scholarly journals An Approach to the Parasitism Genes of the Root Knot Nematode

2012 ◽  
Vol 1 (1) ◽  
pp. 81-87
Author(s):  
Ajit K. Ngangbam ◽  
Nongmaithem B. Devi
Keyword(s):  
Host Plants ◽  
Parasitic Nematodes ◽  
Secretory Proteins ◽  
Single Source ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Root Cells ◽  
Esophageal Gland ◽  
Parasitism Genes ◽  
Plant Parasitic

Plant parasitic nematodes which are highly successful parasites evolved a very specialized feeding relationship with the host plant to cause the destructive root-knot disease. They initiate their parasitic relationship with the host by releasing their secretions into root cells which in turn stimulate the root cells of the host to become specialized feeding cells which are considered as the single source of nutrients essential for the nematode's survival. The parasitism genes expressed in nematode's esophageal gland cells encode secretory proteins that are released through its stylet to direct the interactions of the nematode with its host plants.

scholarly journals Manipulation of Plant Cells by Cyst and Root-Knot Nematode Effectors

2013 ◽  
Vol 26 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Tarek Hewezi ◽  
Thomas J. Baum
Keyword(s):  
Biological Activities ◽  
Defense Responses ◽  
Effector Proteins ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Root Cells ◽  
Gland Cells ◽  
Esophageal Gland ◽  
Plant Parasitic

A key feature of sedentary plant-parasitic nematodes is the release of effector proteins from their esophageal gland cells through their stylets into host roots. These proteinaceous stylet secretions have been shown to be crucial for successful parasitism by mediating the transition of normal root cells into specialized feeding sites and by negating plant defenses. Recent technical advances of purifying mRNA from esophageal gland cells of plant-parasitic nematodes coupled with emerging sequencing technologies is steadily expanding our knowledge of nematode effector repertoires. Host targets and biological activities of a number of nematode effectors are continuously being reported and, by now, a first picture of the complexity of sedentary nematode parasitism at the molecular level is starting to take shape. In this review, we highlight effector mechanisms that recently have been uncovered by studying the host–pathogen interaction. These mechanisms range from mediating susceptibility of host plants to the actual triggering of defense responses. In particular, we portray and discuss the mechanisms by which nematode effectors modify plant cell walls, negate host defense responses, alter auxin and polyamine signaling, mimic plant molecules, regulate stress signaling, and activate hypersensitive responses. Continuous molecular characterization of newly discovered nematode effectors will be needed to determine how these effectors orchestrate host signaling pathways and biological processes leading to successful parasitism.

scholarly journals Application of RNA Interference to Root-Knot Nematode Genes Encoding Esophageal Gland Proteins

2005 ◽  
Vol 18 (7) ◽  
pp. 615-620 ◽  
Author(s):  
M.-N. Rosso ◽  
M. P. Dubrana ◽  
N. Cimbolini ◽  
S. Jaubert ◽  
P. Abad
Keyword(s):  
Rna Interference ◽  
Parasitic Nematodes ◽  
Reverse Genetic ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Double Stranded Rna ◽  
Obligate Parasites ◽  
Esophageal Gland ◽  
Genes Encoding ◽  
Plant Parasitic

Plant parasitic nematodes have been, so far, refractory to transformation or mutagenesis. The functional analysis of nematode genes relies on the development of reverse genetic tools adapted to these obligate parasites. Here, we describe the application of RNA interference (RNAi) to the root-knot nematode Meloidogyne incognita for the knock-down of two genes expressed in the subventral esophageal glands of the nematode and potentially involved in parasitism, the calreticulin (Mi-crt) and the polygalacturonase (Mi-pg-1) genes. Incubation in 1% resorcinol for 4 h induced double-stranded RNA uptake through the alimentary track of the nematodes and led to up to 92% depletion of Mi-crt transcripts. Timecourse analysis of the silencing showed different temporal patterns for Mi-crt and Mi-pg-1. The silencing of Mi-crt was optimal 20 h after soaking, whereas the silencing of Mi-pg-1 was optimal 44 h after soaking. For the two genes, the silencing effect was highly time-limited, since no transcript depletion was detectable 68 h after soaking.

