Identification and Characterization of a Fatty Acid- and Retinoid-Binding Protein Gene (Ar-far-1) from the Chrysanthemum Foliar Nematode, Aphelenchoides ritzemabosi

The chrysanthemum foliar nematode (CFN), Aphelenchoides ritzemabosi, is a migratory, plant-parasitic nematode that is widely distributed and infects the aboveground parts of many plants. The fatty acid- and retinoid-binding proteins (FAR) are nematode-specific proteins that are involved in the development, reproduction, and infection of nematodes and are secreted into the tissues to disrupt the plant defense reaction. In this study, we obtained the full-length sequence of the FAR gene (Ar-far-1) from CFN, which is 727 bp and includes a 546 bp ORF that encodes 181 amino acids. Ar-FAR-1 from CFN has the highest sequence similarity to Ab-FAR-1 from A. besseyi, and they are located within the same branch of the phylogenetic tree. Fluorescence-based ligand-binding analysis confirmed that recombinant Ar-FAR-1 was bound to fatty acids and retinol. Ar-far-1 mRNA was expressed in the muscle layer, intestine, female genital system, and egg of CFN, and more highly expressed in females than in males among the four developmental stages of CFN. We demonstrated that the reproduction number and infection capacity of CFN decreased significantly when Ar-far-1 was effectively silenced by in vitro RNAi. Ar-far-1 plays an important role in the development, reproduction, infectivity, and pathogenesis of CFN and may be used as an effective target gene for the control of CFN. The results provide meaningful data about the parasitic and pathogenic genes of CFN to study the interaction mechanism between plant-parasitic nematodes and hosts.

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Foliar Nematode Aphelenchoides spp. (Nematoda: Aphelenchida: Aphelenchoididae)

EDIS ◽

10.32473/edis-in1279-2020 ◽

2020 ◽

Vol 2020 (3) ◽

Author(s):

Lindsay Wheeler ◽

William Talmadge Crow

Keyword(s):

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Plant Feeding ◽

Plant Parasites ◽

Aphelenchoides Besseyi ◽

The Common ◽

Aphelenchoides Fragariae ◽

Foliar Nematode ◽

Plant Parasitic ◽

Aphelenchoides Ritzemabosi

There are nematodes of several genera that feed on plant stems and foliage, including Aphelenchoides, Bursaphelenchus, Anguina, Ditylenchus and Litylenchus. Herein, we apply the common name “foliar nematode” specifically to plant-feeding nematodes in the genus Aphelechoides, specifically Aphelenchoides besseyi, Aphelenchoides fragariae, and Aphelenchoides ritzemabosi. While most members of Aphelenchoides are fungivorous (feed on fungi), these three species have populations that are facultative plant-parasites that can feed on live plant tissue. Ten other species of Aphelenchoides also are recognized as facultative plant-parasites, but these are not as commonly encountered or as economically significant as the aforementioned species. Unlike most plant-parasitic nematodes, foliar nematodes can infest the aerial portions of plants rather than dwelling strictly in soil and plant roots. Damage from their feeding can reduce yield in food crops and ruin the appearance of ornamentals.https://edis.ifas.ufl.edu/in1279

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Biological attributes of Salibro™, a novel sulfonamide nematicide. Part 2: Impact on the fitness of various non-target nematodes

Nematology ◽

10.1163/15685411-bja10041 ◽

2020 ◽

pp. 1-17 ◽

Cited By ~ 1

Author(s):

Tim C. Thoden ◽

Mariam A. Alkader ◽

John A. Wiles

Keyword(s):

