title: Live Single-Cell Plant Hormone Analysis by Video-Mass Spectrometry.
abstract: Studies have indicated that endogenous concentrations of plant hormones are regulated very locally within plants. To understand the mechanisms underlying hormone-mediated physiological processes, it is indispensable to know the exact hormone concentrations at cellular levels. In the present study, we established a system to determine levels of ABA and jasmonoyl-isoleucine (JA-Ile) from single cells. Samples taken from a cell of Vicia faba leaves using nano-electrospray ionization (ESI) tips under a microscope were directly introduced into mass spectrometers by infusion and subjected to tandem mass spectrometry (MS/MS) analysis. Stable isotope-labeled [D(6)]ABA or [(13)C(6)]JA-Ile was used as an internal standard to compensate ionization efficiencies, which determine the amount of ions introduced into mass spectrometers. We detected ABA and JA-Ile from single cells of water- and wound-stressed leaves, whereas they were almost undetectable in non-stressed single cells. The levels of ABA and JA-Ile found in the single-cell analysis were compared with levels found by analysis of purified extracts with liquid chromatography-tandem mass spectrometry (LC-MS/MS). These results demonstrated that stress-induced accumulation of ABA and JA-Ile could be monitored from living single cells.
authors.affiliation: RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045 Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Department of Biological Sciences, Tokyo Metropolitan University, Hachioji-shi, Tokyo, 192-0397 Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Miyakawa
authors.affiliation: RIKEN Quantitative Biology Center, Suita, Osaka, 565-0874 Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Esaki
authors.affiliation: RIKEN Quantitative Biology Center, Suita, Osaka, 565-0874 Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Mizuno
authors.affiliation: RIKEN Quantitative Biology Center, Suita, Osaka, 565-0874 Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Masujima
authors.affiliation: Department of Biological Sciences, Tokyo Metropolitan University, Hachioji-shi, Tokyo, 192-0397 Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Koshiba
authors.affiliation: RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045 Japan Department of Biological Sciences, Tokyo Metropolitan University, Hachioji-shi, Tokyo, 192-0397 Japan mitsunori.seo@riken.jp.
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Seo
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D002853:Chromatography, Liquid / Q000379:methods; D003517:Cyclopentanes / Q000378:metabolism*; D007532:Isoleucine / Q000031:analogs & derivatives* / Q000378:metabolism; D013058:Mass Spectrometry / Q000379:methods*; D010937:Plant Growth Regulators / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry / Q000166:cytology; D015203:Reproducibility of Results; D059010:Single-Cell Analysis / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods; D031307:Vicia faba / Q000737:chemistry / Q000166:cytology
chemical_list: D003517:Cyclopentanes; D010937:Plant Growth Regulators; C532883:jasmonoyl-isoleucine; D007532:Isoleucine; D000040:Abscisic Acid
keywords: Abscisic acid (ABA); Jasmonoyl-isoleucine (JA-Ile); Mass spectrometry; Single cell; Vicia faba; Water and wound stresses