Toxicity of Endophyte-Infected Tall Fescue Alkaloids and Grass Metabolites on Pratylenchus scribneri

Neotyphodium coenophialum, an endophytic fungus associated with tall fescue grass, enhances host fitness and imparts pest resistance. This symbiotum is implicated in the reduction of stresses, including plant-parasitic nematodes. To substantiate this implication, toxicological effects of root extracts, polyphenolic fraction, ergot, and loline alkaloids from endophyte-infected tall fescue were investigated using Pratylenchus scribneri, a nematode pest of tall fescue. In vitro bioassays and greenhouse studies were used as tests for effects of root fractions and compounds on motility and mortality of this lesion nematode. Greenhouse studies revealed that endophyte-infected tall fescue grasses are essentially nonhosts to P. scribneri, with root populations averaging 3 to 17 nematodes/pot, compared with 4,866 and 8,450 nematodes/pot for noninfected grasses. The in vitro assay indicated that root extracts from infected tall fescues were nematistatic. Polyphenols identified in extracts included chlorogenic acid, 3,5-dicaffeoylquinic acids, caffeic acid, and two unidentified compounds, but these were not correlated with endophyte status, qualitatively or quantitatively. Tests of several ergot alkaloids revealed that ergovaline and α-ergocryptine were nematicidal at 5 and 50 μg/ml, respectively, while ergocornine and ergonovine were nematistatic at most concentrations. Loline (N-formylloline), the pyrrolizidine alkaloid tested, was nematicidal (50 to 200 μg/ml). The ecological benefits of the metabolites tested here should assist in defining their role in deterring this nematode species while offering some probable mechanisms of action against plant-parasitic nematodes in general.

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Nematotoxic effects of endophyte-infected tall fescue toxins and extracts in an in vitro bioassay using the nematode Pratylenchus scribneri

NZGA: Research and Practice Series ◽

10.33584/rps.13.2006.3167 ◽

2007 ◽

Vol 13 ◽

pp. 357-361

Author(s):

A.A. Bacetty ◽

M.E. Snook ◽

A.E. Glenn ◽

C.W. Bacon ◽

P. Nagabhyru ◽

...

Keyword(s):

Tall Fescue ◽

Pyrrolizidine Alkaloid ◽

Ergot Alkaloids ◽

Nematode Species ◽

In Vitro Assay ◽

Total Phenolic ◽

Vitro Assay ◽

Interactive Nature ◽

Pratylenchus Scribneri

Biotypes of the Neotyphodium coenophialum-tall fescue grass symbiota are provided with enhanced protection from grazing vertebrate herbivores due to the production of toxic secondary metabolites. However, considerable controversy exists concerning this symbiotum and its toxicity to nematode species. A sterile in vitro system was developed to determine the interactive nature of known toxins specific to this mutualistic association and compounds within grass extracts known to be nematotoxic. The in vitro assay used Pratylenchus scribneri, the lesion nematode, as the target organism to determine the interactive nature of ergot alkaloids, the pyrrolizidine alkaloid (the lolines), total phenolic fractions, and specific phenolic compounds. The in vitro assay is described along with methods for testing toxicity. The results indicate that only two of three ergot alkaloids were toxic to P. scribneri, and there were possible potentiating or synergistic effects with other alkaloids and water soluble polyphenolics. HPLC analysis and UV mass spectrometry of root extracts revealed the presence of two major polyphenolics, chlorogenic and di-caffeoylquinic acids, both of which are natural constituents of this and other plants and have known toxicity to several species of nematodes. Further, it was determined that there were quantitative differences between the total phenolic and specific phenolic contents in roots of endophyte infected and noninfected tall fescue, cultivar Jesup. This in vitro assay offers a rapid and routine screen for acute testing chemical components of the tall fescue-endophyte symbiotum for toxicity to this nematode species. Keywords: Chlorogenic acid, di-caffeoylquinic acids, ergot alkaloid, lolines, nematode, polyphenolics, Pratylenchus scribneri, pyrrolizidine alkaloid

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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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Five Species of Plant Parasitic Nematodes (Order: Tylenchidae) Affecting Vegetable Crops of Nepal

International Journal of Life Sciences ◽

10.3126/ijls.v10i1.14515 ◽

2016 ◽

Vol 10 (1) ◽

pp. 10-14

Author(s):

Arvind K. Keshari ◽

Ranjana Gupta

Keyword(s):

