title: Coordinated expression of functionally diverse fructosyltransferase genes is associated with fructan accumulation in response to low temperature in perennial ryegrass.
abstract: * Fructan is the major nonstructural carbohydrate reserve in temperate grasses. To understand regulatory mechanisms in fructan synthesis and adaptation to cold environments, the isolation, functional characterization and genetic mapping of fructosyltransferase (FT) genes in perennial ryegrass (Lolium perenne) are described. * Six cDNAs (prft1-prft6) encoding FTs were isolated from cold-treated ryegrass plants, and three were positioned on a perennial ryegrass linkage map. Recombinant proteins were produced in Pichia pastoris and enzymatic activity was characterized. Changes in carbohydrate levels and mRNA levels of FT genes during cold treatment were also analysed. * One gene encodes sucrose-sucrose 1-fructosyltransferase (1-SST), and two gene encode fructan-fructan 6G-fructosyltransferase (6G-FFT). Protein sequences for the other genes (prfts 1, 2 and 6) were similar to sucrose-fructan 6-fructosyltransferase (6-SFT). The 1-SST and prft1 genes were colocalized with an invertase gene on the ryegrass linkage map. The mRNA levels of prft1 and prft2 increased gradually during cold treatment, while those of the 1-SST and 6G-FFT genes first increased, but then decreased before increasing again during a longer period of cold treatment. * Thus at least two different patterns of gene expression have developed during the evolution of functionally diverse FT genes, which are associated in a coordinated way with fructan synthesis in a cold environment.
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hisano
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kanazawa
authors.affiliation: National Agricultural Research Center for Hokkaido Region, Hitsujigaoka, Sapporo 062-8555, Japan.
authors.forename: Midori
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth, Ceredigion SY23 3EB, UK.
authors.forename: Mervyn O
authors.initials: MO
authors.lastname: Humphreys
authors.affiliation: Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Osaka 558-8585, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Iizuka
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kitamura
authors.affiliation: Field Science Center for Northern Biosphere, Hokkaido University, Sapporo 060-0811, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Yamada
mesh_terms: D000595:Amino Acid Sequence; D050260:Carbohydrate Metabolism; D002851:Chromatography, High Pressure Liquid; D002874:Chromosome Mapping; D002999:Clone Cells; D003080:Cold Temperature; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D018744:DNA, Plant / Q000378:metabolism; D005630:Fructans / Q000378:metabolism*; D018628:Gene Dosage; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006602:Hexosyltransferases / Q000737:chemistry / Q000235:genetics*; D008129:Lolium / Q000201:enzymology* / Q000235:genetics*; D008954:Models, Biological; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D001426:Bacterial Proteins
chemical_list: D018076:DNA, Complementary; D018744:DNA, Plant; D005630:Fructans; D006602:Hexosyltransferases; D012333:RNA, Messenger; C021451:inulosucrase; D001426:Bacterial Proteins