APS Abstracts of Presentations

Gene expression in Catharanthus roseus infected with vinca virescence. E. TUMBAN (1), R. Richins (2), and M. Shaw (1). (1) Natural Sciences, NMHU, Las Vegas, NM; (2) NMSU, Las Cruces, NM. Phytopathology 93:S84. Publication no. P-2003-0618-AMA.

Phytoplasmas are wall-less prokaryotes which cause hundreds of plant diseases such as maize bushy stunt, cabbage witches' broom, onion yellows, etc. Vinca virescence is a phytoplasma that causes symptoms of virescence, phyllody and witches' broom. The mechanism(s) by which these symptoms are caused is still unknown, although it has been postulated that they may be due to physiological disturbances such as hormonal imbalance. If hormone imbalances are involved, some genes of the plant may have a role to play at an early stage of protein synthesis. My interest is to investigate which plant genes are involved. RNA isolated from infected C. roseus was transcribed to cDNA and cloned in E. coli. The cDNA was probed with radioactive probes synthesized from mRNA of both infected and healthy plants. Plaques which were expressed differentially were selected and their cDNAs have been sequenced. Preliminary results from BLAST search have identified cDNA clones with homology to enzymes from different plants. Some enzymes of interest cysteine protease, Dna J and CYP77 are currently being analyzed to find out what role they may be playing in the disease symptoms.