We are grateful to N. Shiomi (Hokkaido University, Japan) for the gift of isokestose and neokestose standards; to B. Baxter (Shell, U.K., Sittingbourne) for the gift of isomers of MDMP; to H. Thomas (WPBS, Aberystwyth) and T. Housley (Purdue University, Indiana) for technical advice and to Margaret Mack for typing services. This work was funded under the AFRC Scientific initiative scheme and was carried out during the tenure of NATO grant CRG 0706/87 (to C.J.P.)
Fructan biosynthesis in excised leaves of Lolium temulentum L.
II. Changes in fructosyl transferase activity following excision and application of inhibitors of gene expression
Article first published online: 28 APR 2006
Volume 109, Issue 4, pages 407–413, August 1988
How to Cite
CAIRNS, A. J. and POLLOCK, C. J. (1988), Fructan biosynthesis in excised leaves of Lolium temulentum L. New Phytologist, 109: 407–413. doi: 10.1111/j.1469-8137.1988.tb03716.x
- Issue published online: 28 APR 2006
- Article first published online: 28 APR 2006
- Received 26 January 1988; accepted 21 March 1988
- Key words: Lolium temulentum, leaf, fructosyl transferase, inhibitor, gene expression, fructan oligosaccharide
Following the initiation of soluble carbohydrate accumulation in excised illuminated leaves of Lolium temulentum L., extractable sucrose: sucrose fructosyl transferase activity rose concomitant with the onset of fructan synthesis Extractable enzyme activity was sufficient to account for rates of fructan accumulation in vivo The major trisaccharide products of transferase activity in vitro were isokestose and kestose. This differed from the patterns of trisaccharide accumulation in vivo, where isokestose and neokestose predominated.
Excised leaves treated with inhibitors of protein synthesis and of RNA metabolism accumulated water-soluble carbohydrate at similar rates to control tissue, but did not convert sucrose into fructan. Inhibitor treatment also prevented increase in extractable sucrose: sucrose fructosyl transferase activity, suggesting that initiation of fructan biosynthesis was mediated by altered patterns of gene expression. These results are discussed in relation to the control of the synthesis of the oligofructosides characteristic of this tissue.