title: Cell-specific localization of alkaloids in Catharanthus roseus stem tissue measured with Imaging MS and Single-cell MS.
abstract: Catharanthus roseus (L.) G. Don is a medicinal plant well known for producing antitumor drugs such as vinblastine and vincristine, which are classified as terpenoid indole alkaloids (TIAs). The TIA metabolic pathway in C. roseus has been extensively studied. However, the localization of TIA intermediates at the cellular level has not been demonstrated directly. In the present study, the metabolic pathway of TIA in C. roseus was studied with two forefront metabolomic techniques, that is, Imaging mass spectrometry (MS) and live Single-cell MS, to elucidate cell-specific TIA localization in the stem tissue. Imaging MS indicated that most TIAs localize in the idioblast and laticifer cells, which emit blue fluorescence under UV excitation. Single-cell MS was applied to four different kinds of cells [idioblast (specialized parenchyma cell), laticifer, parenchyma, and epidermal cells] in the stem longitudinal section. Principal component analysis of Imaging MS and Single-cell MS spectra of these cells showed that similar alkaloids accumulate in both idioblast cell and laticifer cell. From MS/MS analysis of Single-cell MS spectra, catharanthine, ajmalicine, and strictosidine were found in both cell types in C. roseus stem tissue, where serpentine was also accumulated. Based on these data, we discuss the significance of TIA synthesis and accumulation in the idioblast and laticifer cells of C. roseus stem tissue.
authors.affiliation: Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan;
authors.forename: Kotaro
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan;
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Laboratory of Analytical and Bio-Analytical Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan;
authors.forename: Hajime
authors.initials: H
authors.lastname: Mizuno
authors.affiliation: Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan;
authors.forename: Aya
authors.initials: A
authors.lastname: Anegawa
authors.affiliation: Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan;
authors.forename: Kimitsune
authors.initials: K
authors.lastname: Ishizaki
authors.affiliation: Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan;
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Fukaki
authors.affiliation: Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan;
authors.forename: Miwa
authors.initials: M
authors.lastname: Ohnishi
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 263-8522, Japan;
authors.forename: Mami
authors.initials: M
authors.lastname: Yamazaki
authors.affiliation: Quantitative Biology Center, RIKEN, Osaka 565-0874, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Masujima
authors.affiliation: Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan; mimura@kobe-u.ac.jp.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Mimura
mesh_terms: D030008:Catharanthus / Q000378:metabolism*; D058503:Mesophyll Cells / Q000166:cytology / Q000378:metabolism*; D019441:Plant Epidermis / Q000166:cytology / Q000378:metabolism*; D018547:Plant Stems / Q000378:metabolism; D010946:Plants, Medicinal / Q000378:metabolism*; D025341:Principal Component Analysis; D046948:Secologanin Tryptamine Alkaloids / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D014748:Vinca Alkaloids / Q000378:metabolism
chemical_list: D046948:Secologanin Tryptamine Alkaloids; D014748:Vinca Alkaloids; C021093:strictosidine; C005709:raubasine; C009244:serpentine (alkaloid); C017836:catharanthine
keywords: Catharanthus roseus; Imaging MS; Single-cell MS; idioblast cell; terpenoid indole alkaloid