Negative Impact ◽

Soil Health ◽

Agar Plate ◽

Parasitic Nematodes ◽

Published Data ◽

Plant Parasitic Nematodes ◽

Free Living ◽

Plant Parasitic ◽

Novel Products

Summary Currently a renaissance in chemical nematicides is taking place with novel products like Nimitz® (a.s. fluensulfone), Velum Prime® (a.s. fluopyram) and Salibro™ (a.s. fluazaindolizine – Reklemel™ active) entering the marketplace. Although a considerable amount of published data is already available on their laboratory and field impact on plant-parasitic nematodes, little is understood of their compatibility with the beneficial or free-living nematodes that are part of the soil health network. In a range of laboratory studies, the effects of these nematicides on the vitality and reproduction of several species was tested, including both cosmopolitan free-living nematodes (Acrobeloides, Cruznema, Panagrobelus) as well as commercially applied entomopathogenic nematodes (Steinernema, Heterorhabditis). Within aqueous exposure and agar plate in vitro assays, species sensitivity to those nematicides differed significantly but their fitness (vitality and reproduction; infectivity to insect hosts) was generally not adversely impacted by concentrations of 5-50 ppm (a.s.) of Salibro. Even at 250 ppm (a.s.) of Salibro only some species of the bacterial-feeding species showed some negative impact. By contrast, both Nimitz at 50 ppm (a.s.) and Velum at 5 ppm (a.s.) consistently demonstrated stronger adverse impacts. In second level soil drenching assays, either no, or occasionally slight, adverse effects on the natural community of free-living nematodes were observed if soils were drenched with different volumes of Salibro at 5-50 ppm (a.s.), while relatively stronger reductions were measured within the plant-parasitic species (especially root-knot nematodes). Both Nimitz and Vydate (a.s. oxamyl) showed some degree of compatibility at 5 and 25 ppm (a.s.), respectively, which was generally higher than for Velum Prime at 5 ppm (a.s.). Overall, these data indicate that, when used at common field rates, Salibro will be one of the best options as part of integrated nematode management programmes where the use of chemical nematicides is required.

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Differential Response of Meloidogyne, Pratylenchus, Globodera, and Xiphinema Species to the Nematicide Fluazaindolizine

Phytopathology ◽

10.1094/phyto-05-20-0189-r ◽

2020 ◽

Vol 110 (12) ◽

pp. 2003-2009

Author(s):

Catherine L. Wram ◽

Inga Zasada

Keyword(s):

Untreated Control ◽

Exposure Dose ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Response Curves ◽

Greenhouse Study ◽

Meloidogyne Spp ◽

The Impact ◽

Plant Parasitic

This research focused on the effects of fluazaindolizine on a diversity of plant-parasitic nematodes. In microwell assays, 24-h dose-response curves were generated for several species and populations of Meloidogyne, Pratylenchus neglectus, P. penetrans, Globodera ellingtonae, and Xiphinema americanum. In a greenhouse study, the impact of fluazaindolizine on fecundity of M. incognita, M. hapla, and M. chitwoodi was tested by exposing nematodes for 24 h in solution and inoculating on tomato. The average 24-h ED50s (dose that resulted in the immobility of 50% of exposed nematodes) for M. hapla, M. chitwoodi, and M. incognita were 325.7, 223.4, and 100.7 ppm, respectively. M. hapla had the most variation among populations, with 24-h ED50s ranging from 72 to 788 ppm. G. ellingtonae had the lowest 24-h ED50 at 30 ppm. Pratylenchus spp. were unaffected by fluazaindolizine. X. americanum was the only species where effects of fluazaindolizine were reversible, but had a 24-h ED50 that fell in the range of the Meloidogyne spp. In the greenhouse study, M. chitwoodi was the least sensitive with reproduction reaching 62% of the untreated control after a pre-exposure to 47 ppm, whereas M. incognita and M. hapla at the same exposure dose had reproduction rates of 27 and 36% of the untreated control, respectively. Despite varying in in vitro responses to fluazaindolizine, reproduction of all Meloidogyne spp. was suppressed after only 24 h of exposure. This study expanded our understanding of how G. ellingtonae, P. thornei, P. penetrans, and X. americanum respond to fluazaindolizine.

