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Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; The potato cyst nematodes Globodera pallida and G. rostochiensis are listed in the EU Plant Health Directive 2000/29/EC and are also subject to the new EU Council Directive 2007/33/EC on the control of potato cyst nematodes, requiring unilateral suppression of these pests in Europe. At the same time there is also pressure to increase world trade in potatoes. Such pressure has to be balanced by the risks involved in the associated spread of these pests and subsequent problems in management. Populations of the potato cyst nematodes from outside Europe, in particular South America, which is considered the origin of G. pallida and G. rostochiensis, pose a risk to those European countries where limited genetic variability of these nematode species has been recorded. The development and usage of resistant cultivars under such conditions has formed a pivotal role in integrated management programmes in Europe. Molecular studies have shown that populations of G. pallida and G. rostochiensis from South America have a different genetic composition from those in Europe. The introduction of such populations would pose a threat to the use of resistant cultivars as a major tool in reducing the potential spread and damage caused by these species. At present, an inability to link precisely genetic variability to the virulence characteristics of a specific nematode population, and quickly identify the virulence status of intercepted populations for inspection purposes, strengthens the case for using plant health legislation to prevent their introduction.

The Globodera pallida SPRYSEC Gp-Rbp-1 gene encodes a secreted protein which induces effector-triggered immunity (ETI) mediated by the Solanum tuberosum disease resistance gene Gpa2. Nonetheless, it is not known how the Andes orogeny, the richness in Solanum species found along the Cordillera or the introduction of the nematode into Europe have affected the diversity of Gp-Rbp-1 and its recognition by Gpa2. We generated a dataset of 157 highly polymorphic Gp-Rbp-1 sequences and identified three Gp-Rbp-1 evolutionary pathways: the ‘Northern Peru’, ‘Peru clade I/European’ and ‘Chilean’ paths. These may have been shaped by passive dispersion of the nematode and by climatic variations that have influenced the nature and diversity of wild host species. We also confirmed that, by an analysis of the selection pressures acting on Gp-Rbp-1, this gene has evolved under positive/diversifying selection, but differently among the three evolutionary pathways described. Using this extended sequence dataset, we were able to detect eight sites under positive selection. Six sites appear to be of particular interest because of their predicted localization to the extended loops of the B30.2 domain and/or support by several computational methods. The P/S 187 position was previously identified for its effect on the interaction with GPA2. The functional importance of the other five amino acid polymorphisms observed was investigated using Agrobacterium transient transformation assays. None of these new residues, however, appears to be directly involved in Gpa2-mediated plant defence mechanisms. Thus, the P/S polymorphism observed at position 187 remains the sole variation sufficient to explain the recognition of Gp-Rbp-1 by Gpa2.

The severity and prognosis of combat-related injuries to the spine and spine injuries sustained unrelated to direct combat have not been previously compared. Differences may have implications on tactics, treatment strategies, and directions for future research.Compare the severity and prognosis of battle and nonbattle injuries to the spine.Retrospective study.American military personnel who were injured in a combat zone and whose medical data were abstracted in the Joint Theater Trauma Registry (JTTR).The JTTR was queried using International Statistical Classification of Diseases, Ninth Revision codes to identify all individuals who sustained battle and nonbattle injuries to the neck, back, spinal column, or spinal cord in Operation Iraqi Freedom or Operation Enduring Freedom from October 2001 to December 2009. Medical records of all identified servicemembers were individually reviewed. Demographic information, including sex, age, military rank, date of injury, and final disposition, was obtained for all patients. Spinal injuries were categorized according to anatomic location, associated neurologic involvement, precipitating mechanism of injury (MOI), and concomitant wounds. These data points were compared for the groups battle spine injuries (BSIs) and nonbattle spine injuries (NBSIs).Five hundred two servicemembers sustained a total of 1,834 battle injuries to the spinal column, including 1,687 fractures (92%), compared with 92 servicemembers sustaining 267 nonbattle spinal column injuries, with 241 (90%) fractures. Ninety-one BSI servicemembers (18% of patients) sustained spinal cord injuries (SCIs) with 41 (45%) complete SCIs, compared with 13 (14% of patients) nonbattle SCIs with six (46.2%) complete injuries (p=.92). The reported MOI for 335 BSI servicemembers (66.7%) was an explosion compared with one NBSI explosive injury. Eighty-four patients (17%) sustained gunshot wounds (GSWs) in battle compared with five (5.2%) nonbattle GSWs. Fifteen patients (3.0%) sustained a battle-related fall compared with 29 (30%) nonbattle-related falls. Battle spine injury servicemembers underwent significantly higher rates of surgical interventions (p.0001), were injured by high-energy injury mechanisms at a significantly greater rate (p.0001), and demonstrated a trend toward lower neurologic recovery rates after SCI (p=.16).Battle spine injury and NBSI are separate entities that may ultimately have disparate long-term prognoses. Nonbattle spine injury patients, although having similar MOIs compared with civilian spinal trauma, maintain a different patient demographic. Further research must be directed at accurately quantifying the long-term disabilities of all spine injuries sustained in a combat theater, whether they are the result of battle or not.

