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A Goverse - One of the best experts on this subject based on the ideXlab platform.

  • monitoring and tackling genetic selection in the Potato Cyst Nematode globodera pallida
    EFSA Supporting Publications, 2020
    Co-Authors: Eric Grenier, Josselin Montarry, Sylvain Fournet, Geert Smant, Johannes Helder, Martijn Holterman, Sebastian Kiewnick, A Goverse
    Abstract:

    Management of plant pests is probably the most serious challenge in sustainable food production and the maintenance of food security. Due to the strict regulation of or ban on major categories of pesticide, the Potato Cyst Nematode Globodera pallida has been managed by a combination of crop rotation and the Potato resistance locus Grp1 , a relatively narrow range resistance gene which was introgressed into a range of commercial Potato cultivars in Europe. However, in 2014, G. pallida populations were described that can no longer be controlled by Grp1 . Most likely similar highly virulent populations will also emerge in all major Potato growing areas in North Western Europe where production practices are very similar. Except for laborious, costly and often moderately accurate pot experiments, there is currently no rapid and reliable method to identify virulent populations. This represents a strong limitation and prevents an accurate and durable management of infestations. The PalAdapt project funded by EFSA represents the first step of a European battle plan against the emergence of virulent G. pallida populations and aims at improving the methods and tools for a fast identification of virulence outbreaks. Four main research questions were investigated during the project: (i) Do resistance breaking populations correspond to novel introductions into Europe? (ii) Can miniaturized in vitro tests be used to get more rapidly an accurate identification of the virulence status?, (iii) Is Cyst size a life history trait useful to estimate the virulence status of a population?, (iv) Can we identify polymorphism to design molecular tools for an accurate virulence monitoring? The EFSA partnering grants initiative was an accurate way to improve the EU risk assessment capacity through a knowledge exchange among partners having complementary resources and expertise.

  • comparative sequence analysis of the Potato Cyst Nematode resistance locus h1 reveals a major lack of co linearity between three haplotypes in Potato solanum tuberosum ssp
    Theoretical and Applied Genetics, 2011
    Co-Authors: A M Finkerstomczak, Jaap Bakker, Geert Smant, U Achenbach, Erin Bakker, Jan M De Boer, Edwin A G Van Der Vossen, Tomasz Golas, Suwardi Suryaningrat, A Goverse
    Abstract:

    The H1 locus confers resistance to the Potato Cyst Nematode Globodera rostochiensis pathotypes 1 and 4. It is positioned at the distal end of chromosome V of the diploid Solanum tuberosum genotype SH83-92-488 (SH) on an introgression segment derived from S. tuberosum ssp. andigena. Markers from a high-resolution genetic map of the H1 locus (Bakker et al. in Theor Appl Genet 109:146–152, 2004) were used to screen a BAC library to construct a physical map covering a 341-kb region of the resistant haplotype coming from SH. For comparison, physical maps were also generated of the two haplotypes from the diploid susceptible genotype RH89-039-16 (S. tuberosum ssp. tuberosum/S. phureja), spanning syntenic regions of 700 and 319 kb. Gene predictions on the genomic segments resulted in the identification of a large cluster consisting of variable numbers of the CC-NB-LRR type of R genes for each haplotype. Furthermore, the regions were interspersed with numerous transposable elements and genes coding for an extensin-like protein and an amino acid transporter. Comparative analysis revealed a major lack of gene order conservation in the sequences of the three closely related haplotypes. Our data provide insight in the evolutionary mechanisms shaping the H1 locus and will facilitate the map-based cloning of the H1 resistance gene.

