Spatially Resolved Plant Metabolomics

Abstract

Primary and secondary metabolism of plants are segregated amidst many differentiated and specialized plant organs, tissues, cells and organelles. The specialized physiology of anatomically distinct components contribute to highly sophisticated, autotrophic systems that are foundational to global energy, ecology, biology and nutrition. An established literature base exists for focused studies of metabolism in specific organs, tissue, cells, and this literature is briefly reviewed here. However, modern metabolic studies are moving towards more global metabolite analyses (i.e. metabolomics and systems biology) with high anatomical, spatial and temporal resolution to better understand the massive complexity of plant systems. Several current examples of such spatially resolved metabolomics experiments are provided here, and the current prospects of metabolite imaging reviewed. Although current metabolomics approaches have been quite informative, they are still constrained by multiple factors. The major challenges that still face plant metabolomics are metabolite annotation, depth-of-coverage or comprehensiveness, instrumental sensitivity and dynamic range. These plant metabolomics challenges are discussed in general and relative to temporally and spatially resolved metabolomics.

Use of mass spectrometry for imaging metabolites in plants

“…In this review, we illustrate recent advances that are being made in applying mass spectrometry (MS) to identify the distribution of metabolites among different tissues and cells of plants. These are relatively new technological applications of MS (Chughtai and Heeren, 2010), and they are providing metabolic insights, which are asserting the ability to decipher new knowledge concerning the spatial organization of metabolic processes in plants (Sumner et al. , 2011).…”

Spatially Resolved Plant Metabolomics: Some Potentials and Limitations of Laser-Ablation Electrospray Ionization Mass Spectrometry Metabolite Imaging

“…This is not only true for all of our food crops, but also for many other species of genera such as Pyrethrum (insecticides), Jasminium and Santalum (perfumes), Hevea (rubber), Nicotiana and Cannabis (drugs), Linum (oils), Artemisia and Taxus (pharmaceuticals), Cinnamomum (flavors), etc. However, despite the importance of plants as a source of exploitable and essential biochemicals, we often still have remarkably limited knowledge of the relevant biosynthetic pathways, the genetics behind the key enzymes, and indeed when, why, and where these metabolites are produced and stored within the plant in question (Fernie, 2007;Sumner et al, 2011;Kueger et al, 2012).…”

The Plant Subcellular Metabolome: Current State and Advances

“…Rapid subcellular fractionation combined to targeted proteomics allowed estimation of subcellular protein concentrations in attomole per 1000 cells of Chlamydomonas reinhardtii (Weinkeeop et al, 2010). Although, the importance of spatial resolution of plant cellular metabolomes has been discussed elsewhere (Sumner et al, 2011) but robust efforts and databases are missing for plant subcellular metabolomes. Recently, the need for understanding the challenges in cellular compartmentalization for successful plant metabolic engineering was identified (Heining et al, 2013).…”