A Localized Effect of Light on the Protoplasmic Viscosity of Plant Cells

(1) The effect of temperature on the viscosity of the protoplasm has been determined in the unripe eggs of Nereis diversicolor by the centrifuge method.The viscosity rises as the temperature falls, the rise becoming rapid near 0°C.(2) These changes of viscosity with temperature are similar to those described by Weber (21) in the protoplasm of certain plant cells.(3) Attention is drawn to the fact that the temperature coefficients of biological processes should be corrected for the viscosity of the protoplasm in which they occur.(4) It is shown that the relative changes of protoplasmic viscosity with temperature are probably of the order required to make the temperature coefficients of biological processes constant when corrected for the viscosity factor.(5) The magnitude of the temperature coefficients of biological processes when corrected for viscosity changes is probably of the same order as that of the temperature coefficients of a chemical process when corrected for changes in the viscosity of its medium.

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The Effect of Light on the Protoplasmic Viscosity

Physiologia Plantarum ◽

10.1111/j.1399-3054.1951.tb07522.x ◽

1951 ◽

Vol 4 (2) ◽

pp. 255-357 ◽

Cited By ~ 63

Author(s):

Hemming I. Virgin

Keyword(s):

Protoplasmic Viscosity ◽

Effect Of Light

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Effect of Light on Caffeine Production by Plant Cells of Coffea arabicaa

Annals of the New York Academy of Sciences ◽

10.1111/j.1749-6632.1990.tb18216.x ◽

1990 ◽

Vol 613 (1 Enzyme Engine) ◽

pp. 538-541 ◽

Cited By ~ 2

Author(s):

HIROYUKI KURATA ◽

MINORU SEKI ◽

SHINTARO FURUSAKI ◽

TSUTOMU FURUYA

Keyword(s):

Plant Cells ◽

Effect Of Light

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Effect of light intensity on the ultrastructure of the filamentous cyanobacterium, Anabaena variabilis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100103565 ◽

1988 ◽

Vol 46 ◽

pp. 300-301

Author(s):

C. S. Bricker ◽

S. R. Barnum ◽

B. Huang ◽

J. G. Jaworskl

Keyword(s):

Fatty Acid ◽

Light Intensity ◽

Acid Content ◽

Fatty Acid Content ◽

Anabaena Variabilis ◽

Chloroplast Envelope ◽

Major Constituent ◽

Filamentous Cyanobacterium ◽

Photosynthetic Membrane ◽

Effect Of Light

Cyanobacteria are Gram negative prokaryotes that are capable of oxygenic photosynthesis. Although there are many similarities between eukaryotes and cyanobacteria in electron transfer and phosphorylation during photosynthesis, there are two features of the photosynthetic apparatus in cyanobacteria which distinguishes them from plants. Cyanobacteria contain phycobiliproteins organized in phycobilisomes on the surface of photosynthetic membrane. Another difference is in the organization of the photosynthetic membranes. Instead of stacked thylakolds within a chloroplast envelope membrane, as seen In eukaryotes, IntracytopIasmlc membranes generally are arranged in three to six concentric layers. Environmental factors such as temperature, nutrition and light fluency can significantly affect the physiology and morphology of cells. The effect of light Intensity shifts on the ultrastructure of Internal membrane in Anabaena variabilis grown under controlled environmental conditions was examined. Since a major constituent of cyanobacterial thylakolds are lipids, the fatty acid content also was measured and correlated with uItrastructural changes. The regulation of fatty acid synthesis in cyanobacteria ultimately can be studied if the fatty acid content can be manipulated.

