Chloroplast DNAs of Spinacia, Petunia and Spirodela have a similar gene organization.

We have located the positions of the genes coding for the α, β and ε subunits of the ATPase complex on Spirodela oligorhiza chloroplast DNA by means of heterologous hybridization with Spinacia cpDNA fragments.The overall cpDNA sequence organization of Petunia hybrida and Spirodela was compared. We hybridized well-characterized, cloned Spirodela cpDNA fragments with size fractionated Petunia cpDNA digested by Sall. It appears that the monocotyledonous Spirodela and the dicotyledonous Petunia cpDNA share a common sequence organization around their entire circumference. These observations, together with data reported in the literature, indicate a strikingly similar genetic organization of the chloroplast genome in widely divergent plants.