The invention provides processes for generating transgenic plants or plant cells transformed on their plastome, comprising introducing into plant plastids a first and a second DNA molecule, wherein the first DNA molecule contains a first region homologous to a region of the plastome for directing plastome integration and a first sequence of interest, and the second DNA molecule contains a second region homologous to a region of the plastome and a second sequence of interest, whereby a sequence segment of the first sequence of interest is homologous to a sequence segment of the second sequence of interest, and selecting transformants having an integration sequence stably integrated in the plastome, whereby the integration sequence contains at least a portion of the first and second sequences of interest as a continuous sequence. The invention further provides plant cells, plants, and seeds of plants produced by such processes.