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Titolo:
Fructan biosynthesis in Lolium perenne: appraisal of soluble and insolubleenzymatic pathways
Autore:
Guerrand, D; Avice, JC; Pavis, N; Prudhomme, MP; Boucaud, J;
Indirizzi:
Univancen, IRBA, UA INRA, Lab Physiol & Biochim Vegetales, F-14032 Caen, Fr Univ Caen Caen France F-14032 siol & Biochim Vegetales, F-14032 Caen, Fr
Titolo Testata:
NEW PHYTOLOGIST
fascicolo: 1, volume: 141, anno: 1999,
pagine: 109 - 118
SICI:
0028-646X(199901)141:1<109:FBILPA>2.0.ZU;2-5
Fonte:
ISI
Lingua:
ENG
Soggetto:
FRUCTOSYL TRANSFERASE-ACTIVITY; EXCISED LEAVES; CARBOHYDRATE CONTENT; DENOVO SYNTHESIS; TEMULENTUM L; KEY ENZYME; SUCROSE; METABOLISM; BARLEY; WHEAT;
Keywords:
defoliation; fructans; fructosyltransferase; Lolium perenne; phlein sucrase;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
27
Recensione:
Indirizzi per estratti:
Indirizzo: Prud'homme, MP Univancen, IRBA, UA INRA, Lab Physiol & Biochim Vegetales, F-14032 Caen, Fr Univ Caen Caen France F-14032 Vegetales, F-14032 Caen, Fr
Citazione:
D. Guerrand et al., "Fructan biosynthesis in Lolium perenne: appraisal of soluble and insolubleenzymatic pathways", NEW PHYTOL, 141(1), 1999, pp. 109-118

Abstract

Previous work on Lolium perenne showed that sucrose:sucrose fructosyltransferase (SST) activity did not increase concomitantly with fructan synthesisin regrowing leaves or in mature leaf blades of plants that have been subjected to carbohydrate-accumulating conditions. This was contrary to the pattern of SST activity in roots and stubble. To obtain further insight into the fructan synthesizing activities and to explain this discrepancy, total fructosyltransferase activity (FT) was assayed by increasing the sucrose andthe soluble enzyme concentrations and was compared to sedimentable phlein sucrase activity (PS) throughout the regrowth period following defoliation in leaves, stubble and roots. Before analysis on 2-month-old plants, PS activity was characterized in dark-grown coleoptiles, using [U-C-14]sucrose. PS activity had a pH optimum of 6.0 and produced 1-kestose in addition to high molecular weight fructans with a mean DP of 9. In 2-month-old plants, sedimentable PS and FT soluble reactions contained an initial sucrose concentration of 160 mM and 400 mM and proteins equivalent to 1.4 and 2.1 g f. wt of tissue, respectively. In stubble and roots, the FT preparation catalysedthe synthesis of large fructans, and the overall pattern resembled the native fructans when separated by anion exchange HPLC. In regrowing leaves, the FT preparation produced low-DB fructans relatively more than in vivo but synthesized the high-DP fructan characteristic of the tissue. Moreover, FT activity did not remain at a low level like SST activity but increased fromday 5 after defoliation when fructans began to accumulate. PS activity formed very few low-DP fructans and 1-kestose was the main product. Trisaccharides generated by PS activity represented 2-5% of the total trisaccharide synthesis. High-DB fructans were detectable only when the products of the reaction were concentrated 100 times. Results are discussed with respect to the relative contribution of FT and PS activities for the synthesis of 1-kestose and fructans in roots, stubble and leaves of Lolium perenne.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 19:36:16