Fig. 4.

Carbohydrate content of arabidopsis plants grown with constant irradiance under fluorescent or LED lights. Arabidopsis thaliana Col-0 plants were grown in controlled environment chambers with a 12-h photoperiod and daily light integral (DLI) of 7 mol m⁻² d⁻¹. Illumination was provided by either white fluorescent tubes (blue) or LEDs (grey) with a constant irradiance during the day, and rosettes were harvested from 4-week-old plants throughout a 24-h diurnal cycle for metabolite analysis. (A) Starch and (B) sucrose were measured enzymatically, and (C) sucrose 6′-phosphate (Suc6P) was measured by LC-MS/MS. Data are means ±SD (n=4, fluorescent; n=3, LED). At each time point, significant differences between the two conditions are indicated as follows: *P<0.05, **P<0.01, ***P<0.001 (Student’s t-test). ZT, zeitgeber time (hours after dawn).