scholarly journals Ultrastructural Changes Associated with the Tanning Process in the Cyst Wall of the Soybean Cyst Nematode, Heterodera glycines ICHINOHE : Ecological significance of dormancy in plant parasitic nematodes. II.

1975 ◽  
Vol 10 (4) ◽  
pp. 247-253
Author(s):  
Eizo KONDO ◽  
Nobuyoshi ISHIBASHI
Keyword(s):  
Cyst Wall ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Ultrastructural Changes ◽  
Parasitic Nematodes ◽  
Ecological Significance ◽  
Plant Parasitic Nematodes ◽  
Tanning Process ◽  
Plant Parasitic

Responses of Heterodera glycines and Meloidogyne incognita to exogenously applied neuromodulators

2007 ◽  
Vol 81 (4) ◽  
pp. 421-427 ◽  
Author(s):  
E.P. Masler
Keyword(s):  
Meloidogyne Incognita ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Body Movement ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Egg Hatch ◽  
Movement Frequency ◽  
Plant Parasitic

AbstractBiogenic amines regulate important behaviours in nematodes and are associated with pharyngeal activity in plant-parasitic nematodes. A robust behavioural assay based upon nematode body movements was developed to expand the study of these and other neuroregulators in plant-parasitic nematodes. Dopamine, octopamine and serotonin each had significant but differing effects on the behaviour of soybean cyst nematode Heterodera glycines and root-knot nematode Meloidogyne incognita juveniles. Body movement frequency was increased twofold in H.glycines by 5 mM dopamine (P = 0.0001), but decreased by 50 mM dopamine in H. glycines (88%) and M. incognita (53%) (P <  0.0001). Movement frequency in both species was increased by 50–70% (P <  0.0001) by 50 mM octopamine, and 5 mM octopamine increased M. incognita movement frequency more than twofold (P <  0.0001). Movement frequency in each species was reduced by more than 90% by 5 mM serotonin (P <  0.0001). While amplitude of body movement in H. glycines was unaffected by any amine, it was significantly reduced in M.incognita by all amines (P <  0.0006). Stylet pulsing frequencies in either species were unaffected by dopamine or octopamine, but 5 mM serotonin stimulated pulsing in H. glycines by nearly 13-fold (P <  0.0001) and in M. incognita by more than 14-fold (P <  0.0001). The invertebrate neuropeptide FLRFamide (N-Phe-Leu-Arg-Phe) increased M. incognita body movement frequency 45% (P = 0.02) at 1 mM but did not affect stylet activity. Finally, H. glycines egg hatch was completely suppressed by 50 mM serotonin, and partially suppressed by 50 mM dopamine (75%; P <  0.0001) and 50 mM octopamine (55%; P <  0.0001).

scholarly journals Differential responses of nematode communities to soybean genotypes resistant and susceptible to Heterodera glycines race 3

2005 ◽  
Vol 30 (1) ◽  
pp. 21-25
Author(s):  
Dinaelia Iva das Neves ◽  
Shiou Pin Huang
Keyword(s):  
Glycine Max ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Parasitic Nematodes ◽  
Trophic Groups ◽  
Total Abundance ◽  
Plant Parasitic Nematodes ◽  
Cyst Nematodes ◽  
Soybean Genotypes ◽  
Plant Parasitic

