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Submitted to: American Phytopathological Society Abstracts
Publication Type: Proceedings Publication Acceptance Date: 8/23/2000 Publication Date: 8/2/2000 Citation: Hartung, J.S. Functional genomics analysis of xylella fastidiosa and xanthomonas axonopodis pv. citri. American Phytopathological Society Abstracts. Interpretive Summary: Technical Abstract: The Virtual Genomics Institute of Sao Paulo Brazil has completed the genomic sequencing of Xylella fastidiosa that causes Citrus Variegated Chlorosis disease, and the genomic sequence of X. axonopodis pv citri is nearly finished. Because X. fastidiosa multiplies only in xylem tissues, which are dead, the Hrp/avr system already established in Xanthomonas is unlikely to be relevant. Instead, the match between the nutritional content of the xylem fluids and the anabolic pathways present in strains of Xylella may be a large part of disease development. The ability of Xylella to move downward in the xylem vessels is also critical for disease development. These aspects can be investigated using micro arrays of Xylella genes. As many as 50% of the open reading frames in X. fastidiosa have no good matches in GenBank, so much can be discovered with this sequence data. The basis for host selection and pathogenicity is well established for X. axonopodis pv. citri based on genetic analysis of Hrp and avr genes. With genomic sequence data, qualitative and quantitative analysis of global gene expression by micro arrays will complement existing knowledge. Research in these areas may lead to control measures for citrus bacterial canker disease in Florida and worldwide, citrus variegated chlorosis disease in Brazil, and Pierce's Disease of grapevines in California. Because of the importance of these diseases, this research is of critical importance to both the citrus and wine grape industries. |
