A Novel In Vitro Tool to Study Cyst Nematode Chemotaxis.

Yohana Laloum,Carole Plasson,Bruno Ngala,Maïté Vicré,Isabelle Boulogne,Éric Nguema-Ona,Azeddine Driouich,Anne-Claire Le Roux,Virginie Gobert,Sylvain Fournet,Mélina Ianszen,Maxime Gotté

doi:10.3389/fpls.2020.01024

Abstract

This study presents a novel three-dimensional (3D) tool “3D in vitro choice” for chemotaxis assays with cyst nematodes. The original 3D in vitro choice was customized through digital printing. Freshly hatched second stage juveniles (J2s) of the cyst nematode Globodera pallida were used as the nematode model to illustrate chemo-orientation behavior in the 3D system. The efficiency and reliability of the 3D in vitro choice were validated with 2% Phytagel as navigation medium, in three biological assays and using tomato root exudates or potato root border cells and their associated mucilage as a positive attractant as compared with water. For each biological assay, J2s were hatched from the same population of a single generation glasshouse-cultured cysts. This novel easy to use and low-cost 3d-device could be a useful replacement to Petri dishes assays in nematode behavioral studies due to the ease of deposition of nematodes and test substances, coupled with its distinctive zones that allow for precision in choice making by the nematodes.

Highlights

Plant-parasitic nematodes are major agricultural pathogens causing severe damage to crops leading to considerable economic losses (Nicol et al, 2011)
According to the result of the three chemotaxis bioassays, chemotaxis index corresponding to the neutral condition were −0.03 ± 0.12; 0.07 ± 0.10 and −0.14 ± 0.16, respectively (Figure 2A)
The data indicate a homogeneous distribution of J2s on the 3D in vitro choice in neutral conditions confirming that in the absence of any attractant or repellent solution, J2s showed an unselective orientation behavior

Summary

Introduction

Plant-parasitic nematodes are major agricultural pathogens causing severe damage to crops leading to considerable economic losses (Nicol et al, 2011). The cyst nematode Globodera pallida is an obligatory parasite specific to solanaceous crops including potato (Solanum tuberosum L.) tomato (Solanum lycopersicum L.) and eggplant (Solanum melongena L.) (Sullivan et al, 2007) and is one of the most devastating quarantine pests of potato crop (Jones et al, 2013). This plant parasitic nematode causes potato tuber losses of up to 9% in Europe every year (Moens et al, 2018).

Methods

Results

Conclusion