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Activity of Saponins from Medicago Species against Phytoparasitic Nematodes

Plants ◽

10.3390/plants9040443 ◽

2020 ◽

Vol 9 (4) ◽

pp. 443 ◽

Cited By ~ 2

Author(s):

Trifone D’Addabbo ◽

Maria Pia Argentieri ◽

Jerzy Żuchowski ◽

Elisa Biazzi ◽

Aldo Tava ◽

...

Keyword(s):

Meloidogyne Incognita ◽

In Vitro Assays ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Phytoparasitic Nematodes ◽

Phytochemical Profile ◽

Medicago Species ◽

Phytoparasitic Nematode ◽

Plant Parasitic

Content of bioactive saponins of Medicago species suggests that they may also exert, as previously demonstrated on M. sativa, nematicidal properties exploitable for the formulation of new products for sustainable phytoparasitic nematode management. This study was addressed to highlight the bioactivity of saponins from five different Medicago species still poorly known for their biological efficacy, i.e., M. heyniana, M. hybrida, M. lupulina, M. murex and M. truncatula, against the plant parasitic nematodes Meloidogyne incognita, Xiphinema index and Globodera rostochiensis. The bioactivity of the extracts from the five Medicago species was assessed by in vitro assays on the juveniles (J2) and eggs of M. incognita and G. rostochiensis and the adult females of X. index. The suppressiveness to M. incognita of soil treatments with the Medicago plant biomasses was also investigated in a tomato experiment. The nematicidal activity of the five Medicago species was reported and discussed in relation to their phytochemical profile.

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Effects of catechin polyphenols and preparations from the plant–parasitic nematode Heterodera glycines on protease activity and behaviour in three nematode species

Journal of Helminthology ◽

10.1017/s0022149x13000254 ◽

2013 ◽

Vol 88 (3) ◽

pp. 349-356 ◽

Cited By ~ 2

Author(s):

E.P. Masler

Keyword(s):

Protease Activity ◽

Heterodera Glycines ◽

Specific Inhibitor ◽

Nematode Species ◽

Infective Juvenile ◽

Parasitic Nematodes ◽

Epicatechin Gallate ◽

Plant Parasitic ◽

Ctl Activity

AbstractProtease activities in preparations from the plant-parasitic nematodes Heterodera glycines and Meloidogyneincognita and the free-living nematode Panagrellus redivivus were inhibited by exposure to a series of eight catechin polyphenol analogues, (+)-catechin, ( − )-epicatechin (EC), ( − )-gallocatechin (GC), ( − )-epigallocatechin (EGC), ( − )-catechin gallate (CG), ( − )-gallocatechin gallate (GCG), ( − )-epicatechin gallate (ECG) and ( − )-epigallocatechin gallate (EGCG) (1 mm each), and by a preparation from H. glycines cysts. General protease activity detected with the FRET-peptide substrate QXL520-KSAYMRF-K(5-FAM)a and proteasome chymotrypsin-like (CTL) activity detected with succinyl-LLVY-AMC were each inhibited significantly more (P< 0.05) by the gallated form of the polyphenol than by the corresponding non-gallated form. Species differences in response to inhibition across all analogues were revealed with the CTL substrate, but CG was a consistently potent inhibitor across all three species and with each substrate. A heat-stable component (CE) from H. glycines cysts inhibited M. incognita CTL activity by 92.07 ± 0.68%, significantly less (P< 0.05) in H. glycines (52.86 ± 2.77%), and by only 17.24 ± 0.55% (P< 0.05) in P. redivivus preparations. CTL activity was, however, inhibited more than 60% in all preparations by the proteasome-specific inhibitor MG-132. Hatching of M. incognita infective juveniles exposed to 1 mm CG, ECG, GCG or EGCG was reduced by 83.88 ± 4.26%, 69.98 ± 9.14%, 94.93 ± 1.71% and 87.93 ± 2.89%, respectively, while hatching of H. glycines was reduced less than 25% by each analogue. CE had no effect on nematode hatch, but did cause a 60% reduction in mobility of H. glycines infective juveniles exposed overnight to CE in vitro, which was more (P< 0.05) than the reduction of M. incognita infective juvenile mobility (20%).

