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Poster: Molecular & Cellular Plant-Microbe Interactions: Biochemistry & Cell Biology


Investigation on the role of molecular composition and lignification of canola plant cell wall in resistance mechanisms associated with CR gene Rcr1
R. LAHLALI (1), T. Song (2), M. Chu (2), F. Yu (3), L. McGregor (2), B. Gossen (2), S. Kumar (2), C. Karunakaran (1), G. Peng (2) (1) Canadian Light Source Inc., Canada; (2) Agriculture and Agri-Food Canada, Canada; (3) Agriculture and Agri-Food Canada, C

Clubroot disease, caused by Plasmodiophora brassicae Woronin, is a serious soil-borne disease of crucifer crops worldwide. It poses a serious threat to canola production in western Canada. Rcr1 is a new clubroot resistance gene identified in Brassica rapa. A multifaceted approach was employed to understand the molecular changes in canola plant cell wall associated with Rcr1-mediated clubroot resistance and the expression of defense-related genes involved in the lignin pathway. Fourier Transform mid Infrared (FTIR) spectral analysis showed that non-inoculated canola roots from both resistant (R) and susceptible (S) populations were grouped together and distinctly separated from those inoculated with P. brassicae. R and S plants responded differentially to the infection; it appeared that the cell-wall components of roots were changed for plants carrying Rcr1, including lipids, proteins, lignin, aromatic and phenolics ring, polysaccharides, and carbohydrates. qPCR identified the upregulation of nine defense-related genes involved in the lignin pathway, as well as in chitinase and xyloglucan endo-transglycosylate activities in roots carrying Rcr1 relative to those of non-inoculated, but the level of increase was more pronounced with plants carrying Rcr1. The changes cell-wall components may reflect differential regulation of genes involved in host defense responses, in particular, the lignin pathways and chitinase synthesis mediated by Rcr1 during clubroot resistance.