High-throughput time series expression profiling of Plasmopara halstedii infecting Helianthus annuus reveals conserved promoter sequence motifs in co-expressed gene

Downy mildew disease of sunflower, caused by the obligate biotrophic oomycete Plasmopara halstedii, can have significant economic impact on sunflower cultivation. With the aim of identifying motifs that might be involved in transcriptional regulation of co-expressed genes, time-series derived gene expression profiles were clustered based on their time-course, and their upstream regulatory gene sequences were analyzed here. Several conserved motifs were found in promoters of co-expressed genes, which might be involved in binding specific transcription factors. Such motifs were also found in virulence related genes, but future studies on a genetically tractable model are needed to clarify, if these promoter regions are involved in regulating different stages of pathogenesis.