Direct profiling and imaging of plant metabolites in intact tissues by using colloidal graphite‐assisted laser desorption ionization mass spectrometry

Abstract

SummaryLaser desorption/ionization (LDI)-based imaging mass spectrometry (MS) has been applied to several biological systems to obtain information about both the identities of the major chemical species and their localization. Colloidal graphite-assisted LDI (GALDI) MS imaging was introduced for the imaging of small molecules such as phospholipids, cerebrosides, oligosaccharides, flavonoids, and other secondary metabolites with high spatial homogeneity due to finely dispersed particles. Mass profiles and images of Arabidopsis thaliana have been recorded directly from various plant surfaces and cross sections. The main targeted metabolites were flavonoids and cuticular waxes, both of which are important in many aspects of functional genomics, proteomics, and metabolomics. The mass spectral profiles revealed tissue-specific accumulation of flavonoids in flowers and petals. In addition, many other location-specific ions were observed. The location and the degree of light-induced accumulation of flavonoids in stem sections were successfully probed by GALDI MS.

MALDI Mass Spectrometry Imaging for the Simultaneous Location of Resveratrol, Pterostilbene and Viniferins on Grapevine Leaves

“…Different matrices are described in the literature for MALDI MS analysis of vegetable material such as 1,5 diamino naphthalene (DAN) or 9-amino acridine (9-AA) in negative ion mode, and tri-hydroxy acetophenone (THAP), α-cyano-4-hydroxy cinamic acid (CHCA) or 2,5 dihydroxy-benzoic acid (DHB) in positive ion mode. Graphite was also used to avoid high matrix ion background in the m/z range of metabolites [34] but it may lead to overmuch carbon deposit on ion lenses during experiments. Consequently, we firstly proceeded to a matrix selection for MSI of phytoalexin by analyzing the standard stilbene compounds by MALDI-TOFMS with different matrices.…”

The Last Step in Cocaine Biosynthesis Is Catalyzed by a BAHD Acyltransferase

“…The adaxial surface of coca leaves has a thick waxy cuticle containing hentriacontane as one of the major lipid components (Leete et al, 1988). Because wax components in the cuticle of Arabidopsis (Arabidopsis thaliana) are known to decrease the abundance of ions corresponding to flavonoids present within the leaf (Cha et al, 2008), cuticle was removed from some leaves. The chloroform treatment of L2 and L3 leaves did not change the abaxial and adaxial distribution pattern of the TAs (Supplemental Fig.…”

In planta localization of stilbenes within Picea abies phloem

“…New mass spectrometry imaging techniques provide significant improvements in the mapping of plant metabolites (Briggs and Seah, 1993;Vickerman and Briggs, 2001;Burrell et al, 2007;Cha et al, 2008;Lee et al, 2012;Bjarnholt et al, 2014;Aoki et al, 2016). To elucidate the synthesis, distribution, and metabolism of secondary Figure 1.…”