Flp-32 Ligand/Receptor Silencing Phenocopy Faster Plant Pathogenic Nematodes

Michael J Kimber,Ciaran J Mccoy,Louise E Atkinson,Nikki J Marks,Mostafa Zamanian,Colin Fleming,Aaron G Maule,Michael Stevenson,Angela Mousley,Tim A Day

doi:10.1371/journal.ppat.1003169

Abstract

Restrictions on nematicide usage underscore the need for novel control strategies for plant pathogenic nematodes such as Globodera pallida (potato cyst nematode) that impose a significant economic burden on plant cultivation activities. The nematode neuropeptide signalling system is an attractive resource for novel control targets as it plays a critical role in sensory and motor functions. The FMRFamide-like peptides (FLPs) form the largest and most diverse family of neuropeptides in invertebrates, and are structurally conserved across nematode species, highlighting the utility of the FLPergic system as a broad-spectrum control target. flp-32 is expressed widely across nematode species. This study investigates the role of flp-32 in G. pallida and shows that: (i) Gp-flp-32 encodes the peptide AMRNALVRFamide; (ii) Gp-flp-32 is expressed in the brain and ventral nerve cord of G. pallida; (iii) migration rate increases in Gp-flp-32-silenced worms; (iv) the ability of G. pallida to infect potato plant root systems is enhanced in Gp-flp-32-silenced worms; (v) a novel putative Gp-flp-32 receptor (Gp-flp-32R) is expressed in G. pallida; and, (vi) Gp-flp-32R-silenced worms also display an increase in migration rate. This work demonstrates that Gp-flp-32 plays an intrinsic role in the modulation of locomotory behaviour in G. pallida and putatively interacts with at least one novel G-protein coupled receptor (Gp-flp-32R). This is the first functional characterisation of a parasitic nematode FLP-GPCR.

Highlights

Plant pathogenic nematodes (PPNs) impose a significant economic burden on global crop cultivation resulting in estimated losses of at least $118 billion per year [1]
Motor functions are known to be modulated by FMRFamide-like peptides (FLPs); the nematode FLPergic system remains unexploited for parasite control
This study investigates the functional biology of flp-32, a commonly expressed nematode flp, and a novel FLP-32 receptor in a plant pathogenic nematode of major agricultural importance, Globodera pallida

Summary

Introduction

Plant pathogenic nematodes (PPNs) impose a significant economic burden on global crop cultivation resulting in estimated losses of at least $118 billion per year [1]. While focused control of PPNs alone has significant merit, the identification of broad spectrum drug targets and chemotherapies which combat diverse nematode infections is highly desirable. Many of the most useful anti-nematode chemotherapeutics target neuromuscular signalling, compromising nerve-muscle function to impair normal parasite biology. Motor functions (reproduction, feeding and locomotion) are known to be modulated by FMRFamide-like peptides (FLPs); the nematode FLPergic system remains unexploited for parasite control (see [3,4,5,6,7,8,9] for review). The potential of FLPergic signalling as a control target resource embedded within nematode neuromuscular functionality has been highlighted [3]. If FLP structural conservation is mirrored by conserved function the potential broad-spectrum utility of drugs directed against FLP signalling targets would be enhanced. PLOS Pathogens | www.plospathogens.org flp-32 Silencing in Plant Pathogenic Nematodes

Author Summary

Conclusions

Findings

Materials and Methods