XVI International Botanical Congess

Freezing-tolerant plants such as wheat and forage grasses accumulate a large amount of water-soluble fructan during hardening. Fructan have been reported to play an important role for several stresses in plant. Accumulation of fructan is highly associated with both freezing tolerance and snow mold resistance of wheat (Yoshida et al., Physiol. Plant. 1998). In this study, it is objective to isolate wheat genes controlling fructan metabolism. Two types of cDNA clones possessing high homology with sucrose-metabolic enzymes, named wft-1 and wft-2, have been successfully isolated from crown tissue of hardened winter wheat. Wft-1 and wft-2 show 93% of identity to 6-SFT (sucrose: fructan 6-fructosyltransferase) gene of barley and 55% identity to sugar cane invertase, respectively. Both clones have several consensus peptide sequences conserved in sugar-metabolic enzymes of vacuole.