A role forLATERAL ORGAN BOUNDARIES-DOMAIN 16during the interaction Arabidopsis-Meloidogynespp. provides a molecular link between lateral root and root-knot nematode feeding site development

Chemical inducers of pathogenesis-related proteins and plant resistance were applied to tomato plants, with the aim of inducing resistance to the root-knot nematode Meloidogyne javanica. Relative to control plants, foliar spray and soil-drenching with dl-β-amino-n-butyric acid (BABA) reduced root-galling 7 days after inoculation, as well as the number of eggs 30 days after inoculation. Other chemicals (α- and γ-amino-n-butyric acid, jasmonic acid, methyl jasmonate, and salicylic acid) were either phytotoxic to tomato plants or did not improve control of root-knot nematodes. Fewer second-stage juveniles invaded BABA-treated tomato roots, and root-galling indices were lower than in control tomato plants. Resistance phenomena in seedlings lasted at least 5 days after spraying with BABA. Nematodes invading the roots of BABA-treated seedlings induced small, vacuolate giant cells. Postinfection treatment of tomato plants with BABA inhibited nematode development. It is speculated that after BABA application tomato roots become less attractive to root-knot nematodes, physically harder to invade, or some substance(s) inhibiting nematode or nematode feeding-site development is produced in roots.

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Enhanced levels of plant cell cycle inhibitors hamper root-knot nematode-induced feeding site development

Plant Signaling & Behavior ◽

10.4161/psb.26409 ◽

2013 ◽

Vol 8 (12) ◽

pp. e26409 ◽

Cited By ~ 4

Author(s):

Paulo Vieira ◽

Gilbert Engler ◽

Janice de Almeida Engler

Keyword(s):

Cell Cycle ◽

Plant Cell ◽

Root Knot Nematode ◽

Feeding Site ◽

Plant Cell Cycle ◽

Site Development ◽

Cell Cycle Inhibitors

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The Amino Acid Permeases AAP3 and AAP6 Are Involved in Root-Knot Nematode Parasitism of Arabidopsis

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-05-12-0123-fi ◽

2013 ◽

Vol 26 (1) ◽

pp. 44-54 ◽

Cited By ~ 25

Author(s):

Heather H. Marella ◽

Erik Nielsen ◽

Daniel P. Schachtman ◽

Christopher G. Taylor

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Expression Patterns ◽

Giant Cells ◽

Root Knot Nematode ◽

Egg Hatching ◽

Feeding Site ◽

Vascular Tissues ◽

Nematode Parasitism ◽

Amino Acid Permeases

The root-knot nematode, Meloidogyne incognita, is an obligate parasite which depends entirely on the host plant for its nutrition. Root-knot nematodes induce the formation of a highly specialized feeding site consisting of several giant cells surrounded by a network of vascular tissues. Nutrients, including amino acids and sugars, are transferred apoplastically from the vascular tissues to the feeding site. Using Arabidopsis thaliana lacking the vascular-expressed amino acid permeases (AAP) AAP3 or AAP6, we demonstrate that disruption of amino acid transport can affect nematode parasitism. Nematode infestation levels are significantly reduced on the aap3 and aap6 mutants. AAP3 and AAP6 act distinctly in the transport of amino acids to the feeding site, as demonstrated by differences in their carrying capacity profiles. Furthermore, analyses of promoter: β-glucuronidase lines show different expression patterns for AAP3 and AAP6 in infected roots. In the aap3-3 mutant, part of the decrease in infestation is connected to a defect in early infection, where juveniles enter but then leave the root. Both aap3-3 and aap6-1 produce fewer females and produce more adult male nematodes. Additionally, detrimental effects are observed in the nematodes harvested from aap3-3 and aap6-1 mutants, including decreased egg hatching and infectivity and lower levels of lipid reserves. The transport of amino acids by AAP3 and AAP6 is important for nematode infection and success of the progeny.

