Poster: Emerging Technologies

Abs # 892: Chipping away at plant viral vector transfection systems

Presenter:	Busto, Jennifer L., jbusto@hawaii.edu
Authors	Busto, Jennifer L. (A)   Kumagai, Monto H. (A)
Affiliations:	(A): University of Hawaii at Manoa

RNA viral vectors have been used to study the effects of gene overexpression or gene silencing in plant systems. Further understanding of perturbation of metabolic pathways and gene knock-out can be acquired by combining these tools with microarray technology. Through differential hybridization, cDNA microarrays enable analysis of expression levels of large numbers of genes, providing insight into the manner in which genes are coordinately regulated. In this study, carotenoid biosynthesis enzymes were overexpressed in solanaceous plants using tobacco mosaic virus (TMV) vector transfection systems, resulting in highly visual phenotypes in plants. Changes in the expression patterns of over 10,000 genes were simultaneously examined by cDNA microarray analysis after transfection with recombinant TMV viral vectors, using 10K potato clone microarrays developed at The Institute for Genomic Research (TIGR). Signal intensity data were obtained using Affymetrix Scanner 418, and expression ratio data were analyzed using GeneSpring (Silicon Genetics). Preliminary results revealed a 2-fold change or greater in approximately 700 genes; of these, 124 show a p-value of < 0.05. Compared to the wild-type, virally transfected plants show evidence of an upregulation of genes involved in pathogen defense, such as heat shock, and further experiments are being conducted to subtract out the effects of the virus. This study shows that a heterologous cDNA microarray system can be utilized to successfully obtain information regarding changes in global gene expression in virally-transfected plants.