ABSTRACT
Numerous scientists have examined the interaction of soybean with SCN at the molecular level with special emphasis on gene expression. Earlier studies examined one or a few soybean genes (Hermsmeier 1998; Vaghchhipawala et al. 2001; Bird and Kaloshian 2003; Alkharouf et al. 2004; Williamson and Gleason 2004). A rst attempt to broaden the spectrum of genes analyzed during interactions of soybean with SCN was made by Khan et al. (2004) using noncommercial microarrays made from approximately 1300 cDNAs printed on glass microscope slides. e expression of soybean genes expressed in compatible roots of cv. Kent was studied 2 days aer infection (dai). Although these data were limited by the number of cDNAs printed on the array, many of the genes identied in this chapter as having increased expression were conrmed in later studies when larger-scale commercial microarrays became available. Genes encoding extensin, peroxidase, aspartic protease, fructose-1,6bisphosphate aldolase, basic chitinase, β-1,3-endoglucanase, and sucrose synthase were found to be upregulated. A second,
larger noncommercial microarray of 6000 printed cDNA inserts was used to measure transcript abundance in roots of soybean infected with SCN over a time course of 6 and 12 h aer infection (hai) and 1,2,4,6, and 8 dai (Alkharouf et al. 2006). A broader range of up-and downregulated genes was identied, including the genes identied by Khan et al. (2004) and genes encoding enzymes in the glycolysis pathway, the phenylpropanoid metabolism, PR genes, cell wall enzymes, and others.
