Downy mildew disease of sunflower, caused by the obligate biotrophic oomycete Plasmopara halstedii, can have significant economic impact on sunflower cultivation. Using high-throughput whole transcriptome sequencing, four developmental phases in 16 time-points of Pl. halstedii infecting Helianthus annuus, were investigated. 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.
