Project description:Flavescence dorée is the most serious grapevine yellows disease in Europe. It is caused by phytoplasmas which are transmitted from grapevine to grapevine by the leafhopper Scaphoideus titanus. Differences in susceptibility among grapevine varieties suggest the existence of specific genetic features associated with resistance to the phytoplasma and/or possibly with its vector. In this work, RNA-Seq was used to compare early transcriptional changes occurring during the three-trophic interaction between the phytoplasma, its vector and the grapevine, represented by two different cultivars, one very susceptible to the disease and the other scarcely susceptible. Background: Flavescence dorée is the most serious grapevine yellows disease in Europe. It is caused by phytoplasmas which are transmitted from grapevine to grapevine by the leafhopper Scaphoideus titanus. Differences in susceptibility among grapevine varieties suggest the existence of specific genetic features associated with resistance to the phytoplasma and/or possibly with its vector. In this work, RNA-Seq was used to compare early transcriptional changes occurring during the three-trophic interaction between the phytoplasma, its vector and the grapevine, represented by two different cultivars, one very susceptible to the disease and the other scarcely susceptible. The comparison of the transcriptomic responses highlighted both passive and active defense mechanisms against the vector and/or the pathogen in the scarcely-susceptible variety, as well as the capacity of the phytoplasmas to repress the defense reaction against the insect in the susceptible variety.
Project description:The adhesion of flavescence dorée phytoplasma to the midgut epithelium cells of their insect vectors is partially mediated by the Variable Membrane Protein A (VmpA), an adhesin which shows lectin properties. In order to identify the insect receptor for VmpA, we lokked for Euscelidius variegatus cells proteins interacting with recombinant VmpA-His6 by mass spectrometry analysis of VmpA-E. variegatus protein complexes formed upon in vitro interaction assays.
Project description:Transcriptional profiling of Vitis vinifera cv. Chardonnay healthy vs. Phytoplasma-infected plants (Bois noir phytoplasma). Study was conducted on grapevine plants grown in the same vineyard (leaf midribs were sampled). Keywords: disease state analysis
Project description:Transcriptional profiling of Vitis vinifera cv. Chardonnay healthy vs. Phytoplasma-infected plants (Bois noir phytoplasma). Study was conducted on grapevine plants grown in the same vineyard (leaf midribs were sampled). Keywords: disease state analysis Two-condition experiment: healthy vs. infected plants/shoots. Biological replicates: 4 healthy, 4 infected. No replicates. Each sample was prepared as a pool of several samples (each sample was collected from a different shoots/plants) of the same disease status. Each sample was co-hybridized to a common reference cRNA (pool of all samples).
Project description:Several systemic diseases affect Vitis vinifera worldwide with important consequent management costs. Phytoplasma and viruses represent the most detrimental pathogens inducing symptoms and metabolic alterations that modify quantitatively the crop production. In the aim to investigate the plant/pathogen interactions, different grapevine samples, naturally affected (in mixed or single infections) by Stolbur phytoplasma (agent of Bois Noir disease) and viruses, in comparison to healthy and recovered controls, to identify the plant response to systemic pathogen infection. The preliminary results showed that expression levels of thousands of genes were altered in infected plants, involving various metabolic pathways.
Project description:Several systemic diseases affect Vitis vinifera worldwide with important consequent management costs. Phytoplasma and viruses represent the most detrimental pathogens inducing symptoms and metabolic alterations that modify quantitatively the crop production. In the aim to investigate the plant/pathogen interactions, different grapevine samples, naturally affected (in mixed or single infections) by Stolbur phytoplasma (agent of Bois Noir disease) and viruses, in comparison to healthy and recovered controls, to identify the plant response to systemic pathogen infection. The preliminary results showed that expression levels of thousands of genes were altered in infected plants, involving various metabolic pathways. Total RNA was extracted from central leaf midribs and petioles from different V. vinifera cultivars in different conditions (healthy, infected and recovered). Microarray analyses were conducted using different biological replicates for treatment. The submitter of this dataset can no longer locate the raw data
Project description:The phytoplasma-borne disease flavescence dorée is still a threat to European viticulture, despite mandatory control measures and prophylaxis against the leafhopper vector. Given the economic importance of grapevine, it is essential to find alternative strategies to contain the spread, in order to possibly reduce the current use of harmful insecticides. Further studies of the pathogen, the vector and the mechanisms of phytoplasma-host interactions could improve our understanding of the disease. In this work, RNA-Seq technology followed by three de novo assembly strategies was used to provide the first comprehensive transcriptomics landscape of flavescence dorée phytoplasma (FD) infecting field-grown Vitis vinifera leaves.With an average of 8300 FD-mapped reads per library, we assembled 347 sequences, corresponding to 215 annotated genes, and identified 10 previously unannotated genes, 15 polycistronic transcripts and three genes supposedly localized in the gaps of the FD92 draft genome. Furthermore, we improved the annotation of 44 genes with the addition of 5'/3' untranslated regions. Functional classification revealed that the most expressed genes were either related to translation and protein biosynthesis or hypothetical proteins with unknown function. Some of these hypothetical proteins were predicted to be secreted, so they could be bacterial effectors with a potential role in modulating the interaction with the host plant. Interestingly, qRT-PCR validation of the RNA-Seq expression values confirmed that a group II intron represented the FD genomic region with the highest expression during grapevine infection. This mobile element may contribute to the genomic plasticity that is necessary for the phytoplasma to increase its fitness and endorse host-adaptive strategies.The RNA-Seq technology was successfully applied for the first time to analyse the FD global transcriptome profile during grapevine infection. Our results provided new insights into the transcriptional organization and gene structure of FD. This may represent the starting point for the application of high-throughput sequencing technologies to study differential expression in FD and in other phytoplasmas with an unprecedented resolution.
Project description:Transcriptional changes in field-grown plants of Vitis Vinifera cultivars 'Chardonnay' and 'Incrocio Manzoni' naturally infected with Bois Noir phytoplasma, compared to healthy samples. SUBMITTER_CITATION: Albertazzi G., Caffagni A., Milc J.A., Francia E., Roncaglia E., Ferrari F., Tagliafico E., Stefani E., Pecchioni N. (2009) Gene expression in grapevine cultivars in response to Bois Noir phytoplasma infection. Plant Science 176: 792-804. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Nicola Pecchioni. The equivalent experiment is VV14 at PLEXdb.] Experiment Overall Design: genotype: Chardonnay - disease type: Bois Noir infected(3-replications); genotype: Chardonnay - disease type: Healthy(3-replications); genotype: Incrocio Manzoni - disease type: Bois Noir infected(2-replications); genotype: Incrocio Manzoni - disease type: Healthy(2-replications)