Submitted to: Cellular and Molecular Biology of Soybean Biennial Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/20/2004
Publication Date: 12/21/2004
Citation: Li, Y., Zou, J., Li, M., Hartman, G.L., Clough, S.J. 2004. Microarray Analysis of Differential Gene Expression Between Resistance and Susceptible Soybean Cultivars in Response to Aphis Glycines [abstract]. Cellular and Molecular Biology of Soybean Biennial Conference. p.121.
Technical Abstract: Soybean aphid, Aphis glycines Matsumura (Homoptera: Aphididae), is a relatively new pest to soybean [Glycine max (L.) Merrill] Sources of aphid resistance were discovered in seven soybean accessions, but the molecular basis of the resistance is unknown. The objective of this study was to identify genes induced or repressed in response to aphid feeding and to identify candidate genes associated with aphid resistance in soybean. The gene expression profiling in resistant and susceptible soybean was compared using cDNA microarrays representing over 18,000 soybean expressed sequence tags. Aphid-induced responses were studied at 6 and 12 hours after aphid application (hai) by microarray and then at five times points by real-time quantitative PCR of a handful of genes. Based on an ANOVA statistical test and fold-change thresholds, differentially expressed genes between resistant and susceptible cultivars were selected. Significantly differentially expressed genes were further classified into functional categories. Expression pattern of three selected defense-related genes was examined at 6, 12, 24, 48, and 72 hai in resistant and susceptible soybean cultivars by qRT-PCR. The results suggested that the timing of the defense induction in resistant soybean was earlier and the resistant soybean had stronger responses than susceptible soybean before 48 hai, which coincides with the observed aphid behavior on resistant and susceptible soybean. The constitutive difference between the resistant and susceptible soybean was compared in a repeated dye-swap microarray experiment using the leaf RNA without any treatment. Candidate genes associated with aphid resistance were proposed.