  • dynamics in the tomato root transcriptome on infection with the Potato Cyst Nematode globodera rostochiensis
    Molecular Plant Pathology, 2009
    Co-Authors: Magdalena Swiecicka, Jaap Bakker, Ling Qin, A Goverse, Marcin Filipecki, D E Lont, Joke Van Vliet, Johannes Helder
    Abstract:

    Plant parasitic Nematodes infect roots and trigger the formation of specialized feeding sites by substantial reprogramming of the developmental process of root cells. In this article, we describe the dynamic changes in the tomato root transcriptome during early interactions with the Potato Cyst Nematode Globodera rostochiensis. Using amplified fragment length polymorphism-based mRNA fingerprinting (cDNA-AFLP), we monitored 17 600 transcript-derived fragments (TDFs) in infected and uninfected tomato roots, 1-14 days after inoculation with Nematode larvae. Six hundred and twenty-four TDFs (3.5%) showed significant differential expression on Nematode infection. We employed GenEST, a computer program which links gene expression profiles generated by cDNA-AFLP and databases of cDNA sequences, to identify 135 tomato sequences. These sequences were grouped into eight functional categories based on the presence of genes involved in hormone regulation, plant pathogen defence response, cell cycle and cytoskeleton regulation, cell wall modification, cellular signalling, transcriptional regulation, primary metabolism and allocation. The presence of unclassified genes was also taken into consideration. This article describes the responsiveness of numerous tomato genes hitherto uncharacterized during infection with endoparasitic Cyst Nematodes. The analysis of transcriptome profiles allowed the sequential order of expression to be dissected for many groups of genes and the genes to be connected with the biological processes involved in compatible interactions between the plant and Nematode.

  • expression of two functionally distinct plant endo beta 1 4 glucanases is essential for the compatible interaction between Potato Cyst Nematode and its hosts
    Molecular Plant-microbe Interactions, 2008
    Co-Authors: Aneta Karczmarek, Jaap Bakker, Miroslaw Sobczak, Slawomir Janakowski, Sylwia Fudali, Malgorzata Lichocka, Wojciech Kurek, Jan Roosien, Wladyslaw Golinowski, A Goverse
    Abstract:

    For the proliferation of their feeding sites (syncytia), the Potato Cyst Nematode Globodera rostochiensis is thought to recruit plant endo-beta-1,4-glucanases (EGases, EC. 3.2.1.4). Reverse-transcription polymerase chain reaction experiments on tomato (Solanum lycopersicum) indicated that the expression of two out of the at least eight EGases, namely Sl-cel7 and Sl-cel9C1, is specifically upregulated during syncytium formation. In situ hybridization and immunodetection studies demonstrated that both EGases are specifically expressed inside and adjacent to proliferating syncytia. To assess the importance of Sl-cel7 and Sl-cel9C1 for Nematode development, we decided to knock them out individually. Sl-cel9C1 probably is the only class C EGase in tomato, and we were unable to regenerate Sl-cel9C1-silenced plants. Potato (S. tuberosum), a close relative of tomato, harbors at least two class C EGases, and St-cel7-or St-cel9C1-silenced Potato plants showed no obvious aberrant phenotype. Infection with Potato Cyst Nematodes resulted in a severe reduction of the number of adult females (up to 60%) and a sharp increase in the fraction of females without eggs (up to 89%). Hence, the recruitment of CEL7, an enzyme that uses xyloglucan and noncrystalline cellulose as natural substrates, and CEL9C1, an enzyme that uses crystalline cellulose, is essential for growth and development of Potato Cyst Nematodes.

  • structural and functional characterization of a novel host penetration related pectate lyase from the Potato Cyst Nematode globodera rostochiensis
    Molecular Plant Pathology, 2007
    Co-Authors: U Kudla, Jaap Bakker, H.a. Overmars, Ling Qin, Adina L Milac, Erwin Roze, A Goverse, Martijn Holterman, Andreijose Petrescu, Johannes Helder
    Abstract:

