title: Transgenic potato (Solanum tuberosum) tubers synthesize the full spectrum of inulin molecules naturally occurring in globe artichoke (Cynara scolymus) roots.
abstract: The ability to synthesize high molecular weight inulin was transferred to potato plants via constitutive expression of the 1-SST (sucrose:sucrose 1-fructosyltransferase) and the 1-FFT (fructan: fructan 1-fructosyltransferase) genes of globe artichoke (Cynara scolymus). The fructan pattern of tubers from transgenic potato plants represents the full spectrum of inulin molecules present in artichoke roots as shown by high-performance anion exchange chromatography, as well as size exclusion chromatography. These results demonstrate in planta that the enzymes sucrose:sucrose 1-fructosyltransferase and fructan:fructan 1-fructosyltransferase are sufficient to synthesize inulin molecules of all chain lengths naturally occurring in a given plant species. Inulin made up 5% of the dry weight of transgenic tubers, and a low level of fructan production also was observed in fully expanded leaves. Although inulin accumulation did not influence the sucrose concentration in leaves or tubers, a reduction in starch content occurred in transgenic tubers, indicating that inulin synthesis did not increase the storage capacity of the tubers.
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Golm, Germany.
authors.forename: E M
authors.initials: EM
authors.lastname: Hellwege
authors.forename: S
authors.initials: S
authors.lastname: Czapla
authors.forename: A
authors.initials: A
authors.lastname: Jahnke
authors.forename: L
authors.initials: L
authors.lastname: Willmitzer
authors.forename: A G
authors.initials: AG
authors.lastname: Heyer
mesh_terms: D019659:Asteraceae / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D005630:Fructans / Q000378:metabolism; D015870:Gene Expression; D006602:Hexosyltransferases / Q000096:biosynthesis* / Q000235:genetics; D007444:Inulin / Q000096:biosynthesis*; D008970:Molecular Weight; D009844:Oligosaccharides / Q000378:metabolism; D010940:Plant Proteins; D018517:Plant Roots / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000378:metabolism; D011198:Solanum tuberosum / Q000378:metabolism*; D001426:Bacterial Proteins
chemical_list: D005630:Fructans; D006602:Hexosyltransferases; D007444:Inulin; D009844:Oligosaccharides; D010940:Plant Proteins; C114852:1,2-beta-fructan 1(F)-fructosyltransferase; C021451:inulosucrase; D001426:Bacterial Proteins