Figure 6.

Effect of light on the expression of the ΔA-NR and ΔS-NR chimeric genes. A, Plants grown in the greenhouse were placed in the dark and leaves were harvested at the beginning of a normal day/night cycle (I) and after 72 h of darkness (II). B, Northern analysis of total RNA (5 μg) using as a probe the 1.6-kb EcoRI fragment of the tobacco Nia2 NR cDNA. Ethidium bromide staining of rRNA (total RNA) is shown as a control for homogenous loading. Abbreviations of the genotypes of the transgenic lines are as defined in the legend to Figure 3 (A2′ is another sample from the A2 line).