Figure 1.

Dynamic photosynthetic acclimation in Arabidopsis. A, Maximum photosynthetic capacity, measured at 1,500 μmol m⁻² s⁻¹ white light and 2,000 μL L⁻¹ CO₂ in eight accessions of Arabidopsis grown for 8 weeks at an irradiance of 100 μmol m⁻² s⁻¹ and then maintained in the same conditions (white bars) or transferred to 400 μmol m⁻² s⁻¹ light (hatched bars) for 9 d. Accessions measured were Ws-2, Col-0, Landsberg erecta (Ler), Nossen (No), Oystese (Oy), Martuba (Mt), Cape Verdi Island (Cvi), and C24. Asterisk (*) indicates that treated plants differ significantly from their respective control (P < 0.05). B, Changes in maximum rate of photosynthesis in Ws following a step increase in light from 100 to 400 μmol m⁻² s⁻¹ (black circles) compared to plants maintained at 100 μmol m⁻² s⁻¹ (white circles). C, Net CO₂ assimilation of Ws as a function of irradiance, in plants grown at 100 μmol m⁻² s⁻¹ (white circles) or transferred to 400 μmol m⁻² s⁻¹ (black circles) for 9 d. All data represent the mean (±se) of at least three replicates.