The nucleic acid content of chloroplasts isolated from spinach and tobacco leaves

Nucleic Acid Synthesis in the Chloroplasts of Acetabularia mediterranea

“…These techniques also demonstrated that these chloroplasts synthesize RNA. It was found that label from thymine was also incorporated into DNA and RNA in these chloroplasts.With the establishment of protein and nucleic acid synthesis in Acetabutlaria chloroplasts, it is clear that these chloroplasts carry out those metabolic processes which are most characteristic of autonomous cells.To demonstrate the presence and/or synthesis of DNA in chloroplasts, it is of the utmost importance to be able to eliminate completely any possibility of nuclear DNA's interferring with the determination.Acctabularia is the ideal organism for these studies:it can easily be enucleated, its cells live for several months in this enucleated state, and its size and growth habit make it ideally suited for the various manipulations required in the experiments.Primiary emphasis in studying chloroplast DNA has been placed on establishing the presence of the DNA in chloroplast preparations (2,5,6,7,9,11,18,20).There are many characteristics of chloroplasts that would lead one to expect that this DNA is an active DNA that is replicating and synthesizing RNA (22). For example, it has been recognized for some time that chloroplasts are capable of growing and dividing independently of the growth and division of the cell.…”

“…Primiary emphasis in studying chloroplast DNA has been placed on establishing the presence of the DNA in chloroplast preparations (2,5,6,7,9,11,18,20).…”

Some Chemical Properties of Isolated Pea Nucleoli

“…The results here reported on the sedimentation properties of DNA released by disruption of nuclei have a bearing on claims that plant mitochondria and chloroplasts contain DNA (12,13). These claims are based on the presence of DNA in isolated preparations of these subcellular particles, nuclear contamination being denied either because there are no stainable nuclear fragments in the preparations (13) or because it is believed that nuclei are not readily fragmented and hence nuclear DNA should be restricted to an easily sedimentable fraction (12).…”

“…These claims are based on the presence of DNA in isolated preparations of these subcellular particles, nuclear contamination being denied either because there are no stainable nuclear fragments in the preparations (13) or because it is believed that nuclei are not readily fragmented and hence nuclear DNA should be restricted to an easily sedimentable fraction (12). Neither of these arguments, however, appears to be valid in the case of pea and wheat embryos.…”

Macromolecular Physiology of Plastids V

“…In recent years many reports on nucleic acids in chloroplasts have appeared. Biochemical analysis of isolated chloroplasts from various species have revealed the presence of both RNA and DNA (JACENDORF, 1955;BEHRENS and THALACKER, 1957;CHIBA and SUGAHARA, 1957 ;COOPER and LORING, 1957;STOCKING, 1959;IWAMURA, 1960;BIGGINS and PARK, 1961;MEGO and JAGENDORF, 1961;SZAR-KOWSKI andGOLASZEWSKI, 1961 a, 1961 b;BRAWERMAN, 1961BRAWERMAN, , 1963LYTTLETON, 1962; POCO ef a [., 1962;HEBER, 1963;KIRK, 1963KIRK, a, 1963KIRK, b, 1964KIRK, a, 1964ORTH and CORNWELL, 1963;RUPPEL, 1964; RUPPEL and VAN WYK, 1965;PARTHIER and WOLLGIEIIN, 1966). In chemical analy-ses of isolated plastids, artifacts can arise from contamination by other cell fragments, by microorganisms or loss of compounds during isolation from the cellular homogenate.…”