Defence response of Sitka spruce before and after inoculation with Heterobasidion annosum: 1H NMR fingerprinting of bark and sapwood metabolites

Abstract
Metabolites were extracted from the bark of Picea sitchensis clones differing in resistance and/or susceptibility to wounding and artificial inoculation with the white rot fungus Heterobasidion annosum. Metabolite fingerprinting was carried out by 1H NMR to determine whether metabolites would differ in resistant and/or susceptible clones, in the fungal as compared to the control treatment (wounding, no fungus) and the reference (healthy sample), in different host locations, and at different sampling times (0, 3, and 43 days). Multivariate statistical analysis carried out with an unsupervised technique (principal component analysis, PCA) showed highly significant effects of location and time and significant effects of clone and fungus. The complex metabolic mixture detected by NMR did not allow for clear discrimination between clones, although on average resistant clones developed shorter axial lesions and had greater peak levels in the aromatic region than more susceptible clones. Similarly, effect of fungal inoculation was not clearly clustered from effect of wounding; however, both treatments conspicuously differed from healthy (reference) samples. By contrast, effect of location resulted in greater peak levels in the aromatic region at a greater distance from lesion boundary than at the boundary. Effect of time was similar to that of location: greater peak levels were detected in the aromatic region at 43 days sampling than at 3 days. Reference samples showed greater levels of peaks in the aliphatic and carbohydrate regions of the spectra. Results of bark metabolites are compared with sapwood metabolites in part 2; a general discussion on the possible role of ... will also follow.
Year
2012
Category
Refereed journal
Output Tags
SG 2006-2011 P1 Plants - Miscellaneous