scholarly journals Toward genetic modification of plant-parasitic nematodes: delivery of macromolecules to adults and expression of exogenous mRNA in second stage juveniles

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Olaf Kranse ◽  
Helen Beasley ◽  
Sally Adams ◽  
Andre Pires-daSilva ◽  
Christopher Bell ◽  
...  
Keyword(s):  
Food Security ◽  
Genetic Modification ◽  
The Body ◽  
Forward Genetics ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Cyst Nematodes ◽  
Plant Parasitic

Abstract Plant-parasitic nematodes are a continuing threat to food security, causing an estimated 100 billion USD in crop losses each year. The most problematic are the obligate sedentary endoparasites (primarily root knot nematodes and cyst nematodes). Progress in understanding their biology is held back by a lack of tools for functional genetics: forward genetics is largely restricted to studies of natural variation in populations and reverse genetics is entirely reliant on RNA interference. There is an expectation that the development of functional genetic tools would accelerate the progress of research on plant-parasitic nematodes, and hence the development of novel control solutions. Here, we develop some of the foundational biology required to deliver a functional genetic tool kit in plant-parasitic nematodes. We characterize the gonads of male Heterodera schachtii and Meloidogyne hapla in the context of spermatogenesis. We test and optimize various methods for the delivery, expression, and/or detection of exogenous nucleic acids in plant-parasitic nematodes. We demonstrate that delivery of macromolecules to cyst and root knot nematode male germlines is difficult, but possible. Similarly, we demonstrate the delivery of oligonucleotides to root knot nematode gametes. Finally, we develop a transient expression system in plant-parasitic nematodes by demonstrating the delivery and expression of exogenous mRNA encoding various reporter genes throughout the body of H. schachtii juveniles using lipofectamine-based transfection. We anticipate these developments to be independently useful, will expedite the development of genetic modification tools for plant-parasitic nematodes, and ultimately catalyze research on a group of nematodes that threaten global food security.

The role of plant-parasitic nematodes in reducing yield of sugarcane in fine-textured soils in Queensland, Australia

2007 ◽  
Vol 47 (5) ◽  
pp. 620 ◽  
Author(s):  
B. L. Blair ◽  
G. R. Stirling
Keyword(s):  
Growth And Yield ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Population Densities ◽  
Lesion Nematode ◽  
Yield Responses ◽  
The Impact ◽  
Stalk Length ◽  
Plant Parasitic

Damage to sugarcane caused by root-knot nematode (Meloidogyne spp.) is well documented in infertile coarse-textured soils, but crop losses have never been assessed in the fine-textured soils on which more than 95% of Australia’s sugarcane is grown. The impact of nematodes in these more fertile soils was assessed by repeatedly applying nematicides (aldicarb and fenamiphos) to plant and ratoon crops in 16 fields, and measuring their effects on nematode populations, sugarcane growth and yield. In untreated plant crops, mid-season population densities of lesion nematode (Pratylenchus zeae), root-knot nematode (M. javanica), stunt nematode (Tylenchorhynchus annulatus), spiral nematode (Helicotylenchus dihystera) and stubby-root nematode (Paratrichodorus minor) averaged 1065, 214, 535, 217 and 103 nematodes/200 mL soil, respectively. Lower mean nematode population densities were recorded in the first ratoon, particularly for root-knot nematode. Nematicides reduced populations of lesion nematode by 66–99% in both plant and ratoon crops, but control of root-knot nematode was inconsistent, particularly in ratoons. Nematicide treatment had a greater impact on shoot and stalk length than on shoot and stalk number. The entire community of pest nematodes appeared to be contributing to lost productivity, but stalk length and final yield responses correlated most consistently with the number of lesion nematodes controlled. Fine roots in nematicide-treated plots were healthier and more numerous than in untreated plots, and this was indicative of the reduced impact of lesion nematode. Yield responses averaged 15.3% in plant crops and 11.6% in ratoons, indicating that nematodes are subtle but significant pests of sugarcane in fine-textured soils. On the basis of these results, plant-parasitic nematodes are conservatively estimated to cost the Australian sugar industry about AU$82 million/annum.

