Figure 7.

NR activation state in leaves of wild-type and transgenic N. plumbaginifolia plants during prolonged darkness. Plants were grown in the greenhouse. Leaves were first collected at the beginning of a normal day/night cycle (L), the plants were subsequently placed in the dark, and leaves were harvested at the indicated times from four different plants of the same genotype. NR activity was assayed in crude extracts for 10 min with or without EDTA (15 mm). The NR activation state is the percentage of active NR, which corresponds to the ratio between NR activity assayed without EDTA and NR activity assayed with EDTA. Abbreviations of the genotypes of the transgenic lines are as defined in the legend to Figure 3.