Dr. Mark Belmont, University of Manitoba
This seminar will provide insights into the utility of next generation, RNAi-based molecular fungicides and their applicability to control crop pathogens. Sclerotina sclerotiorum, the causal agent of white mold, infects over 450 species of plants worldwide. This fungal phytopathogen has become a major threat to crops including canola which contributes $27 billion to the Canadian economy. Sclerotinia is a persistent problem for canola growers that has traditionally been managed using broad-spectrum fungicides. However, current fungicide strategies have proven to be ineffective. Thus, there is an immediate need to manage Sclerotinia using novel species-specific control methods. Our strategy exploits the inherent cellular defense process known as RNA interference (RNAi). Upon encountering a double stranded RNA (dsRNA) molecule, the cell processes the dsRNA specifically targeting transcripts with sequence homology. Sclerotinia-specific target genes were identified using bioinformatics. RNAi knockdown was confirmed using qRT-PCR on RNA isolated from fungal cultures. Transgenic plants over-expressing the dsRNA showed a profound and prolonged tolerance to Sclerotinia.
Dr. Adam Mott, Dept Biology, Univ Toronto, Scarborough Campus
To thrive, plants must be able to quickly recognize and respond to changing environmental conditions and pathogen attack. The perception of many signals is accomplished through the collective action of members of the leucine-rich repeat receptor kinase (LRR-RK) family, of which there are 225 in Arabidopsis. Upon detection of an extracellular signal, these receptors physically interact to form signaling-competent structures able to integrate complex signals to guide plant defence and growth. Using a high-throughput interaction screen we determined the physical interactions between 200 of the LRR-RLKs from Arabidopsis. Using network analysis and community detection we have detected distinct, but interconnected, subnetworks that show evidence of specialized biological activity and demonstrated novel function for several previous unstudied receptors. In addition, we show that the overall network structure is critical for proper signaling responses, and disruptions can have unexpected consequences at a distance.