotechnology

 
Description Genetics Society Training Grant
Amount £1,000 (GBP)
Organisation The Genetics Society 
Sector Charity/Non Profit
Country United Kingdom
Start 08/2017 
End 09/2017
 
Description PhD - Investigation and characterisation of diamide insecticide resistance due to target site mutations in the ryanodine receptor of lepidopteran pests 
Organisation Bayer
Department Bayer CropScience Ltd
Country United Kingdom 
Sector Private 
PI Contribution Main PhD supervisor. Co-supervisor.
Collaborator Contribution Co-supervisors. Access to equipment & facilities
Impact Work in progress
Start Year 2015
 
Description PhD - Investigation and characterisation of diamide insecticide resistance due to target site mutations in the ryanodine receptor of lepidopteran pests 
Organisation Cardiff University
Department School of Medicine
Country United Kingdom 
Sector Academic/University 
PI Contribution Main PhD supervisor. Co-supervisor.
Collaborator Contribution Co-supervisors. Access to equipment & facilities
Impact Work in progress
Start Year 2015
 
Description Genetics society article: Injection steps for CRISPR/Cas9 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact A written article for the Genetics Society Magazine, detailing best practice for CRISPR/Cas9 oocyte injection in Drosophila melanogaster. The article was prompted by a visit made, under funding from the society, to a specialist genomic engineering faculty in Maryland, USA.
Year(s) Of Engagement Activity 2018
 
Description Hack.Agtech 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact 50 engineers, scientists and students from diverse backgrounds attended a three-day meeting in order to make partnerships towards developing solutions for boosting food security in the developing world
Year(s) Of Engagement Activity 2017