Differential gene expression in Ginny cattleya orchids due to infection with the odontoglossum ringspot virus : the culmination of a year's work : an honors thesis (HONRS 499)

The BSU Wheeler Orchid collection is a reservoir of rare species and one of the most varied species collections in the world. As a species bank, it acts as a clearinghouse for information and provides plant tissue for orchid collections worldwide. It is important to maintain such an important collection in healthy conditions, however plants are subjected to pathogens resulting from crowding and introduction of new plants that may carry disease. A better understanding of orchid-pathogen relationships is necessary to ensure survival of these endangered species. Thus, understanding orchid-virus interactions at the molecular level may perhaps lead to new strategies for the introduction of specific regulatory genes whose expression may provide preventive protection. In prior research, an orchid was infected with the Odontoglossum Ringspot Virus (ORSV) in hopes of inducing a plant defense response known to prevent viral spread. Molecular subtraction was performed on mRNAs isolated before and after infection to obtain specific rare mRNAs expressed in response to ORSV challenge. The rare mRNA fragments were reverse transcribed and cloned into a vector molecule. The clones were then amplified by PCR, and transformed into Escherichia coli from which a differentially expressed cDNA library was formed. DNA miniprep isolations were done to ascertain the diversity and the size of the cloned fragments. Some clones from this library have been sequenced and have yielded homology to certain universal viral genes found in plants. In the near future, the timing and expression of these virally activated genes resulting from pathogenic attack wilt be pinpointed via Northern analysis of induced mRNA obtained from the same orchid plant.Honors CollegeThesis (B.?.