International audience; Like microbial pathogens, nematodes secrete a repertoire of effectors with diverse functions. In the case of sedentary nematodes, completion of the life cycle requires the maintenance of the biotrophic interaction for several weeks and the induction of a permanent feeding site. These essential processes require fine tuning of plant cell responses. About a hundred candidate effectors have been isolated from nematodes to date that have roles in the invasion of host tissues, evasion of plant defences, suppression of plant defences or manipulation of plant cell fate. Evolutionary studies suggest that several distinct mechanisms have led to the acquisition of these effectors during the evolution of plant parasitism. In addition, since any compound secreted by the parasite can potentially be perceived as nonself by the plant, nematode effectors are subject to selective pressure to escape plant immunity. This chapter reviews the latest findings on nematode effector functions and evolutionary traits.

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; While pectate lyases are major parasitism factors in plant-parasitic nematodes, there is little information on the variability of these genes within species and their utility as pathotype or host range molecular markers. We have analysed polymorphisms of pectate lyase 2 (pel-2) gene, which degrades the unesterified polygalacturonate (pectate) of the host cell-wall, in the genus Globodera. Molecular variability of the pel-2 gene and the predicted protein was evaluated in populations of G. rostochiensis, G. pallida, G. "mexicana" and G. tabacum. Seventy eight pel-2 sequences were obtained and aligned. Point mutations were observed at 373 positions, 57% of these affect the coding part of the gene and produce 129 aa replacements. The observed polymorphism does not correlate either to the pathotypes proposed in potato cyst nematodes (PCN) or the subspecies described in tobacco cyst nematodes. The trees reveal a topology different from the admitted species topology as G. rostochiensis and G. pallida sequences are more similar to each other than to G. tabacum. Species-specific sites, potentially applicable for identification, and sites distinguishing PCN from tobacco cyst nematodes, were identified. As both G. rostochiensis and G. pallida display the same host range, but distinct from G. tabacum, which cannot parasitize potato plants, it is tempting to speculate that pel-2 genes polymorphism may be implicated in this adaptation, a view supported by the fact that no active pectate lyase 2 was found in G. "mexicana", a close relative of G. pallida that is unable to develop on cultivated potato varieties

Summary Globodera pallida and G.'mexicana' are closely related nematode species that can mate and form viable hybrids on tomato but usually develop on different Solanaceous plants. Identification of nematode genes involved in parasitism is important for elucidation of disease resistance mechanisms in plants. In this study, we have used suppression subtractive hybridization (SSH) to investigate differences between the transcriptomes of G. pallida and G.'mexicana' J2s. This provides a basis for further studies characterizing pathogenicity factors in these nematodes. None of the cDNA fragments isolated in the SSH experiments appeared to be completely absent from the other transcriptome. Differences in expression levels of some of the isolated cDNAs between the two species were detected. Sequence analysis revealed that nearly 85% of the cloned sequences are nematode specific and a high proportion were pioneer genes for which no putative homologues were present in the databases. However, homologues of a cellulase and a putative pathogenicity factor previously described from G. rostochiensis were isolated. The putative roles of these sequences in parasitism are discussed.

