Figure 1.

Map of ndh genes (yellow) in the circular plastid DNA typical of higher plants. Some other representative genes are also indicated. Those inside the circle are transcribed clockwise (inner arrow) and those on the complementary strand counterclockwise (outer arrow) and are depicted outside. The thick lines in the circle correspond to the inverted repeated regions. Inside the circle, the ndh gene map in Arabidopsis is compared with the homologous gene map of Synechocystis as a model cyanobacterium.