Metabolome analysis using multiple data mining approaches suggests luteolin biosynthesis in Physcomitrella patens

• Published in: Plant Biotechnology Vol. 37; no. 3; pp. 377 - 381
• Main Authors: Hiraga, Yasuhide, Ara, Takeshi, Nagashima, Yoshiki, Shimada, Norimoto, Sakurai, Nozomu, Suzuki, Hideyuki, Kera, Kota
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese Society for Plant Biotechnology 25.09.2020; Japan Science and Technology Agency; Japanese Society for Plant Cell and Molecular Biology
• Subjects: Biosynthesis; Chemical composition; Data mining; Flavones; flavonoid; Flavonoids; Ions; Isomers; Isotopes; LC-MS; Liquid chromatography; Mass spectrometry; Mass spectroscopy; Metabolites; metabolome; Physcomitrella patens; Searching; Secondary metabolites; stable isotope; Stable isotopes; Ultraviolet radiation
• ISSN: 1342-4580; 1347-6114
• DOI: 10.5511/plantbiotechnology.20.0525b

The model land plant Physcomitrella patens synthesizes flavonoids which may act as protectant of ultraviolet-B radiation. We aimed to uncover its flavonoid profile, for which metabolome analysis using liquid chromatography coupled with Ion trap/Orbitrap mass spectrometry was performed. From the 80% methanol extracts, 661 valid peaks were detected. Prediction of the elemental compositions within a mass accuracy of 2 ppm indicated that 217 peaks had single elemental composition. A compound database search revealed 47 peaks to be annotated as secondary metabolites based on the compound database search. Comprehensive substituent search by ShiftedIonsFinder showed there were 13 peaks of potential flavonoid derivatives. Interestingly, a peak having m/z 287.0551, corresponding to that of luteolin, was detected, even though flavone synthase has never been identified in P. patens. Using P. patens labeled with stable isotopes (13C-, 15N-, 18O-, and 34S), we confirmed the elemental composition of the peak as C15H10O6. By a comparison of MS/MS spectra with that of authentic standard, the peak was identified as luteolin or related flavone isomers. This is the first report of luteolin or related flavones synthesis and the possibility of the existence of an unknown enzyme with flavone synthase activity in P. patens.