Mass spectrometry imaging of plant metabolites - principles and possibilities

New mass spectrometry imaging (MSI) techniques are gaining importance in the analysis of plant metabolite distributions, and significant technological improvements have been introduced in the past decade. This review provides an introduction to the different MSI techniques and their applications in plant science. The most common methods for sample preparation are described, and the review also features a comprehensive table of published studies in MSI of plant material. A number of significant works are highlighted for their contributions to advance the understanding of plant biology through applications of plant metabolite imaging. Particular attention is given to the possibility for imaging of surface metabolites since this is highly dependent on the methods and techniques which are applied in imaging studies.