Comparative analysis of ESTs involved in grape responses to Xylella fastidiosa infection

Twelve tissue specific subtractive suppression hybridization (SSH) cDNA libraries derived from a time course sampling scheme were constructed from stems, leaves and shoots of PD resistant and susceptible sibling genotypes (V. rupestris × V. arizonica) in response to Xf infection. A total of 5,794 sequences were obtained from these cDNA libraries from which 993 contigs and 949 singletons were derived. Using Gene Ontology (GO) hierarchy, the non-redundant sequences were classified into the three principal categories: molecular function (30%), cellular components (9%) and biological processes (7%). Comparative analysis found variations in EST expression pattern between infected and non-infected PD resistant and PD susceptible grape genotypes. Among the three tissues, libraries from stem tissues showed significant differences in transcript quality suggesting their important role in grape-Xylella interaction.This study constitutes the first attempt to characterize the Vitis differential transcriptome associated with host-pathogen interactions from different explants and genotypes. All the generated ESTs have been submitted to GenBank and are also available through our website for further functional studies.Pierce's disease (PD) has been a chronic problem for California's grape industry since the 1880s. The threat from this disease has recently become more severe with the introduction and establishment of a more effective vector, the glassy-winged sharpshooter (Homalodisca coagulate). The disease is caused by Xylella fastidiosa, a xylem-limited, gram negative bacterium that is hosted by a wide range of plant species in and around vineyards in the southern United States and Mexico [1]. Over the past few years, federal, state governments, and the grape industry have funded PD research. Much of this research has focused on means of controlling the vector with insecticides and natural predators as a critical first step in integrated crop management. However, even low populati