Plant NB-LRR proteins confer robust protection against microbes and metazoan parasites by recognizing pathogen-derived avirulence (Avr) proteins that are delivered to the host cytoplasm. Microbial Avr proteins usually function as virulence factors in compatible interactions; however, little is known about the types of metazoan proteins recognized by NB-LRR proteins and their relationship with virulence. In this report, we demonstrate that the secreted protein RBP-1 from the potato cyst nematode Globodera pallida elicits defense responses, including cell death typical of a hypersensitive response (HR), through the NB-LRR protein Gpa2. Gp-Rbp-1 variants from G. pallida populations both virulent and avirulent to Gpa2 demonstrated a high degree of polymorphism, with positive selection detected at numerous sites. All Gp-RBP-1 protein variants from an avirulent population were recognized by Gpa2, whereas virulent populations possessed Gp-RBP-1 protein variants both recognized and non-recognized by Gpa2. Recognition of Gp-RBP-1 by Gpa2 correlated to a single amino acid polymorphism at position 187 in the Gp-RBP-1 SPRY domain. Gp-RBP-1 expressed from Potato virus X elicited Gpa2-mediated defenses that required Ran GTPase-activating protein 2 (RanGAP2), a protein known to interact with the Gpa2 N terminus. Tethering RanGAP2 and Gp-RBP-1 variants via fusion proteins resulted in an enhancement of Gpa2-mediated responses. However, activation of Gpa2 was still dependent on the recognition specificity conferred by amino acid 187 and the Gpa2 LRR domain. These results suggest a two-tiered process wherein RanGAP2 mediates an initial interaction with pathogen-delivered Gp-RBP-1 proteins but where the Gpa2 LRR determines which of these interactions will be productive., Author Summary Biotrophic plant pathogens produce effector proteins that are delivered to the host cytoplasm where they alter defense responses and metabolism to favor pathogen colonization. In turn, plants have evolved intra-cellular proteins to recognize pathogen effector proteins, known as NB-LRR proteins, which are similar in structure to animal NOD-LRR immune receptors. While effector proteins recognized by NB-LRR proteins have been identified from many organisms, the identification of such proteins from metazoan plant parasites has presented unique challenges due to the lack of genetically tractable model species. The potato Gpa2 protein confers resistance to some isolates of the potato pale cyst nematode, Globodera pallida. In this report, we show that Gpa2 recognizes certain variants of the G. pallida protein, Gp-RBP-1, which is highly polymorphic both within and between populations. This recognition in turn induces defense responses, including a form of programmed cell death characteristic of plant immune receptor activation. Moreover, we show that a Gpa2-interacting protein, RanGAP2, is required for Gpa2 function and that activation of Gpa2 is enhanced when Gp-RBP-1 is artificially tethered to RanGAP2. Thus, our findings suggest that RanGAP2 acts as a recognition co-factor for Gpa2, and have important implications for our understanding of the mechanisms and evolution of pathogen recognition by NB-LRR proteins.

National audience; Inscrits parmi les parasites de quarantaine, les nématodes à kyste, Globodera rostochiensis et Globodera pallida sont présents dans de nombreux bassins de production de pomme de terre où les dégâts sont parfois considérables. La lutte contre ces ravageurs est préventive dans les zones de culture indemnes, condition indispensable à la production de plant de pomme de terre. Des pratiques agronomiques adéquates et l’utilisation de variétés résistantes conduisent à la réduction du taux d’infestation des terrains contaminés. Dans certaines situations géographiques, le traitement du sol par solarisation peut remplacer efficacement l’emploi de nématicides destinés à être interdits. La résistance génétique représente le moyen de lutte le plus efficace. L’introgression de nouvelles formes de résistance a été entreprise à partir d’autres espèces tubéreuses, notamment Solanum vernei. La récente caractérisation moléculaire de nouveaux facteurs génétiques de la résistance chez les espèces Solanum spegazzinii et Solanum sparsipilum et l’étude de leur association devraient faire progresser le travail de sélection variétale. La combinaison des différents moyens de lutte présentés en fonction des situations devrait aboutir à la mise en pratique d’une véritable lutte intégrée en culture de pomme de terre de consommation.

