Date Published: February 28, 2013
Publisher: Public Library of Science
Author(s): Louise E. Atkinson, Michael Stevenson, Ciaran J. McCoy, Nikki J. Marks, Colin Fleming, Mostafa Zamanian, Tim A. Day, Michael J. Kimber, Aaron G. Maule, Angela Mousley, David Bird.
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.
Plant pathogenic nematodes (PPNs) impose a significant economic burden on global crop cultivation resulting in estimated losses of at least $118 billion per year . The control of PPNs relies heavily on nematicides, basic crop rotation approaches, and the use of resistant crop cultivars; significantly many nematicides have diminishing utility as a consequence of their environmental toxicity. Consequently, global crop production remains under threat from PPNs for which no effective management strategies currently exist. While the PPN problem results from an absence of effective, legal control methods, deficiencies in animal and human parasite therapies are associated with escalating reports of resistance to chemotherapeutics . Thus, 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.