Life Sciences ◽

Nematode Species ◽

Parasitic Nematodes ◽

Kathmandu Valley ◽

Vegetable Crops ◽

Plant Parasitic Nematodes ◽

Morphometric Data ◽

First Time ◽

Plant Parasitic

During a survey for plant parasitic nematodes affecting various vegetable crops grown in three hilly districts surrounding Kathmandu Valley, Nepal, five species of order Tylenchidae are reported for the first time from Nepal.The nematode species are Hoplolaimus indicus, Tylenchorhynchus mashhoodi, Helicotylenchus incisus, Microposthonia paraxestis and Hemicriconemoides cocophilus.All the species are illustrated with line diagrams and described with their morphometric data along with localities and host plants.International Journal of Life Sciences 10 (1) : 2016; 10-16

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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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Molecular Characterization and Phylogenetic Relationships of Plant-Parasitic Nematodes Associated with Turfgrasses in North Carolina and South Carolina, United States

Plant Disease ◽

10.1094/pdis-10-14-1060-re ◽

2015 ◽

Vol 99 (7) ◽

pp. 982-993 ◽

Cited By ~ 5

Author(s):

Yongsan Zeng ◽

Weimin Ye ◽

James Kerns ◽

Lane Tredway ◽

Samuel Martin ◽

...

Keyword(s):

North Carolina ◽

South Carolina ◽

Dna Sequences ◽

Phylogenetic Relationships ◽

Parasitic Nematode ◽

Nematode Species ◽

Plant Parasitic Nematode ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Plant Parasitic

The near-full-length 18S ribosomal DNA (rDNA) gene and internal transcribed spacer 1 region were amplified and sequenced from 52 nematode populations belonging to 28 representative species in 13 families recovered from turfgrasses in North Carolina (38 populations) and South Carolina (14 populations). This study also included 13 nematode populations from eight other plant hosts from North Carolina for comparison. Nematodes were molecularly characterized and the phylogenetic relationships were explored based on 18S rDNA sequences. Phylogenetic analysis using Bayesian inference was performed using five groups of the plant-parasitic nematode populations Tylenchids, Criconematids, Longidorids, Xiphinematids, and Trichodorids. The 65 nematode populations were clustered correspondingly within appropriate positions of 13 families, including Belonolaimidae, Caloosiidae, Criconematidae, Dolichodoridae, Hemicycliophoridae, Hoplolaimidae, Heteroderidae, Longidoridae, Meloidogynidae, Paratylenchidae, Pratylenchidae, Telotylenchidae, and Trichodoridae. This study confirms previous morphological-based identification of the plant-parasitic nematode species found in turfgrasses and provides a framework for future studies of plant-parasitic nematodes associated with turfgrasses based upon DNA sequences and phylogenetic relationships.

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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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Use of Entomopathogenic Nematodes and Thyme Oil to Suppress Plant-Parasitic Nematodes on English Boxwood

Plant Disease ◽

10.1094/pd-90-0471 ◽

2006 ◽

Vol 90 (4) ◽

pp. 471-475 ◽

Cited By ~ 7

Author(s):

Enrique E. Pérez ◽

Edwin E. Lewis

Keyword(s):

Population Growth ◽

Entomopathogenic Nematodes ◽

Parasitic Nematode ◽

Nematode Species ◽

Plant Parasitic Nematode ◽

Nematode Population ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Thyme Oil ◽

Plant Parasitic

A 2-year experiment was conducted to test suppression of plant-parasitic nematodes on English boxwood using entomopathogenic nematodes and 3.5% thyme oil formulated as Promax. Treatments were Steinernema riobrave formulated as BioVector and S. feltiae formulated as Nemasys, both applied at a rate of 2.5 billion infective juveniles/ha, thyme oil at rate of 9.3 liters/ha, and nontreated control. In the 2001 season, treatment with S. feltiae reduced (P ≤ 0.05) the population growth of Tylenchorhynchus sp. 7 days after treatment and Hoplolaimus sp. 30 and 60 days after treatment. Treatment with S. riobrave reduced (P ≤ 0.05) the population growth of all plant-parasitic nematode species at all sampling dates, with the exception of Mesocriconema sp. 30 days after treatment and Tylenchorhynchus sp. and Rotylenchus buxophilus 60 days after treatment. Treatment with thyme oil reduced (P ≤ 0.05) the population growth of all plant-parasitic nematode genera at all sampling dates except Tylenchorhynchus sp. and R. buxophilus 60 days after treatment. In the 2002 season, treatment with S. feltiae had no effect on nematode population growth. Treatment with S. riobrave reduced (P ≤ 0.05) the population growth of R. buxophilus 7 days after treatment, and all plant-parasitic nematodes 30 and 60 days after treatment except Hoplolaimus sp. 30 days after treatment and Mesocriconema sp. 60 days after treatment. Treatment with thyme oil reduced (P ≤ 0.05) the population growth at all sampling dates of plant-parasitic nematodes except Mesocriconema sp. 60 days after treatment.

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