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Root-knot nematode (Meloidogyne incognita) and its management: a review

Journal of Agriculture and Natural Resources ◽

10.3126/janr.v3i2.32298 ◽

2020 ◽

Vol 3 (2) ◽

pp. 21-31

Author(s):

Sudeep Subedi ◽

Bihani Thapa ◽

Jiban Shrestha

Keyword(s):

Meloidogyne Incognita ◽

Host Cells ◽

Effective Management ◽

Root Knot Nematode ◽

Biotic And Abiotic Stresses ◽

Management Options ◽

Feeding Site ◽

Second Stage ◽

Stage Juvenile ◽

Growth Quality

Root-knot nematode (RKN) Meloidogyne incognita stands out among the most harmful polyphagous endoparasite causing serious harm to plants, and distributed all over the globe. RKN causes reduced growth, quality and yield along with reduced resistance of the host against biotic and abiotic stresses. Infective second stage juvenile enters host roots with the help of the stylet and becomes sedentary getting into the vascular cylinder. Dramatic changes occur in host cells, making a specialized feeding site, induced by the secretion of effector protein by RKN. M. incognita can be controlled by nematicides, biocontrol agents, botanicals essential oils and growing resistant cultivars. Nematicides are no longer allowed to use in many parts of the world because of environmental hazards and toxicity to humans and other organisms. Researchers are concentrating on searching suitable alternatives to nematicides for effective management of M. incognita. This review mainly tries to explain the biology of M. incognita and different management options recommended in recent years. However, an effective and economical management of M. incognita remains an immense challenge.

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Root-Knot Nematode Parasitism Suppresses Host RNA Silencing

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-08-16-0160-r ◽

2017 ◽

Vol 30 (4) ◽

pp. 295-300 ◽

Cited By ~ 4

Author(s):

E. Walsh ◽

J. M. Elmore ◽

C. G. Taylor

Keyword(s):

Rna Silencing ◽

Plant Pathogens ◽

Giant Cells ◽

Root Knot Nematode ◽

Root Cells ◽

Feeding Site ◽

Nematode Parasitism ◽

Silencing Pathways ◽

Plant Pathosystems ◽

Viral Suppressors

Root-knot nematodes damage crops around the world by developing complex feeding sites from normal root cells of their hosts. The ability to initiate and maintain this feeding site (composed of individual “giant cells”) is essential to their parasitism process. RNA silencing pathways in plants serve a diverse set of functions, from directing growth and development to defending against invading pathogens. Influencing a host’s RNA silencing pathways as a pathogenicity strategy has been well-documented for viral plant pathogens, but recently, it has become clear that silencing pathways also play an important role in other plant pathosystems. To determine if RNA silencing pathways play a role in nematode parasitism, we tested the susceptibility of plants that express a viral suppressor of RNA silencing. We observed an increase in susceptibility to nematode parasitism in plants expressing viral suppressors of RNA silencing. Results from studies utilizing a silenced reporter gene suggest that active suppression of RNA silencing pathways may be occurring during nematode parasitism. With these studies, we provide further evidence to the growing body of plant-biotic interaction research that suppression of RNA silencing is important in the successful interaction between a plant-parasitic animal and its host.

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The predicted Meloidogyne javanica effectome is governed by the 9-hydroxide oxylipin of linolenic acid

10.21203/rs.2.11241/v1 ◽

2019 ◽

Author(s):

Nathalia Fitoussi ◽

Eli Borrego ◽

Michael V Kolomiets ◽

Qing Xue ◽

Patricia Bucki ◽

...

Keyword(s):

Differentially Expressed Genes ◽

Meloidogyne Javanica ◽

Immune Defense ◽

Nematode Infection ◽

Differentially Expressed ◽

Root Knot Nematode ◽

Feeding Site ◽

Defense Signaling ◽

Stressful Environment ◽

Tomato Roots

Abstract Background: The sedentary root-knot nematode Meloidogyne spp. secretes effectors in a spatial and temporal manner to interfere with and mimic multiple physiological and morphological mechanisms, supporting construction and maintenance of nematodes' feeding sites. For successful parasitism, many effectors act as immunomodulators, aimed to manipulate and suppress immune defense signaling triggered upon nematode invasion. Results: Comprehensive oxylipin profiling of tomato roots, performed using LC–MS/MS, indicated a sharp fluctuation in oxylipin profile following Root Knot Nematode infection. To identify genes that might respond to the lipidomic defense pathway mediated through oxylipins, RNA-Seq was performed by exposing Meloidogyne javanica second-stage juveniles to tomato protoplasts and the oxylipin 9-HOT, early induced in tomato roots upon nematode infection. A total of 4810 differentially expressed genes were identified. To target putative effectors, we explored differentially expressed genes carrying a predicted secretion signal peptide. Among these, several were homologous with known effectors in other nematode species; other unknown, potentially secreted proteins may have a role as root-knot nematode effectors that are induced by plant lipid signals. These include effectors functioning in the manipulation of plant defense signaling and root lipidomics, cell-wall weakening, detoxifying the stressful environment at the plant-nematode interface, allowing feeding site construction and development. Conclusions: Being an integral part of the plant's defense response, oxylipins may play an important signaling role in the regulation of nematode effectors. Herein we uncover activation of specific oxylipins signaling pathways upon nematode infection, which in turn result in reprogramming the nematode effector repertoires responsible for promotion of feeding site construction and nematode parasitism.

