The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Laurene Levy - One of the best experts on this subject based on the ideXlab platform.
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Multiplex Real-Time PCR Assays for the Identification of the Potato Cyst and Tobacco Cyst Nematodes
Plant disease, 2010Co-Authors: Mark K Nakhla, Kristina J Owens, Gang Wei, Andrea M. Skantar, Laurene LevyAbstract:TaqMan primer-probe sets were developed for the detection and identification of potato Cyst Nematodes (PCNs) Globodera pallida and G. rostochiensis using two-tube, multiplex real-time polymerase chain reaction (PCR). One tube contained a primer-probe set specific for G. pallida (pale potato Cyst nematode) multiplexed with another primer-probe set specific for G. rostochiensis (golden potato Cyst nematode). A second tube consisted of the G. pallida-specific primer-probe set multiplexed with a primer-probe set specific for G. tabacum (the morphologically similar tobacco Cyst nematode). This internal transcribed spacer rDNA-based system was specific for the Globodera spp. of interest and successfully identified several populations of PCN. This rapid, sensitive, and specific quantitative PCR assay presents a useful tool for PCN regulatory response and management programs.
Mark K Nakhla - One of the best experts on this subject based on the ideXlab platform.
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Multiplex Real-Time PCR Assays for the Identification of the Potato Cyst and Tobacco Cyst Nematodes
Plant disease, 2010Co-Authors: Mark K Nakhla, Kristina J Owens, Gang Wei, Andrea M. Skantar, Laurene LevyAbstract:TaqMan primer-probe sets were developed for the detection and identification of potato Cyst Nematodes (PCNs) Globodera pallida and G. rostochiensis using two-tube, multiplex real-time polymerase chain reaction (PCR). One tube contained a primer-probe set specific for G. pallida (pale potato Cyst nematode) multiplexed with another primer-probe set specific for G. rostochiensis (golden potato Cyst nematode). A second tube consisted of the G. pallida-specific primer-probe set multiplexed with a primer-probe set specific for G. tabacum (the morphologically similar tobacco Cyst nematode). This internal transcribed spacer rDNA-based system was specific for the Globodera spp. of interest and successfully identified several populations of PCN. This rapid, sensitive, and specific quantitative PCR assay presents a useful tool for PCN regulatory response and management programs.
Xiaohong Wang - One of the best experts on this subject based on the ideXlab platform.
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soybean resistance locus rhg1 confers resistance to multiple Cyst Nematodes in diverse plant species
Phytopathology, 2019Co-Authors: Katelyn J Butler, Shiyan Chen, John M Smith, Xiaohong Wang, Andrew F BentAbstract:Cyst Nematodes consistently threaten agricultural production, causing billions of dollars in losses globally. The Rhg1 (resistance to Heterodera glycines 1) locus of soybean (Glycine max) is the most popular resistance source used against soybean Cyst Nematodes (H. glycines). Rhg1 is a complex locus that has multiple repeats of an ≈30-kilobase segment carrying three genes that contribute to resistance. We investigated whether soybean Rhg1 could function in different plant families, conferring resistance to their respective Cyst nematode parasites. Transgenic Arabidopsis thaliana and potato (Solanum tuberosum) plants expressing the three soybean Rhg1 genes were generated. The recipient Brassicaceae and Solanaceae plant species exhibited elevated resistance to H. schachtii and Globodera rostochiensis and to G. pallida, respectively. However, some negative consequences including reduced root growth and tuber biomass were observed upon Rhg1 expression in heterologous species. One of the genes at Rhg1 encodes a toxic version of an alpha-SNAP protein that has been demonstrated to interfere with vesicle trafficking. Using a transient expression assay for Nicotiana benthamiana, native Arabidopsis and potato alpha-SNAPs (soluble NSF [N-ethylamine sensitive factor] attachment protein) were found to compensate for the toxicity of soybean Rhg1 alpha-SNAP proteins. Hence, future manipulation of the balance between Rhg1 alpha-SNAP and the endogenous wild-type alpha-SNAPs (as well as the recently discovered soybean NSF-RAN07) may mitigate impacts of Rhg1 on plant productivity. The multispecies efficacy of soybean Rhg1 demonstrates that the encoded mechanisms can function across plant and Cyst nematode species and offers a possible avenue for engineered resistance in diverse crop species.
