scholarly journals Changes in mRNA Abundance within Heterodera schachtii-Infected Roots of Arabidopsis thaliana

2000 ◽  
Vol 13 (3) ◽  
pp. 309-315 ◽  
Author(s):  
Dieter Hermsmeier ◽  
Jennifer K. Hart ◽  
Marina Byzova ◽  
Steven R. Rodermel ◽  
Thomas J. Baum
Keyword(s):  
Arabidopsis Thaliana ◽  
Differential Display ◽  
Tissue Sample ◽  
Mrna Abundance ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Cdna Clones ◽  
Cyst Nematodes ◽  
Tissue Samples ◽  
Feeding Site

Gene expression changes in plant roots infected by plant-parasitic cyst nematodes are involved in the formation of nematode feeding sites. We analyzed mRNA abundance changes within roots of Arabidopsis thaliana during the early compatible interaction with Heterodera schachtii, the sugarbeet cyst nematode. Approximately 1,600 root sections, each containing a single parasitic nematode and its feeding site, and 1,600 adjacent, nematode-free root sections were excised from aseptic A. thaliana cultures 3 to 4 days after inoculation with H. schachtii. These tissue samples were termed infected and uninfected, respectively. Preparasitic nematodes were added to the uninfected tissue sample to maintain the nematode to plant tissue proportion. mRNA extracted from these two tissue samples was subjected to differential display analysis. Thirty-six cDNA clones corresponding to mRNA species with different abundance between both tissue samples were isolated. Of these clones, 24 were of A. thaliana origin and 12 were from H. schachtii. Differential display data predicted that the A. thaliana cDNA clones corresponded to 13 transcripts that were more abundant in the infected root sections and 11 transcripts that were more abundant in the uninfected root sections. H. schachtii cDNA clones were predicted to correspond to four transcripts that were more abundant in parasitic nematodes and to eight transcripts that were more abundant in preparasitic nematodes. In situ hybridization experiments confirmed the mRNA abundance changes in A. thaliana roots predicted by the differential display analyses for two A. thaliana clones.

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.

How do nematodes get their sweets? Solute supply to sedentary plant-parasitic nematodes

Nematology ◽  
2007 ◽  
Vol 9 (4) ◽  
pp. 451-458 ◽  
Author(s):  
Julia Hofmann ◽  
Florian Grundler
Keyword(s):  
Nutrient Supply ◽  
Heterodera Schachtii ◽  
Transport Systems ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Cyst Nematodes ◽  
Root Knot Nematodes ◽  
Feeding Sites ◽  
Inorganic Solutes ◽  
Nematode Development

AbstractSedentary cyst and root-knot nematodes withdraw large amounts of solutes from feeding structures induced in host roots. The feeding structures are specialised cells with a high metabolic activity and a tremendous capacity in translocation of nutrients. The required nutrients are provided by the plant transport systems – water and inorganic solutes from the xylem, assimilates such as sugars and amino acids from the phloem. Here we discuss the available data on the mechanisms by which nutrients are translocated into the nematode feeding sites. The interaction between Heterodera schachtii and Arabidopsis thaliana serves as a model system for cyst nematodes. In this case sufficient data are available to propose a conclusive concept for the mechanisms of nutrient flow: basically, in the early stages of nematode development syncytia are symplasmically isolated, so that transport proteins are responsible for the nutrient supply. Later, connections to the phloem via plasmodesmata are established, so that developing females are well supplied with assimilates. The interactions of root-knot nematodes with their hosts share a number of similarities but the data currently available are not sufficient to draw similar conclusions. As nutrient supply and functionality of feeding structures are the basis of biotrophic parasitism of sedentary nematodes, it is tempting to unravel the mechanisms by which both plant and nematodes influence each other via nutrient fluxes.

The genome and lifestage-specific transcriptomes of a plant-parasitic nematode and its host reveal susceptibility genes involved in trans-kingdom synthesis of vitamin B5

2021 ◽  
Author(s):  
Shahid Siddique ◽  
Zoran S. Radakovic ◽  
Clarissa Hiltl ◽  
Clement Pellegrin ◽  
Thomas J. Baum ◽  
...  
Keyword(s):  
Metabolic Pathways ◽  
Crop Production ◽  
Susceptibility Genes ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Cyst Nematodes ◽  
Novel Approach ◽  
Vitamin B5 ◽  
Dual Analysis ◽  
Plant Parasitic

