scholarly journals Comparison of gene expression in Solanum bulbocastanum infected with virulent and avirulent isolates of Meloidogyne chitwoodi

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 721-722
Author(s):  
J. Wishart ◽  
M.S. Phillips ◽  
A. Paterson ◽  
V.C. Blok
Keyword(s):  
Solanum Species ◽  
Infection Process ◽  
Cdna Libraries ◽  
Solanum Bulbocastanum ◽  
Root Knot Nematode ◽  
Suppression Subtractive Hybridisation ◽  
Infected Root ◽  
In The Wild ◽  
Subtractive Hybridisation ◽  
Host Parasite

Resistance to root knot nematode M. chitwoodi has been identified in the wild tuber-bearing Solanum species, S. bulbocastanum. Three pathotypes were identified suggesting at least two different genetic factors for virulence and resistance in the pathogen and the host species, respectively. Roots of S. bulbocastanum were infested with two isolates of M. chitwoodi differing in virulence. The infection process was monitored by histological examination of roots allowing time points to be identified. cDNA libraries were constructed from infected root tissue using Suppression Subtractive Hybridisation (SSH) to enrich for transcripts from either compatible or incompatible interactions, at three days and seven days post infection. Both plant and nematode genes, which may be important during the host/parasite interaction, were identified.

Identification ofTrichinella spiralisearly antigens at the pre-adult and adult stages

Parasitology ◽  
2010 ◽  
Vol 138 (4) ◽  
pp. 463-471 ◽  
Author(s):  
ALEKSANDAR ZOCEVIC ◽  
PAULINE MACE ◽  
ISABELLE VALLEE ◽  
RADU BLAGA ◽  
MINGYUAN LIU ◽  
...  
Keyword(s):  
Cdna Library ◽  
Serine Proteases ◽  
Trichinella Spiralis ◽  
Serine Proteinase ◽  
Secretory Protein ◽  
Cdna Libraries ◽  
Sequence Identity ◽  
Muscle Larvae ◽  
Serine Protease Family ◽  
Host Parasite

SUMMARYThree expression cDNA libraries fromTrichinella spiralisworms 14 h, 20 h and 48 h post-infection (p.i.) were screened with serum from pigs experimentally infected with 20 000T. spiralismuscle larvae. Twenty-nine positive clones were isolated from the 14 h p.i. cDNA library, corresponding to 8 different genes. A putative excretory-secretory protein similar to that ofT. pseudospiraliswas identified. Three clones corresponded to aT. spiralisserine proteinase inhibitor known to be involved in diverse functions such as blood coagulation and modulation of inflammation. Screening of the 20 h p.i. cDNA library selected 167 positive clones representing 12 different sequences. The clone with the highest redundancy encoded a small polypeptide having no sequence identity with any known proteins fromTrichinellaor other organisms. Fourteen clones displayed sequence identity with the heat shock protein (HSP) 70. HSPs are produced as an adaptive response of the parasite to the hostile environment encountered in the host intestine but their mechanism of action is not yet well defined. From the 48 h p.i.T. spiraliscDNA library, 91 positive clones were identified representing 7 distinct sequences. Most of the positive clones showed high similarity with a member of a putativeT. spiralisserine protease family. This result is consistent with a possible major role for serine proteases during invasive stages ofTrichinellainfection and host-parasite interactions.

scholarly journals Analysis of expressed sequence tags derived from the endophytic fungus Neotyphodium lolii grown in vitro and in association with its host plant perennial ryegrass

2007 ◽  
Vol 13 ◽  
pp. 501-504
Author(s):  
R. Johnson ◽  
A. Khan ◽  
C. Voisey ◽  
S. Bassett ◽  
C. Gaborit ◽  
...  
Keyword(s):  
Expressed Sequence Tags ◽  
Virulence Genes ◽  
In Planta ◽  
Suppression Subtractive Hybridisation ◽  
The Public ◽  
Neotyphodium Lolii ◽  
Subtractive Hybridisation ◽  
Plant Genes ◽  
Expressed Sequence

