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<p>Root-knot nematodes (RKN; <italic>Meloidogyne</italic> spp.) are among the most damaging pests to tomato production in the USA and worldwide, with yield losses ranging from 25 to 100%. Host resistance conferred by the <italic>Mi</italic> gene in tomato is effective against some species of RKN (e.g. <italic>M. incognita</italic>, <italic>M. javanica</italic>, and <italic>M. arenaria</italic>); however, there are virulent species and lines including <italic>M. hapla</italic> and <italic>M. eterolobii</italic> that break <italic>Mi</italic>-mediated resistance. Plant innate immunity is another possible form of defense against pathogen attack and is known to be induced by chemical elicitors. Nicotinamide adenine dinucleotide (NAD) is one such chemical elicitor that regulates plant defense responses to multiple biotic stresses. In this study, we investigated the role of NAD in the context of induced tomato innate immunity and RKN pathogenicity in two tomato cultivars; VFN and Rutgers, with and without <italic>Mi</italic>, respectively. Single soil drench application of NAD 24 hr before nematode inoculation significantly induced defense response pathways, reduced infective-juveniles penetration, number of galls, and increased plant mass in both cultivars. Importantly, we observed no direct toxic effects of NAD on nematode viability and infectivity. The results presented here suggest that NAD induces resistance against RKN pathogenicity likely through the accumulation of tomato basal defense responses rather than the direct effect on the infective-juveniles behavior.</p>
</abstract>

Root-knot nematodes (RKN; Meloidogyne spp.) are among the most damaging pests to tomato production in the USA and worldwide, with yield losses ranging from 25 to 100%. Host resistance conferred by the Mi gene in tomato is effective against some species of RKN (e.g. M. incognita, M. javanica, and M. arenaria); however, there are virulent species and lines including M. hapla and M. eterolobii that break Mi-mediated resistance. Plant innate immunity is another possible form of defense against pathogen attack and is known to be induced by chemical elicitors. Nicotinamide adenine dinucleotide (NAD) is one such chemical elicitor that regulates plant defense responses to multiple biotic stresses. In this study, we investigated the role of NAD in the context of induced tomato innate immunity and RKN pathogenicity in two tomato cultivars; VFN and Rutgers, with and without Mi, respectively. Single soil drench application of NAD 24 hr before nematode inoculation significantly induced defense response pathways, reduced infective-juveniles penetration, number of galls, and increased plant mass in both cultivars. Importantly, we observed no direct toxic effects of NAD on nematode viability and infectivity. The results presented here suggest that NAD induces resistance against RKN pathogenicity likely through the accumulation of tomato basal defense responses rather than the direct effect on the infective-juveniles behavior.

Nicotinamide adenine dinucleotide induced resistance against root-knot nematode <italic>Meloidogyne hapla</italic> is based on increased tomato basal defense

Journal of Nematology

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Nicotinamide adenine dinucleotide induced resistance against root-knot nematode  is based on increased tomato basal defense

running-head

Nicotinamide adenine dinucleotide induced resistance against root-knot nematode

Root-knot nematodes (RKN; Meloidogyne spp.) are among the most damaging pests to tomato production in the USA and worldwide, with yield losses ranging from 25...

Nicotinamide adenine dinucleotide induced resistance against root-knot nematode Meloidogyne hapla is based on increased tomato basal defense

Article Category: Arts & Humanities

Published Online: Apr 15, 2019

Page range: 1 - 10

Received: Oct 23, 2018

DOI: https://doi.org/10.21307/jofnem-2019-022

© 2019 Noor Abdelsamad et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.