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Nondestructive Imaging of Plant-Parasitic Nematode Development and Host Response to Nematode Pathogenesis

Phytopathology ◽

10.1094/phyto-08-13-0240-r ◽

2014 ◽

Vol 104 (5) ◽

pp. 497-506 ◽

Cited By ~ 10

Author(s):

Phuong T. Y. Dinh ◽

Michael Knoblauch ◽

Axel A. Elling

Keyword(s):

Giant Cells ◽

Infection Process ◽

Heterodera Schachtii ◽

In Planta ◽

Feeding Site ◽

Site Development ◽

Wide Range ◽

Plant Nematode ◽

Negative Effect ◽

Nondestructive Imaging

The secluded lifestyle of endoparasitic plant nematodes hampers progress toward a comprehensive understanding of plant–nematode interactions. A novel technique that enables nondestructive, long-term observations of a wide range of live nematodes in planta is presented here. As proof of principle, Pratylenchus penetrans, Heterodera schachtii, and Meloidogyne chitwoodi were labeled fluorescently with PKH26 and used to infect Arabidopsis thaliana grown in microscopy rhizosphere chambers. Nematode behavior, development, and morphology were observed for the full duration of each parasite's life cycle by confocal microscopy for up to 27 days after inoculation. PKH26 accumulated in intestinal lipid droplets and had no negative effect on nematode infectivity. This technique enabled visualization of Meloidogyne gall formation, nematode oogenesis, and nematode morphological features, such as the metacorpus, vulva, spicules, and cuticle. Additionally, microscopy rhizosphere chambers were used to characterize plant organelle dynamics during M. chitwoodi infection. Peroxisome abundance strongly increased in early giant cells but showed a marked decrease at later stages of feeding site development, which suggests a modulation of plant peroxisomes by root-knot nematodes during the infection process. Taken together, this technique facilitates studies aimed at deciphering plant–nematode interactions at the cellular and subcellular level and enables unprecedented insights into nematode behavior in planta.

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Expression of Nematode Resistance in Plant Introductions of Arachis hypogaea

Peanut Science ◽

10.3146/i0095-3679-27-2-8 ◽

2000 ◽

Vol 27 (2) ◽

pp. 78-82 ◽

Cited By ~ 5

Author(s):

P. Timper ◽

C. C. Holbrook ◽

H. Q. Xue

Keyword(s):

Arachis Hypogaea ◽

Nematode Resistance ◽

Root Knot Nematode ◽

Feeding Site ◽

Plant Introductions ◽

Arachis Hypogaea L ◽

Cultivated Peanut ◽

Race 1 ◽

Moderately Resistant ◽

Resistant Genotypes

Abstract The peanut root-knot nematode (Meloidogyne arenaria, race 1) is a world-wide pest of peanut (Arachis hypogaea L.). Several moderately resistant genotypes have been identified in the cultivated peanut species. Our objective was to determine the expression of resistance for six of these genotypes. We examined four potential expressions of resistance—(a) fewer second-stage juveniles (J2) penetrate the roots, (b) fewer J2 establish functional feeding sites, (c) slower maturation, and (d) reduced fecundity (eggs per female). Seedlings of the susceptible cultivar Florunner and the resistant genotypes were inoculated with J2 of M. arenaria, and transplanted 3 d later to synchronize nematode development. Penetration was assessed at 3 and 10 d; development at 10 (or 12), 17, 22, and 27 d; and fecundity at 60 d after inoculation. The experiments were conducted in a greenhouse or growth chamber. The number of J2 within the roots was similar in resistant and susceptible peanut after 3 d; however, numbers were lower in two of the resistant genotypes than in Florunner after 10 d. A greater percentage of J2 failed to develop in all of the resistant genotypes (72 to 79%) than in Florunner (50%) after 17 d. Of the J2 that did begin to develop, the rate of maturation and fecundity was similar in resistant and susceptible genotypes. A lack of development indicates that the J2 failed to establish a feeding site. Therefore, the primary expression of resistance in the six peanut genotypes appears to be a reduction in the percentage of J2 that establish a functional feeding site. The decline in J2 after infection may be related to the failure to establish a feeding site.

