Differences in chain length distribution of inulin fromCynara scolymusandHelianthus tuberosusare reflected in a transient plant expression system using the respective 1‐FFT cDNAs

Abstract

A newly isolated cDNA clone, Cy3, encoding the fructan fructan 1-fructosyltransferase (1-FFT) from artichoke was expressed using tobacco protoplasts as expression system. Analysis of the inulin molecules synthesized upon incubation of protoplast extracts with a mixture of oligofructans (DP3^5) shows the production of inulins with a degree of polymerization (DP) of up to 23, whereas parallel experiments performed using a 1-FFT cDNA from Jerusalem artichoke led to the production of fructans with a DP of up to only 12. The results of in vitro fructan synthesis catalyzed by transiently expressed enzymes therefore reflect the difference of in vivo fructan composition of Jerusalem artichoke (M h = 8^10) and artichoke (M h = 65). These data suggest that the fructan pattern in a given species is mainly defined by the enzymatic characteristics of 1-FFT.z 1998 Federation of European Biochemical Societies.

Transgenic potato ( Solanum tuberosum ) tubers synthesize the full spectrum of inulin molecules naturally occurring in globe artichoke ( Cynara scolymus ) roots

“…Alternatively, distinct enzymatic properties should be taken into account. We have reported that 1-FFT of globe artichoke shows a preference for higher DP substrates as acceptor of transferred fructosyl residues than does the enzyme from Jerusalem artichoke (18). Under conditions where high invertase activity prevents accumulation of lower molecular weight inulin molecules, which are the main products formed by the H. tuberosus 1-FFT, the C. scolymus enzyme would be more efficient in synthesizing higher-order inulin molecules, which are less accessible to invertases (31).…”

“…The 1-SST (17) and 1-FFT cDNAs (18) were subcloned separately into the binary vector pBinAR, a derivative of the pBin19 vector (19). The cDNAs contain endogenous signal sequences for a predicted vacuolar localization of the encoded enzymes.…”

“…In 19 of 41 antibiotic-resistant plants 1-SST mRNA accumulation and oligofructan synthesis could be observed. Of those we chose three transgenic lines and transformed them with the 1-FFT gene (18), again under the control of the 35S promoter. We obtained 10 transgenic lines accumulating high molecular weight inulin.…”

Molecular Characterization of Sucrose:Sucrose 1-Fructosyltransferase and Sucrose:Fructan 6-Fructosyltransferase Associated with Fructan Accumulation in Winter Wheat during Cold Hardening

“…11,16) Sprenger et al 16)ˆr st reported the cloning of a plant gene of the fructan biosynthesis enzyme 6-SFT from Hordeum vulgare. Since then, several genes encoding enzymes in fructan biosynthesis have been cloned from various plants: 1-SST from C. intybus; 19) 1-SST and 1-FFT from Cynara scolymus 20,21) and from H. tuberosus; 22) 1-SST and 6G-FFT from Allium cepa; 18,23) and 1-SST from Festuca arundinacea; 24) and 6-SFT from Agropyron cristatum. 12) We have identiˆed cDNAs for 1-SST and 6-SFT from wheat, and this is theˆrst report of cloning 1-SST and 6-SFT from the same plant.…”

Gene Cloning and Functional Characterization by Heterologous Expression of the Fructosyltransferase of Aspergillus sydowi IAM 2544

“…Fungal as well as plant genes have successfully been expressed in yeast systems (20,31), and several plant fructosyltransferases have been expressed in transformed plants or protoplasts (7,16,38,39,47). Because plant fructosyltransferases are vacuolar enzymes (9), it can be assumed that posttranslational modification is necessary for enzymatic function and thus prevents functional expression in bacterial systems.…”