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current status of potato Cyst Nematodes in north america
Annual Review of Phytopathology, 2019Co-Authors: Louisemarie Dandurand, Benjamin Mimee, Xiaohong Wang, Inga A Zasada, Walter De Jong, Richard G Novy, Jonathan L Whitworth, Joseph C KuhlAbstract:The potato Cyst Nematodes (PCNs) Globodera rostochiensis and Globodera pallida are internationally recognized quarantine pests. Although not widely distributed in either the United States or Canada, both are present and are regulated by the national plant protection organizations (NPPOs) of each country. G. rostochiensis was first discovered in New York in the 1940s, and G. pallida was first detected in a limited area of Idaho in 2006. In Canada, G. rostochiensis and G. pallida were first detected in Newfoundland in 1962 and 1977, respectively, and further detections of G. rostochiensis occurred in British Columbia and Quebec, most recently in 2006. Adherence to a stringent NPPO-agreed-upon phytosanitary program has prevented the spread of PCNs to other potato-growing areas in both countries. The successful research and regulatory PCN programs in both countries rely on a network of state, federal, university, and private industry cooperatorspursuing a common goal of containment, management/eradication, and regulation. The regulatory and research efforts of these collaborative groups spanning from the 1940s to the present are highlighted in this review.
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endogenous cellulases in animals isolation of β 1 4 endoglucanase genes from two species of plant parasitic Cyst Nematodes
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: G. Smant, Richard S Hussey, Eric L Davis, Thomas J Baum, Xiaohong Wang, F. J. Gommers, J P W G Stokkermans, J M De Boer, Bernard Henrissat, J HelderAbstract:β-1,4-Endoglucanases (EGases, EC 3.2.1.4) degrade polysaccharides possessing β-1,4-glucan backbones such as cellulose and xyloglucan and have been found among extremely variegated taxonomic groups. Although many animal species depend on cellulose as their main energy source, most omnivores and herbivores are unable to produce EGases endogenously. So far, all previously identified EGase genes involved in the digestive system of animals originate from symbiotic microorganisms. Here we report on the synthesis of EGases in the esophageal glands of the Cyst Nematodes Globodera rostochiensis and Heterodera glycines. From each of the nematode species, two cDNAs were characterized and hydrophobic cluster analysis revealed that the four catalytic domains belong to family 5 of the glycosyl hydrolases (EC 3.2.1, 3.2.2, and 3.2.3). These domains show 37–44% overall amino acid identity with EGases from the bacteria Erwinia chrysanthemi, Clostridium acetobutylicum, and Bacillus subtilis. One EGase with a bacterial type of cellulose-binding domain was identified for each nematode species. The leucine-rich hydrophobic core of the signal peptide and the presence of a polyadenylated 3′ end precluded the EGases from being of bacterial origin. Cyst Nematodes are obligatory plant parasites and the identified EGases presumably facilitate the intracellular migration through plant roots by partial cell wall degradation.
Shahid Siddique - One of the best experts on this subject based on the ideXlab platform.
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genome wide association study uncovers a novel qtl allele of ats40 3 that affects the sex ratio of Cyst Nematodes in arabidopsis
Journal of Experimental Botany, 2018Co-Authors: Muhammad Arslan Anwer, Florian M W Grundler, Syed Jehangir Shah, Muhammad Shahzad Anjam, Shamim M Hasan, Ali Ahmad Naz, Shahid SiddiqueAbstract:Plant-parasitic Cyst Nematodes are obligate sedentary parasites that infect the roots of a broad range of host plants. Cyst Nematodes are sexually dimorphic, but differentiation into male or female is strongly influenced by interactions with the host environment. Female populations typically predominate under favorable conditions, whereas male populations predominate under adverse conditions. Here, we performed a genome-wide association study (GWAS) in an Arabidopsis diversity panel to identify host loci underlying variation in susceptibility to Cyst nematode infection. Three different susceptibility parameters were examined, with the aim of providing insights into the infection process, the number of females and males present in the infected plant, and the female-to-male sex ratio. GWAS results suggested that variation in sex ratio is associated with a novel quantitative trait locus allele on chromosome 4. Subsequent candidate genes and functional analyses revealed that a senescence-associated transcription factor, AtS40-3, and PPR may act in combination to influence nematode sex ratio. A detailed molecular characterization revealed that variation in nematode sex ratio was due to the disturbed common promoter of AtS40-3 and PPR genes. Additionally, single nucleotide polymorphisms in the coding sequence of AtS40-3 might contribute to the natural variation in nematode sex ratio.
