|SHEPHERD, LOUISE - The James Hutton Institute
|HACKET, CHRISTINE - Biomathematics And Statistics Scotland (BIOSS)
|ALEXANDER, COLIN - The James Hutton Institute
|MCNICOL, JAMES - The James Hutton Institute
|SUNGURTAS, JULIA - The James Hutton Institute
|STEWART, DEREK - The James Hutton Institute
|DAVIES, HOWARD - The James Hutton Institute
Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/10/2014
Publication Date: 4/24/2015
Citation: Shepherd, L., Hacket, C., Alexander, C., McNicol, J., Sungurtas, J., Stewart, D., McCue, K.F., Belknap, W.R., Davies, H.V. 2015. Modifying glycoalkaloid content in transgenic potato – Metabolome impacts. Food Chemistry. 187:437-443.
Interpretive Summary: Glycoalkaloids are undesirable specialty metabolites naturally occurring in potatoes and other crops in the Solanaceae family, including tomatoes and eggplants. Although levels are monitored in new crop varieties, these compounds are subject to a variety of environmental, genetic and stress factors. For this reason we have developed transgenic technologies to modify the accumulation of these compounds. However, the question remains what effects these modifications and the mechanism of modification, precise molecular breeding, have on both the target and other unpredicted compounds. In this study a comprehensive examination of multiple classes of metabolites from both control and modified plant lines were examined. Both predicted and unpredicted effects were observed, some obvious effects on the target modification and some differences with less obvious connections to the target. Although variations of expected and non-expected metabolites were significant, none was indicative of any food safety issues for commercial materials developed for human consumption.
Technical 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 Components Analysis (PCA) and ANalysis Of VAriance (ANOVA). Compared with the wild-type (WT) control, LC-MS revealed not only the expected changes in specific glycoalkaloid levels in the genetically modified (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.