ContactOffice Location Life Sciences Building, 329D
Phone Number (416)736-2100 x 33890 (Voicemail)
Plants are often considered nature’s best chemists. As sedentary organisms, plants cope with pathogens and environmental stresses by synthesizing a vast variety of bioactive metabolites. Phytoalexins are wide variety of defense metabolites that are synthesized by plants specifically in response to pathogens or particular environmental stresses. Phytoalexins are generally toxic to microbial pathogens and frequently have medicinal activities in mammalian cells. For example, glyceollins are the isoflavonoid phytoalexins from soybean that have broad-spectrum anticancer and neuroprotective activities. The problem is that phytoalexins such as glyceollins can be uneconomical to synthesize using chemistry methods and are only produced transiently and in low amounts in stressed plants. The goal of our research is to understand how plant cells become reprogrammed to express all of the genes that synthesize phytoalexin molecules. Our research involves a combination of biochemistry, molecular biology, genetic engineering, and systems biology to understand the gene networks that regulate the synthesis of phytoalexins.
Two current research areas: 1) Understanding how the same two transcription factors (TFs) regulate distinct phytoalexin biosynthetic pathways in different plant species. We have recently published the first conserved TF that regulates diverse phytoalexin synthesis pathways. Until our discovery, it was thought that phytoalexin TFs are as diverse as the biosynthetic pathways that they regulate. However, we discovered that the TF that activates the expression of indole alkaloid synthesis genes in Arabidopsis also activates glyceollin synthesis genes in soybean. This was unexpected since these phytoalexin biosynthetic pathways are very different, with indole alkaloids and glyceollins being synthesized from tyrosine and phenylalanine, respectively. We have recently submitted another report identifying a second TF that regulates the biosynthesis of glyceollins and stilbene phytoalexins in soybean and grapevine, respectively. These findings are pointing towards the possible existence of a conserved TF complex that regulates diverse phytoalexin biosynthetic pathways. 2) Searching for the missing TFs of the glyceollin gene regulatory network. The two TFs that we have recently identified are essential for activating glyceollin biosynthesis, but they are insufficient to activate the entire glyceollin biosynthetic pathway on their own. Thus, we are searching for the missing TF(s) that are required to activate the entire glyceollin biosynthetic pathway.
Systems Biology, Genetics, Biochemistry, Plant Biotechnology