Heterodera glycines and Helicotylenchus dihystera were the two most abundant plant-parasitic nematodes found in two H. glycines race 3-infested fields, Chapadão do Céu, MS and Campo Alegre, MG. These fields had been planted with resistant (R) and susceptible (S) plants to cyst nematodes. In the first field, soybean (Glycine max) FT-Cristalina (S) was susceptible to H. glycines but resistant to H. dihystera, while GOBR93 122243 (R) was just the opposite. In the second field, M-Soy 8400 (R) was more resistant to the spiral nematode than M-Soy8411 (S), but the resistance to the cyst nematode was not different between the two genotypes. The total abundance of nematodes was not different between the susceptible and resistant plants in the two fields, suggesting that H. dihystera and/or bacterial feeders and other trophic groups replaced the reduced abundance of the cyst nematodes in resistant plants. Bacterial feeders acted as a compensatory factor to plant-parasitic nematodes in ecological function. The populations of fungal feeders were higher in GOBR93 122243 (R) than in susceptible FT-Cristalina (S) in Chapadão do Céu, but lower in M-Soy 8400 (R) than in M-Soy 8411 (S) in Campo Alegre. This is being attributed to the different periods of soil samplings that were made at the florescent period in the first field, and at the final growing cycle in the second field. Only four nematodes, H. glycines, H. dihystera, Acrobeles sp. and Panagrolaimus sp. dominated the nematode resistant community GOBR93 122243 (R) in Chapadão do Céu, but dominance was shared by ten genera in Campo Alegre, which explains why the five diversity indexes (S, d, Ds, H' and T) were higher in resistant plants than in susceptible plants in field two.

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

Nematology ◽  
2012 ◽  
Vol 14 (7) ◽  
pp. 869-873 ◽  
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.

scholarly journals Identification and characterisation of serotonin signalling in the potato cyst nematode Globodera pallida reveals new targets for crop protection

2018 ◽  
Author(s):  
Anna Crisford ◽  
Fernando Calahorro ◽  
Elizabeth Ludlow ◽  
Jessica M.C. Marvin ◽  
Jennifer K. Hibbard ◽  
...  
Keyword(s):  
Biogenic Amines ◽  
Tryptophan Hydroxylase ◽  
Plant Root ◽  
Crop Protection ◽  
Cyst Nematode ◽  
Potato Cyst Nematode ◽  
Globodera Pallida ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Plant Parasitic

AbstractPlant parasitic nematodes are microscopic pests that invade plant roots and cause extensive damage to crops worldwide. To investigate mechanisms underpinning their parasitic behaviour we used a chemical biology approach: We discovered that reserpine, a plant alkaloid known for its antagonism of the mammalian vesicular monoamine transporter VMAT and ability to impart a global depletion of synaptic biogenic amines in the nervous system, potently impairs the ability of the potato cyst nematode Globodera pallida to enter the host plant root. We show that this effect of reserpine is mediated by an inhibition of serotonergic signalling that is essential for activation of the stylet, a lance-like organ that protrudes from the mouth of the worm and which is used to pierce the host root to gain access. Prompted by this we identified core molecular components of G. pallida serotonin signalling encompassing the target of reserpine, VMAT; the synthetic enzyme for serotonin, tryptophan hydroxylase; the G protein coupled receptor SER-7 and the serotonin-gated chloride channel MOD-1. We found that inhibitors of tryptophan hydroxylase, SER-7 and MOD-1 phenocopy the plant protecting action of reserpine. Thus targeting the serotonin signalling pathway presents a promising new route to control plant parasitic nematodes.SummaryIndian snakeroot, an herbal medicine prepared from the roots of the shrub Rauwolfia serpentina, has been used for centuries for its calming action. The major active constituent is reserpine which works by depleting a specific class of mood regulating chemical in the brain, the biogenic amines. We have discovered a remarkable effect of reserpine on a pest of global concern, the plant parasitic nematodes. These microscopic worms invade the roots of crops presenting a severe threat to food production. We show that reserpine disables serotonin signalling in the worm’s ‘brain’ that regulates the rhythmic thrusting of the stylet: a lance-like structure that protrudes from its mouth to pierce the plant root and which is essential to its parasitic lifecycle. Thus, reserpine joins nicotine as another intriguing example of Nature evolving its own protection against pests. We have identified key components of the serotonin signalling pathway in the potato cyst nematode Globodera pallida and show that chemicals that target these sites inhibit the ability of the nematode to invade its host plant. We conclude that biogenic amine transmitters are intimately involved in the worm’s parasitic behaviour and provide a new discrete route to crop protection.

