W742 Transcriptome Response to Cantharidin and the Herbicide Endothall in Arabidopsis

Date: Tuesday, January 17, 2012
Time: 12:00 PM
Room: Pacific Salon 4-5 (2nd Floor)
Zhiqiang Pan , USDA-ARS-NPURU, University, MS
Cantharidin, a type of terpenoid found in many species of blister beetle, is a potent and selective inhibitor of serine/threonine protein phosphatases (PPs). Protein phosphatases and kinases maintain a sensitive balance between phosphorylated and dephosphorylated forms of proteins, thereby playing important roles in signal transduction pathways and regulation of gene expression, cellular proliferation, cell differentiation, apoptosis, and other processes. To better understand at the genetic level the effect of cantharidin on the plant genome, we performed gene expression profiling using the model plant Arabidopsis thaliana. Our experiment showed that inhibition of PPs significantly reduces transcription of genes associated with auxin and light signaling and induces expression of genes involved in hypersensitive response, flagellin and abscisic acid signaling. Endothall, an older commercial herbicide possessing a chemical structure closely related to cantharidin, also exhibits a similar phytotoxicity by completely inhibiting PPs. Further investigation of the expression of selected genes within several pathways that are affected by cantharidin in A. thaliana revealed that the transcription of these genes was affected similarly by endothall, but in a more pronounced way. Therefore, the molecular target site of endothall in plants is likely similar to that of cantharidin in animals, namely, PPs responsible for regulating an array of biochemical processes.