Cell wall components of Leptosphaeria maculans enhance the resistance of Brassica napus

Kim P. D., Sašek V., Burketová L., Copíková J., Synytsya A., Jindřichová B., Valentova O.

Keywords: Leptosphaeria maculans, Brassica napus, resistance
Abstract: Preparations with elicitation activity were obtained from the mycelium of Leptosphaeria maculans, fungal pathogen of oil seed rape (Brassica napus). Crude delipidated and deproteinized extract from fungal cell walls induced expression of pathogenesis related gene 1 (PR1), hydrogen peroxide accumulation and enhanced resistance of B. napus plants toward the infection by L. maculans. Elicitation activity significantly decreased after treatment of a crude extract with α- or β-glucanase. Monosaccharide composition analysis of a crude extract purified by ion-exchange chromatography revealed glucose (~58 mol %), mannose (~22 mol %) and galactose (~18 mol %) as the major sugars. FT-IR and NMR spectra confirmed the presence of both carbohydrate and polypeptide components in the purified product. Correlation NMR experiments defined trisaccharide bound to O-3 of serine residue α-D-Glcp-(1→2)-β-D-Galf-(1→6)-α-D-Manp-(1→3)-L-Ser. Terminal α-D-Glcp and (1→6)-β-D-glucan were also detected. Obtained results strongly support our conclusion that these carbohydrates induce defense response in B.napus plants.
IEB authors: Lenka Burketová, Barbora Jindřichová