International audience; Ditylenchus dipsaci, the stem nematode of alfalfa (Medicago sativa), Mycosphaerella pinodes, cause of Ascochyta blight in pea (Pisum sativum) and Aphanomyces euteiches, cause of pea root rot, result in major yield losses in French alfalfa and pea crops. These diseases are difficult to control and the partial resistances currently available are not effective enough. Medicago truncatula, the barrel medic, is the legume model for genetic studies, which should lead to the identification and characterization of new resistance genes for pathogens. We evaluated a collection of 34 accessions of M. truncatula and nine accessions from three other species (two from M. italica, six from M. littoralis and one from M. polymorpha) for resistance to these three major diseases. We developed screening tests, including standard host references, for each pathogen. Most of the accessions tested were resistant to D. dipsaci, with only three accessions classified as susceptible. A very high level of resistance to M. pinodes was observed among the accessions, none of which was susceptible to this pathogen. Conversely, a high level of variation, from resistant to susceptible accessions, was identified in response to infection by A. euteiches

International audience; In order to identify genes involved in pathogenicity, we compared the closely related species Globodera pallida (GP) and Globodera "mexicana" (GM) that have different host ranges and are able to produce viable and fertile hybrids. Three pioneer genes were previously identified as differentially expressed between GP and GM: GPLIA7 and GPLIB3 were found to be more highly expressed in GP, whereas GMLIVG9 was found more highly expressed in GM. In this study, we showed that Ia7 and IVg9 genes probably encode products secreted by the subventral oesophageal glands and the dorsal oesophageal gland, respectively. No Blast homolog was found in the databases, but a metridin-like ShK (Stichodactyla helianthus) toxin domain was identified in the Ia7 sequence. Analysis of the full-length sequences of these 2 genes between GP and GM revealed a high level of interspecies variability (8% for the Ia7 transcript and 17% for the IVg9 transcript) and a high proportion (90%) of nonsynonymous mutations among the substitutions observed. This suggested that these 2 pioneer genes are under strong diversifying selection pressures and therefore may be involved in pathogenicity. Further investigations of the sequence polymorphism of Ia7 and IVg9 genes were conducted in GP x GM hybrid lines that were selected in laboratory conditions for their different ability to develop on potato and black nightshade. As similar sequences were obtained for all the hybrid lines tested independently of their pathogenicity status, no correlation could be established between IA7 and IVG9 amino acid changes and the host range differences observed between GP and GM

DNA polymorphism in the Ditylenchus dipsaci complex was investigated using amplified fragment length polymorphism (AFLP) to determine the relationships among populations growing mainly on Vicia faba and to develop diagnostic markers. Twenty-two populations of D. dipsaci originating from different geographical areas and one population of Ditylenchus myceliophagus were used. AFLP proved to be a powerful method to reveal intraspecific polymorphism even within the giant type. The analysis showed a clear distinction between the giant and normal populations, with genetic distances similar to those observed between normal populations and D. myceliophagus or giant populations and D. myceliophagus, strengthening the hypothesis that these two nematode types could be considered distinct species. Two specific AFLP markers differentiating the two types were converted into sequenced characterized amplified region (SCAR) markers. Used in a multiplex PCR, the SCAR primers proved to be a rapid and efficient tool to identify the giant and the normal types of D. dipsaci.Key words: Ditylenchus dipsaci, Vicia faba, giant type, AFLP, SCAR.

