Molecular characterization of sucrose:sucrose 1-fructosyltransferase and sucrose:fructan 6-fructosyltransferase associated with fructan accumulation in winter wheat during cold hardening.
We isolated two cDNAs of winter wheat (Triticum aestivum L.), designated wft1 and wft2, which encoded sucrose:fructan 6-fructosyltransferase (6-SFT) and sucrose:sucrose 1-fructosyltransferase (1-SST; EC 2.4.1.99), respectively, which are involved in the synthesis of fructan in wheat. wft1 and wft2 were cloned by screening of a cDNA library with probed-cDNA fragments corresponding to plant fructosyltransferase and invertase. The identity of the clones was verified by functional characterization of recombinant proteins expressed in methylotrophic yeast, Pichiapastoris. Northern blotting showed that the level of wft2 transcripts increased from autumn to early winter in the crown tissues of all field-grown wheat cultivars examined. Higher levels of wft1 and wft2 transcripts were found in leaf tissues of snow mold-resistant cultivars, which accumulated more fructan than other cultivars. Our results showed that Wft1 and Wft2 were important in fructan accumulation during cold hardening of winter wheat.
Kawakami
Akira
A
National Agricultural Research Center for Hokkaido Region, Hitsujigaoka, Sapporo 062-8555, Japan.
Yoshida
Midori
M
D000595:Amino Acid Sequence; D001665:Binding Sites; D015152:Blotting, Northern; D002241:Carbohydrates / Q000032:analysis; D003001:Cloning, Molecular; D003080:Cold Temperature; D016384:Consensus Sequence; D018076:DNA, Complementary / Q000235:genetics; D005630:Fructans / Q000032:analysis* / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D006602:Hexosyltransferases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010843:Pichia / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012621:Seasons; D012639:Seeds / Q000254:growth & development; D013395:Sucrose / Q000378:metabolism; D014908:Triticum / Q000201:enzymology / Q000378:metabolism*; D043324:beta-Fructofuranosidase; D001426:Bacterial Proteins
D002241:Carbohydrates; D018076:DNA, Complementary; D005630:Fructans; D006026:Glycoside Hydrolases; D006602:Hexosyltransferases; D011994:Recombinant Proteins; D013395:Sucrose; D043324:beta-Fructofuranosidase; C097181:sucrose - fructan 6-fructosyltransferase; C021451:inulosucrase; D001426:Bacterial Proteins