scholarly journals Avicta and Clariva Affect the Biology of the Soybean Cyst Nematode, Heterodera glycines

Plant Disease ◽  
2018 ◽  
Vol 102 (12) ◽  
pp. 2480-2486
Author(s):  
Jared P. Jensen ◽  
Upender Kalwa ◽  
Santosh Pandey ◽  
Gregory L. Tylka
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Seed Treatments ◽  
Upper Midwest ◽  
Row Crops ◽  
Specific Effects ◽  
New Strategy ◽  
Nematode Development

Nematicidal seed treatments are a relatively new strategy for managing plant-parasitic nematodes in row crops. Two such seed treatments, Avicta (abamectin) and Clariva (Pasteuria nishizawae), are marketed by Syngenta for use against Heterodera glycines in soybean production in the upper Midwest. The specific effects of these seed treatments on the biology of the nematode have not been previously reported. The effects of Avicta and Clariva on H. glycines hatching, movement, attraction, penetration, development, and reproduction were determined in controlled-environment experiments. Avicta inhibited juvenile movement and penetration at the seed depth and 3 cm below the seed. Clariva inhibited juvenile movement and penetration 3 and 5 cm below the seed and nematode development within the roots of young plants. Both seed treatments affected nematodes in 10- and 20-day-old plants, but effects were not detected on nematodes developing in older plants (30 and 60 days) with larger root systems. These results provide details of the specific mechanisms of early-season protection provided by Avicta and Clariva seed treatments.

The impact of management strategies on the development and status of potato cyst nematode populations in Switzerland: An overview from 1958 to present

Plant Disease ◽  
2021 ◽  
Author(s):  
Andrea Caroline Ruthes ◽  
Paul Dahlin
Keyword(s):  
Integrated Management ◽  
Abiotic Factors ◽  
Management Strategies ◽  
Monitoring Program ◽  
Cyst Nematode ◽  
Globodera Pallida ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
The Impact ◽  
Plant Parasitic

Globodera rostochiensis and Globodera pallida are some of the most successful and highly specialized plant-parasitic nematodes, and appear among the most regulated quarantine pests globally. In Switzerland, they have been monitored by annual surveys since their first detection in Swiss soil, in 1958. The dataset created was reviewed to give an overview of the development and actual status of PCN in Switzerland. Positive fields represent 0.2% of all the samples analyzed, and currently their distribution is limited to central-west and western Switzerland, suggesting that new introduction of PCN and the spread of the initial introduced PCN populations did not occur. In this way, the integrated management used in Switzerland appears to be effective. However, the increasing availability of potato varieties with resistance to G. rostochiensis and the limited availability of varieties with resistance to G. pallida, together with other biotic and abiotic factors promoted changes in the dominance of either species. Consequently, an extended monitoring program would be of interest to Swiss farmers, to avoid favoring virulent traits that could be present within Swiss Globodera populations.

scholarly journals Functional Analysis of Pathogenicity Proteins of the Potato Cyst Nematode Globodera rostochiensis Using RNAi

2005 ◽  
Vol 18 (7) ◽  
pp. 621-625 ◽  
Author(s):  
Qing Chen ◽  
S. Rehman ◽  
G. Smant ◽  
John T. Jones
Keyword(s):  
Functional Analysis ◽  
Host Location ◽  
Globodera Rostochiensis ◽  
Cyst Nematode ◽  
Potato Cyst Nematode ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Modified Method ◽  
Plant Parasitic

RNA interference (RNAi) has been used widely as a tool for examining gene function and a method that allows its use with plant-parasitic nematodes recently has been described. Here, we use a modified method to analyze the function of secreted β-1,4, endoglucanases of the potato cyst nematode Globodera rostochiensis, the first in vivo functional analysis of a pathogenicity protein of a plant-parasitic nematode. Knockout of the β-1,4, endoglucanases reduced the ability of the nematodes to invade roots. We also use RNAi to show that gr-ams-1, a secreted protein of the main sense organs (the amphids), is essential for host location.

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