Figure 3.

Accumulation of fumarate and Suc in different environmental conditions. Fumarate (A) and Suc (B) levels were determined by enzyme-linked assays following exposure for one photoperiod to different environmental conditions. Plants of Col-0 and fum2.2 were grown under 100 µmol m² s⁻¹ light, 8 h light/16 h dark, 500 µL L⁻¹ CO₂, and 20°C light/18°C dark conditions for 8 weeks. Plants were then transferred to control (identical) conditions, low temperature (4°C), high carbon dioxide (1500 µL L⁻¹), or high light (400 µmol m² s⁻¹ light) for one photoperiod. Measurements were taken at the end of the photoperiod (8 h) from liquid N₂ flash-frozen, fully expanded leaves, as in Figure 2.