Figure 5.

Light–photosynthetic response curves based on mean NCERs from experiment 1. Data represent average NCERs of 8 plantlets (n = 8). Error bars represent standard errors of mean. Depicted are (A) NCER values at 400 ppm [CO₂] (B) NCER values at 1200 ppm normalized by leaf areas. Two mean values at 0 µmol m⁻² s⁻¹ PPFD are indicative of respiration prior to and following light exposure, respectively. Two means at 50 µmol m⁻² s⁻¹ PPFD show NCERs during initial exposure from darkness to 50 µmol m⁻² s⁻¹ PPFD and exposure to the same light intensity when sequentially reduced from 400 µmol m⁻² s⁻¹ PPFD back to darkness. Respiration rates were similar before and after the light exposures, whereas NCERs at 50 µmol m⁻² s⁻¹ PPFD were reduced by approximately 10–20% at the end of experimentation.