Identification and Characterization of a Dual-Acting Antinematodal Agent against the Pinewood Nematode, Bursaphelenchus xylophilus

Abstract

The pinewood nematode (PWN), Bursaphelenchus xylophilus, is a mycophagous and phytophagous pathogen responsible for the current widespread epidemic of the pine wilt disease, which has become a major threat to pine forests throughout the world. Despite the availability of several preventive trunk-injection agents, no therapeutic trunk-injection agent for eradication of PWN currently exists. In the characterization of basic physiological properties of B. xylophilus YB-1 isolates, we established a high-throughput screening (HTS) method that identifies potential hits within approximately 7 h. Using this HTS method, we screened 206 compounds with known activities, mostly antifungal, for antinematodal activities and identified HWY-4213 (1-n-undecyl-2-[2-fluorphenyl] methyl-3,4-dihydro-6,7-dimethoxy-isoquinolinium chloride), a highly water-soluble protoberberine derivative, as a potent nematicidal and antifungal agent. When tested on 4 year-old pinewood seedlings that were infected with YB-1 isolates, HWY-4213 exhibited a potent therapeutic nematicidal activity. Further tests of screening 39 Caenorhabditis elegans mutants deficient in channel proteins and B. xylophilus sensitivity to Ca2+ channel blockers suggested that HWY-4213 targets the calcium channel proteins. Our study marks a technical breakthrough by developing a novel HTS method that leads to the discovery HWY-4213 as a dual-acting antinematodal and antifungal compound.

Conserved behavioral and genetic mechanisms in the pre-hatching molt of the nematode Pristionchus pacificus

“…Although the four molts after hatching in C. elegans appear to be the ancestral phenotype, there are several examples that deviate from this pattern in plant and animal parasites [ 6 ]. Nematodes that molt prior to hatching include the parasitic pinewood nematode Bursaphelenchus xylophilus and the potato cyst nematode Globodera pallida [ 3 , 7 , 8 ], as well as the vertebrate parasites Ascaris lumbricoides and Toxocara cati [ 3 , 9 ] . Among non-parasitic nematodes, larvae that undergo the first molt within the eggshell have been described in the Pristionchus and Oigolaimella species in the family Diplogastridae [ 10 ].…”

Inhibition effects of fennel extract (Foeniculum vulgare Mill) on pine wood nematode and the bacteria it carries

“…Despite the availability of several preventive trunkinjection chemicals, no one agent has been found yet to PWN eradication (Oh et al, 2009). Oh et al (2009) displayed 206 compounds through an established highthroughput screening (HTS) methods with known activities, mostly antifungal, for anti-nematodal activities and identified HWY-4213 [1-n-undecyl-2-(2-fluorphenyl) methyl-3,4-dihydro-6,7-dimethoxy-isoquinolinium chloride], a highly water-soluble protoberberine derivative, as a potent nematicidal and antifungal agent. In previous studies, extracts of some higher plants, particularly Asteraceous and Euphorbiaceous plants, have been found to possess good nematicidal activity against B.…”

“…East Asia and Eastern Europe. Conventionally, chemicals are used to control this disease, however, since these may have undesirable environmental effects, efforts have turned to bio-controls and controls using natural products, but to date, no such products can eradicate PWD at present (Oh et al, 2009). Recently, some natural products from plants and plant extracts were found to be excellent nematicidal.…”

Biological control of the pinewood nematode Bursaphelenchus xylophilus by application of the endoparasitic fungus Esteya vermicola

“…Subsequently, the plate was cultured for 6-8 days until the fungal mycelia had been completely consumed (Oh et al 2009). The cultured nematodes were separated from the culture medium using the Baermann funnel technique (Baermann 1917).…”