Project description:Solanum torvum Sw is worldwide employed as rootstock for eggplant cultivation because of its vigour and resistance/tolerance to the most serious soil-borne diseasesas bacterial, fungal wilts and root-knot nematodes. A 30,0000 features custom combimatrix chip was designed and microarray hybridizations were conducted for both control and 14 dpi (day post inoculation) with Meloidogyne incognita-infected roots samples. We also tested the chip with samples from the phylogenetically-related nematode-susceptible eggplant species Solanum melongena.The genes identified from S. torvum catalogue, bearing high homology to knownnematode resistance genes, were further investigated in view of their potential role in the nematode resistance mechanism.
Project description:Plant-parasitic nematodes and especially the root-knot nematodes are ubiquitous pathogens. Eggs of root-knot nematodes (Meloidogyne javanica) were extracted from greenhouse cultures and second-stage juveniles (J2) were hatched in tap, sterile water on 30 µm sieves. Solanum tubersum cv. Desiree explants, i.e., stem including an axillary bud, were sectioned, under sterile conditions from in vitro growing seedlings and transferred to Magenta boxes containing Gamborg's media. Seedlings, 4 weeks post transferring to Gamborg's media were planted in pots containing autoclaved quartz sand. Three weeks later the plants were infected with 3000 M. javanica infective juveniles, applied to the soil in tap, sterile water. Control uninfected plants were mock-inoculated with tap, sterile water. Roots from 6 infected and 6 mock-inoculated plants were collected at a series of time points, including 5, 10 and 15 days post nematode infection/mock inoculation. Roots were observed under the microscope, and nematode feeding sites were selectively dissected, from young lateral roots. To control for the effect of tissue sectioning on gene expression, young lateral roots of the mock inoculated roots were dissected similarly to the infected roots, and collected. Dissected roots were snapped-freeze in liquid nitrogen and immediately stored in -80 C freezer. Total RNA was extracted using Qiagen RNAEasy kit. The experiment for each time point was duplicated, each duplicate derived from independent biological repeat. All RNA samples were amplified using the Ambion kit Message Amp catalog no. 1750, using as starting material 2.5 to 5 µg of total RNA. Keywords: Reference design
Project description:In order to study the similarities and differences in embryonic development between plant-parasitic nematodes and free-living nematodes, we performed RNA-seq on embryos of three plant-parasitic nematodes at a total of 11 stages from the single-cell stage to the J1 stage
Project description:Solanum torvum Sw is worldwide employed as rootstock for eggplant cultivation because of its vigour and resistance/tolerance to the most serious soil-borne diseasesas bacterial, fungal wilts and root-knot nematodes. A 30,0000 features custom combimatrix chip was designed and microarray hybridizations were conducted for both control and 14 dpi (day post inoculation) with Meloidogyne incognita-infected roots samples. We also tested the chip with samples from the phylogenetically-related nematode-susceptible eggplant species Solanum melongena.The genes identified from S. torvum catalogue, bearing high homology to knownnematode resistance genes, were further investigated in view of their potential role in the nematode resistance mechanism. total RNA was extracted from control and 14 days post-infection (infection with root-knot nematode Meloidogyne incognita) from roots of Solanum torvum and Solanum melongena. Three biological replicates were used for each condition and genotype for a total of 12 samples.
Project description:Here we have compared adult wildtype (N2) C. elegans gene expression when grown on different bacterial environments/fod sources in an effort to model naturally occuring nematode-bacteria interactions at the Konza Prairie. We hypothesize that human-induced changes to natural environments, such as the addition of nitrogen fertalizer, have effects on the bacterial community in soils and this drives downstream changes in the structure on soil bacterial-feeding nematode community structure. Here we have used transcriptional profiling to identify candidate genes involved in the interaction of nematodes and bacteria in nature.
Project description:Biotrophic plant pathogens have evolved sophisticated strategies to manipulate their host. They derive all of their nutrients from living plant tissues, by making intimate contact with their host while avoiding a resistance response. Rice is one of the most important crop plants worldwide and an excellent model system for studying monocotyledonous plants. Estimates of annual yield losses due to plant-parasitic nematodes on this crop range from 10 to 25% worldwide. One of the agronomically most important nematodes attacking rice is the rice root knot nematode Meloidogyne graminicola. Attack of plant roots by sedentary plant parasitic nematodes, like the root knot nematodes (RKN; Meloidogyne spp.) involves the development of specialized feeding cells in the vascular tissue. The second stage juvenile of the RKN punctures selected vascular cells with its stylet, injects pharyngeal secretions, and this ultimately leads to the reorganisation of these cells into typical feeding structures called giant cells (GCs), from which the nematode feeds for the remainder of its sedentary life cycle (Gheysen & Mitchum, 2011). Morphological and physiological reprogramming of the initial feeding cell leads to nucleus enlargement, proliferation of mitochondria and plastids, metabolic activation, cell cycle alterations and cell wall changes (Gheysen and Mitchum, 2011). The hyperplasia and hypertrophy of the surrounding cells leads to the formation of a root gall, which is typically formed at the root tips in the case of the rice RKN M. graminicola. In comparison with other RKN, M. graminicola has a very fast life cycle, with swelling of the root tips observed as early as 1 day after infection (dai). At 3 dai, terminal hook-like galls are clearly visible (Bridge et al., 2005). After 3 moults the nematodes are mature, around 10 dai. The M. graminicola females lay their eggs inside the galls, while most other RKN deposit egg masses at the gall surface, and hatched juveniles can reinfect the same or adjacent roots. In well-drained soil at 22-29ºC the life cycle of M. graminicola is completed in 19 days.