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Poster: Molecular & Cellular Plant-Microbe Interactions: Plant Defense Responses


Use of synchrotron Fourier transform spectroscopy to shed light on the chemical composition of cell wall appositions papillae on winter wheat leaf
R. LAHLALI (1), T. Song (2), C. Karunakaran (1), G. Peng (2), Y. Wei (3) (1) Canadian Light Source Inc., Canada; (2) Agriculture and Agri-Food Canada, Canada; (3) Department of Biology, University of Saskatchewan, Canada

Papillae formation is known as one of the most important plant immunity mechanisms. Its major function is to prevent the entry of fungal pathogens into the host plant cells. In this study, a synchrotron based Fourier transform spectroscopy (sFTIR) was used to elucidate the chemical composition of the cell wall of forming papillae and non-forming papillae in response to powdery mildew infection. Spectroscopic results indicated an increase in peaks intensity of asymmetric and symmetric stretching vibrations of CH3 and CH2 that correspond to fatty acid groups, phenolics groups, lignification, cellulose, hemicellulose, and glucans following pathogenic infection. Principal Component Analysis (PCA) applied to sFTIR spectra confirmed these findings and distinguished two different groups with significant differences in cell wall composition including lignin, phenolics, polysaccharides and carbohydrates. This study highlighted, for the first time, the potential application of synchrotron-based infrared technique to study the in situ composition of lignified papillae and plant cell in the plant disease resistance, which remained to be a challenge with biochemical approaches. Subsequently, further studies with more cultivars, as well as other synchrotron imaging techniques will be undertaken to confirm these preliminary findings and explore other defense response mechanisms.