Marker free transgenic plants: engineering the chloroplast genome without the use of antibiotic selection

摘要

Integration and expression plastid vectors competent for stably transforming the plastid genome where growth is inhibited by an antibiotic-free phytotoxic agent comprises an expression cassette comprising, as operably joined components, a 5' part of the plastid DNA sequence inclusive of a spacer sequence, a promoter operative in the plastid, a DNA sequence encoding a detoxifying enzyme or protein acting as a selectable marker which is capable of detoxifying the antibiotic-free phytotoxic agent in the cells to the corresponding nontoxic compound, at least one restriction site for the insertion of a heterologous target gene, a transcription termination region functional in the plastid, and the 3' part of a plastid DNA sequence inclusive of the spacer sequence. Preferably the DNA sequence encodes betaine aldehyde dehydrogenase (BADH). Stably transformed plants and methods for transforming plastid genomes of a plant cell in which selection is antibiotic-free and based upon chlorophyll synthesis in the dark or feedback inhibition are described.