Plant cell, electron micrograph

Plant cell, electron micrograph 13 Plant cells and tissues 29, 30 fiber 11... 

This chapter is an introduction to methods-oriented microscopy. Because the contributing authors present methods in relation to their researches, plant cell structure-function relationships as revealed by light and electron microscopies are reviewed. Much of this conceptual and terminological information is summarized in tables that are augmented with references to either photomicrographs or electron micrographs of cells and tissues. 

Electron crystallography 131 Electron micrograph of bacteria 4 of cell junctions 27 of plant cell 13 of starch granules 172 of viruses 246... 

Fibril arrangements in the cell wall of Valonia (12,000 X), (Electron micrograph from A. Frey-Wyssling and K. Miihlethaler, Ultrastructural Plant Cytology, Elsevier Science Publishers, Amsterdam, 1965, p. 298. Reprinted with permission from Elsevier Science Publishers.)... 

Fig. 13. Thylakoid-membrane structure. (A) a (spinach) leaf and (B) a cross-sectional view of the leaf (C) an electron micrograph of a single chloroplast and (O ) a sketch showing idealized structure of a chloroplast (D) magnified view of a portion of the chloroplast interior and (O ) a sketch showing a portion of the thylakoids. See text for discussion. (C) and (D) kindly furnished by Dr. Andrew Staehelin (D ) from Anderson and Beardall (1991) Molecular Activities of Plant Cells. An Introduction to Plant Biochemistry, p 42. Blackwell Sci Publ.

The x-ray approach has few peers as regards nondestructive definition of structure at the secondary level. Although microscopy is more direct, the preparative problems and necessary subjectiveness in the interpretation of photo- and electron micrographs make absolutely necessary the joint use of the two techniques. The work of Preston and his school on the structural polysaccharides of plants is a good example of how the two techniques should be combined. A rough textural model of the molecular architecture of a cell wall of a plant is capable of quantitative and detailed definition by means of the complete, wide and small angle, x-ray scattering curve. This application is, perhaps, one of the potentially more fruitful, areas of future study it is part of the major, solid-state... 

Fig. 2. Transmission electron micrograph (16,000x enlargement) through an infected root cell of a soybean plant. The subcellular organelles of the host cell [mitochondria and plasts (a)] are present at the periphery of the cell adjacent to the host cell wall (b). The nitrogen-fixing bacteroids (c) are kept apart from the host cell cytoplasm (the location of leghemoglobin) by the peribacteroid space (d) and the peribacteroid membrane (e), which regulates transport of materials to and from the bacteroids.

The seeds of many plants contain fat as the major carbon reserve in some, such as those of castor bean, this is stored in the endosperm tissue surrounding the embryo, while in those of cucurbits and other plants it is stored in the cotyledons. Electron micrographs of the storage tissue show that the cells are almost completely occupied by spherosomes (membrane-bound vesicles of fat) and by protein bodies (e.g.. Vigil, 1970). 

Fig. 2.11. Electron micrograph of a replica of a frozen and etched wheat (Triticum) root tip cell. Sheets of ER have been fractured and exposed both in transverse and surface view. Fenestrations in the ER are visible (F) and there are also casts of two unidentified cytoplasmic organelles (C). (From F. A. L. Clowes and B. E. Juniper, Plant Cells, Blackwell Scientific Publications, Oxford, 1968. Micrograph by Dr. D. H. Northcote.)...

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