Opportunities in Phytochemistry, Ecophysiology and Wood Research via Laser Ablation Direct Analysis in Real Time-Imaging Mass Spectrometry.

Analysis of wood transects in a manner that preserves the spatial distribution of the metabolites present is highly desirable in order to among other things: (1) facilitate ecophysiology studies that reveal the association between chemical makeup and environmental factors or climactic events over time; (2) investigate the mechanisms of the synthesis and trafficking of small molecules within specialized tissues. While a variety of techniques could be applied to achieve these goals, most remain challenging and impractical. LADI-MS was successfully used to survey the chemical profile of wood, while also preserving the small-molecule spatial distribution. The tree species Entandrophragma candollei Harms, Millettia laurentii De Wild., Pericopsis elata (Harms) Meeuwen, Dalbergia nigra (Vell.) Benth. and Dalbergia normandii Bosser & R.Rabev were analyzed. Several compounds were associated with anatomical features. A greater diversity was detected in the vessels and parenchyma compared to the fibers. Analysis of single vessels revealed that the chemical fingerprint used for timber identification is mainly determined by vessel content. LADI-MS offers unprecedented opportunities to investigate the distribution of metabolites within wood samples while circumventing the issues associated with previous methods. This technique opens up new vistas for the discovery of small-molecule biomarkers that are linked to environmental events.