Overview:
Plant-parasitic nematodes are major, and in some cases dominant, threats to crop production around the world. Like all pathogens, they use effectors – proteins delivered into the host during infection – to manipulate plant development, immunity, metabolism, and physiology in order to cause disease.
We recently discovered that effector deployment at the earliest stages of infection by plant-parasitic nematodes is defined by a feedforward signaling loop, stimulated by plant-derived signals. Understanding the nature and perception of these so called “effectostimulins” in sufficient detail to disrupt them has intuitive routes to impact, and is the focus of this project.
Two main objectives are envisaged:
- Understanding the natural variation in effectostimulins production in plants.
- Understanding the pathway of effectostimulins perception in the nematode.
Importance of Research:
This project will build foundational knowledge on an ancienct singalling pathway between two Kingdoms of life. This foundational knowledge is intended to drive innovation by informing strategies which may disrupt the signalling, the parasitic interaction which follows, and thereby the threat to global food security. The importance of this research is underscored by the facts that i) there is at least one species of nematode able to parasitise all major food crops of the world, and ii) together plant-parasitic nematodes are estimated to cost over $100 billion to world agriculture, per year.
Project Summary:
Two main objectives are envisaged:
- Understanding the natural variation in effectostimulins production in plants.Our preliminary identifies substantive natural variation in effectostimulin production in divserse accessions of A. thaliana. Screening a mapping population for effectostimulins production will identify candidate loci, which can be tested using tDNA insertion mutants. Together, these experiments will define the pathway(s) in the plant which are required for effectostimulin production.
- Understanding the pathway of effectostimulins perception in the nematode. Nematodes respond to effectostimulins by upregulating the master regulator of virulence SUGR1 (Pellegrin and Damm et al., PNAS, 2025). In this objective, we aim to understand the steps inbetween – i.e. how is the signal perceived by the nematode, and transmitted to the effector-producing tissues using known blockers of neuronal signalling.
What will the successful applicant do?
The exact nature of the experiments will of course be tailored to the experience and/or interests of the successful applicant. However, experiments can include forward genetic screens, transcriptional profiling and RNAseq, mutation and pathogen assays, and chemical genetics.
References:
C. Pellegrin, A. Damm, A.L. Sperling, B. Molloy, D.S. Shin, J. Long, P. Brett, T.C. Iguh, O.P. Kranse, A.D. Bravo, S.J. Lynch, B. Senatori, P. Vieira, J. Mejias ,A. Kumar, R.E. Masonbrink, T.R. Maier, T.J. Baum, & S. Eves-van den Akker, The SUbventral-Gland Regulator (SUGR-1) of nematode virulence, Proc. Natl. Acad. Sci. U.S.A. 122 (11) e2415861122, DOI:10.1073/pnas.2415861122