As a first step towards a functional genomics approach to gain a greater understanding of this important symbiosis, we have generated, sequenced and analysed two EST libraries from cultures of N. lolii and six in planta subtracted EST libraries enriched for differentially expressed genes. A total of 12871 ESTs were sequenced which, after filtering for quality, clustered into 1066 contigs and 3230 singletons to give a set of 4296 unique sequences or unigenes. BLASTX analysis revealed that 60% of fungal sequences derived from cultures were of unknown function with a sub-set of these corresponding to orphans. For the in planta-derived ESTs, most of the sequences with homologs in the public databases (98%) were of ryegrass origin. Comparisons made against fully sequenced genomes revealed that most fungal ESTs were homologous to genes present in both pathogenic and non-pathogenic ascomycete filamentous fungi, whereas the subtracted libraries comprised mostly plant genes. A range of sequences having significant homology to demonstrated pathogenicity/virulence genes in other fungal pathosystems were also identified, as well as some ESTs with proven roles in endophyte secondary metabolism. Keywords: ESTs, cDNA, Neotyphodium lolii, Lolium perenne, symbiosis, mutualism, suppression subtractive hybridisation

scholarly journals Blood parasites in vectors reveal a united blackfly community in the upper canopy

2020 ◽  
Author(s):  
Nayden Chakarov ◽  
Helge Kampen ◽  
Anja Wiegmann ◽  
Doreen Werner ◽  
Staffan Bensch
Keyword(s):  
Forest Canopy ◽  
Habitat Preferences ◽  
Blood Parasites ◽  
Avian Host ◽  
Haemosporidian Parasite ◽  
Host Group ◽  
Haemosporidian Parasites ◽  
Blood Sucking ◽  
In The Wild ◽  
Host Parasite

Abstract Background: The behaviour of blood-sucking arthropods is a crucial determinant of blood protozoan distribution and hence of host-parasite coevolution, but it is very challenging to study in the wild. The molecular identification of parasite lineages in vectors can be a useful key to understand the behaviour and transmission patterns realised by these vectors. Methods: In this study, we collected blackflies around nests of three raptor species in the upper forest canopy in central Europe and examined the presence of vertebrate DNA and haemosporidian parasites in them. We molecularly analysed 156 blackfly individuals, their vertebrate blood meals, and the haemosporidian parasite lineages they carried. Results: We identified nine species of Simulium blackflies, largely belonging to the subgenera Nevermannia and Eusimulium. Only 1% of the collected specimens was visibly engorged, and only 4% contained remains of host DNA. However, in 29% of the blackflies Leucocytozoon lineages were identified, which is evidence of a previous blood meal on an avian host. Based on the known vertebrate hosts of the recorded Leucocytozoon lineages, we can infer that large and/or abundant birds, such as thrushes, crows, pigeons, birds of prey, owls and tits are the main targets of ornithophilic blackflies in the canopy. Blackfly species contained similar proportions of host group-specific parasite lineages and thus do not appear to be associated with particular host groups. Conclusions: The Leucocytozoon clade infecting thrushes, crows, and pigeons present in most represented blackfly species suggests a lack of association between hosts and blackflies, which can increase the probability of host switches of blood parasites. However, the composition of the simuliid species differed between nests of common buzzards, goshawks and red kites. This segregation can be explained by coinciding habitat preferences between host and vector, and may lead to the fast speciation of Leucocytozoon parasites. Thus, subtle ecological preferences and lack of host preference of vectors in the canopy may enable both parasite diversification and host switches, and enforce a habitat-dependent evolution of avian malaria parasites and related haemosporidia.

Single pass cDNA sequencing - a powerful tool to analyse gene expression in preparasitic juveniles of the southern root-knot nematode Meloidogyne incognita

Nematology ◽  
2001 ◽  
Vol 3 (2) ◽  
pp. 129-139 ◽  
Author(s):  
Jaap Bakker ◽  
Fred Gommers ◽  
Geert Smant ◽  
Pierre Abad ◽  
Marie-Noëlle Rosso ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cdna Library ◽  
Meloidogyne Incognita ◽  
Sequence Data ◽  
Homo Sapiens ◽  
Large Fraction ◽  
Nematode Species ◽  
Cdna Libraries ◽  
Parasitic Nematodes ◽  
Root Knot Nematode

