The use of Xspecies microarray to study changes in gene expression in phytoplasma-infected Catharanthus roseus
M. G. TUFFEN (1)
(1) University of Nottingham, Loughborough, UNITED KINGDOM
Phytopathology 100:S127

Phytoplasmas are specialised plant pathogenic bacteria that are responsible for several economically important diseases of crops. They are spread by sap sucking insects such as leafhoppers and within the plant are limited to the phloem; they can not be cultured in vitro. Catharanthus roseus, or Madagascar periwinkle, is used an experimental host for phytoplasmas as it is susceptible to many phytoplasma strains and gives a good range of representative symptoms. The Xspecies microarray technique allows a microarray to be used on a species it was not designed for. In this study, gene expression was compared between healthy and sweet potato little leaf phytoplasma infected Catharanthus roseus, which shows symptoms of dramatically reduced leaf size, chlorosis and increased branching. Sixty-six differentially regulated genes were identified, including up regulation of auxin related genes and a decrease in the expression of photosynthesis related genes. A number of these identified genes have subsequently been isolated from C. roseus and quantitative PCR has been used to confirm the expression results.