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Differential feeding site development and reproductive fitness of Meloidogyne incognita and M. javanica on zucchini, a source of resistance to M. incognita

Nematology ◽

10.1163/15685411-00003135 ◽

2018 ◽

Vol 20 (2) ◽

pp. 187-199 ◽

Cited By ~ 4

Author(s):

Miguel Talavera-Rubia ◽

Alejandro Pérez De Luque ◽

Manuel López-Gómez ◽

Soledad Verdejo-Lucas

Keyword(s):

Meloidogyne Incognita ◽

Giant Cells ◽

Egg Laying ◽

Post Inoculation ◽

Critical Events ◽

Feeding Site ◽

Abnormal Growth ◽

Plant Parasitism ◽

Site Development ◽

Juvenile Development

The development of Meloidogyne incognita and M. javanica on zucchini ‘Amalthee’ was compared to characterise critical events in plant parasitism. Meloidogyne incognita was much less successful parasitising zucchini than M. javanica despite similarities in penetration rates and juvenile development. The increased frequency of undersized individuals, immature females and empty galls evidenced a failure in M. incognita development. Meloidogyne incognita induced larger feeding sites that contained more and larger giant cells than did M. javanica. Malformation of the M. incognita giant cells and abnormal growth of the surrounding tissues was observed at both 11 and 25 days post-inoculation. Critical events in parasitism differentiating the nematode isolates were the transition from fourth-stage juveniles to females, and the reduced fertility of the egg-laying females. Zucchini can be considered a source of resistance to M. incognita because it restricted nematode proliferation by supporting less fertile egg-laying females and producing fewer egg masses and total eggs.

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Histopathology of the nematodes Radopholus similis, Pratylenchus coffeae, Rotylenchulus reniformis and Meloidogyne incognita in plantain (Musa acuminata x M. balbisiana, AAB).

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v90i1-2.2963 ◽

1969 ◽

Vol 90 (1-2) ◽

pp. 83-97

Author(s):

Domingo Oramas-Nival ◽

Jessé Román

Keyword(s):

Meloidogyne Incognita ◽

Distal Portion ◽

Cellular Level ◽

Similar Reaction ◽

Radopholus Similis ◽

Rotylenchulus Reniformis ◽

Root Knot Nematode ◽

Cortical Cells ◽

Feeding Site ◽

Parenchymal Cells

Radopholus similis produced sunken lesions that modified the normal cylindrical anatomy of the plantain root under severe necrotic conditions. The lesions caused by R. similis were similar to those caused by Pratylenchs coffeae, except that the latter did not alter the turgid condition of the root. At cellular level, R. similis induced hypertrophy of the nucleus and nucleolus of the cortical cells; however, P. coffeae did not produce a similar reaction. Rotylenchulus reniformis concentrated the parasitic activity on the feeder roots, thus causing necrosis at the feeding site. The reniform nematode induced a syncytia made up mainly of fourteen to twenty longitudinal and circumferential cells of the pericycle.The cells, the nucleus and the nucleolus of the syncytia were hypertrophied. Two nucleoli were observed in some of the syncytial cells. The cytoplasm of the syncytia was granular, dense and had spheric inclusions. A solid and mustache-like structure that we called feeding filter was observed between the feeding cell and the pericycle. The root-knot nematode, Meloidogyne incognita, caused profuse root galls and cortical cracks in the roots and exposition of the internal tissue, mainly at the distal portion of the main roots. Meloidogyne incognita penetrated the endodermis and the pericycle and induced hypertrophy on five to seven of the vascular parenchymal cells with multiple hypertrophied nuclei.

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