Cytoskeleton-Organelle Interaction: Higher Plant Chloroplasts Are Contained In Actin Baskets And Attached To Actin Filaments And Bundles

2000 ◽  
Vol 6 (S2) ◽  
pp. 296-297
Author(s):  
M.K. Kandasamy ◽  
R.B. Meagher
Keyword(s):  
Cell Proliferation ◽  
Actin Filaments ◽  
Higher Plants ◽  
Plant Cells ◽  
Latrunculin B ◽  
Higher Plant ◽  
Photosynthetic Productivity ◽  
Structural Relationships ◽  
Plant Organelles

Plant organelles, including the dominant chloroplasts, migrate intracellularly on cytoplasmic strands (Fig. 1A-D). The chloroplasts in the leaf cells orient and redistribute in response to light to ensure maximum photosynthetic productivity. Their orderly distribution is also essential for proper transmission of organelle genome during cell proliferation. The movement and positioning of chloroplasts have been suggested to be mediated by the actin and tubulin-based cytoskeleton in green algae and higher plants. However, the actin structures controlling these processes have not been clearly delineated because of the difficulty in preserving and detecting the fine actin filaments in plant cells using conventional fixation methods and currently available antibodies.We investigated the role of the actin cytoskeleton in the regulation of chloroplast movement and positioning by studying: 1) the structural relationships of microfilaments and chloroplasts in leaf cells of Arabidopsis; and 2) effects of an anti-actin drug, Latrunculin B (LAT-B), on intracellular distribution of chloroplasts.

scholarly journals Cell Cycle-Specific Disruption of the Preprophase Band of Microtubules in Fern Protonemata: Effects of Displacement of the Endoplasm by Centrifugation

1992 ◽  
Vol 101 (1) ◽  
pp. 93-98 ◽  
Author(s):  
TAKASHI MURATA ◽  
MASAMITSU WADA
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Plant Cells ◽  
Preprophase Band ◽  
Higher Plant ◽  
The Future ◽  
Prophase Nucleus ◽  
Original Region ◽  
Fern Protonemata

The preprophase band (PPB) of microtubules (MTs), which appears at the future site of cytokinesis prior to cell division in higher plant cells, disappears by metaphase. Recent studies have shown that displacement of the endoplasm from the PPB region by centrifugation delays the disappearance of the PPB. To study the role of the endoplasm in the cell cycle-specific disruption of the PPB, the filamentous protonemal cells of the fern Adiantum capilius-veneris L. were centrifuged twice so that the first centrifugation displaced the endoplasm from the site of the PPB and the second returned it to its original location. The endoplasm, including the nucleus of various stages of mitosis, could be returned by the second centrifugation to the original region of the PPB, which persists during mitosis in the centrifuged cells. When endoplasm with a prophase nucleus was returned to its original location, the PPB was not disrupted. When endoplasm with a prometa-phase telophase nucleus was similarly returned, the PPB was disrupted within 10 min of termination of centrifugation. In protonemal cells of Adiantum, a second PPB is often formed near the displaced nucleus after the first centrifugation. In cells in which the endoplasm was considered to have been returned to its original location at the prophase/prometaphase transition, the second PPB did not disappear even though the initial PPB was disrupted by the endoplasm. These results suggest that cell cycle-specific disruption of the PPB is regulated by some factor(s) in the endoplasm, which appears at prometaphase, i.e. the stage at which the PPB is disrupted in non-centrifuged cells.

Microhabitat availability and seedling recruitment ofLobelia urens: a rare plant species at its geographical limit

2000 ◽  
Vol 10 (4) ◽  
pp. 471-487 ◽  
Author(s):  
J.M. Dinsdale ◽  
M.P. Dale ◽  
M. Kent
Keyword(s):  
Large Scale ◽  
Seedling Recruitment ◽  
Higher Plants ◽  
Plant Cover ◽  
Soil Surface ◽  
Potential Effect ◽  
Plant Litter ◽  
Higher Plant ◽  
Precise Role

AbstractIn Britain,Lobelia urens(L.) (the heath lobelia) occurs in rough grassland, is rare and only found in southern England, where it is at the northern limit of its range. Emergence and survival ofL. urenswas investigated at six locations in two geographically distinct sites experiencing spring, autumn or no grazing in two consecutive years. Four factors were evaluated qualitatively, as a means of characterizing microhabitats for germination and survival: all permutations of higher plant cover, bryophytes, plant litter and surface depressions. The potential effect of adjacent plants on recruitment was also assessed using the nearest neighbour distance (NND). Grazing created depressions, removed plant litter and increased the proportion of sites with higher plant cover. It also resulted in a more open sward with higher NNDs. None of these changes stimulated recruitment. Instead, small increases in the frequency of some rare or very rare microhabitat types were vital in making grazed rough grassland more suitable for emergence. Reduced litter loads and a greater quantity of moss were two key responses. Overall, survival ofL. urenswas less than 1% and was particularly favoured by moss and an increase in NNDs. Shading from higher plants, with or without plant litter, decreased emergence, but the precise role of litter was complex and most probably related to its quantity. In an experimental seed bed, only empty depressions favoured emergence. The microhabitat relationships ofL. urenswere unusually consistent among locations and consecutive years.L. urensrequires high soil surface temperatures but also adequate water for large scale recruitment, and such conditions are encouraged by grazing. The particular problems of experimental design and statistical analysis of data from recruitment experiments are also discussed.

scholarly journals Monoclonal antibody to intermediate filament antigen cross-reacts with higher plant cells.

