Single-Cell Metabolite Profiling of Stalk and Glandular Cells of Intact Trichomes with Internal Electrode Capillary Pressure Probe Electrospray Ionization Mass Spectrometry

T. NAKASHIMA, ; H. WADA, ; S. MORITA, ; ERRA BALSELLS, ROSA; K. HIRAOKA; H. NONAMI

ANALYTICAL CHEMISTRY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2016 vol. 88 p. 3049 - 3057

0003-2700

In this report, we developed the pressure probe14 electrospray ionization-mass spectrometry with internal15 electrode capillary (IEC-PPESI-MS) which enables high16 spatial-resolution cell sampling, precise postsampling manip-17 ulation, and high detection sensitivity. Using this technique, a18 comparative in situ single-cell metabolite profiling of stalk and19 glandular cells, the two adjacent cell types comprising a20 trichome unit in tomato plants (Solanum lycopersicum L.), were21 performed to clarify the extent of metabolic differentiation22 between two cell types as well as among different types of23 trichomes. Owing to high sensitivity of the system, less than a24 picoliter cell sap from a single stalk cell sufficiently yielded a number of peaks of amino acids, organic acids, carbohydrates, and25 flavonoids. The minimal cell sap removal from a stalk cell without severe disturbance of trichome structure enabled sequential26 analysis of adjacent glandular cell on the same trichome, which showed the presence of striking differences in metabolite27 compositions between two adjacent cell types. Comparison among different types of trichome also revealed significant variations28 in metabolite profiles, particularly in flavonoids and acyl sugars compositions. Some metabolites were found only in specific cell29 types or particular trichome types. Although extensive metabolomics analysis of glandular cells of tomato trichomes has been30 previously documented, this is the first report describing cell-to-cell variations in metabolite compositions of stalk and glandular31 cells as well as in different trichome types. Further application of this technique may provide new insights into distinct32 metabolism in plant cells displaying variations in shape, size, function and physicochemical properties.