scholarly journals Peach Root-knot Nematode

EDIS ◽  
2018 ◽  
Vol 2018 (4) ◽  
Author(s):  
Mary Ann D. Maquilan ◽  
Ali Sarkhosh ◽  
Donald W. Dickson
Keyword(s):  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
The Subject ◽  
Plant Parasitic

One of the production issues that peach growers in Florida must contend with is plant-parasitic nematodes. One such species is the more recently discovered peach root-knot nematode, Meloidogyne floridensis, which is the subject of this 5-page publication. Written by Mary Ann D. Maquilan, Ali Sarkhosh, and Donald Dickson and published by the UF/IFAS Horticultural Sciences Department, July 2018. http://edis.ifas.ufl.edu/hs1320

scholarly journals Biochemical Analysis Based on Zinc Uptake of Chickpea (Cicer arietinum L.) Varieties Infected by Meloidogyne incognita

2021 ◽  
pp. 186-192
Author(s):  
Pranaya Pradhan ◽  
Dhirendra Kumar Nayak ◽  
Manaswini Mahapatra
Keyword(s):  
Cicer Arietinum ◽  
Zinc Content ◽  
Cost Effective ◽  
Zinc Uptake ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Cicer Arietinum L ◽  
Chickpea Plant ◽  
Plant Parasitic

The significant constraints in Chickpea (Cicer arietinum L.) production hampers a bit more than 14% global yield loss due to plant-parasitic nematodes. Root-knot nematode (Meloidogyne sp.) is an endoparasite and a significant species affecting the chickpea plant. So, the chemical basis of management is more cost-effective, and pest resurgence building is enhanced in the pathogen. So, ecological-based nematode management is requisite, which also is got hampered due to breeding for resistance against such plant-parasitic nematodes. This was the primary reason to conduct this experiment to enhance resistance in the chickpea plants based on Zinc uptake by using bioagent, Pseudomonas fluorescens alone or in combination. where Different treatments including nematode, bacterium, and chemicals were used sustaining the enhancement of disease resistance in chickpea cultivars, RSG 974, GG 5, GNG 2144. Zinc content of chickpea variety GNG 2144 was found the highest in treatment, when only bacterium (P. fluorescens) was inoculated, i.e., 3.14 mg/100g of root followed by GG 5, i.e., 2.79 mg/100g of root and RSG 974 was, i.e., 2.35 mg/100g of root respectively in a descending order. Application of P. fluorescence combined or alone gradually increased the Zn concentration in roots of chickpea plants compared to healthy check followed by chemical treated plants.

Population dynamics of plant parasitic nematodes in Queensland pineapple fields and the effects of these nematodes on pineapple production

1993 ◽  
Vol 33 (2) ◽  
pp. 197 ◽  
Author(s):  
GR Stirling ◽  
A Nikulin
Keyword(s):  
Population Dynamics ◽  
Population Density ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Ratoon Crop ◽  
Original Population ◽  
Ethylene Dibromide ◽  
Nematode Population Density ◽  
Plant Parasitic

Twelve pineapple fields with various densities of root-knot nematode were selected during a ratoon crop. Nematode populations were monitored regularly after the crop was ploughed out. Regardless of the original population density, rootknot nematodes were almost nondetectable at the end of the subsequent 3-6-month fallow intercycle period. In the absence of nematicide treatment there were marked differences between sites in the manner in which rootknot nematodes increased in the newly planted crop. At some sites, they were detectable 9-15 months after planting, whereas at other sites, nematodes were not observed at 15 months. Increases in ratoon crop yield following application of ethylene dibromide or fenamiphos were related to root-knot nematode population density. Significant increases in yield were not obtained at sites where the nematode was not detectable at 15 months. The results suggest that some pineapple growers are needlessly applying nematicides and that nematode diagnostic services should be developed to provide growers with advice on their nematode management programs.