    The cell wall, a strong extraprotoplasmic layer surrounding plant cells that mainly consists of a variety of polysaccharides, constitutes a major barrier for potential parasites. Plant-parasitic Nematodes are well equipped to overcome this barrier as they produce and secrete cell-wall-degrading enzymes. Expression profiling of various life stages of the Potato Cyst Nematode Globodera rostochiensis revealed a novel pectate lyase gene (Gr-pel2, 759 bp). The Gr-PEL2 protein showed highest similarity to pectate lyases from the facultative plant-parasitic Nematodes Bursaphelenchus mucronatus and B. xylophilus and the soil-inhabiting saprophytic Streptomyces and Frankia species (i.e. 40-42% identity and 58-60% similarity), whereas only a remote relatedness to the previously identified Gr-PEL1 was observed (i.e. 28% identity and 43% similarity). Transient expression of Gr-pel2 in leaves of Nicotiana benthamiana resulted in severe malformations of the infiltrated tissues, not relating to maceration and soft rot symptoms. Ca2+ is known to be essential for pectate lyase activity, and the most likely calcium-binding site was identified in the Gr-PEL2 protein by combining homology modelling of the three-dimensional structure, site-directed mutagenesis and transient expression in leaves. A highly charged cleft in Gr-PEL2, which is likely to be involved in substrate binding and which is also significantly more hydrophobic in Gr-PEL1, was shown to be essential for protein activity. Our results underline the broad spectrum of pectate lyases and cell-wall-degrading enzymes necessary for successful parasitism by Cyst Nematodes

M. S. Phillips - One of the best experts on this subject based on the ideXlab platform.

  • dynamics and management of the white Potato Cyst Nematode globodera pallida in commercial Potato crops
    Annals of Applied Biology, 2014
    Co-Authors: David L Trudgill, M. S. Phillips, M J Elliott
    Abstract:

    Eight trials were conducted in commercial Potato fields infested with the white Potato Cyst Nematode (wPCN, Globodera pallida) and one in a field infested with the yellow PCN (yPCN, Globodera rostochiensis). Our aims were to produce data to validate and refine a computer-based program (The Model) for the long-term management of PCN, to determine nematicide effectiveness and to assess rates of PCN population decline between Potato crops. Prior to planting, each farmer applied an overall nematicide treatment to his field, except for ten untreated plots that were widely spaced to encompass a range of PCN population densities. Each untreated plot was paired with a similar plot in the adjacent treated area and all plots were intensively sampled for PCN population densities at planting (Pi) and again at harvest (Pf) when tuber yields were determined. Four trials were re-sampled 2–4 years later to determine PCN population decline rates. Regressions that form the basis of ‘The Model’ and described the relationship between Pi and tuber yield and PCN population density at harvest were fitted to the results from both the untreated and nematicide treated plots. These regressions also enabled us to estimate the yield potential at each site in the absence of PCN and showed that nematicide treatment generally did not increase yield potential and that both tuber yield and PCN multiplication decreased with increasing Pi. However, there were major differences between sites and cultivars. When untreated, the yield of cv. Maris Piper was hardly affected in a highly organic soil with Pi > 200 eggs g−1 whereas the yield of partially resistant cv. Sante was decreased from a potential of c. 60 t ha−1 to c. 20 t ha−1 in a light silt with Pi = 20 egg g−1 soil. Similarly, untreated wPCN multiplication rates at a low Pi ranged from 46-fold to >100-fold. Nematicide effectiveness was estimated from the regressions and, at several sites, yield was decreased despite nematicide treatment. Control of wPCN multiplication was even poorer. In only two of seven trials planted with susceptible cultivars was more than 50% control achieved – maximum populations in treated plots usually exceeded 250 eggs g−1. Partially resistant Sante decreased the multiplication rate of wPCN in the two trials where it was planted. An alternative analysis using Genstat indicated that The Model tended to underestimate the maximum multiplication rate and overestimate the maximum population density. When four sites were re-sampled 2–4 years after harvest the populations of wPCN had declined by between 15% and 33.5% per annum with a mean of 26% per annum. Modelling indicated that rotations longer than 8 years were required to control wPCN unless other effective control measures, such as growing a partially resistant cultivar, were used.

