Abdelsamad Noor, Regmi H, Desaeger J, DiGennaro P
Department of Entomology and Nematology, College of Agriculture and Animal Science, University of Florida , Gainesville.
Department of Entomology and Nematology, College of Agriculture and Animal Science, University of Florida , Gainesville ; Gulf Coast Research and Education Center, University of Florida , Wimauma.
J Nematol. 2019;51:1-10. doi: 10.21307/jofnem-2019-022.
Root-knot nematodes (RKN; 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 gene in tomato is effective against some species of RKN (e.g. , , and ); however, there are virulent species and lines including and that break -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 , 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. Root-knot nematodes (RKN; 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 gene in tomato is effective against some species of RKN (e.g. , , and ); however, there are virulent species and lines including and that break -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 , 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.
根结线虫（RKN； 属）是美国乃至全球番茄生产中最具破坏性的害虫之一，产量损失在25%至100%之间。番茄中 基因赋予的寄主抗性对某些根结线虫物种（如 、 和 ）有效；然而，存在包括 和 在内的能打破 介导抗性的致病物种和品系。植物先天免疫是抵御病原体攻击的另一种可能的防御形式，已知可由化学激发子诱导。烟酰胺腺嘌呤二核苷酸（NAD）就是这样一种化学激发子，它调节植物对多种生物胁迫的防御反应。在本研究中，我们分别在有 和没有 的两个番茄品种VFN和罗格斯中，研究了NAD在诱导番茄先天免疫和根结线虫致病性背景下的作用。在接种线虫前24小时对土壤进行单次NAD浇灌，显著诱导了防御反应途径，减少了侵染性幼虫的侵入、根瘤数量，并增加了两个品种的植株生物量。重要的是，我们观察到NAD对线虫的活力和感染性没有直接毒性作用。此处呈现的结果表明，NAD可能通过积累番茄的基础防御反应而非直接影响侵染性幼虫的行为来诱导对根结线虫致病性的抗性。根结线虫（RKN； 属）是美国乃至全球番茄生产中最具破坏性的害虫之一，产量损失在25%至100%之间。番茄中 基因赋予的寄主抗性对某些根结线虫物种（如 、 和 ）有效；然而，存在包括 和 在内的能打破 介导抗性的致病物种和品系。植物先天免疫是抵御病原体攻击的另一种可能的防御形式，已知可由化学激发子诱导。烟酰胺腺嘌呤二核苷酸（NAD）就是这样一种化学激发子，它调节植物对多种生物胁迫的防御反应。在本研究中，我们分别在有 和没有 的两个番茄品种VFN和罗格斯中，研究了NAD在诱导番茄先天免疫和根结线虫致病性背景下的作用。在接种线虫前24小时对土壤进行单次NAD浇灌，显著诱导了防御反应途径，减少了侵染性幼虫的侵入、根瘤数量，并增加了两个品种的植株生物量。重要的是，我们观察到NAD对线虫的活力和感染性没有直接毒性作用。此处呈现的结果表明，NAD可能通过积累番茄的基础防御反应而非直接影响侵染性幼虫的行为来诱导对根结线虫致病性的抗性。