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The use of Pluronic F-127 to study the development of the potato cyst nematode, Globodera pallida

Nematology ◽

10.1163/156854112x631944 ◽

2012 ◽

Vol 14 (7) ◽

pp. 869-873 ◽

Cited By ~ 5

Author(s):

Ayano Sasaki-Crawley ◽

Rosane Curtis ◽

Michael Birkett ◽

Apostolos Papadopoulos ◽

Rod Blackshaw ◽

...

Keyword(s):

Aqueous Solution ◽

Solanum Tuberosum ◽

Transgenic Plants ◽

Cyst Nematode ◽

Potato Cyst Nematode ◽

Globodera Pallida ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Plant Parasitic

This paper demonstrates a simple novel in vitro method using Pluronic F-127 aqueous solution to study the development of the potato cyst nematode, Globodera pallida, in Solanum spp. without any need for sterilisation of either the plants or the nematodes. In this study, this method was successfully applied to comparative studies on the development of G. pallida in Solanum tuberosum (potato) or S. sisymbriifolium (sticky nightshade). The protocol described here could be useful for screening transgenic plants or different plant cultivars/species for their ability to allow development not only of G. pallida but also any other plant-parasitic nematodes.

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Toxicity of ethanol solutions and vapours against Meloidogyne incognita

Nematology ◽

10.1163/15685411-00003046 ◽

2017 ◽

Vol 19 (3) ◽

pp. 271-280 ◽

Cited By ~ 6

Author(s):

Julio C.P. Silva ◽

Vicente P. Campos ◽

Eduardo S. Freire ◽

Willian C. Terra ◽

Liliana E. Lopez

Keyword(s):

Root System ◽

Meloidogyne Incognita ◽

Parasitic Nematodes ◽

Infested Soil ◽

Large Reduction ◽

Plant Parasitic Nematodes ◽

Second Stage ◽

Plant Parasitic

Ethanol (EtOH) is less harmful to humans than currently available nematicide molecules. This study evaluated the efficacy of EtOH in controlling Meloidogyne incognita in vitro and in lettuce plants under glasshouse conditions. Aqueous EtOH solutions (5-70% volume) and their vapours caused an acute nematicidal effect in vitro in second-stage juveniles (J2) of M. incognita and reduced hatching of J2. There was a large reduction of galls and eggs in the root system when 40 ml of EtOH was applied to M. incognita-infested soil at concentrations of 40 and 70%. Water exposed to EtOH vapours for 1 h became toxic, and a 12-h exposure caused 100% J2 mortality. Use of a plastic cover did not increase the efficiency of EtOH in controlling M. incognita in lettuce plants. The observed EtOH effects indicate its prospective use in controlling plant-parasitic nematodes, especially in glasshouses.

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Responses of Heterodera glycines and Meloidogyne incognita to exogenously applied biogenic amines

Nematology ◽

10.1163/156854108786161436 ◽

2008 ◽

Vol 10 (6) ◽

pp. 911-917 ◽

Cited By ~ 6

Author(s):

Edward Masler

Keyword(s):

Biogenic Amines ◽

Meloidogyne Incognita ◽

Head Movement ◽

Heterodera Glycines ◽

Parasitic Nematodes ◽

Stage Juvenile ◽

Quantitative Analyses ◽

Effective Doses ◽

Plant Parasitic

AbstractHatching and head movement behaviours of second-stage juvenile (J2) of two agriculturally important plant-parasitic nematodes were affected by the in vitro application of biogenic amines. The behavioural responses of Heterodera glycines and Meloidogyne incognita to treatments of serotonin, octopamine and dopamine were qualitatively similar, but significant quantitative differences between the species were revealed. The frequency of J2 head movement was decreased by as little as 250 μM serotonin in H. glycines and 500 μM serotonin in M. incognita, with effective doses (ED50) of 0.73 mM for H. glycines and 1.72 mM for M. incognita. Octopamine had the opposite effect of serotonin, increasing J2 head movement frequency at thresholds of 2 mM in H. glycines and 1 mM in M. incognita. Octopamine ED50 values were 32.35 mM and 1.91 mM, respectively. Dopamine had no effect on head movement in either species up to concentrations of 20 mM. Serotonin inhibited hatch in both species but was more potent against H. glycines (90% inhibition at 1 mM) than M. incognita (40% inhibition at 5 mM). Octopamine reduced hatch equally in both species with over 95% inhibition at 80 mM. Dopamine had no effect on hatch in M. incognita but did inhibit H. glycines hatch over 60% at 40 mM. The value of detailed quantitative analyses of plant-parasitic nematode responses to biogenic amines for studies on nematode control is discussed.