Amplified fragment length polymorphism (AFLP) was used to obtain information on the within-species geneticvariability of the tobacco cyst – nematode (TCN) complex. AFLP was found to be well suited to this type ofstudy. The current classification of TCN was confirmed. Results indicate that the Globodera tabacum solanacearumgroup, believed to be restricted to the U.S.A., also occurs in Mexico. The within-species variability of TCN is considerable.Populations from Mexico may form a new subgroup. AFLP group-specific markers were identified for two ofthe TCN subgroups: Globodera tabacum tabacum and Globodera tabacum solanacearum.; La technique dite de l'AFLP a été utilisée sur les nématodes à kystes du tabac (TCN) afin d'acquérir des connaissances sur leur polymorphisme moléculaire intra-spécifique. L'efficience de la technique AFLP pour ce type d'études a été réaffirmée. La classification intra-spécifique des TCN communément admise est confirmée. Les résultats indiquent que le groupe Globodera tabacum solanacearum, jusqu'à présent décrit uniquement aux États-Unis, existe également au Mexique. Une variabilité intra-spécifique élargie est mise en évidence au sein des TCN. Des populations originaires du Mexique pourraient former un nouveau sous-groupe. Des marqueurs AFLP spécifiques pour deux des sous-groupes du complexe des TCN, Globodera tabacum tabacum et Globodera tabacum solanacearum, sont mis en évidence.Mots clés : Heteroderinae, classification, marqueurs, diversité génétique, distribution géographique.

There is currently no information on the genome size and complexity in the entomoparasitic nematodes Steinernema and Heterorhabditis. DNA reassociation kinetics were used to determine the genome size and complexity in 2 species: Steinernema carpocapsae and Heterorhabditis bacteriophora. C0t curves derived from renaturation kinetics of denatured DNA indicate that the genomes of these entomoparasitic rhabditids are different both in size and complexity. Genome sizes were estimated at 2·3 × 108 bp for S. carpocapsae and 3·9 × 107 bp for H. bacteriophora and repetitive DNA contents were found to represent 39% and 51% of these respective genomes.

The success of alternative crop protection practices against plant-parasitic nematodes using host resistance genes depends fundamentally upon identification of the species and pathotypes effectively controlled by these genes. In the same way, biological control of insects by entomopathogenic nematodes will work only if the nematode strains used are indeed active against the pests to be eliminated. For these applications, the accurate interspecific and/or intraspecific identification of nematodes is thus of outstanding importance. Here, Eric Grenier, Philippe Castagnone-Sereno and Pierre Abad discuss the recent use of satellite DNA sequences in nematode taxonomic diagnostics.

SUMMARYThree satellite DNAs previously isolated from the entomopathogenic nematodesSteinernema carpocapsae, Heterorhabditis bacteriophoraandHeterorhabditis indicusgive hybridization signals only with theS. carpocapsae, H. bacteriophoraandH. indicuspopulations tested, indicating that these satellite sequences are species-specific. Because of their reiteration and their variabilities, we have shown that these sequences are able to discriminate at the interspecific level between theSteinernemaandHeterorhabditisspecies, but also at the intraspecific level betweenS. carpocapsaestrains. Furthermore, in simple squashed nematode experiments, we are able to unambiguously identifyS. carpocapsae,H. bacteriophoraandH. indicuspopulations. This last procedure is effective even on a single infective juvenile, with the main advantage that it avoids time-consuming DNA extractions.

Two AluI tandemly repeated DNAs were cloned from two entomopathogenic nematodes: the first one from Steinernema glaseri and the second one from Heterorhabditis bacteriophora. The monomeric units of these two satellite DNAs have a repeat length of 174 and 168 bp, respectively. These AluI repeated element families appear to constitute 5.5% of the S. glaseri genome and 5% of the H. bacteriophora genome. Their A + T contents were estimated at 55% and 57%. Moreover, the monomers of these two families are quite homogeneous in sequence, showing, on average, 3.9% and 2.7% divergence from their respective consensus sequence. These results suggest that some mechanism is acting to maintain the homogeneity of these repeated DNAs despite their abundance. We have also shown that these two DNA families are species-specific and therefore could be used for the identification of Steinernema and Heterorhabditis entomopathogenic nematode species.

