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.
Project description:Expression profiling of 7,530 Heterodera glycines probesets present on the Affymetrix Soybean Genome Array GeneChip throughout the life cycle of the nematode (egg, infective J2, parasitic J2, J3, J4, adult female).
Project description:Sugar beet (Beta vulgaris subsp. vulgaris) is an economically important crop and provides nearly one third of the global sugar production annually. The beet cyst nematode (BCN), Heterodera schachtii, causes major yield losses in sugar beet worldwide. The most effective and economic approach to control this nematode is growing tolerant or resistant cultivars. To identify candidate genes involved in susceptibility and resistance, the transcriptome of sugar beet and BCN in compatible and incompatible interactions at two time points, was studied using mRNA-seq. In total, 16 cDNA libraries were constructed and 442 691 707raw reads were obtained. In the compatible interaction, many alterations in phytohormone-related genes were detected. The effect of exogenous application of methyl jasmonate and ethephon was therefore investigated and the results revealed significant reduction of J2s infection and female development rates in treated susceptible plants. Our results revealed candidate genes putatively involved in the Hs1pro1-induced resistance, such as genes related to phenylpropanoid pathway, putative R genes and genes encoding F-box proteins, zinc finger and NAC transcription factors, ABC transporters, BURP and CYSTM proteins. Also, the transcriptome of BCN in the infected root samples was analyzed and several nematode effector genes were found. Our study is the first investigation of the transcriptome profile in the compatible and incompatible interactions between sugar beet and BCN.
Project description:The cereal cyst nematode (CCN, Heterodera avenae) is a major pest of wheat (Triticum spp) that reduces crop yields in many countries. Cyst nematodes are obligate sedentary endoparasites that reproduce by amphimixis. Here, we report the first transcriptome analysis of two parasitic stages of H. avenae.
