Flavonoid comparative analysis of GM/wt wheat

A rapid, non-sophisticated and reproducible analytical HPLC/UV method was developed to qualitatively and quantitatively compare the flavonoid content of wild and transgenic type Swiss spring wheat plants. Well characterized homozygotic, T4 generations of transgenic Frisal, Golin and Greina wheat varieties were obtained by transformation with antifungal genes of broad spectrum effect like chitinase and glucanase, ribosome-inactivating protein (RIP), as well as with a transgene of a specific effect – KP4 against smuts and bunts. HPLC/UV profiles of wheat GM varieties were compared with the respective wild type plant. This comparative profiling was coupled with computerized tools enabling a statistical processing of the data including cluster analyses. The structures of the major detected flavonoid derivatives were elucidated on-line including LC/DAD-UV analysis with post-column addition of UV shift reagents and LC/MSⁿ experiments. Different lines of transgenic wheat with increased antifungal resistance showed only small differences to their respective wild type, whereas differences between varieties were remarkable. These results indicated that the insertion of those specific resistance genes did not interfere with the biosynthetic pathways of flavonoids and provide a simple, robust and reliable methodology for the comparative profiling of flavonoid-containing plants.

Reference: Clausen, M. et al. (2000), Nat. Biotechnol. 18: 446–449.