Agronomical & Environmental Genomes

Abstract

The complete sequencing of the Pierce's Disease (PD) strain of X. fastidiosa will eventually show all the differences between its genome and the genome of the Citrus Variegated Chlorosis (CVC) strain. Nevertheless, having in advance some information about what and where are these differences in the bacterial chromosome can help in the sequencing strategy and in the assembling of the reads. We propose to apply Suppression Subtractive Hybridization (SSH) to compare the genomes of CVC and PD strains of X. fastidiosa. Also, we propose to apply SSH to identify Citrus sinensis genes that are induced during Systemic Acquired Resistance (SAR). Salicylic acid and/or analogue molecules will be applied to citrus leaves and cDNAs frorn these will be subtracted by SSH using cDNAs from non-induced control leaves. Besides the genes that encode pathogenesis-related proteins (PR-proteins), that are usually associated with SAR, we expect to find genes involved in the signal transduction pathway and others that may be involved in disease resistance mechanisms such as cell wall reinforcement, synthesis of inhibitory low molecular weight compounds, and lytic enzymes. (AU)