abstract
Metabolite profiling has been used to assess the potential for unintended composition changes in potato
(Solanum tuberosum L. cv. Desirée) tubers, which have been genetically modified (GM) to reduce
glycoalkaloid content, via the independent down-regulation of three genes SGT1, SGT2 and SGT3 known
to be involved in glycoalkaloid biosynthesis. Differences between the three groups of antisense lines
and control lines were assessed using liquid chromatography–mass spectrometry (LC–MS) and gas
chromatography (GC)–MS, and data analysed using principal component analysis and analysis of
variance. Compared with the wild-type (WT) control, LC–MS revealed not only the expected changes
in specific glycoalkaloid levels in the GM lines, but also significant changes in several other metabolites,
some of which were explicable in terms of known pathways. Analysis of polar and non-polar metabolites
by GC–MS revealed other significant (unintended) differences between SGT lines and the WT, but also
between the WT control and other control lines used.