  • Segregation and Recombination of a Multipartite Mitochondrial DNA in Populations of the Potato Cyst Nematode Globodera pallida
    Journal of Molecular Evolution, 2007
    Co-Authors: Miles R Armstrong, M. S. Phillips, Dirk Husmeier, Vivian C. Blok
    Abstract:

    The discovery that the Potato Cyst Nematode Globodera pallida has a multipartite mitochondrial DNA (mtDNA) composed, at least in part, of six small circular mtDNAs (scmtDNAs) raised a number of questions concerning the population-level processes that might act on such a complex genome. Here we report our observations on the distribution of some scmtDNAs among a sample of European and South American G. pallida populations. The occurrence of sequence variants of scmtDNA IV in population P4A from South America, and that particular sequence variants are common to the individuals within a single Cyst, is described. Evidence for recombination of sequence variants of scmtDNA IV in P4A is also reported. The mosaic structure of P4A scmtDNA IV sequences was revealed using several detection methods and recombination breakpoints were independently detected by maximum likelihood and Bayesian MCMC methods.

  • characterization of susceptibility and resistance responses to Potato Cyst Nematode globodera spp infection of tomato lines in the absence and presence of the broad spectrum Nematode resistance hero gene
    Molecular Plant-microbe Interactions, 2005
    Co-Authors: Miroslaw Sobczak, M. S. Phillips, Anna O Avrova, Justyna Jupowicz, Karin Ernst, Amar Kumar
    Abstract:

    The tomato Hero A gene is the only member of a multigene family that confers a high level (>80%) of resistance to all the economically important pathotypes of Potato Cyst Nematode (PCN) species Globodera rostochiensis and G. pallida. Although the resistance levels of transgenic tomato lines were similar to those of the tomato line LA1792 containing the introgressed Hero multigene family, transgenic Potato plants expressing the tomato Hero A gene are not resistant to PCNs. Comparative microscopy studies of in vitro infected roots of PCN-susceptible tomato cv. Money Maker, the resistant breeding line LA1792, and transgenic line L10 with Ro1 pathotype have revealed no statistically significant difference in the number of juveniles invading roots. However, syncytia (specialized feeding cells) induced in LA1792 and L10 roots mostly were found to have degenerated a few days after their induction, and a few surviving syncytia were able to support only the development of males rather than females. Thus, the ratio between males and females was biased towards males on LA1792 and L10 roots. A series of changes occur in resistant plants leading to formation of a layer of necrotic cells separating the syncytium from stellar conductive tissues and this is followed by degradation of the syncytium. Although the Hero A gene is expressed in all tissues, including roots, stems, leaves, and flower buds, its expression is upregulated in roots in response to PCN infection. Moreover, the expression profiles of the Hero A correlates with the timing of death of the syncytium.

  • identification of globodera rostochiensis and g pallida in the ukraine by pcr
    European Journal of Plant Pathology, 2005
    Co-Authors: L A Pylypenko, M. S. Phillips, T Uehara, D D Sigareva, Vivian C. Blok
    Abstract:

    Multiplex polymerase chain reaction was used to identify the Potato Cyst Nematodes in soil samples from the Ukraine. The results show the occurrence of Globodera pallida in the Uzhhorod region (Zakarpats’ka oblast’), where only G. rostochiensis had been previously reported. In the mixed Potato Cyst Nematode (PCN) populations, G. pallida was less prevalent (2–5%) than G. rostochiensis (95–98%). A phylogenetic analysis based on ribosomal DNA internal transcribed spacer sequences showed that the Ukrainian population of G. pallida had >99% sequence identity with other G. pallida pa2/3 isolates from Europe. This study has demonstrated that polymerase chain reaction-mediated amplification of specific regions of the Potato Cyst Nematode genome is not only highly effective as a species diagnostic tool but is also a sensitive method which can be used for taxonomic purposes with Cyst collections which vary in age.

  • the white Potato Cyst Nematode globodera pallida a critical analysis of the threat in britain
    Annals of Applied Biology, 2003
    Co-Authors: David L Trudgill, K Evans, M J Elliott, M. S. Phillips
    Abstract:

