title: Untargeted Metabolomics Reveals Predominant Alterations in Lipid Metabolism Following Light Exposure in Broccoli Sprouts.
abstract: The consumption of vegetables belonging to the family Brassicaceae (e.g., broccoli and cauliflower) is linked to a reduced incidence of cancer and cardiovascular diseases. The molecular composition of such plants is strongly affected by growing conditions. Here we developed an unbiased metabolomics approach to investigate the effect of light and dark exposure on the metabolome of broccoli sprouts and we applied such an approach to provide a bird's-eye view of the overall metabolic response after light exposure. Broccoli seeds were germinated and grown hydroponically for five days in total darkness or with a light/dark photoperiod (16 h light/8 h dark cycle). We used an ultra-performance liquid-chromatography system coupled to an ion-mobility, time-of-flight mass spectrometer to profile the large array of metabolites present in the sprouts. Differences at the metabolite level between groups were analyzed using multivariate statistical analyses, including principal component analysis and correlation analysis. Altered metabolites were identified by searching publicly available and in-house databases. Metabolite pathway analyses were used to support the identification of subtle but significant changes among groups of related metabolites that may have gone unnoticed with conventional approaches. Besides the chlorophyll pathway, light exposure activated the biosynthesis and metabolism of sterol lipids, prenol lipids, and polyunsaturated lipids, which are essential for the photosynthetic machinery. Our results also revealed that light exposure increased the levels of polyketides, including flavonoids, and oxylipins, which play essential roles in the plant's developmental processes and defense mechanism against herbivores. This study highlights the significant contribution of light exposure to the ultimate metabolic phenotype, which might affect the cellular physiology and nutritional value of broccoli sprouts. Furthermore, this study highlights the potential of an unbiased omics approach for the comprehensive study of the metabolism.
authors.affiliation: Food and Nutrition Research Centre, Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria (CRA), 00184 Roma, Italy. maldiniluce@gmail.com.|Department of Chemistry and Pharmacy, University of Sassari, 07100 Sassari, Italy. maldiniluce@gmail.com.
authors.forename: Mariateresa
authors.initials: M
authors.lastname: Maldini
authors.affiliation: Food and Nutrition Research Centre, Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria (CRA), 00184 Roma, Italy. fausta.natella@entecra.it.
authors.forename: Fausta
authors.initials: F
authors.lastname: Natella
authors.affiliation: Food and Nutrition Research Centre, Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria (CRA), 00184 Roma, Italy. simona.baima@entecra.it.
authors.forename: Simona
authors.initials: S
authors.lastname: Baima
authors.affiliation: Food and Nutrition Research Centre, Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria (CRA), 00184 Roma, Italy. giorgio.morelli@entecra.it.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Morelli
authors.affiliation: Food and Nutrition Research Centre, Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria (CRA), 00184 Roma, Italy. cristina.scaccini@entecra.it.
authors.forename: Cristina
authors.initials: C
authors.lastname: Scaccini
authors.affiliation: Waters Corporation, Health Sciences, Milford, MA 01757, USA. James_langridge@waters.com.
authors.forename: James
authors.initials: J
authors.lastname: Langridge
authors.affiliation: Waters Corporation, Health Sciences, Milford, MA 01757, USA. giuseppe_astarita@waters.com.|Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, DC 20057, USA. giuseppe_astarita@waters.com.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Astarita
mesh_terms: D001937:Brassica / Q000378:metabolism / Q000528:radiation effects*; D050356:Lipid Metabolism; D055442:Metabolome; D036226:Seedlings / Q000378:metabolism / Q000528:radiation effects; D013472:Sunlight
keywords: ion mobility; lipidomics; lipids; metabolomics; nutrition; oxylipins; sterol lipids