Figure 4
From: Production of Phloroglucinol, a Platform Chemical, in Arabidopsis using a Bacterial Gene
Identification of the PG conjugate in the transgenic extract by GC-MS (left) and UPLC-QTOF-MS (right).
(a–c) A prominent m/z 342 signal was detected at 14.78 min in transgenic lines (b,c) and not in wild-type (a). (d) EIC of m/z 342 for orange peel extract supporting that orange peel has the same metabolite as that observed in the transgenic lines. (e) Mass spectral match for the metabolite detected at 14.78 minutes for the transgenic line 19–2 and orange peel. (f) UPLC-QTOF analysis of plant extracts showing a prominent signal eluted at 0.83 min with mass  m/z 287.076 in the transgenic line (upper panel) and not detected in the wild-type (bottom panel). (g) In-source fragmentation of the 287.076 compound showing a fragment at 125.0239, which indicates a hexose conjugate of PG. MS/MS analysis confirms that 125.0239 is a product ion of 287.0764, a pattern consistent with orange peel extract. (h) In source MS/MS fragmentation of putative PG conjugate from transgenic line 19–2 and PG standard in positive ionization mode showing that the in source 127.0375 fragment of PG conjugate matches that of PG standard and strongly indicate that the novel compound in transgenic plants represents a hexose conjugate of PG.