AbstractExpressed sequence tags (EST) have been widely used to assist in gene discovery in various organisms (e.g., Arabidopsis thaliana, Caenorhabditis elegans, Mus musculus, and Homo sapiens). In this paper we describe an EST project, which aims to investigate gene expression in Meloidogyne incognita at the onset of parasitism. Approximately 1000 5′-end sequence tags were produced from a cDNA library made of freshly hatched preparasitic second stage juveniles (J2). The EST were identified in the primary transformants of the cDNA library, and assigned to nine different functional groups, including (candidate) parasitism genes. A large fraction of the EST (45%) did not have a putative homologue in public databases. Sixty five percent of the EST that could be clustered into a functional group had putative homologues in other nematode species. EST were found for virtually all parasitism related genes that have been cloned from M. incognita to date. In addition, several novel genes were tagged, including a xylanase and a chitinase gene. The efficiency of EST projects, which produce sequence data for thousands of genes in months time without any difficult pre-selections of mRNA pools, makes random sequencing cDNA libraries a superior method to identify candidates for parasitism related genes in plant-parasitic nematodes. The sequences in this paper are retrievable from Genbank with the accession numbers BE191640 to BE191741, BE217592 to BE217720, BE225324 to BE225598, BE238852 to BE239221, and BE240829 to BE240865.

scholarly journals A new source of root-knot nematode resistance from Arachis stenosperma incorporated into allotetraploid peanut (Arachis hypogaea)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Carolina Ballén-Taborda ◽  
Ye Chu ◽  
Peggy Ozias-Akins ◽  
Patricia Timper ◽  
C. Corley Holbrook ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Snp Array ◽  
Nematode Resistance ◽  
Major Effect ◽  
Root Knot Nematode ◽  
Breeding Programs ◽  
Genes Encoding ◽  
In The Wild ◽  
Arachis Batizocoi ◽  
Lrr Protein

AbstractRoot-knot nematode is a very destructive pathogen, to which most peanut cultivars are highly susceptible. Strong resistance is present in the wild diploid peanut relatives. Previously, QTLs controlling nematode resistance were identified on chromosomes A02, A04 and A09 of Arachis stenosperma. Here, to study the inheritance of these resistance alleles within the genetic background of tetraploid peanut, an F2 population was developed from a cross between peanut and an induced allotetraploid that incorporated A. stenosperma, [Arachis batizocoi x A. stenosperma]4×. This population was genotyped using a SNP array and phenotyped for nematode resistance. QTL analysis allowed us to verify the major-effect QTL on chromosome A02 and a secondary QTL on A09, each contributing to a percentage reduction in nematode multiplication up to 98.2%. These were validated in selected F2:3 lines. The genome location of the large-effect QTL on A02 is rich in genes encoding TIR-NBS-LRR protein domains that are involved in plant defenses. We conclude that the strong resistance to RKN, derived from the diploid A. stenosperma, is transferrable and expressed in tetraploid peanut. Currently it is being used in breeding programs for introgressing a new source of nematode resistance and to widen the genetic basis of agronomically adapted peanut lines.

Deep modifications of the microbiome of rice roots infected by the parasitic nematode Meloidogyne graminicola in highly infested fields in Vietnam

2020 ◽  
Vol 96 (7) ◽  
Author(s):  
Anne-Sophie Masson ◽  
Hai Ho Bich ◽  
Marie Simonin ◽  
Hue Nguyen Thi ◽  
Pierre Czernic ◽  
...  
Keyword(s):  
Parasitic Nematode ◽  
Bacterial Community Composition ◽  
Root Knot Nematode ◽  
Root Tips ◽  
Meloidogyne Graminicola ◽  
Rice Roots ◽  
Functional Capabilities ◽  
Infected Root ◽  
Plant Parasitic ◽  
Root Microbiome

ABSTRACT Meloidogyne graminicola, also known as the rice root-knot nematode, is one of the most damaging plant-parasitic nematode, especially on rice. This obligate soilborne parasite induces the formation of galls that disturb the root morphology and physiology. Its impact on the root microbiome is still not well described. Here, we conducted a survey in Northern Vietnam where we collected infected (with galls) and non-infected root tips from the same plants in three naturally infested fields. Using a metabarcoding approach, we discovered that M. graminicola infection caused modifications of the root bacterial community composition and network structure. Interestingly, we observed in infected roots a higher diversity and species richness (+24% observed ESVs) as well as a denser and more complex co-occurrence network (+44% nodes and +136% links). We identified enriched taxa that include several hubs, which could serve as potential indicators or biocontrol agents of the nematode infection. Moreover, the community of infected roots is more specific suggesting changes in the functional capabilities to survive in the gall environment. We thus describe the signature of the gall microbiome (the ‘gallobiome’) with shifting abundances and enrichments that lead to a strong restructuration of the root microbiome.

