Organelle DNA Isolation

Green plants and photosynthetic organisms are unique among eukaryotes since they possess three genomes: the nuclear, the mitochondrial and the plastid. The first indication that genes were present in the cytoplasm was discovered by the inheritance of certain traits that did not follow Mendel’s rules. Even though these observations were made as early as the beginning of the 20th century, it was not until the 1960s that convincing physical evidence was obtained regarding presence of unique DNA in chloroplasts (Chun et al. 1963; Sager and Ishida 1963) and mitochondria (Luck and Reich 1964). Since then, the rapid development in molecular techniques has contributed enormously to our knowledge about genome organization, gene content and gene structure. For details of the genetics and molecular biology of the organelles in higher plants, the readers are referred to review articles in the field (Lonsdale 1989; Gray 1990; Bogorad and Vasil 1991; Herrmann 1992).