Identification of Resistance-related Defense Responses in Soybean against Aphis glycines

Gene expression profiles in resistant (cv. Dowling) and susceptible (Williams 82) soybean genotypes [Glycine max (L.) Merrill] were compared at 6 and 12 h with and without aphid (Aphis glycines Matsumura) infestation using cDNA microarrays consisting of approximately 18,000 soybean-expressed sequence tags. More genes were induced in Dowling than Williams 82 at 6 h after infestation. Genes that were differentially expressed between aphid and control treatments were selected as aphid-response genes. Eighty-four genes showed specific responses in Dowling and included genes related to defense and other processes. Expression of three defense-related genes was examined at 6, 12, 24, 48, and 72 h after infestation in both genotypes by quantitative real-time PCR. The increases in the transcripts of three defense-related genes were earlier and stronger at 6, 12 and 24 h after infestation in Dowling compared to Williams 82. The differential gene expression between the two genotypes without aphids was determined, and five genes with constitutively higher expression levels were found in Dowling. Keywords = genomic Keywords = Defense Responses Keywords = plant Keywords = DNA-binding protein Keywords = PR proteins Keywords = plant resistance Keywords = signal transduction keywords = insect Keywords: susceptible vs resistant loop design (6 hpi and 12 hpi) and Dye swap (0 hpi). 6 biological samples, 2 microarray slide sets and 2 biological repeats