    Summary Over the last 30 years, there has been an epidemic of the white Potato Cyst Nematode (wPCN, Globodera pallida). It has progressively replaced the yellow species (yPCN, G. rostochiensis) throughout most of England and Wales and is now a widespread problem. As damaging populations of wPCN are enormous (>109 eggs ha−1), several crops of Potato cultivars resistant only to yPCN were required to produce this change. The threat it poses is reflected in an increase in the numbers of soil samples being tested and in nematicide use, which has increased to > 25 000 ha of Potatoes being treated annually. Computer modelling shows that current management of wPCN is mostly ineffective and populations will continue to increase. The multiplication rate of wPCN is inversely related to its population density at planting and, because of this, modelling shows that sufficient eggs are likely to survive to enable large populations of wPCN to “rebound” following nematicide treatment. This is supported by recent trial results showing that wPCN population increase was almost as great in nematicides-treated plots as in the untreated. Modelling also showed that current rotations (typically Potatoes once every 5 or 6 years) are too short to prevent wPCN populations from progressively increasing, even when used in conjunction with a nematicide. Similarly, except with avirulent populations, the partially resistant cultivars currently available will not prevent wPCN from increasing. However, as the effectiveness of partially resistant cultivars is independent of population density, they can be very effective when integrated with a nematicide. Unfortunately, only c. 8% of the Potato area is planted with partially resistant cultivars, and much of that is in land not known to be infested with wPCN. Consequently, the current epidemic of wPCN is likely to become progressively more serious. However, many farmers are failing to recognise and respond to this threat until it is too late because of the slow rate of increase of wPCN, the difficulties of detecting small populations and the costs of nematicides. To respond to the current epidemic of wPCN, the greatest priority is to have available an increased number of commercially-attractive partially resistant cultivars.

W J Stiekema - One of the best experts on this subject based on the ideXlab platform.

  • mapping of resistance to the Potato Cyst Nematode globodera rostochiensis from the wild Potato species solanum vernei
    Molecular Breeding, 1996
    Co-Authors: Jeanne M E Jacobs, Herman J. Van Eck, Karin Horsman, Paul Arens, Brigitte Verkerkbakker, E Jacobsen, Andy Pereira, W J Stiekema
    Abstract:

    A population of diploid Potato (Solanum tuberosum) was used for the genetic analysis and mapping of a locus for resistance to the Potato Cyst Nematode Globodera rostochiensis, introgressed from the wild Potato species Solanum vernei. Resistance tests of 108 genotypes of a F1 population revealed the presence of a single locus with a dominant allele for resistance to G. rostochiensis pathotype Ro1. This locus, designated GroV1, was located on chromosome 5 with RFLP markers. Fine-mapping was performed with RAPD and SCAR markers. The GroV1 locus was found in the same region of the Potato genome as the S. tuberosum ssp. andigena H1 Nematode resistance locus. Both resistance loci could not excluded to be allelic. The identification of markers flanking the GroV1 locus offers a valuable strategy for marker-assisted selection for introgression of this Nematode resistance.

  • mapping of loci involved in quantitatively inherited resistance to the Potato Cyst Nematode globodera rostochiensis pathotype ro1
    Theoretical and Applied Genetics, 1993
    Co-Authors: C M Kreike, Christiane Gebhardt, J R A De Koning, J H Vinke, J W Van Ooijen, W J Stiekema
    Abstract:

    We report the identification and mapping of two quantitative trait loci (QTLs) of Solanum spegazzinii BGRC, accession 8218-15, involved in resistance to the Potato Cyst-Nematode Globodera rostochiensis pathotype Ro1, by means of restriction fragment length polymorphisms (RFLPs). For this purpose we crossed a susceptible diploid S. tuberosum with the resistant S. spegazzinii, and tested the F1 population for resistance to the Ro1 pathotype. Since the F1 segregated for the resistance, the S. spegazzinii parent was concluded to be heterozygous at the Nematode resistance loci. For the mapping of the resistance loci we made use of RFLP markers segregating for S. spegazzinii alleles in the F1. One hundred and seven RFLP markers were tested in combination with four different restriction enzymes; 29 of these displayed a heterozygous RFLP pattern within S. spegazzinii and were used for mapping. Analysis of variance (ANOVA) was applied to test the association of the RFLP patterns of these markers with Nematode resistance. Two QTLs involved in disease resistance to Globodera rostochiensis pathotype Ro1 were identified and mapped to chromosomes 10 and 11 respectively.

Catherine J Lilley - One of the best experts on this subject based on the ideXlab platform.

