Project description:Pathogens can trigger a broad array of changes in gene expression in plants. In this study we report the changes in gene expression patterns that occurred when greenhouse grown Washington Navel oranges (C. sinensis) was graft innoculated with citrus pathogens. Candidatus Liberibacter asiaticus, Spiroplasma citri, and two isolates of citrus tristeza virus were studied.
Project description:In previous studies (A. Marais, J. M. Bove, and J. Renaudin, J. Bacteriol. 178:862-870, 1996), we have shown that the recA gene of Spiroplasma citri R8A2 was restricted to the first 390 nucleotides of the N-terminal part. PCR amplification and sequencing studies of five additional strains of S. citri have revealed that these strains had the same organization at the recA region as the R8A2 strain. In contrast to S. citri, Spiroplasma melliferum was found to contain a full-length recA gene. However, in all five S. melliferum strains tested, a TAA stop codon was found within the N-terminal region of the recA reading frame. Our results suggest that S. melliferum, as well as S. citri, is RecA deficient. In agreement with the recA mutant genotype of S. citri and S. melliferum, we have shown that these organisms are highly sensitive to UV irradiation.
