Microinjection of DNA into chloroplasts in vivo
Microinjection of DNA directly into chloroplasts should also be possible in future, although there may be technical problems which will have to be overcome. For instance, in higher plants, each cell has many plastids and each plastid has several genomes.
Therefore, number of plastids per cell may have to be artificially reduced and the optimal number of chloroplasts to be injected per cell will have to be determined. This will be difficult, because the fate of chloroplasts and their genomes during regeneration of protoplasts is not fully understood.
However, microinjection as a method for transformation of Chlamydomonas chloro­plasts should be a distinct possibility, due to its large size and the presence of a single chloroplast per cell.