scholarly journals Effect of Glomus Mosseae (Arbuscular Mycorrhizal Fungus) On Host - Parasite Relationship of Meloidogyne Incognita (Southern Root-Knot Nematode) on Four Improved Cowpea Varieties

2010 ◽  
Vol 50 (3) ◽  
pp. 321-325 ◽  
Author(s):  
Ishola Odeyemi ◽  
Steve Afolami ◽  
Olufemi Sosanya
Keyword(s):  
Meloidogyne Incognita ◽  
Glomus Mosseae ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Root Knot Nematode ◽  
Parasite Relationship ◽  
Cowpea Varieties ◽  
Host Parasite ◽  
Southern Root Knot Nematode ◽  
Relationship Of

Effect of Glomus Mosseae (Arbuscular Mycorrhizal Fungus) On Host - Parasite Relationship of Meloidogyne Incognita (Southern Root-Knot Nematode) on Four Improved Cowpea VarietiesTwo pot experiments and a field study were conducted in a Randomized Complete Block Design (RCBD). The experiments were conducted to determine the effect ofGlomus mosseae, a mycorrhiza fungus, on the reaction of four improved cowpea varieties toMeloidogyne incognita.Cowpea plants were inoculated with a single or a combination of 5 000 eggs ofM. incognitaand 50 g ofG. mosseaeinoculum containing 5 spores/g of soil. The standardized method of screening and reporting resistance of crop germplasm to root-knot nematodes at 60 days after planting, and the modified version of including yield for resistance rating at harvest were used for this study. Root galling due toM. incognitainfection was significantly lower on all the cowpea varieties treated withG. mosseaeand more significantly on IT90K-277-2 and IT89KD-288 in the screenhouse.G. mosseae, suppressed root-knot nematode reproduction on all the varieties compared to cowpea plants infected only byM. incognitaboth in the screenhouse and field experiments. Also,G. mosseaemitigated the damage attributable to the root-knot nematode on all these varieties. Using Gall Index (GI), reproduction factor and yield,G. mosseaewas effective in improving the resistance of the cowpea varieties toM. incognita.IT90K-76 cowpea variety was consistently resistant to the root-knot nematode, while IT90K-277-2 was tolerant withM. incognitainfection but resistant withG. mosseaetreatment. IT90K-941-1 variety was resistant in the screenhouse. The results of this study also confirmedG. mosseaeas a potential bio-control agent forM. incognitaon these cowpea varieties.

scholarly journals Performance of Transgenic Potato Containing the Late Blight Resistance Gene RB

Plant Disease ◽  
2008 ◽  
Vol 92 (3) ◽  
pp. 339-343 ◽  
Author(s):  
Dennis A. Halterman ◽  
Lara Colton Kramer ◽  
Susan Wielgus ◽  
Jiming Jiang
Keyword(s):  
Late Blight ◽  
Resistance Gene ◽  
Late Blight Resistance ◽  
Transgenic Potato ◽  
Field Trials ◽  
Blight Resistance ◽  
Solanum Bulbocastanum ◽  
Wild Potato Species ◽  
Foliar Resistance ◽  
In The Wild

Late blight of potato, caused by Phytophthora infestans, is one of the most devastating diseases of potato. A major late blight resistance gene, called RB, previously was identified in the wild potato species Solanum bulbocastanum through map-based cloning. The full-length gene coding sequence, including the open reading frame and promoter, has been integrated into cultivated potato (S. tuberosum) using Agrobacterium-mediated transformation. RB-containing transgenic plants were challenged with P. infestans under optimal late blight conditions in greenhouse experiments. All transgenic lines containing RB exhibited strong foliar resistance. Field-grown transgenic tubers also were tested for resistance to P. infestans. In contrast to the foliar resistance phenotype, RB-containing tubers did not exhibit increased resistance. Two years of field trials were used to ascertain whether the presence of RB had any effect on tuber yield. We were unable to detect any significant effect on tuber size or yield after addition of the resistance gene to several S. tuberosum cultivars.

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