Gene silencing in root lesion nematodes (Pratylenchus spp.) significantly reduces reproduction in a plant host

Root lesion nematodes (RLNs, Pratylenchus species) are a group of economically important migratory endoparasitic plant pathogens that attack host roots of major crops such as wheat and sugarcane, and can reduce crop yields by 7-15%. Pratylenchus thornei and Pratylenchus zeae were treated with double stranded RNA (dsRNA) to study gene silencing, (RNA interference, RNAi), as a potential strategy for their control. Mixed stages of nematodes of both species ingested dsRNA when incubated in a basic soaking solution in the presence of the neurostimulant octopamine. Incubation for up to 16. h in soaking solutions containing 10-50. mM octopamine, 0.1-1.0. mg/mL FITC, and 0.5-6. mM spermidine did not affect vitality. Spermidine phosphate salt hexahydrate rather than spermidine or spermidine trihydrochloride increased uptake of FITC by nematodes, and this resulted in more effective gene silencing. Silencing pat-10 and unc-87 genes of P. thornei and P. zeae resulted in paralysis and uncoordinated movements in both species, although to a higher degree in P. thornei. There was also a greater reduction in transcript of both genes in P. thornei indicating that it may be more susceptible to RNAi. For P. thornei treated with dsRNA of pat-10 and unc-87 there was a significant reduction (77-81%) in nematode reproduction on carrot mini discs over a 5. week period. The results show that RLNs are clearly amenable to gene silencing, and that in planta delivery of dsRNA to target genes in these nematodes should confer host resistance. Moreover, for the two genes, dsRNA derived from either nematode species silenced the corresponding gene in both species. This implies cross-species control of nematodes via RNAi is possible

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Scanning24286-91SCNN

Automatic IC Die Positioning in the SEM

Conference Proceedings from the International Symposium for Testing and Failure Analysis469-47

Application of gene silencing for nematode control

Root lesion nematodes (Pratylenchus spp., RLNs) are major pests of most crops, and reduce yields of wheat in Western Australia by up to 15%, with Australia-wide losses of more than $36 million per annum. The aim of this project is to investigate the use of RNA interference (RNAi) as an approach to confer resistance to RLNs. RNAi is a well established technology that can be used to silence specific genes in animals and plants. Exposure to artificially introduced double-stranded RNA (dsRNA) leads to the silencing of endogenous genes with homologous sequence. RNAi can silence genes in Caenorhabditis elegans, and some success has been reported in root-knot nematodes. There is no evidence yet that RNAi works for RLNs. RLNs are migratory endoparasitic nematodes, and so mobility is an important aspect of parasitism. In this study, we are investigating genes involved in locomotion in RLNs via RNAi. We have shown that P.thornei and P.zeae are indeed amenable to RNAi. Exposure to dsRNA for locomotion specific genes by 14 hours soaking in medium containing M9 buffer with 50 mM octopamine, 3 mM spermidine and 0.05% gelatin led to locomotion impairment in both of these species. In addition, dsRNA originating from P.thornei also led to abnormalities in the closely related species P.zeae and vice versa, indicating that inter-species gene knockdown is possible. The outcome of this study is economically significant as no reported natural resistance genes have broad effectiveness against RLNs. Bioengineered crops expressing dsRNA that silence essential target genes to interrupt the parasitic process represents a potential approach to develop novel, broadly applicable and durable RLN-resistance in crop plants

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Prosthetics and Orthotics International173180-188POIN

Three-dimensional porous silk tumor constructs in the approximation of in vivo osteosarcoma physiology

10.1016/j.biomaterials.2011.04.084Biomaterials32266131-6137BIMA

Characterization of knitted polymeric scaffolds for potential use in ligament tissue engineering

10.1163/1568562054798491Journal of Biomaterials Science, Polymer Edition1691179-119

Enhanced detection sensitivity with pulsed laser digital signal integration algorithm

Conference Proceedings from the International Symposium for Testing and Failure Analysis2006234-23

Laser-induced detection sensitivity enhancement with laser pulsing

Electronic Device Failure Analysis10318-2