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amino acid permease 6 modulates host response to Cyst Nematodes in wheat and arabidopsis
Nematology, 2018Co-Authors: Shree R Pariyar, Jenish Nakarmi, Muhammad Arslan Anwer, Shahid Siddique, Abdelnaser Elashry, Jens Leon, Abdelfattah Adnan Dababat, Muhammad Ilyas, Florian M W GrundlerAbstract:Cyst Nematodes are plant parasites that cause significant crop loss in wheat and other crops. Infective juveniles invade roots and induce syncytial feeding structures as the only source of nutrients throughout their life. A previous genome-wide association study in wheat identified amino acid permease 6 ( TaAAP6 ) to be linked to susceptibility to the cereal Cyst nematode Heterodera filipjevi . To characterise the role of AAP6 during nematode parasitism, we analysed the expression of TaAAP6 and the Arabidopsis orthologue AtAAP6 . TaAAP6 was found to be highly expressed in nematode-infected roots of susceptible wheat, whereas it was not upregulated in nematode-infected roots of resistant accessions. AtAAP6 was also found to be highly upregulated in nematode-induced syncytia compared with non-infected roots. Infection assays with an AtAAP6 knock-out mutant revealed reduction in developing females, female size, and size of female-associated syncytia, thus indicating the importance of AAP6 in Cyst nematode parasitism.
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Damage-associated responses of the host contribute to defence against Cyst Nematodes but not root-knot Nematodes.
Journal of experimental botany, 2017Co-Authors: Syed Jehangir Shah, Muhammad Arslan Anwer, Florian M W Grundler, Muhammad Shahzad Anjam, Badou Mendy, Samer S. Habash, Jose L. Lozano-torres, Shahid SiddiqueAbstract:When Nematodes invade and subsequently migrate within plant roots, they generate cell wall fragments (in the form of oligogalacturonides; OGs) that can act as damage-associated molecular patterns and activate host defence responses. However, the molecular mechanisms mediating damage responses in plant–nematode interactions remain unexplored. Here, we characterized the role of a group of cell wall receptor proteins in Arabidopsis, designated as polygalacturonase-inhibiting proteins (PGIPs), during infection with the Cyst nematode Heterodera schachtii and the root-knot nematode Meloidogyne incognita. PGIPs are encoded by a family of two genes in Arabidopsis, and are involved in the formation of active OG elicitors. Our results show that PGIP gene expression is strongly induced in response to Cyst nematode invasion of roots. Analyses of loss-of-function mutants and overexpression lines revealed that PGIP1 expression attenuates infection of host roots by Cyst Nematodes, but not root-knot Nematodes. The PGIP1-mediated attenuation of Cyst nematode infection involves the activation of plant camalexin and indole-glucosinolate pathways. These combined results provide new insights into the molecular mechanisms underlying plant damage perception and response pathways during infection by Cyst and root-knot Nematodes, and establishes the function of PGIP in plant resistance to Cyst Nematodes.
P E L Van Der Putten - One of the best experts on this subject based on the ideXlab platform.
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field performance of solanum sisymbriifolium a trap crop for potato Cyst Nematodes ii root characteristics
Annals of Applied Biology, 2007Co-Authors: B G H Timmermans, J Vos, T J Stomph, J G W Van Nieuwburg, P E L Van Der PuttenAbstract:Hatching of potato Cyst Nematodes is induced by root exudates of Solanaceae, such as Solanum sisymbriifolium, and is therefore related to root length distribution of this crop. A mathematical model was derived to relate the hatching potential to root length density (RLD). A series of field experiments was carried out to study actual root length distribution of S.?sisymbriifolium in relation to shoot properties and to provide input into the model. Using a modified Poisson distribution formula for the three-dimensional distribution of roots in a volume of soil, the relation between the zone of influence of hatching agents and the RLD could be derived. On this basis, the minimal RLD was estimated, which is needed to expose 75%, 90% or 95% of Cysts to root exudates, as a function of the length of the zone of influence of hatching agents on Cysts. The logarithm of the total root length showed a linear relation with the logarithms of above-ground biomass and with leaf area index. Root diameter distribution was the same for all crops examined and independent of soil depth. Fine roots (