Resistance and tolerance of grapevine rootstocks to plant parasitic nematodes in vineyards in north-east Victoria

1989 ◽  
Vol 29 (1) ◽  
pp. 129 ◽  
Author(s):  
M Edwards
Keyword(s):  
Large Population ◽  
Parasitic Nematodes ◽  
Cabernet Sauvignon ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
North East ◽  
Tylenchulus Semipenetrans ◽  
Effect On Yield ◽  
Citrus Nematode ◽  
Plant Parasitic

Three grapevine rootstock trials in North-East Victoria, Australia, were sampled over several summers to determine nematode populations and the resistance or the tolerance of some commonly used winegrape varieties and rootstocks to plant parasitic nematodes. Rootstocks on which nematodes failed to reproduce or reproduced poorly were considered resistant, rootstocks which supported high populations of nematodes with no apparent effect on yield were considered tolerant. Susceptible rootstocks supported high numbers of nematodes and yielded poorly. The varieties studied were: Shiraz, Chardonnay, Cabernet Sauvignon; and the rootstocks were: Harmony, Richter 110, Schwarzmann, ARG No. 1, 5A Teleki, Rupestris du Lot, 5BB Kober, SO4, Ramsey, K5 1-32 and 1202. The plant parasitic nematodes found on the trial sites were root-knot (Meloidogyne javanica (Treub) Chitwood) and citrus (Tylenchulus semipenetrans Cobb) nematodes. Cabernet Sauvignon, Chardonnay, Shiraz and ARG No. 1 were susceptible to the root-knot nematode. Harmony exhibited tolerance to the citrus nematode and was a good host, allowing a large population to build up. Ramsey appeared to be resistant to the citrus nematode, at least in the Cabernet Sauvignon rootstock trial at Wahgunyah.

scholarly journals A Profile of Putative Parasitism Genes Expressed in the Esophageal Gland Cells of the Root-knot Nematode Meloidogyne incognita

2003 ◽  
Vol 16 (5) ◽  
pp. 376-381 ◽  
Author(s):  
Guozhong Huang ◽  
Bingli Gao ◽  
Tom Maier ◽  
R. Allen ◽  
Eric L. Davis ◽  
...  
Keyword(s):  
Meloidogyne Incognita ◽  
Secretory Proteins ◽  
Cdna Clones ◽  
Root Knot Nematode ◽  
Long Distance ◽  
Gland Cells ◽  
Esophageal Gland ◽  
Genes Encoding ◽  
Nematode Parasitism ◽  
Parasitism Genes

Identifying parasitism genes encoding proteins secreted from a nematode's esophageal gland cells and injected through its stylet into plant tissue is the key to understanding the molecular basis of nematode parasitism of plants. Meloidogyne incognita parasitism genes were cloned by microaspirating the cytoplasm from the esophageal gland cells of different parasitic stages to provide mRNA to create a gland cell-specific cDNA library by long-distance reverse-transcriptase polymerase chain reaction. Of 2,452 cDNA clones sequenced, deduced protein sequences of 185 cDNAs had a signal peptide for secretion and, thus, could have a role in root-knot nematode parasitism of plants. High-throughput in situ hybridization with cDNA clones encoding signal peptides resulted in probes of 37 unique clones specifically hybridizing to transcripts accumulating within the subventral (13 clones) or dorsal (24 clones) esophageal gland cells of M. incognita. In BLASTP analyses, 73% of the predicted proteins were novel proteins. Those with similarities to known proteins included a pectate lyase, acid phosphatase, and hypothetical proteins from other organisms. Our cell-specific analysis of genes encoding secretory proteins provided, for the first time, a profile of putative parasitism genes expressed in the M. incognita esophageal gland cells throughout the parasitic cycle.

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