Vitis (41528 population) - Age: 13 month. Dev.stage (Boyes et al. Plant Cell 2001): green cuttings with 10 developed leaves.
Name:i - pathogen - pathogen infection,p. viticola inoculation:time 6hour . The sixth leaves from the top of plants were used. One leaf disc (14 mm diameter) was punched from each of the 18 plants and inoculated with a suspension of P. viticola sporangia (10000 sporangia per ml) by contact of the abaxial leaf surface in one petri dish. Six hours later, discs were collected and frozen. 10 000 sporangia per ml
leaf - Plants were grown in the greenhouse in potting soil (compost) during three months (March, April, May)
Grapevine downy mildew caused by the Oomycete Plasmopara viticola is one of the most important diseases affecting Vitis spp. However, all cultivated European grapevine varieties are susceptible to P. viticola and the resistance needs to be introduced from other Vitaceae. Segregating populations derived from Muscadinia rotundifolia, a species closely related to Vitis, lead to the identification and mapping of two resistance genes, named Rpv1 and Rpv2. The macroscopic phenotypes of the resistance mediated by the two loci are different. Rpv2 plants completely inhibit P. viticola sporulation and produce very small necrotic lesions. In contrast, Rpv1 plants allow a rather limited but visible sporulation of P. viticola. The aim of the study is to understand the gene expression changes associated with downy mildew resistance mediated by these two loci. Gene expression patterns after P. viticola inoculation or mock inoculation are compared in incompatible (resistant plants bearing Rpv1 or Rpv2 locus) and compatible (susceptible plants with no resistance loci) interactions, using the Vitis vinifera GeneChip from Affymetrix.
The data were normalized with the gcrma algorithm (Irizarry et al., 2003), available in the Bioconductor package (Gentleman and Carey, 2002).