Relationships between trehalose, Tre6P and sucrose content of Arabidopsis thaliana rosettes. Rosettes were harvested from 4-week-old plants at 4-h intervals through a 24-h diurnal cycle for metabolite analysis: (A,D,G) wild-type Col-0 grown at 20°C, (B,E,H) pgm mutant grown at 20°C, and (C,F,I) wild-type Col-0 grown at 20°C for 3 weeks and at 8°C for 1 week (see Figure 3). The plots show pairwise comparisons of metabolite data from individual samples. Dark symbols represent samples harvested at night, pale symbols those harvested in the light. The Pearson correlation coefficient (r) was calculated for each pair of metabolites using SigmaPlot 11 (Systat Software, Inc., Chicago, IL, USA), and significant P values are indicated by asterisks: *P<0.05, **P<0.01, ***P<0.001.