  • the gpia7 effector from the Potato Cyst Nematode globodera pallida targets Potato ebp1 and interferes with the plant cell cycle
    Journal of Experimental Botany, 2021
    Co-Authors: Mirela C Coke, John T Jones, Catherine J Lilley, Peter Thorpe, Sophie Mantelin, Kathryn M Wright, Daniel S Shaw, Adams Chande
    Abstract:

    The Potato Cyst Nematode Globodera pallida acquires all of its nutrients from an elaborate feeding site that it establishes in a host plant root. Normal development of the root cells is re-programmed in a process coordinated by secreted Nematode effector proteins. The biological function of the G. pallida GpIA7 effector was investigated in this study. GpIA7 is specifically expressed in the subventral pharyngeal glands of pre-parasitic stage Nematodes. Ectopic expression of GpIA7 in Potato plants affected plant growth and development, suggesting a potential role for this effector in feeding site establishment. Potato plants overexpressing GpIA7 were shorter, with reduced tuber weight and delayed flowering. We provide evidence that GpIA7 associates with the plant growth regulator StEBP1 (ErbB-3 epidermal growth factor receptor-binding protein 1). GpIA7 modulates the regulatory function of StEBP1, altering the expression level of downstream target genes, including ribonucleotide reductase 2, cyclin D3;1, and retinoblastoma related 1, which are down-regulated in plants overexpressing GpIA7. We provide an insight into the molecular mechanism used by the Nematode to manipulate the host cell cycle and demonstrate that this may rely, at least in part, on hindering the function of host EBP1.

  • the gpia7 effector from the Potato Cyst Nematode globodera pallida targets Potato ebp1 and interferes with the plant cell cycle programme
    Journal of Experimental Botany, 2021
    Co-Authors: Mirela C Coke, John T Jones, Catherine J Lilley, Peter Thorpe, Sophie Mantelin, Kathryn M Wright, Daniel S Shaw, Adams Chande
    Abstract:

    The Potato Cyst Nematode Globodera pallida acquires all of its nutrients from an elaborate feeding site that it establishes in a host plant root. Normal development of the root cells is re-programmed in a process coordinated by secreted Nematode effector proteins. The biological function of the G. pallida GpIA7 effector was investigated in this study. GpIA7 is specifically expressed in the subventral pharyngeal glands of pre-parasitic stage Nematodes. Ectopic expression of GpIA7 in Potato plants affected plant growth and development, suggesting a potential role for this effector in feeding site establishment. Potato plants overexpressing GpIA7 were shorter, with reduced tuber weight and delayed flowering. We provide evidence that GpIA7 associates with the plant growth regulator StEBP1 (ErbB-3 epidermal growth factor receptor-binding protein 1). GpIA7 modulates the regulatory function of StEBP1, altering the expression level of downstream target genes, including ribonucleotide reductase 2, cyclin D3;1 and retinoblastoma related 1, which are downregulated in plants overexpressing GpIA7. We provide an insight into the molecular mechanism used by the Nematode to manipulate the host cell cycle and provide evidence that this may rely, at least in part, on hindering the function of host EBP1.

  • identification and characterisation of serotonin signalling in the Potato Cyst Nematode globodera pallida reveals new targets for crop protection
    bioRxiv, 2018
    Co-Authors: Anna Crisford, Catherine J Lilley, James Kearn, Fernando Calahorro, Elizabeth Ludlow, Jessica Marvin, Jennifer K Hibbard, Francesca Keefe, Rachael Harmer, Peter E Urwin
    Abstract:

    Plant 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.

