Changes in chloroplast DNA during development in tobacco, Medicago truncatula, pea, and maize

• Published in: Planta Vol. 224; no. 1; pp. 72 - 82
• Main Authors: Shaver, J.M, Oldenburg, D.J, Bendich, A.J
• Format: Journal Article
• Language: English
• Published: Berlin Springer-Verlag 01.06.2006; Springer; Springer Nature B.V
• Subjects: Alfalfa; Bacteria; Biological and medical sciences; Cell Fractionation; Chloroplast DNA; Chloroplasts; Chloroplasts - drug effects; Chloroplasts - genetics; Complexity; Corn; Deoxyribonucleases - pharmacology; Deoxyribonucleic acid; Deproteinization; DNA; DNA structure; DNA, Chloroplast - metabolism; Electrophoresis; Ethidium; Ethidium bromide; Fluorescence; fluorescence microscopes; Fundamental and applied biological sciences. Psychology; Gel electrophoresis; Genomes; Leaf development; Leaves; Medicago truncatula; Medicago truncatula - cytology; Medicago truncatula - genetics; Medicago truncatula - growth & development; Microbiology; Microscopy, Fluorescence; Nicotiana - cytology; Nicotiana - genetics; Nicotiana - growth & development; Nicotiana tabacum; Peas; Pisum sativum; Pisum sativum - cytology; Pisum sativum - genetics; Pisum sativum - growth & development; Plant cells; Plant growth. Development of the storage organs; Plant Leaves - cytology; Plant Leaves - genetics; Plant Leaves - growth & development; Plant physiology and development; Plastids; Pulsed-field gel electrophoresis; Regeneration; Somatic cells; Staining; Tobacco; Vegetative apparatus, growth and morphogenesis. Senescence; Zea mays; Zea mays - cytology; Zea mays - genetics; Zea mays - growth & development; Medicago truncatula; Monocotyledones; Zea mays; Chloroplast DNA; DAPI; Plant leaf; Plastid; Nicotiana tabacum; Regeneration; Pulsed-field gel electrophoresis; Leguminosae; Gramineae; Dicotyledones; Pisum sativum; Angiospermae; Development; Spermatophyta; Solanaceae; Chloroplast; Fluorescence microscopy
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-005-0195-7

We examined the DNA from chloroplasts obtained from young and fully expanded leaves of tobacco (Nicotiana tabacum L.), Medicago truncatula, pea (Pisum sativum L.), and maize (Zea mays L.). The changes in plastid DNA content and structure were monitored by four independent methods: 4',6-diamidino-2-phenylindole (DAPI) staining with intact chloroplasts, in situ DAPI staining of cytological sections, ethidium bromide staining at the single-molecule level after exhaustive deproteinization of lysed chloroplasts, and pulsed-field gel electrophoresis. During leaf development, we found a decline of chloroplast DNA (cpDNA) in all four plants. For tobacco, for which plants can readily be regenerated from somatic cells, cpDNA persisted longer than in the other three plants. We also found a striking progression from complex multigenomic DNA molecules to simple subgenomic molecules during plastid development. Although the decrease in molecular size and complexity paralleled the decrease in DNA content per plastid, 6% of the chloroplasts in a fully expanded tobacco leaf still contained DNA in complex branched structure, whereas no such complex structures were found in mature leaves for the hard-to-regenerate maize.