Anion-Sensitive H+-ATPases from Higher Plant Cells: The Role of Chloride in Stimulating Proton Transport

1985 ◽  
pp. 175-183
Author(s):  
Alan B. Bennett
Keyword(s):  
Proton Transport ◽  
Plant Cells ◽  
Higher Plant

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.

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.

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.

A Theoretical Analysis of the Role of Pyrophosphate,Fructose 6-P,1-Phosphotransferase in Energy Dissipation During the Conversion of Fructose 6-Phosphate to Fructose 1,6-Bisphosphate in Plant Cells

1997 ◽  
Vol 05 (03) ◽  
pp. 389-401
Author(s):  
Junli Liu ◽  
John W. Crawford ◽  
Roberto Viola
Keyword(s):  
Energy Dissipation ◽  
Theoretical Analysis ◽  
Plant Cells ◽  
Theoretical Work ◽  
Glycolytic Flux ◽  
Energetic Efficiency ◽  
Higher Plant ◽  
Net Flux ◽  
Fructose 1,6 Bisphosphate

A theoretical analysis of the effect of pyrophosphate,fructose 6-P,1-phosphotransferase (PFP) on energy dissipation in the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate is presented. The conclusion depends sensitively on whether PFP is in equilibrium, or catalyses a net flux in the directions of gluconeogenesis or glycolysis. It is shown that the conditions under which PFP is in equilibrium are rather restricted. Furthermore, experimental evidence supports the theoretical prediction that PFP catalyses a net flux in real systems. When PFP catalyses a net glycolytic flux, the system where both PFP and PFK are active always dissipates less energy than the system where only PFK exists. However, when PFP catalyses a net flux in gluconeogenesis, the PFK-PFP system dissipates more energy than the system where only PFK exists. By comparing the theoretical work with experimental results, the evidence suggests that PFP in higher plant cells catalyses a net glycolytic flux, and its presence increases the energetic efficiency of glycolysis.

scholarly journals Nanobiotechnology for Agriculture: Smart Technology for Combating Nutrient Deficiencies with Nanotoxicity Challenges

2021 ◽  
Vol 13 (4) ◽  
pp. 1781
Author(s):  
Gaurav Chugh ◽  
Kadambot H. M. Siddique ◽  
Zakaria M. Solaiman
Keyword(s):  
Targeted Delivery ◽  
Plant Cells ◽  
Agricultural Practices ◽  
Nutrient Deficiencies ◽  
Holistic View ◽  
Synthesis Of Nanoparticles ◽  
Toxicity Potential ◽  
Stimulate Plant Growth ◽  
Sustainable Agricultural Practices

Nanobiotechnology in agriculture is a driver for modern-day smart, efficient agricultural practices. Nanoparticles have been shown to stimulate plant growth and disease resistance. The goal of sustainable farming can be accomplished by developing and sustainably exploiting the fruits of nanobiotechnology to balance the advantages nanotechnology provides in tackling environmental challenges. This review aims to advance our understanding of nanobiotechnology in relevant areas, encourage interactions within the research community for broader application, and benefit society through innovation to realize sustainable agricultural practices. This review critically evaluates what is and is not known in the domain of nano-enabled agriculture. It provides a holistic view of the role of nanobiotechnology in multiple facets of agriculture, from the synthesis of nanoparticles to controlled and targeted delivery, uptake, translocation, recognition, interaction with plant cells, and the toxicity potential of nanoparticle complexes when presented to plant cells.

scholarly journals Viroids as a Tool to Study RNA-Directed DNA Methylation in Plants

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1187
Author(s):  
Michael Wassenegger ◽  
Athanasios Dalakouras
Keyword(s):  
Dna Methylation ◽  
Rna Interference ◽  
Gene Silencing ◽  
Plant Cells ◽  
Transcriptional Gene Silencing ◽  
Rnai Machinery ◽  
Double Stranded Rna ◽  
Post Transcriptional Gene Silencing ◽  
Cumulative Amount

Viroids are plant pathogenic, circular, non-coding, single-stranded RNAs (ssRNAs). Members of the Pospiviroidae family replicate in the nucleus of plant cells through double-stranded RNA (dsRNA) intermediates, thus triggering the host’s RNA interference (RNAi) machinery. In plants, the two RNAi pillars are Post-Transcriptional Gene Silencing (PTGS) and RNA-directed DNA Methylation (RdDM), and the latter has the potential to trigger Transcriptional Gene Silencing (TGS). Over the last three decades, the employment of viroid-based systems has immensely contributed to our understanding of both of these RNAi facets. In this review, we highlight the role of Pospiviroidae in the discovery of RdDM, expound the gradual elucidation through the years of the diverse array of RdDM’s mechanistic details and propose a revised RdDM model based on the cumulative amount of evidence from viroid and non-viroid systems.

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