Profiling of phenylpropanoids in transgenic low-sinapine oilseed rape (Brassica napus)

Silencing UDP-glucose:sinapate glucosyltransferase (UGT84A9) in Brassica napus seeds by a dsRNAi approach led to significant changes in composition and concentration of sinapate esters. Besides strong reduction of the amount of known components, eleven newly appearing minor hitherto unknown glucosylated constituents were isolated and identified by high-field NMR spectroscopy and high resolution electrospray ionization mass spectrometry. Glucosylation might be a means to cope with a disordered metabolism of the phenylpropanoid network in the transgenic seeds.