  • progressive metabolic impairment underlies the novel nematicidal action of fluensulfone on the Potato Cyst Nematode globodera pallida
    Pesticide Biochemistry and Physiology, 2017
    Co-Authors: James Kearn, Catherine J Lilley, Peter E Urwin, Vincent Oconnor, Lindy Holdendye
    Abstract:

    Abstract Background Fluensulfone is a new nematicide with an excellent profile of selective toxicity against plant parasitic Nematodes. Here, its effects on the physiology and biochemistry of the Potato Cyst Nematode Globodera pallida have been investigated and comparisons made with its effect on the life-span of the free-living Nematode Caenorhabditis elegans to provide insight into its mode of action and its selective toxicity. Results Fluensulfone exerts acute effects (≤ 1 h; ≥ 100 μM) on stylet thrusting and motility of hatched second stage G. pallida juveniles (J2s). Chronic exposure to lower concentrations of fluensulfone (≥ 3 days; ≤ 30 μM), reveals a slowly developing metabolic insult in which G. pallida J2s sequentially exhibit a reduction in motility, loss of a metabolic marker for cell viability, high lipid content and tissue degeneration prior to death. These effects are absent in adults and dauers of the model genetic Nematode Caenorhabditis elegans. Conclusion The nematicidal action of fluensulfone follows a time-course which progresses from an early impact on motility through to an accumulating metabolic impairment, an inability to access lipid stores and death.

  • The genome of the yellow Potato Cyst Nematode, Globodera rostochiensis, reveals in-sights into the bases of parasitism and virulence
    2016
    Co-Authors: S. Eves-van Den Akker, Catherine J Lilley, Peter Thorpe, Dominik R Laetsch, Martine Da Rocha, Corinne Rancurel, Etienne Danchin, N. E. Holroyd, J. A. Cotton, Amir Szitenberg
    Abstract:

    The yellow Potato Cyst Nematode Globodera rostochiensis is a devastating plant pathogen of global economic importance, classified into pathotypes of different plant resistance-breaking phenotypes. G. rostochiensis secretes effectors, some of which were acquired by horizontal gene transfer (HGT), from pharyngeal glands into the host to manipulate host processes and promote parasitism. We generated a high-quality genome assembly for G. rostochiensis pathotype Ro1 and identified putative effectors and HGT events, mapped gene expression through the life cycle focusing on key parasitic transitions, and sequenced the genomes of eight populations including three additional pathotypes.

John T Jones - One of the best experts on this subject based on the ideXlab platform.

  • the gpia7 effector from the Potato Cyst Nematode globodera pallida targets Potato ebp1 and interferes with the plant cell cycle programme
    Journal of Experimental Botany, 2021
    Co-Authors: Mirela C Coke, John T Jones, Catherine J Lilley, Peter Thorpe, Sophie Mantelin, Kathryn M Wright, Daniel S Shaw, Adams Chande
    Abstract:

    The Potato Cyst Nematode Globodera pallida acquires all of its nutrients from an elaborate feeding site that it establishes in a host plant root. Normal development of the root cells is re-programmed in a process coordinated by secreted Nematode effector proteins. The biological function of the G. pallida GpIA7 effector was investigated in this study. GpIA7 is specifically expressed in the subventral pharyngeal glands of pre-parasitic stage Nematodes. Ectopic expression of GpIA7 in Potato plants affected plant growth and development, suggesting a potential role for this effector in feeding site establishment. Potato plants overexpressing GpIA7 were shorter, with reduced tuber weight and delayed flowering. We provide evidence that GpIA7 associates with the plant growth regulator StEBP1 (ErbB-3 epidermal growth factor receptor-binding protein 1). GpIA7 modulates the regulatory function of StEBP1, altering the expression level of downstream target genes, including ribonucleotide reductase 2, cyclin D3;1 and retinoblastoma related 1, which are downregulated in plants overexpressing GpIA7. We provide an insight into the molecular mechanism used by the Nematode to manipulate the host cell cycle and provide evidence that this may rely, at least in part, on hindering the function of host EBP1.

