Project description:Similar to other plant-parasitic nematodes, root lesion nematodes possess an array of enzymes that are involved in degradation of the plant cell wall. Here we report the identification of a gene encoding a cell wall degrading enzyme, pectin methylesterase PME (EC 3.1.1.11), in the root lesion nematode Pratylenchus penetrans. Both genomic and coding sequences of the gene were cloned for this species, showing the presence of four introns that excluded a potential bacterial contamination. Expression of the Pp-pme gene was localized in the esophageal glands of P. penetrans as determined by in situ hybridization. Temporal expression of Pp-pme in planta was validated for early time points of infection. The possible function and activity of the gene were assessed by transient expression of Pp-pme in N. benthamiana plants via a Potato virus X-based vector. To our knowledge, this is the first report on identification and characterization of a PME gene within the phylum Nematoda.
2019-02-28 | PXD012419 | Pride
Project description:Plant-parasitic nematode field sampling
Project description:Angiostrongylus costaricensis is a relatively uncharacterized nematode that causes abdominal angiostrongyliasis in Latin America, a human parasitic disease. Currently, no effective pharmacological treatment for angiostrongyliasis exists. Peptidases are known to be druggable targets for a variety of diseases and are essential for several biological processes in parasites. Therefore, this study aimed to systematically characterize the peptidase activity of A. costaricensis in different developmental stages of this parasitic nematode.
Project description:Strongyloides ratti is a parasitic nematode of rats and a laboratory model for nematode infection more generally. The aim of this experiment was to determine the gene expression response of parasitic females to abiotic factors in its environment ex vivo that may be relevant to its natural environment in the gut in vivo. Thus, we used cDNA arrays to assay transcriptional responses to high and low salt, to RPMI versus PBS media and to 37C versus 40C. A moderate number of gene expression changes were observed.
Project description:Cereal cyst nematode (Heterodera avenae) can be attracted by wheat roots before infestation, while largely is unknown underlying this phenomenon. Here, we examined the transcriptional responses of both wheat roots and nematodes during the attraction stage by mRNA sequencing analysis (with and without reference genome, respectively). We found that consistent with their respective mobility, the immobile host wheat root only had 93 DEGs (27 up-regulated and 66 down-regulated), while the mobile plant parasitic nematode H. avenae reacted much more actively with 879 DEGs (867 up-regulated and 12 down-regulated). Among the DEGs, a number of wheat DEGs (most down-regulated) were involved in biotic stress pathways, while several putative effector genes (up-regulated) were found in the nematode DEGs. Results of the experiments demonstrated that nematode responds more actively than wheat during the attraction stage of parasitism, and the parasite responses mainly involved up-regulation whereas the host responses mainly involved down-regulation.
Project description:Plant-parasitic cyst nematodes induce the formation of hypermetabolic feeding sites, termed syncytia, as their sole source of nutrients. The formation of the syncytium is orchestrated by the nematode in part by modulation of phytohormone responses, including cytokinin. In response to infection by the nematode H. schachtii, cytokinin signaling is transiently induced at the site of infection and in the developing syncytium. Arabidopsis lines with reduced cytokinin sensitivity show reduced susceptibility to nematode infection, indicating that cytokinin signaling is required for optimal nematode development. Furthermore, lines with increased cytokinin sensitivity also exhibit reduced nematode susceptibility. To ascertain why cytokinin hypersensitivity reduces nematode parasitism, we examined the transcriptomes in wild-type and a cytokinin-hypersensitive type-A arr Arabidopsis mutant in response to H. schachtii infection. Genes involved in the response to biotic stress and defense response were elevated in the type-A arr mutant in the absence of nematodes and were hyper-induced following H. schachtii infection, which suggests that the Arabidopsis type-A arr mutants impede nematode development because they are primed to respond to pathogen infection. These results suggest that cytokinin signaling is required for optimal H. schachtii parasitism of Arabidopsis, but that elevated cytokinin signaling triggers a heightened immune response to nematode infection.
