Diurnal changes in sucrose, Tre6P and trehalose content of Arabidopsis thaliana rosettes. (A-C) Wild-type A. thaliana Col-0 plants and (D-F) plastidial phosphoglucomutase (pgm) mutant plants were grown in a 12 h light/12 h dark diurnal cycle at 20°C. (G-I) Wild type Col-0 plants were also grown at 20°C for 3 weeks and then transferred to 8°C for 1 week. Rosettes were harvested from 4-week-old plants at 4-h intervals through a complete 24-h diurnal cycle for measurement of trehalose and other metabolites. n.b. expanded y-axis scale for sucrose content of Col-0 plants at 8°C (G). Data are mean ± SD, n = 4 (WT, 20°C) or 5 (WT, 8°C and pgm).