To obtain greater insight into the molecular events underlying plant disease susceptibility, we studied transcriptome changes induced by a host-selective toxin of Pyrenophora tritici-repentis, Ptr ToxA (ToxA), on its host plant, wheat. Transcriptional profiling of ToxA-treated leaves of a ToxA-sensitive wheat cultivar was performed using the GeneChip® Wheat Genome Array. An improved and up-to-date annotation of the wheat microarray was generated and a new tool for array data analysis (BRAT) was developed, and both are available for public use via a web-based interface. Our data indicate that massive transcriptional reprogramming occurs due to ToxA treatment, including cellular responses typically associated with defense. In addition, this study supports previous results indicating that ToxA-induced cell death is triggered by impairment of the photosynthetic machinery and accumulation of reactive oxygen species. Based on results of this study, we propose that ToxA acts as both an elicitor and a virulence factor.
Bibliographical noteFunding Information:
This project is supported by a grant to L.M.C. from the National Research Initiative (NRI) Microbial Biology: Microbial Associations with Plants Program of the USDA Cooperative State Research, Education and Extension Service (CSREES, grant number 2006–55600–16619 ). Funding for M.F.B. was provided by the National Science Foundation under a grant awarded in 2007. This work was partially supported by the Oregon State University Computational and Genome Biology Initiative and startup funds to T.C.M.
- Defense responses
- Fungal pathogenesis
- Gene expression
- Host-selective toxin
- Plant-microbe interactions
- Transcriptome analysis