AbstractPlant-parasitic nematodes are a major, and in some cases a dominant, threat to crop production in all agricultural systems. The relative scarcity of classical resistance genes highlights a pressing need to identify new ways to develop nematode-resistant germplasm. Here, we sequence and assemble a high-quality genome of the model cyst nematode Heterodera schachtii to provide a platform for the first system-wide dual analysis of host and parasite gene expression over time, covering all major stages of the interaction. This novel approach enabled the analysis of the hologenome of the infection site, to identify metabolic pathways that were incomplete in the parasite but complemented by the host. Using a combination of bioinformatic, genetic, and biochemical approaches, we show that the highly atypical completion of vitamin B5 biosynthesis by the parasitic animal, putatively enabled by a horizontal gene transfer from a bacterium, is critically important for parasitism. Knockout of either the plant-encoded or the now nematode-encoded steps in the pathway blocks parasitism. Our experiments establish a reference for cyst nematodes, use this platform to further our fundamental understanding of the evolution of plant-parasitism by nematodes, and show that understanding congruent differential expression of metabolic pathways represents a new way to find nematode susceptibility genes, and thereby, targets for future genome editing-mediated generation of nematode-resistant crops.

scholarly journals The Arabidopsis RboHB Encoded by At1g09090 Is Important for Resistance against Nematodes

2020 ◽  
Vol 21 (15) ◽  
pp. 5556 ◽  
Author(s):  
Abdalmenem I. M. Hawamda ◽  
Adil Zahoor ◽  
Amjad Abbas ◽  
Muhammad Amjad Ali ◽  
Holger Bohlmann
Keyword(s):  
Reactive Oxygen Species ◽  
Respiratory Burst ◽  
Reactive Oxygen ◽  
Heterodera Schachtii ◽  
Oxygen Species ◽  
Cyst Nematodes ◽  
Feeding Site ◽  
Plant Life ◽  
Respiratory Burst Oxidase ◽  
Respiratory Burst Oxidase Homologue

Reactive oxygen species are a byproduct of aerobic metabolic processes but are also produced by plants in defense against pathogens. In addition, they can function as signaling molecules that control various aspects of plant life, ranging from developmental processes to responses to abiotic and biotic stimuli. In plants, reactive oxygen species can be produced by respiratory burst oxidase homologues. Arabidopsis contains 10 genes for respiratory burst oxidase homologues that are involved in different aspects of plant life. Plant pathogenic cyst nematodes such as Heterodera schachtii induce a syncytium in the roots of host plants that becomes a feeding site which supplies nutrients throughout the life of the nematode. In line with this function, the transcriptome of the syncytium shows drastic changes. One of the genes that is most strongly downregulated in syncytia codes for respiratory burst oxidase homologue B. This gene is root-specific and we confirm here the downregulation in nematode feeding sites with a promoter::GUS (β-glucuronidase) line. Overexpression of this gene resulted in enhanced resistance against nematodes but also against leaf-infecting pathogens. Thus, respiratory burst oxidase homologue B has a role in resistance. The function of this gene is in contrast to respiratory burst oxidase homologues D and F, which have been found to be needed for full susceptibility of Arabidopsis to H. schachtii. However, our bioinformatic analysis did not find differences between these proteins that could account for the opposed function in the interaction with nematodes.

Reduction of phytate by down-regulation of Arabidopsis thaliana MIPS and IPK1 genes alters susceptibility to beet cyst nematodes

Nematology ◽  
2015 ◽  
Vol 17 (4) ◽  
pp. 401-407 ◽  
Author(s):  
Ritushree Jain ◽  
Catherine J. Lilley ◽  
Peter E. Urwin
Keyword(s):  
Arabidopsis Thaliana ◽  
Cyst Nematode ◽  
Nematode Infection ◽  
Microbial Pathogens ◽  
Heterodera Schachtii ◽  
Cyst Nematodes ◽  
Down Regulation ◽  
Kinase Gene ◽  
Basal Resistance ◽  
Altered Expression

Phytates are mixed cationic salts of phytic acid formed by sequential phosphorylation of myo-inositol. Phytate is a phosphorus storage molecule essential for cellular and hormonal signalling in plants but exhibits anti-nutrient properties in animals. Low phytate plants have reduced basal resistance towards microbial pathogens and reduced tolerance to environmental stresses resulting in compromised yields. We report that three mutant lines of Arabidopsis thaliana, each with altered expression of myo-inositol-3-phosphate synthase (MIPS) isoforms, show altered susceptibility towards infection by the beet cyst nematode, Heterodera schachtii. Disruption of MIPS2 accompanied by increased MIPS1 expression results in reduced cyst nematode infection. Lack of MIPS3 resulted in a higher proportion of second-stage juveniles in the early phase of infection, suggesting delayed nematode development on mips3 mutants. Reduction in total phytate by down-regulation of the inositol polyphosphate kinase gene (IPK1) resulted in higher susceptibility to cyst nematode infection but a reduced average size of adult females. However, specific down-regulation of MIPS gene expression reduces susceptibility as myo-inositol is required to feed into the myo-inositol oxygenase pathway, which has an important role in development of the cyst nematode feeding site.

