• fructan;
  • sucrose;
  • meristem;
  • chilling;
  • Gramineae


Plants of Lolium temulentum L. grown at 20 °C were transferred to 5 °C at the beginning of the light period. Sucrose accumulation was much more marked at low temperatures, with increases in rate detectable about 1 h following transfer. Exposure to low temperature over 7 d resulted in appearance of fructan, initially as oligosaccharides, and eventually as polymers of higher molecular weight. Sucrose accumulation was most marked in the blades of mature leaves, whereas the accumulation of fructan was maximal in the meristernatic regions of developing leaves. Chilling also led to a rise in activity of sucrose: sucrose fructosyltransferase, the first enzyme specifically involved in the biosynthesis of fructans. This activity was also higher in leaf meristems than in other regions of the plant.