Figure 6.

NR activation rate is reduced in low B55 dosage plants. Plants were grown in 16-h light/8-h darkness for 3 weeks. Three hours into the photoperiod when NR activity was at a high level samples were harvested before subjected to darkness. Samples were then harvested after 45 min of darkness. Plants were transferred back to light for activation of NR, and sampled after 15 and 30 min of light (150 μmol m⁻² s⁻¹). Data are means of five samples at 0, 45, and 60 min, and three samples at 75 min. se is given. The plants used were first determined by PCR to be heterozygous for the mutation T-DNA insert in Bα and homozygous for insert in Bβ (homozygosis for insert in both genes appeared lethal, see text).