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:The potato is susceptible to water stress at all stages of development. We examined four clones of tetraploid potato, Cardinal, Desirée, Clone 37 FB and Mije, from the germplasm bank of the National Institute of Agricultural Research (INIA) in Chile. Water stress was applied by suspending irrigation at the beginning of tuberization. Stomatal conductance, tuber and plant fresh and dry weight was used to categorize water stress tolerance. Cardinal had high susceptibility to water stress. Desirée was less suscepetible than Cardinal and had some characteristics of tolerance. Mije had moderate and Clon 37 FB high tolerance. Differential gene expression in leaves from plants with and without water stress were examined using transcriptome sequencing. Water stress susceptible Cardinal had the fewest differentially expressed genes at 101, compared to Desirée at 1867, Clon 37 FB at 1179 and Mije at 1010. Water stress tolerance was associated with up-regulation of expression of transcription factor genes and genes involved in osmolyte and polyamine biosynthesis. Increased expression of genes encoding late embryogenesis abundant (LEA) and dehydrin proteins along with decreased expression of genes involved in nitrate assimilation and amino acid metabolism were found for clones showing water stress tolerance. The results also show that water deficit was associated with reduced biotic stress responses. Additionally, heat shock protein genes were differentially expressed in all clones except for highly susceptible Cardinal. Together the gene expression study demonstrates variation in the molecular pathways and biological processes in response to water stress contributing to tolerance and susceptibility.
Project description:The intent was to study, from transcriptome analysis, shade and drought responses in Solanum tuberosum (potato). We performed Illumina 50 bp single-end RNA-seq in tissues of control and treated var. Spunta wild-type plants. Drought experiments also included two independent AtBBX21-overexpressing (BBX21-OE) potato lines.
Project description:Potato virus YNTN (PVYNTN) is one of the most devastating potato virus causing great losses in the potato production industry. PVYNTN induces severe symptoms on inoculated leaves and a disease known as potato tuber necrosis ringspot disease (PTNRD) develops on tubers. Closely related PVYN isolate induces only mild symptoms on inoculated potato leaves and no symptoms on tubers. The early response of sensitive potato cvs. Igor and Nadine to inoculation with PVYNTN and PVYN was analysed allowing identification of genes involved in severe symptoms induction. Microarray and quantitative-PCR analysis was carried out to identify differentially expressed genes after inoculation with both virus isolates. Two distinct groups of genes were shown to have a role in severe symptoms development – one group of genes related to energy production and a second group of genes connected with virus spread. Earlier accumulation of sugars and decrease in photosynthesis was observed in leaves inoculated with aggressive PVYNTN isolate than in leaves inoculated with milder PVYN isolate. PVYNTN isolate was shown not to activate differential expression of antioxidant metabolism and pectinmethylesterase inhibitor (PMEI) leading to a delay in plant response and on the other hand it limited callose deposition enabling faster virus spread through the plant.