Project description:Three grapevines cultivars (Merlot, Cabernet-Sauvignon and Ugni Blanc) were infected by E. lata. The expression profiles of the wood part near the infection point were determined for both infected and non infected plant for each cultivars with Nimblegen microarrays vitis. Three plants were used for biological replicates. Comparisons between infected and non infected conditions allow, for each cultivars, the identifcation of genes which the expression is modified by E. lata.
Project description:Study of gene expression during Plasmopara viticola infection in the resistant Vitis vinifera cultivar 'Regent'. The oomycete fungus Plasmopara viticola (Berk. et Curt.) Berl. et de Toni is responsible for grapevine downy mildew disease. Most of the cultivated grapevines are sensitive to this pathogen, thus requiring intensive fungicide treatments. The molecular basis of resistance to this pathogen is poorly understood. We have carried out a cDNA microarray transcriptome analysis to identify grapevine genes associated with resistance traits. Early transcriptional changes associated with downy mildew infection in the resistant Vitis vinifera cultivar ‘Regent’, when compared to the susceptible cultivar ‘Trincadeira’, were analyzed. Transcript levels were measured at three time-points: 0, 6 and 12 hours post inoculation (hpi). Our data indicate that resistance in V. vinifera ‘Regent’ is induced after infection. This study provides the identification of several candidate genes that may be related to ‘Regent’ defense mechanisms, allowing a better understanding of this cultivar's resistance traits.
Project description:WRKY genes are transcription factors involved in plant response to pathogen attacks in many plant species. These proteins have been shown to activate expression of defence genes in a salicylic acid- and/or jasmonic acid-dependent signalling pathway. To understand the molecular mechanisms involved in grapevine defence, we previously identified a WRKY gene, VvWRKY1, which was able to enhance tolerance to fungal pathogens when overexpressed in tobacco. To elucidate its role in grapevine, we generated transgenic grapevines that overexpress VvWRKY1. Microarray analyses were performed to compare global gene expression in leaves of the transgenic and wild-type lines. Results showed that expression of genes encoding defence-related proteins was enhanced in the transgenic 35S::VvWRKY1 line. Quantitative RT-PCR analysis confirmed that three genes putatively involved in jasmonic acid signalling pathway, two genes encoding JASMONATE ZIM-domain (JAZ) proteins and one lipoxygenase, are over-expressed. The ability of VvWRKY1 to trans-activate their corresponding promoters was confirmed by transient expression assay in grape protoplasts. After challenging with the downy mildew pathogen Plasmopara viticola, resistance was enhanced in the transgenic line compared to the wild-type line. These results suggest that VvWRKY1 transcription factor is able to control plant disease resistance to one of the main grapevine pathogen by activating jasmonic acid signalling pathway in grapevine.
Project description:Nebbiolo genome assembly allows surveying the occurrence and functional implications of genomic structural variations in grapevines (Vitis vinifera L.)
Project description:To elucidate the effect of heat stress and the following recovery on grapevines and identify some regulated genes representing the classical heat stress response and thermotolerance mechanisms, transcript abundance of grapevine (Vitis vinifera L.) were quantified using the Affymetrix Grape Genome oligonucleotide microarray (15,700 transcripts), followed by quantitive Real-Time PCR validation for some transcript profiles. The treatment: heat stress(5h) and the following recovery (18.5h), sampling were conducted at two time respectively. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Lijun Wang. The equivalent experiment is VV40 at PLEXdb.]
Project description:Dormant grapevine buds from 4 genotypes were collected over a variable time series after being exposed to growth room temperatures. Buds were collected from the field during winter and assessed for the loss of cold hardiness (deacclimation) in tandem with analysis of gene expression changes. DEGs are examined for various enriched pathways. Wild grapevines deacclimate faster than cultivated grapevines and the entire gene regulation cascade was also faster in wild grapevines. No keystone genes were identified that could explaint he faster phenotype, suggesting all the regulatory pathways are tuned faster in wild grapes.