scholarly journals A parasitic nematode releases cytokinin that controls cell division and orchestrates feeding site formation in host plants

2015 ◽  
Vol 112 (41) ◽  
pp. 12669-12674 ◽  
Author(s):  
Shahid Siddique ◽  
Zoran S. Radakovic ◽  
Carola M. De La Torre ◽  
Demosthenis Chronis ◽  
Ondřej Novák ◽  
...  
Keyword(s):  
Cell Division ◽  
Host Plants ◽  
Plant Hormone ◽  
Parasitic Nematode ◽  
Heterodera Schachtii ◽  
Cytokinin Signaling ◽  
Cyst Nematodes ◽  
Root Cells ◽  
Feeding Site ◽  
Plant Parasitic

Sedentary plant-parasitic cyst nematodes are biotrophs that cause significant losses in agriculture. Parasitism is based on modifications of host root cells that lead to the formation of a hypermetabolic feeding site (a syncytium) from which nematodes withdraw nutrients. The host cell cycle is activated in an initial cell selected by the nematode for feeding, followed by activation of neighboring cells and subsequent expansion of feeding site through fusion of hundreds of cells. It is generally assumed that nematodes manipulate production and signaling of the plant hormone cytokinin to activate cell division. In fact, nematodes have been shown to produce cytokinin in vitro; however, whether the hormone is secreted into host plants and plays a role in parasitism remained unknown. Here, we analyzed the spatiotemporal activation of cytokinin signaling during interaction between the cyst nematode, Heterodera schachtii, and Arabidopsis using cytokinin-responsive promoter:reporter lines. Our results showed that cytokinin signaling is activated not only in the syncytium but also in neighboring cells to be incorporated into syncytium. An analysis of nematode infection on mutants that are deficient in cytokinin or cytokinin signaling revealed a significant decrease in susceptibility of these plants to nematodes. Further, we identified a cytokinin-synthesizing isopentenyltransferase gene in H. schachtii and show that silencing of this gene in nematodes leads to a significant decrease in virulence due to a reduced expansion of feeding sites. Our findings demonstrate the ability of a plant-parasitic nematode to synthesize a functional plant hormone to manipulate the host system and establish a long-term parasitic interaction.

Identification of reference genes for qRT-PCR studies of gene expression in giant cells and syncytia induced in Arabidopsis thaliana by Meloidogyne incognita and Heterodera schachtii

Nematology ◽  
2007 ◽  
Vol 9 (3) ◽  
pp. 317-323 ◽  
Author(s):  
Florian Grundler ◽  
Julia Hofmann
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Reference Genes ◽  
18S Rrna ◽  
Housekeeping Genes ◽  
Nematode Infection ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Qrt Pcr

AbstractSedentary plant-parasitic nematodes, such as cyst and root-knot nematodes, induce feeding structures in the host root that undergo extensive changes in the gene expression. This phenomenon has previously been studied by gene chip analysis and qRT-PCR. Housekeeping genes are often used routinely as internal references for relative qRT-PCR analyses. However, due to the strong influence of nematode infection on host cell metabolism and physiology, expression of housekeeping genes may be altered considerably, thus limiting reliability of qRT-PCR analyses. Therefore, in the present work we tested UBQ10, ACT2, EF1a, UBP22 and 18S rRNA as potential candidates for relative qRT-PCR studies of gene expression in nematode infection sites in roots of Arabidopsis thaliana. Among the tested candidates only UBP22 and 18S rRNA were stably expressed and, therefore, are reliable reference genes for studying cyst and root-knot nematode infections.

scholarly journals Differential Display Analysis of the Early Compatible Interaction Between Soybean and the Soybean Cyst Nematode

1998 ◽  
Vol 11 (12) ◽  
pp. 1258-1263 ◽  
Author(s):  
Dieter Hermsmeier ◽  
Mitra Mazarei ◽  
Thomas J. Baum
Keyword(s):  
Gene Expression ◽  
Differential Display ◽  
Soybean Cyst Nematode ◽  
Cyst Nematode ◽  
Site Formation ◽  
Cdna Clones ◽  
Mrna Levels ◽  
Compatible Interaction ◽  
Feeding Site ◽  
Differential Display Analysis