1985 ◽  
Vol 100 (5) ◽  
pp. 1793-1798 ◽  
Author(s):  
P J Dawson ◽  
J S Hulme ◽  
C W Lloyd
Keyword(s):  
Monoclonal Antibody ◽  
Intermediate Filament ◽  
Higher Plants ◽  
Plant Cells ◽  
Heterologous Proteins ◽  
Root Tips ◽  
Suspension Cells ◽  
Higher Plant ◽  
Meristematic Cells ◽  
Carrot Protoplasts

The monoclonal antibody (anti-IFA) raised (Pruss et al., 1981, Cell 27:419-428) against an intermediate filament antigen, which is widespread throughout phylogeny, has been shown here to cross-react with higher plants. On immunoblotting, anti-IFA cross-reacted with proteins in homogenates of carrot suspension cells and of meristematic cells from onion root tips. A 50-kD cross-reactive protein was enriched in a fraction that consisted of detergent-insoluble bundles of 7-nm fibrils from carrot protoplasts (Powell et al., 1982, J. Cell Sci. 56:319-335). By use of indirect immunofluorescence, anti-IFA stained formaldehyde-fixed onion meristematic cells and carrot protoplasts in patterns approximating those obtained with monoclonal anti-tubulins. That anti-IFA was not recognizing plant tubulins was established by use of immunoblots of two-dimensional gels on which the proteins that comprised isolated fibrillar bundles and taxol-purified carrot tubulins had been separated. The two groups of proteins had different positional coordinates: anti-IFA recognized the fibrillar bundle proteins, and anti-tubulins recognized plant microtubule proteins with no cross-reaction to the heterologous proteins. Likewise, formaldehyde-fixed taxol microtubules from carrot cells could be stained with anti-tubulin but not with anti-IFA. It is concluded that an epitope common to intermediate filaments from animals co-distributes with microtubules in higher plant cells.

scholarly journals One to only two: a short history of the centrosome and its duplication

2014 ◽  
Vol 369 (1650) ◽  
pp. 20130455 ◽  
Author(s):  
Greenfield Sluder
Keyword(s):  
Plant Cells ◽  
Spindle Assembly ◽  
Centrosome Duplication ◽  
Short History ◽  
Animal Cells ◽  
Higher Plant ◽  
Bipolar Spindle ◽  
Mother Centriole ◽  
History Of

This review discusses some of the history of the fundamental, but not fully solved problem of how the centrosome duplicates from one to only two as the cell prepares for mitosis. We start with some of the early descriptions of the centrosome and the remarkably prescient but then controversial inferences drawn concerning its function in the cell. For more than 100 years, one of the most difficult issues for the concept of the centrosome has been to integrate observations that centrosomes appear to be important for spindle assembly in animal cells yet are not evident in higher plant cells and some animal cells. This stirred debate over the existence of centrosomes and their importance. A parallel debate concerned the role of the centrioles in organizing centrosomes. The relatively recent elucidation of bipolar spindle assembly around chromatin allows a re-examination of the role of centrioles in controlling centrosome duplication in animal cells. The problem of how centrosomes precisely double in preparation for mitosis in animal cells has now moved to the mystery of how only one procentriole is assembled at each mother centriole.

The active transport of ions in plant cells

1970 ◽  
Vol 3 (3) ◽  
pp. 251-294 ◽  
Author(s):  
E. A. C. MacRobbie
Keyword(s):  
Active Transport ◽  
Experimental Work ◽  
Higher Plants ◽  
Plant Cells ◽  
Transport Processes ◽  
Ion Pump ◽  
Higher Plant ◽  
Active Transport Of Ions ◽  
Wide Range ◽  
Transport Of Ions

In a recent review of the transport of salts and water across multicellular secretory tissues in animals (Keynes, 1969), a summary was given of the various types of active transport of ions necessary to explain the experimental observations in a very wide range of tissues, and five basic types of ion pump were discussed. The question of whether plants and animals have any common mechanisms for the transport of salts and water was specifically excluded. The original aim of the present review was to survey the types of ion pump found in plant cells and tissues, and to compare these with those found in animals. Its aims narrowed very considerably in writing. It now reviews ion transport processes in giant algal cells, and tries to assess progress towards understanding the mechanisms involved. It indicates the existence of similar ion transports in higher plant cells, but it does not present a complete review of the experimental work on higher plants.

Brefeldin A affects the endomembrane system and vesicle trafficking in higher plants

1993 ◽  
Vol 51 ◽  
pp. 192-193
Author(s):  
Béatrice Satiat-Jeunemaitre ◽  
Jancy Henderson ◽  
David Evans ◽  
Kim Crooks ◽  
Mark Fricker ◽  
...  
Keyword(s):  
Golgi Apparatus ◽  
Higher Plants ◽  
Fatty Acid Derivative ◽  
Plant Cells ◽  
Brefeldin A ◽  
Endomembrane System ◽  
Animal Cells ◽  
Higher Plant ◽  
Membrane Flow ◽  
Golgi Stack

In plant cells, as in animal cells, many macromolecules and membranes are transported by vesicle vectors through both the exocytotic and endocytotic pathways. In order to elucidate the mechanisms and molecular events of such trafficking we are using a set of drugs known to perturb membrane flow in plant cells in combination with immunocytochemical studies using a bank of monoclonal antibodies to various components of the endomembrane system and cell surface. In animal cells, one such drug, Brefeldin A, a fungal fatty acid derivative which causes disruption of the Golgi apparatus, has recently been used as a tool to dissect the mechanisms of vesicle flow from the endoplasmic reticulum to the Golgi apparatus and down the cisternae of the Golgi stack (1). It has been demonstrated that BFA also has a dramatic effect on the Golgi apparatus in higher plant cells (2,3,4).In this paper we report on recent work on the disruption of the plant Golgi apparatus with BFA and the redistribution of endomembrane marker epitopes after drug treatment of roots and suspension culture cells.

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