The Use of RNA Interference in Enhancing Plant Resistance against Nematodes

Plant-parasitic nematodes caused severe yield loss in major crops all over the world. The most wild-used strategies to combat the nematodes is the chamical nematicides, but the overuse of synthetic nematicides threaten sustainable agriculture development. Other strategies, like resistance cultivars and crop rotation, have limited efficiency. Thus, the utilization of molecular biotechnology like RNA interference (RNAi) would be one of the alternative ways to enhance plant resistance against nematodes. RNAi has already used as a tool for gene functional analysis in a wide range of species, especially in the non-parasitic nematode, Caenorhabtidis elegans. In plant-parasitic nematodes, RNAi is induced by soaking nematodes with double-strand RNA(dsRNA) solution mixed with neurostimulants, which is called in vitro RNAi delivery method. In another way around, in planta RNAi method, which is Host-mediated RNAi approach also showed a great success in conferring the resistance against root-knock nematodes. Two main advantages of RNAi-based transgenics are RNAi technology do not produce any functional foreign proteins and it target organisms in a sequence-specific way. Even though the development of RNAi-based transgenics against plant-parasitic nematodes is still in the initial phase, it offers the prospect into a novel nematode control strategy in the future.

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Getting to the root of neuronal signalling in plant-parasitic nematodes using RNA interference

Nematology ◽

10.1163/156854107781351981 ◽

2007 ◽

Vol 9 (3) ◽

pp. 301-315 ◽

Cited By ~ 2

Author(s):

Steven McMaster ◽

Susan McKinney ◽

Aaron Maule ◽

Michael Kimber ◽

Colin Fleming ◽

...

Keyword(s):

Rna Interference ◽

Control Strategies ◽

Large Family ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

In Planta ◽

Nematode Parasites ◽

Neuronal Signalling ◽

Plant Parasitic

AbstractA variety of genes expressed in preparasitic second-stage juveniles (J2) of plant-parasitic nematodes appear to be vulnerable to RNA interference (RNAi) in vitro by coupling double-stranded (ds)RNA soaking with the artificial stimulation of pharyngeal pumping. Also, there is mounting evidence that the in planta generation of nematode-specific double-stranded RNAs (dsRNAs) has real utility in the control of these pests. Although neuronally-expressed genes in Caenorhabditis elegans are commonly refractory to RNAi, we have discovered that neuronally-expressed genes in plant-parasitic nematodes are highly susceptible to RNAi and that silencing can be induced by simple soaking procedures without the need for pharyngeal stimulation. Since most front-line anthelmintics that are used for the control of nematode parasites of animals and humans act to disrupt neuromuscular coordination, we argue that intercellular signalling processes associated with neurons have much appeal as targets for transgenic plant-based control strategies for plant-parasitic nematodes. FMRFamide-like peptides (FLPs) are a large family of neuropeptides which are intimately associated with neuromuscular regulation, and our studies on flp gene function in plant-parasitic nematodes have revealed that their expression is central to coordinated locomotory activities. We propose that the high level of conservation in nervous systems across nematodes coupled with the RNAi-susceptibility of neuronally-expressed genes in plant-parasitic nematodes provides a valuable research tool which could be used to interrogate neuronal signalling processes in nematodes.

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RNA interference in plant parasitic nematodes: a summary of the current status

Parasitology ◽

10.1017/s0031182011002071 ◽

2012 ◽

Vol 139 (5) ◽

pp. 630-640 ◽

Cited By ~ 69

Author(s):

C. J. LILLEY ◽

L. J. DAVIES ◽

P. E. URWIN

Keyword(s):

Rna Interference ◽

Gene Silencing ◽

Cell Types ◽

Current Status ◽

Parasitic Nematodes ◽

Rnai Phenotype ◽

Plant Parasitic Nematodes ◽

Systemic Rnai ◽

Plant Parasitic

SUMMARYRNA interference (RNAi) has emerged as an invaluable gene-silencing tool for functional analysis in a wide variety of organisms, particularly the free-living model nematode Caenorhabditis elegans. An increasing number of studies have now described its application to plant parasitic nematodes. Genes expressed in a range of cell types are silenced when nematodes take up double stranded RNA (dsRNA) or short interfering RNAs (siRNAs) that elicit a systemic RNAi response. Despite many successful reports, there is still poor understanding of the range of factors that influence optimal gene silencing. Recent in vitro studies have highlighted significant variations in the RNAi phenotype that can occur with different dsRNA concentrations, construct size and duration of soaking. Discrepancies in methodology thwart efforts to reliably compare the efficacy of RNAi between different nematodes or target tissues. Nevertheless, RNAi has become an established experimental tool for plant parasitic nematodes and also offers the prospect of being developed into a novel control strategy when delivered from transgenic plants.

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Marine Organisms for the Sustainable Management of Plant Parasitic Nematodes

Plants ◽

10.3390/plants10020369 ◽

2021 ◽

Vol 10 (2) ◽

pp. 369

Author(s):

Pasqua Veronico ◽

Maria Teresa Melillo

Keyword(s):

Crop Production ◽

Control Strategies ◽

Marine Organisms ◽

New Drugs ◽

Effective Control ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Wide Range ◽

Plant Growth Stimulants ◽

Plant Parasitic

Plant parasitic nematodes are annually responsible for the loss of 10%–25% of worldwide crop production, most of which is attributable to root-knot nematodes (RKNs) that infest a wide range of agricultural crops throughout the world. Current nematode control tools are not enough to ensure the effective management of these parasites, mainly due to the severe restrictions imposed on the use of chemical pesticides. Therefore, it is important to discover new potential nematicidal sources that are suitable for the development of additional safe and effective control strategies. In the last few decades, there has been an explosion of information about the use of seaweeds as plant growth stimulants and potential nematicides. Novel bioactive compounds have been isolated from marine cyanobacteria and sponges in an effort to find their application outside marine ecosystems and in the discovery of new drugs. Their potential as antihelmintics could also be exploited to find applicability against plant parasitic nematodes. The present review focuses on the activity of marine organisms on RKNs and their potential application as safe nematicidal agents.

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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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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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Recent progress in the development of RNA interference for plant parasitic nematodes

Molecular Plant Pathology ◽

10.1111/j.1364-3703.2007.00422.x ◽

2007 ◽

Vol 8 (5) ◽

pp. 701-711 ◽

Cited By ~ 57

Author(s):

CATHERINE J. LILLEY ◽

MANJULA BAKHETIA ◽

WAYNE L. CHARLTON ◽

PETER E. URWIN

Keyword(s):

Rna Interference ◽

Recent Progress ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Plant Parasitic

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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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