title: Spatially resolved metabolic distribution for unraveling the physiological change and responses in tomato fruit using matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI).
abstract: Information on spatiotemporal metabolic behavior is indispensable for a precise understanding of physiological changes and responses, including those of ripening processes and wounding stress, in fruit, but such information is still limited. Here, we visualized the spatial distribution of metabolites within tissue sections of tomato (Solanum lycopersicum L.) fruit using a matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) technique combined with a matrix sublimation/recrystallization method. This technique elucidated the unique distribution patterns of more than 30 metabolite-derived ions, including primary and secondary metabolites, simultaneously. To investigate spatiotemporal metabolic alterations during physiological changes at the whole-tissue level, MALDI-MSI was performed using the different ripening phenotypes of mature green and mature red tomato fruits. Although apparent alterations in the localization and intensity of many detected metabolites were not observed between the two tomatoes, the amounts of glutamate and adenosine monophosphate, umami compounds, increased in both mesocarp and locule regions during the ripening process. In contrast, malate, a sour compound, decreased in both regions. MALDI-MSI was also applied to evaluate more local metabolic responses to wounding stress. Accumulations of a glycoalkaloid, tomatine, and a low level of its glycosylated metabolite, esculeoside A, were found in the wound region where cell death had been induced. Their inverse levels were observed in non-wounded regions. Furthermore, the amounts of both compounds differed in the developmental stages. Thus, our MALDI-MSI technique increased the understanding of the physiological changes and responses of tomato fruit through the determination of spatiotemporally resolved metabolic alterations. Graphical abstract ᅟ.
authors.affiliation: Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581, Japan.
authors.forename: Junya
authors.initials: J
authors.lastname: Nakamura
authors.affiliation: Innovation Center for Medical Redox Navigation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Morikawa-Ichinose
authors.affiliation: Innovation Center for Medical Redox Navigation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Fujimura
authors.affiliation: Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Hayakawa
authors.affiliation: National Institute of Advanced Industrial Science and Technology, 2-41-6 Aomi, Koto-ku, Tokyo, 135-0064, Japan.
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Innovation Center for Medical Redox Navigation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Ishii
authors.affiliation: Innovation Center for Medical Redox Navigation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan. daipon@agr.kyushu-u.ac.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Miura
authors.affiliation: Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581, Japan. hirowari@agr.kyushu-u.ac.jp.|Innovation Center for Medical Redox Navigation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan. hirowari@agr.kyushu-u.ac.jp.|Bio-architecture Center, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581, Japan. hirowari@agr.kyushu-u.ac.jp.|Faculty of Arts and Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan. hirowari@agr.kyushu-u.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Wariishi
mesh_terms: D005638:Fruit / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D018551:Solanum lycopersicum / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D055442:Metabolome; D055432:Metabolomics / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
keywords: Localization; MALDI–MSI; Metabolic alterations; Physiological changes and responses; Tomato fruit (Solanum lycopersicum L.)