TY - JOUR

T1 - Visualizing metabolite distribution and enzymatic conversion in plant tissues by desorption electrospray ionization mass spectrometry imaging

AU - Li, Bin

AU - Baden, Camilla Knudsen

AU - Hansen, Natascha Kristine Krahl

AU - Jørgensen, Kirsten

AU - Kannangara, Rubini Maya

AU - Bak, Søren

AU - Takos, Adam Matthew

AU - Rook, Frederik

AU - Hansen, Steen Honoré

AU - Møller, Birger Lindberg

AU - Janfelt, Christian

AU - Bjarnholt, Nanna

N1 - © 2013 The Authors. The Plant Journal © 2013 Blackwell Publishing Ltd.

PY - 2013

Y1 - 2013

N2 - In comparison to the technology platforms developed to localize transcripts and proteins, imaging tools for visualization of metabolite distributions in plant tissues are less well developed and lack versatility. This hampers our understanding of plant metabolism and dynamics. In this study we demonstrate that Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI-MSI) of tissue imprints on porous Teflon can be used to accurately image the distribution of even labile plant metabolites such as hydroxynitrile glucosides, which normally undergo enzymatic hydrolysis by specific ß-glucosidases upon cell disruption. This fast and simple sample preparation resulted in no substantial differences in the distribution and ratios of all hydroxynitrile glucosides between leaves from wildtype Lotus japonicus and a ß-glucosidase mutant plant lacking the ability to hydrolyze certain hydroxynitrile glucosides. In wildtype, the enzymatic conversion of hydroxynitrile glucosides and the concomitant release of glucose was easily visualized when a restricted area of the leaf tissue was damaged prior to sample preparation. The gene encoding the first enzyme in hydroxynitrile glucoside biosynthesis in L. japonicus leaves, CYP79D3, was found to be highly expressed during the early stages of leaf development, and the hydroxynitrile glucoside distribution in mature leaves reflected this early expression pattern. Direct DESI-MSI of plant tissue was demonstrated using cryo-sections of cassava (Manihot esculenta) tubers. The hydroxynitrile glucoside levels were highest in the outer cell layers, as verified by LC-MS analyses. The unexpected discovery of a hydroxynitrile derived di-glycoside shows the potential of DESI-MSI to discover and guide investigations into new metabolic routes. © 2013 The Authors. The Plant Journal © 2013 Blackwell Publishing Ltd.

AB - In comparison to the technology platforms developed to localize transcripts and proteins, imaging tools for visualization of metabolite distributions in plant tissues are less well developed and lack versatility. This hampers our understanding of plant metabolism and dynamics. In this study we demonstrate that Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI-MSI) of tissue imprints on porous Teflon can be used to accurately image the distribution of even labile plant metabolites such as hydroxynitrile glucosides, which normally undergo enzymatic hydrolysis by specific ß-glucosidases upon cell disruption. This fast and simple sample preparation resulted in no substantial differences in the distribution and ratios of all hydroxynitrile glucosides between leaves from wildtype Lotus japonicus and a ß-glucosidase mutant plant lacking the ability to hydrolyze certain hydroxynitrile glucosides. In wildtype, the enzymatic conversion of hydroxynitrile glucosides and the concomitant release of glucose was easily visualized when a restricted area of the leaf tissue was damaged prior to sample preparation. The gene encoding the first enzyme in hydroxynitrile glucoside biosynthesis in L. japonicus leaves, CYP79D3, was found to be highly expressed during the early stages of leaf development, and the hydroxynitrile glucoside distribution in mature leaves reflected this early expression pattern. Direct DESI-MSI of plant tissue was demonstrated using cryo-sections of cassava (Manihot esculenta) tubers. The hydroxynitrile glucoside levels were highest in the outer cell layers, as verified by LC-MS analyses. The unexpected discovery of a hydroxynitrile derived di-glycoside shows the potential of DESI-MSI to discover and guide investigations into new metabolic routes. © 2013 The Authors. The Plant Journal © 2013 Blackwell Publishing Ltd.

U2 - 10.1111/tpj.12183

DO - 10.1111/tpj.12183

M3 - Journal article

C2 - 23551340

VL - 74

SP - 1059

EP - 1071

JO - Plant Journal

JF - Plant Journal

SN - 0960-7412

IS - 6

M1 - 74

ER -