Gene expression profiles of Washington navel oranges (Citrus sinensis (L) Osbeck) graft innoculated with Candidatus Liberibacter asiaticus, Spiroplasma citri, or two citrus tristeza isolates

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. Greenhouse grown Washington navels (C. sinensis (L) Osbeck) were grafted innoculated with Candidatus Liberibacter asiaticus, Spiroplasma citri, or one of two isolates of of citrus tristeza virus: one mild (T30 isolate 07539) and one that causes stem-pitting in susceptible plants (CCTEA-107). Addition trees were graft innoculated with CLas and either of the CTV isolates. Control plants were mock innoculted by recieving grafts of tissue from healthy source plants. Leaf samples were collected 2, 4, and 8 months for RNA extraction and gene expression analysis.