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SEM study of the morphological effects of kinetin and zeatin on the growth and development of the apical meristem in wheat

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141263 ◽

1995 ◽

Vol 53 ◽

pp. 978-979

Author(s):

G. M. Hutchins ◽

J. S. Gardner

Keyword(s):

Growth And Development ◽

Furfuryl Alcohol ◽

Apical Meristem ◽

Plant Cells ◽

Triticum Aestivum L ◽

Morphological Development ◽

Naturally Occurring ◽

Chinese Spring Wheat ◽

Sem Study ◽

Moist Environment

Cytokinins are plant hormones that play a large and incompletely understood role in the life-cycle of plants. The goal of this study was to determine what roles cytokinins play in the morphological development of wheat. To achieve any real success in altering the development and growth of wheat, the cytokinins must be applied directly to the apical meristem, or spike of the plant. It is in this region that the plant cells are actively undergoing mitosis. Kinetin and Zeatin were the two cytokinins chosen for this experiment. Kinetin is an artificial hormone that was originally extracted from old or heated DNA. Kinetin is easily made from the reaction of adenine and furfuryl alcohol. Zeatin is a naturally occurring hormone found in corn, wheat, and many other plants.Chinese Spring Wheat (Triticum aestivum L.) was used for this experiment. Prior to planting, the seeds were germinated in a moist environment for 72 hours.

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Confocal microscopy of the cytoskeleton in living plant cells following microinjection of fluorescent probes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146497 ◽

1993 ◽

Vol 51 ◽

pp. 130-131

Author(s):

Ann Cleary

Keyword(s):

Cell Division ◽

Fluorescent Probes ◽

Actin Filaments ◽

Intracellular Transport ◽

Cell Structure ◽

Plant Cells ◽

Cell Plate ◽

Cell Cortex ◽

Living Plant ◽

Rhodamine Phalloidin

Microinjection of fluorescent probes into living plant cells reveals new aspects of cell structure and function. Microtubules and actin filaments are dynamic components of the cytoskeleton and are involved in cell growth, division and intracellular transport. To date, cytoskeletal probes used in microinjection studies have included rhodamine-phalloidin for labelling actin filaments and fluorescently labelled animal tubulin for incorporation into microtubules. From a recent study of Tradescantia stamen hair cells it appears that actin may have a role in defining the plane of cell division. Unlike microtubules, actin is present in the cell cortex and delimits the division site throughout mitosis. Herein, I shall describe actin, its arrangement and putative role in cell plate placement, in another material, living cells of Tradescantia leaf epidermis.The epidermis is peeled from the abaxial surface of young leaves usually without disruption to cytoplasmic streaming or cell division. The peel is stuck to the base of a well slide using 0.1% polyethylenimine and bathed in a solution of 1% mannitol +/− 1 mM probenecid.

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Scanning electron microscopy of plant cells using a variable-pressure SEM and cryogenic techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100147144 ◽

1993 ◽

Vol 51 ◽

pp. 260-261

Author(s):

M. Yamada ◽

K. Ueda ◽

K. Kuboki ◽

H. Matsushima ◽

S. Joens

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Saturated Vapor ◽

Plant Cells ◽

Variable Pressure ◽

Specimen Preparation ◽

Operating Pressure ◽

Vapor Pressures ◽

Low Temperature Microscopy ◽

Scanning Electron

Use of variable Pressure SEMs is spreading among electron microscopists The variable Pressure SEM does not necessarily require specimen Preparation such as fixation, dehydration, coating, etc which have been required for conventional scanning electron microscopy. The variable Pressure SEM allows operating Pressure of 1˜270 Pa in specimen chamber It does not allow microscopy of water-containing specimens under a saturated vapor Pressure of water. Therefore, it may cause shrink or deformation of water-containing soft specimens such as plant cells due to evaporation of water. A solution to this Problem is to lower the specimen temperature and maintain saturated vapor Pressures of water at low as shown in Fig. 1 On this technique, there is a Published report of experiment to have sufficient signal to noise ratio for scondary electron imaging at a relatively long working distance using an environmental SEM. We report here a new low temperature microscopy of soft Plant cells using a variable Pressure SEM (Hitachi S-225ON).

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