Direct and indirect effects of fungal endophytes on plant-parasitic nematodes

Schouten, A. (Speaker)

Activity: Talk or presentationOral presentationOther

Description

Although notorious for their pathogenicity, it is becoming evident that most Fusarium oxysporum isolates
encountered in nature are harmless to plants, some of which can even play a beneficial role as true
endophytes, meaning that they can colonise plants without ever provoking a disease phenotype, by
antagonizing plant-parasitic nematodes. The involved mechanisms in this quantitative antagonism are only
superficially understood. There is evidence that the presence of the endophyte increases plant vigour and
induces plant defence responses toward the nematode. Direct negative effects of the endophyte on nematode
performance and behaviour cannot be ruled out as well.
Metabolites, produced by the fungal nematode control endophyte, F. oxysporum 162 (Fo162), were isolated
and fully characterized. Of the eleven resolved compounds, six were isolated from a Fusarium spp. for the first
time. Toxicity assays showed that, 4-hydroxybenzoic acid (4-HBA), indole-3-acetic acid (IAA) and gibepyrone D
were the most potent toward nematodes, being almost as good as the best commercial nematocide. IAA is a
well-known phytohormone and known to play a role in plant development and triggering defences. 4-HBA is
reported to increase abiotic stress tolerance. This finding thus suggests that individual metabolites, produced
by Fo162, can have a dual activity, i.e. inducing defence mechanisms and/or tolerance toward nematodes in
plants and directly killing or compromising nematodes. Such compounds may serve as important leads in the
development of sustainable and environmental friendly nematocides.
Period2017
Event titlePresidential Meeting 2017, null
Event typeConference
LocationNottingham, United Kingdom
Degree of RecognitionInternational