Figure 1.
Figure 1.

Experimental design. Panel A. Hybridizations of slides followed a “loop design”. Panel B. Control noninoculated samples were directly compared including a dye swap. In each diagram, the balls correspond to samples and each arrow corresponds to one slide. Samples in the arrowheads were labeled with Cy5 and samples in arrow tails were labeled with Cy3.

 


Figure 2.
Figure 2.

Differential response observed in soybean plants to S. sclerotiorum infection. Williams 82 (S) is a fully susceptible genotype and PI 194639 (R) shows partial resistance. Fifteen-day-old plantlets were inoculated with growing mycelia on cut stems. The infection progression was faster in S compared to R; arrows point to the infection front. Red coloration is observable at the infection front of R. DPI = days post inoculation.

 


Figure 3.
Figure 3.

Functional classification of differentially expressed genes. Genes with FDR corrected p-value <0.05 were classified into functional categories using sequence homology to entries in public databases. Panel A. Genes with statistically significant change in abundance in the comparison between time points on soybean plants inoculated with S. sclerotiorum. Panel B. Genes with statistically significant difference in abundance between genotypes.

 


Figure 4.
Figure 4.

Phenylpropanoid pathway. Changes in abundance at 14 hpi as compared to 8 hpi of genes coding for enzymes in the phenylpropanoid pathway in soybean challenged with S. sclerotiorum. Squares represent individual cDNAs. Red color represents increased expression levels in 14 vs. 8 hpi, green decreased, and grey no change.

 


Figure 5.
Figure 5.

Quantitative real-time RT-PCR confirmation. QRT-PCR was used to confirm the accuracy of the microarray analysis. Panel A. Six genes showing increased abundance at 14 vs. 8 hour after inoculation with S. sclerotiorum in both genotypes: Williams 82 (S) and PI 194639 (R). Panel B. Seven genes with increased or reduced abundance in R vs. S at 8 and 14 hpi.