An HaeIII satellite DNA family has been cloned from the entomopathogenic nematode Steinernema carpocapsae. This repeated sequence appears to be an unusually abundant satellite DNA, since it constitutes about 62% of the S. carpocapsae genome. The nucleotide sequences of 13 monomers have been determined. This satellite DNA family is represented by two sub-families: one with monomeric units of 170 bp and the other with monomeric units of 182 bp. These monomers are quite homogeneous in sequence, showing an average intermonomer variability of 6% from the consensus sequence. These results suggest that some homogenizing mechanism is acting to maintain the homogeneity of this satellite DNA. After hybridization with the genomic DNA of several other Steinernema species, this DNA sequence appears to be specific to the S. carpocapsae genome. Therefore, the species specificity and the high copy number of the HaeIII satellite DNA sequence should provide a rapid and powerful tool which could contribute to the identification of Steinernema species.

BACKGROUND: While combat spinal injuries have been documented since the fourth century BC, a comprehensive analysis of such injuries has not been performed for any American military conflict. Recent literature has suggested that spinal injuries account for substantial disability in wounded service members. METHODS: The Joint Theater Trauma Registry was queried to identify all American military personnel who sustained injuries to the back, spinal column, and/or spinal cord in Iraq or Afghanistan from October 2001 to December 2009. Spinal injuries were categorized according to anatomic location, neurological involvement, mechanism of injury, and concomitant wounds. RESULTS: Of 10,979 evacuated combat casualties, 598 (5.45%) sustained 2101 spinal injuries. Explosions accounted for 56% of spinal injuries, motor vehicle collisions for 29%, and gunshots for 15%. Ninety-two percent of all injuries were fractures, with transverse process, compression, and burst fractures the most common. Spinal cord injuries were present in 17% (104) of the 598 patients. Concomitant injuries frequently occurred in the abdomen, chest, head, and face. CONCLUSIONS: The incidence of spine trauma sustained by military personnel in Iraq and Afghanistan is higher than that reported for previous conflicts, and the nature of these injuries may be similar to those in severely injured civilians. Further research into optimal management and rehabilitation is critical for military service members and severely injured civilians with spine trauma. Language: en

International audience

Potato cyst nematodes of the genus Globodera are microscopic and heterotrophic worms, that parasite the roots of the Solanaceaous plants. They are obligatory endoparasitic organisms that establish an intimate relationship with their host plant. They can feed through their elaborate feeding site. This feeding structure is induced by the nematode secreted proteins that are directly injected in plant cells through their stylet (anterior structure like a needle). The function of pathogenicity proteins identified to date is often unknown. We studied the variability and the evolutionary pattern of genes encoding such proteins in the cyst nematode family. The pathogenicity genes seemed to have an accelerated evolutionary tempo compared to housekeeping genes and seemed to be under diversifying selective pressures.; Les nématodes à kyste du genre Globodera sont des vers microscopiques, hétérotrophes qui parasitent les racines des plantes essentiellement de la famille des Solanacées. Ces organismes sont des endoparasites obligatoires qui établissent une relation très étroite avec leur plante hôte. Ils peuvent ainsi se nourrir par le biais d'un site nourricier très élaboré. Celui-ci est mis en place grâce à des protéines sécrétées par le nématode, directement injectées dans les cellules végétales grâce à leur stylet (organe de la partie antérieure assimilable à une aiguille creuse). La fonction des protéines du pouvoir pathogènes identifiées est très souvent inconnue. Nous avons étudié la variabilité des gènes codant ces protéines au sein de la famille des nématodes à kyste ainsi que leur mode évolutif. Les gènes du pouvoir pathogène semblent avoir des tempos d'évolution nettement plus rapide que les gènes de ménage et semblent être soumis à des pressions de sélection diversificatrices.