The marked cellular changes during feeding site formation of the soybean cyst nematode (Heterodera glycines) indicate major changes in soybean gene expression. We used differential display of mRNA to detect host gene expression changes during the early compatible interaction between soybean and H. glycines. Fifteen cDNA clones corresponding to mRNAs with different abundances in H. glycines-infected versus uninfected roots were identified. Differential display results indicated that abundances of five mRNAs increased in infected roots, whereas abundances of 10 mRNAs decreased. Transcripts for nine of these 15 cDNAs could be detected on RNA blots, and their hybridization signals confirmed the differential display results for eight of these nine cDNAs. Sequence analyses identified five cDNAs with decreased mRNA levels in infected roots as corresponding to two putative aldolase genes, a transcription-factor TFIIA homologue, the soybean small GTP-binding protein gene sra1, and the soybean auxin down-regulated gene ADR12. RNA blot analyses of other auxin down-regulated genes revealed a decrease in their mRNA abundances in H. glycines-infected roots as well.

The role of flavonoids produced in response to cyst nematode infection of Arabidopsis thaliana

Nematology ◽  
2007 ◽  
Vol 9 (5) ◽  
pp. 671-677 ◽  
Author(s):  
Cleber Furlanetto ◽  
Mark Phillips ◽  
John Jones
Keyword(s):  
Arabidopsis Thaliana ◽  
Plant Pathogens ◽  
Nematode Infection ◽  
Heterodera Schachtii ◽  
Leguminous Plant ◽  
Feeding Site ◽  
Feeding Sites ◽  
Site Development ◽  
Normal Feeding ◽  
Mutant Lines

AbstractFlavonoids have diverse roles in plants, including defence against plant pathogens and regulation of local auxin transport. Flavonoids have been shown to be produced in feeding sites of root-knot nematodes induced in a leguminous plant, and it has previously been suggested that they may be responsible for manipulation of local auxin levels that underlie early feeding site development. Here we show that flavonoids are also produced in developing syncytia induced by Heterodera schachtii and in galls induced by Xiphinema diversicaudatum in a non-leguminous plant, Arabidopsis thaliana. We further investigated whether flavonoids are required for normal feeding site development by screening mutant lines of A. thaliana, defective in various parts of the flavonoid biosynthetic pathway, with H. schachtii. None of the lines showed a reduced capacity to support nematode infection and some showed a statistically significant increase in the numbers of female nematodes that developed. These data suggest that flavonoids are produced as part of the defence response to nematode infection rather than being an integral component of the mechanisms used by nematodes to induce feeding sites.

scholarly journals Host factors influence the sex of nematodes parasitizing roots of Arabidopsis thaliana

2018 ◽  
Author(s):  
Muhammad Shahzad Anjam ◽  
Syed Jehangir Shah ◽  
Christiane Matera ◽  
Elżbieta Różańska ◽  
Miroslaw Sobczak ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Nutrient Deficiency ◽  
Heterodera Schachtii ◽  
Sexually Dimorphic ◽  
Loss Of Function ◽  
Cyst Nematodes ◽  
Structural Modifications ◽  
Adverse Conditions ◽  
Favorable Conditions

AbstractPlant-parasitic cyst nematodes induce hypermetabolic syncytial nurse cells in the roots of their host plants. Syncytia are their only food source. Cyst nematodes are sexually dimorphic, with their differentiation into male or female strongly influenced by host environmental conditions. Under favorable conditions with plenty of nutrients, more females develop, whereas mainly male nematodes develop under adverse conditions such as in resistant plants. Here, we developed and validated a method to predict the sex of beet cyst nematode (Heterodera schachtii) during the early stages of its parasitism in the host plant Arabidopsis thaliana. We collected root segments containing male-associated syncytia (MAS) or female-associated syncytia (FAS), isolated syncytial cells by laser microdissection, and performed a comparative transcriptome analysis. Genes belonging to categories of defense, nutrient deficiency, and nutrient starvation were overrepresented in MAS as compared to FAS. Conversely, gene categories related to metabolism, modification, and biosynthesis of cell walls were overrepresented in FAS. We used β-glucuronidase (GUS) analysis, qRT-PCR, and loss-of-function mutants to characterize FAS- and MAS-specific candidate genes. Our results demonstrated that various plant-based factors, including immune response, nutrient availability, and structural modifications, influence the sexual fate sex determination of cyst the nematodes.

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