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Membranes of Mesophyll Cells of Nicotiana Rustica and Phaseolus Vulgaris with Particular Reference to the Chloroplast

1962; Wiley; Volume: 49; Issue: 8 Linguagem: Inglês

10.2307/2439692

1537-2197

T. E. Weier, William W. Thomson,

Magnetic and Electromagnetic Effects

American Journal of BotanyVolume 49, Issue 8 p. 807-820 Article MEMBRANES OF MESOPHYLL CELLS OF NICOTIANA RUSTICA AND PHASEOLUS VULGARIS WITH PARTICULAR REFERENCE TO THE CHLOROPLAST† T. E. Weier, T. E. Weier Department of Botany, University of California, Davis, CaliforniaSearch for more papers by this authorW. W. Thomson, W. W. Thomson Department of Botany, University of California, Davis, CaliforniaSearch for more papers by this author T. E. Weier, T. E. Weier Department of Botany, University of California, Davis, CaliforniaSearch for more papers by this authorW. W. Thomson, W. W. Thomson Department of Botany, University of California, Davis, CaliforniaSearch for more papers by this author First published: 01 September 1962 https://doi.org/10.1002/j.1537-2197.1962.tb15013.xCitations: 21 †It is a pleasure to acknowledge our indebtedness to T. Risley for the micrographs for Fig. 8, 16, and to Ann Harrison and Rodney Asmundson for technical assistance. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract Weier, T. E., and W. W. Thomson. (U. California, Davis.) Membranes of mesophyll cells of Nicotiana rustica and Phaseolus vulgaris with particular reference to the chloroplast. Amer. Jour. Bot. 49(8): 807–820. Illus. 1962.—The endoplasmic reticulum in mesophyll cells is represented by short lengths of irregularly disposed, paired membranes. It is occasionally associated with a typically double nuclear envelope. Groups of irregularly parallel, paired membranes suggesting disorganized dictyosomes occur infrequently. Mitochondria are unevenly distributed in mesophyll; they are large and have sparse tubular cristae around their periphery. In the great majority of instances the bounding membrane is diffusely stained with KMnO4. When it is sharp and distinct, it may be double as usually pictured, or it may have well-delineated stretches of a single membrane bounding 25–50% of its circumference. The tonoplast and ectoplast are very fragile, the former appearing as a single dark line. In young leaves the ectoplast is visualized as a continuous single membrane adjacent to the cell wall, but in our micrographs of mature leaves it is always discontinuous. The plastid membrane sometimes is distinctly double, having 2 dark components bounding a light component. In the great majority of cases, however, this membrane is either a solid dark line, or the clear component of the double membrane is crossed by delicate dark lines giving the membrane a braided, or scalariform appearance. The various appearances of the membrane may intergrade with each other. The width of the plastid membrane is variable, ranging from 200 to 400 A. The inner component may invaginate into the stroma, and bodies may form in the clear space between the 2 outer membrane components. Micrographs suggest that these bodies, and others formed by small masses of stroma, may be expelled into the hyaloplasm, where they exist as spherical single-membraned particulates. The reality of the variable structure of the plastid membrane is discussed in light of concepts of membrane activity, molecular structure, and the relation of these factors to possible artifacts. Citing Literature Volume49, Issue8September 1962Pages 807-820 RelatedInformation