The dimorphic chloroplasts of the C4 plant panicum maximum contain identical genomes

Walbot, V (1977) The dimorphic chloroplasts of the C4 plant panicum maximum contain identical genomes. Cell, 11 (4). pp. 729-737.

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Abstract

The physical properties, including contour length, buoyant density and Tm, of chloroplast DNA isolated from purified mesophyll (MC) and bundle sheath chloroplasts (BSC) of a C4 plant are identical. DNA renaturation measurements indicate that both DNAs have a complexity of 9.1 × 107 daltons. BSC and MC chloroplast are homologous as measured using 203Hg-labeled DNA hybridized as a tracer with an excess of the second DNA type, retention of heteroduplexes on a sulfhydryl affinity column and testing for mismatch by measuring the release of 203Hg-C after digestion with S1 single-strand-specific nuclease. The Sal restriction endonuclease patterns determined by electron microscopic measurement of DNA fragment lengths of the two DNA types are identical. The only detectable difference between the two chloroplasts is the DNA content: bundle sheath chloroplasts contain approximately 50 copies of the genome as opposed to 20 in mesophyll chloroplasts. Chloroplasts DNAs from the C4 plant share approximately 95% homology with the chloroplast DNA of a C3 (Calvin cycle pathway) plant of the same genus. Thus the significant differences in physiology and morphology between mesophyll and bundle sheath chloroplasts of C4 plants and between the plastids of C3 and C4 plants are not due to major differences in the genetic complement of mature plastids.

Item Type:	Article
Author Affiliation:	Washington University, St Louis, Missori
Subjects:	Plant Production Crop Improvement
Divisions:	General
Depositing User:	Library ICRISAT-InfoSAT
Date Deposited:	25 Feb 2012 08:41
Last Modified:	25 Feb 2012 08:41
Official URL:	http://dx.doi.org/10.1016/0092-8674(77)90287-2
URI:	http://eprints.icrisat.ac.in/id/eprint/3246

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