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Chromatin landscape dynamics in development of the plant parasitic nematode Meloidogyne incognita

10.1101/2021.05.11.443567 ◽

2021 ◽

Author(s):

Rahim Hassanaly-Goulamhoussen ◽

Ronaldo De Carvalho Augusto ◽

Nathalie Marteu-Garello ◽

Arthur Péré ◽

Bruno Favery ◽

...

Keyword(s):

Gene Expression ◽

Histone Modifications ◽

Meloidogyne Incognita ◽

Developmental Stages ◽

Model Organisms ◽

Parasitic Nematodes ◽

Epigenetic Mechanisms ◽

Root Knot Nematode ◽

Dynamic Regulation ◽

Plant Parasitic

In model organisms, epigenome dynamics underlies a plethora of biological processes. The role of epigenetic modifications in development and parasitism in nematode pests remains unknown. The root-knot nematode Meloidogyne incognita adapts rapidly to unfavorable conditions, despite its asexual reproduction. However, the mechanisms underlying this remarkable plasticity and their potential impact on gene expression remain unknown. This study provides the first insight into contribution of epigenetic mechanisms to this plasticity, by studying histone modifications in M. incognita. The distribution of five histone modifications revealed the existence of strong epigenetic signatures, similar to those found in the model nematode Caenorhabditis elegans. We investigated their impact on chromatin structure and their distribution relative to transposable elements (TE) loci. We assessed the influence of the chromatin landscape on gene expression at two developmental stages: eggs, and pre-parasitic juveniles. H3K4me3 histone modification was strongly correlated with high levels of expression for protein-coding genes implicated in stage-specific processes during M. incognita development. We provided new insights in the dynamic regulation of parasitism genes kept under histone modifications silencing. In this pioneering study, we establish a comprehensive framework for the importance of epigenetic mechanisms in the regulation of the genome expression and its stability in plant-parasitic nematodes.

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Identification and in situ and in vitro characterization of secreted proteins produced by plant-parasitic nematodes

Parasitology ◽

10.1017/s0031182000067640 ◽

1996 ◽

Vol 113 (6) ◽

pp. 589-597 ◽

Cited By ~ 17

Author(s):

R. H. C. Curtis

Keyword(s):

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Root Cells ◽

Feeding Site ◽

In Vitro Characterization ◽

Plant Nematode ◽

Plant Parasitic

SUMMARYSecretions of plant-parasitic nematodes which are released into plant tissue may play critical roles in plant-nematode interactions. The identification and characterization of these molecules are of fundamental importance and may help to facilitate the development of novel strategies to interfere with nematode infection of plants and thereby decrease nematode-induced damage to crops. An antibody-based approach was used to isolate molecules present on the nematode surface and in nematode secretions. Monoclonal antibodies (MAbs) were produced to secretions and to whole Heterodera avenue 2nd-stage juveniles; several of these MAbs recognized molecules present in nematode secretions produced in vitro. Three of these molecules have been partly characterized in H. avenae, Globodera rostochiensis, G. pallida and Meloidogyne incognita. A MAb reacting with the surfaces of these nematodes recognized antigens of different molecular weight in each of the species tested. This difference in antigenicity might be related to specific functions in these nematodes. Preliminary results show that this antibody also localized the antigen in root cells surrounding the feeding site induced by M. incognita in Arabidopsis thaliana.

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