Project description:Potato virus YNTN (PVYNTN), causing potato tuber ring necrosis disease, dramatically lowers the quantity and the quality of the potato yield all over the world. The cultivar Igor is one of the most susceptible cultivars, developing severe disease symptoms on plants as well as on tubers. Finding genes differentially expressed in the early response to infection, when the host response is more defense- than infection- related, could improve our understanding of the potato - PVYNTN interaction. Differential gene expression in early response of potato cv. Igor plants to PVYNTN infection was studied using potato TIGR cDNA-microarrays. Expression was compared between mock inoculated and virus infected plants 12 hours after inoculation, in four biological replicates. Keywords: direct comparison
Project description:The goal of these studies is analysis of gene expression profiles in potato plants infected with potato virus Y (necrotic strain - PVYN). A prototypic plant pathogen interaction system used to study disease resistance is tobacco (Nicotiana tabacum) and tobacco mosaic virus (TMV). In tobacco, the resistance response comprises two phenomena, known as the hypersensitive response (HR) and systemic acquired resistance (SAR). HR is typically characterized by a local necrosis surrounding the site of viral entry leading to restriction of pathogen replication and spread. SAR is the enhanced ability of the plant to resist a secondary challenge by the same or a different pathogen inoculated elsewhere on the plant. The identity of the signal(s) that induces HR and SAR is still poorly understood. Plants of S. tuberosum cv. Rywal, resistant to all known (N, 0, NTN) PVY strains, were grown in growth chambers using 16 h period of light (22°C) and 8 h of darkness (18°C). For all experiments, 6-week-old plants were used. For inoculation with PVY, carborundum-dusted leaves were rubbed with water (mock control) or PVYN solution (1 µg ml-1). Two to four leaves were inoculated on each plant and harvested together at 1, 3, and 6 days post inoculation (dpi). Separately, noninoculated leaves were harvested at the same time points (upper leaves). The first time point (1 dpi) has been chosen to study the early stage of plant response before necrotic lesion formation. At 3 dpi necrotic lesions start to appear, and at 6 dpi necroses are fully developed which correlates with the maximum of salicylic acid increase in virus inoculated leaves. Keywords: Direct comparison
Project description:Phloem localization of plant viruses is advantageous for acquisition by sap-sucking vectors but hampers host-virus protein interaction studies. In this study, Potato leafroll virus (PLRV)-host protein complexes were isolated from systemically infected potato, a natural host of the virus. Comparing two different co-immunoprecipitation support matrices coupled to mass spectrometry, we identified 44 potato proteins and one viral protein (P1) specifically associated with virus isolated from infected phloem. An additional 142 proteins interact in complex with virus at varying degrees of confidence. Greater than 80% of these proteins were previously found to form high confidence interactions with PLRV isolated from the model host Nicotiana benthamiana. Bioinformatics revealed that these proteins are enriched for functions related to plasmodesmata, organelle membrane transport, translation and mRNA processing. Our results show that model system proteomics experiments are extremely valuable for understanding protein interactions regulating infection in recalcitrant pathogens such as phloem-limited viruses.
Project description:Potato leaves From Solanum tuberosum var. Kennebec will be wounded and oral secretions from 4th instar CPB will be isolated and added to the plants as described by Kruzmane et al (2002, Physiol. Plantarum 115:577-584). The leaf from the 6th node of the potato plant will be wounded or wounded and treated with oral secretions from CPB. Unwounded leaves from node 1-5 of the wounded and wounded plus oral secretions plants will be harvested as systemic material. The leaves will be harvested after 4 hrs and RNA will be isolated. 4 hrs was chosen because this represents a time when early and late induced genes should both be present. In addition, the leaf from the 6th node will be subjected to feeding by CPB that have been raised on potato leaves and starved for 16 hrs immediately prior to infestation. Insects will be allowed to feed for 1 hr and the leaves will be harvested after 3 additional hrs. An additional set of plants will be used to infest the leaf on the 6th node for 4 hrs. Leaves from the 6th node will be collected from uninfested plants after 4 hrs as a control. Three sets of 6-12 plants will be used for each sample. Keywords: Direct comparison
Project description:Potato virus YNTN (PVYNTN), causing potato tuber ring necrosis disease, dramatically lowers the quantity and the quality of the potato yield all over the world. While cultivar Igor is one of the most susceptible cultivars, developing severe disease symptoms on plants as well as on tubers, cv. Sante is resistant and thus not affected by the virus. Finding genes differentially expressed in the early response to infection, when the host response is more defense- than infection- related, could improve our understanding of the potato - PVYNTN interaction. Moreover, the differences in the response of the sensitive and resistant cultivar can pinpoint the genes involved in differential sensitivity of the cultivars. Differential gene expression in the early response of potato cvs. Igor and Sante to PVYNTN infection was studied using potato TIGR cDNA-microarrays. Expression was compared between mock inoculated and virus infected plants 0.5 and 12 hours after inoculation.