  • the gpia7 effector from the Potato Cyst Nematode globodera pallida targets Potato ebp1 and interferes with the plant cell cycle
    Journal of Experimental Botany, 2021
    Co-Authors: Mirela C Coke, John T Jones, Catherine J Lilley, Peter Thorpe, Sophie Mantelin, Kathryn M Wright, Daniel S Shaw, Adams Chande
    Abstract:

    The Potato Cyst Nematode Globodera pallida acquires all of its nutrients from an elaborate feeding site that it establishes in a host plant root. Normal development of the root cells is re-programmed in a process coordinated by secreted Nematode effector proteins. The biological function of the G. pallida GpIA7 effector was investigated in this study. GpIA7 is specifically expressed in the subventral pharyngeal glands of pre-parasitic stage Nematodes. Ectopic expression of GpIA7 in Potato plants affected plant growth and development, suggesting a potential role for this effector in feeding site establishment. Potato plants overexpressing GpIA7 were shorter, with reduced tuber weight and delayed flowering. We provide evidence that GpIA7 associates with the plant growth regulator StEBP1 (ErbB-3 epidermal growth factor receptor-binding protein 1). GpIA7 modulates the regulatory function of StEBP1, altering the expression level of downstream target genes, including ribonucleotide reductase 2, cyclin D3;1, and retinoblastoma related 1, which are down-regulated in plants overexpressing GpIA7. We provide an insight into the molecular mechanism used by the Nematode to manipulate the host cell cycle and demonstrate that this may rely, at least in part, on hindering the function of host EBP1.

  • functional analysis of pathogenicity proteins of the Potato Cyst Nematode globodera rostochiensis using rnai
    Molecular Plant-microbe Interactions, 2005
    Co-Authors: Q Chen, Geert Smant, Sajid Rehman, John T Jones
    Abstract:

    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.

  • glutathione peroxidases of the Potato Cyst Nematode globodera rostochiensis
    Gene, 2004
    Co-Authors: John T Jones, Geert Smant, B Reavy, Alison Prior
    Abstract:

    We report the cloning and characterisation of full-length DNAs complementary to RNA (cDNAs) encoding two glutathione peroxidases (GpXs) from a plant parasitic Nematode, the Potato Cyst Nematode (PCN) Globodera rostochiensis. One protein has a functional signal peptide that targets the protein for secretion from animal cells while the other is predicted to be intracellular. Both genes are expressed in all parasite stages tested. The mRNA encoding the intracellular GpX is present throughout the Nematode second stage juvenile and is particularly abundant in metabolically active tissues including the genital primordia. The mRNA encoding the secreted GpX is restricted to the hypodermis, the outermost cellular layer of the Nematode, a location from which it is likely to be secreted to the parasite surface. Biochemical studies confirmed the secreted protein as a functional GpX and showed that, like secreted GpXs of other parasitic Nematodes, it does not metabolise hydrogen peroxide but has a preference for larger hydroperoxide substrates. The intracellular protein is likely to have a role in metabolism of active oxygen species derived from internal body metabolism while the secreted protein may protect the parasite from host defences. Other functional roles for this protein are discussed.

  • characterization of a chorismate mutase from the Potato Cyst Nematode globodera pallida
    Molecular Plant Pathology, 2003
    Co-Authors: John T Jones, Vivian C. Blok, M. S. Phillips, Cleber Furlanetto, E Bakker, Bryony Banks, Q Chen, Alison Prior
    Abstract:

    SUMMARY Some plant endoparasitic Nematodes are biotrophic and induce remarkable changes in their hosts in order to ensure a continuous supply of food. Proteins secreted from oesophageal gland cells have been implicated in this pathogenic process. A potentially secreted chorismate mutase has been isolated from the Potato Cyst Nematode Globodera pallida. The gene encoding this protein is expressed in the subventral oesophageal gland cells of the Nematode, and the mRNA derived from this gene is only present in the early parasitic stages. Sequence analysis of this gene shows that, like other genes involved in the host-parasite interaction of plant parasitic Nematodes, it is likely to have been acquired by horizontal gene transfer from bacteria. The presence of a signal peptide in the deduced amino acid sequence of the G. pallida chorismate mutase and its expression in the subventral oesophageal gland cells suggest that it is secreted from the Nematode, pointing to a role for the protein in the host-parasite interaction. The shikimate pathway, of which chorismate mutase is normally a part, is not found in animals but is present in plants and bacteria. In plants it gives rise to a variety of compounds which are important in amino acid synthesis and defence signalling pathways, as well as auxins, which have been implicated in the early development of Nematode feeding sites. The potential roles of a Nematode chorismate mutase are discussed.