scholarly journals Short-Term Boron Deprivation Inhibits Endocytosis of Cell Wall Pectins in Meristematic Cells of Maize and Wheat Root Apices

2002 ◽  
Vol 130 (1) ◽  
pp. 415-421 ◽  
Author(s):  
Qin Yu ◽  
Andrej Hlavacka ◽  
Toru Matoh ◽  
Dieter Volkmann ◽  
Diedrik Menzel ◽  
...  
Keyword(s):  
Cell Wall ◽  
Wheat Root ◽  
Short Term ◽  
Meristematic Cells ◽  
Root Apices

Histological aspects of the cryopreservation of potato

2008 ◽  
Vol 56 (3) ◽  
pp. 341-348
Author(s):  
P. Pepó ◽  
A. Kovács
Keyword(s):  
Cell Wall ◽  
Low Temperatures ◽  
Cell Walls ◽  
Cellular Level ◽  
Adaptive Mechanism ◽  
Epidermal Layer ◽  
Freezing And Thawing ◽  
Meristematic Cells ◽  
Suitable Solution ◽  
Vacuolated Cells

Cryopreservation appears to be a suitable solution for the maintenance of potato germplasms. The protocol described in this paper can be applied for the vitrification and preservation of meristems. During histo-cytological studies it is possible to observe modifications at the cellular level and to understand the adaptive mechanism to low temperatures. Control potato meristem tissue contained a number of meristematic cells with a gradient of differentiation. After freezing there were a large number of vacuolated cells, some of which exhibited broken cell walls and plasmolysis. The thickening of the cell wall, giving them a sinuous appearance, was observed after freezing and thawing the meristems, with ruptures of the cuticle and epidermal layer.

The preprophase band: possible involvement in the formation of the cell wall

1976 ◽  
Vol 22 (2) ◽  
pp. 403-411 ◽  
Author(s):  
M.J. Packard ◽  
S.M. Stack
Keyword(s):  
Cell Wall ◽  
Allium Cepa ◽  
Cell Walls ◽  
Preprophase Band ◽  
Adjacent Cell ◽  
Root Tips ◽  
Meristematic Cells ◽  
Narrow Region ◽  
The Matrix

Numerous vesicles were observed among the microtubules of the “preprophase” band in prophase cells from root tips of Allium cepa. The content of these vesicles looks similar to the matrix of adjacent cell walls, and these vesicles often appear to be involved in exocytosis. In addition, the cell walls perpendicular to the plane of (beneath) the preprophase band are often differentially thickened compared to the walls lying parallel to the plane of the band. Our interpretation of these observations is that the preprophase band may direct or channel vesicles containing precursors of the cell wall to localized regions of wall synthesis. The incorporation of constituents of the cell wall into a narrow region defined by the position of the preprophase band may be a mechanism that ensures unidirecitonal growth of meristematic cells.

Effect of Short-Term Ozone Treatments on Tomato (Solanum lycopersicumL.) Fruit Quality and Cell Wall Degradation

2010 ◽  
Vol 58 (1) ◽  
pp. 594-599 ◽  
Author(s):  
Luis Rodoni ◽  
Natalia Casadei ◽  
Analía Concellón ◽  
Alicia R. Chaves Alicia ◽  
Ariel R. Vicente
Keyword(s):  
Cell Wall ◽  
Fruit Quality ◽  
Cell Wall Degradation ◽  
Short Term ◽  
Ozone Treatments

Distribution within the plant or compartmentation does not contribute substantially to the detoxification of excess boron in sunflower (Helianthus annuus)

1999 ◽  
Vol 26 (2) ◽  
pp. 95 ◽  
Author(s):  
Frank Dannel ◽  
Heidrun Pfeffer ◽  
Volker Römheld
Keyword(s):  
Cell Wall ◽  
Helianthus Annuus ◽  
Term Treatment ◽  
Substantial Contribution ◽  
Insoluble Residue ◽  
Tolerance Mechanism ◽  
Additional Experiment ◽  
Short Term ◽  
Short Term Treatment ◽  
Helianthus Annuus L

Distribution and compartmentation of boron as possible mechanisms for the notable tolerance of sunflower (Helianthus annuus L.) to excess B supply have been studied. Following a short- term treatment (6 h) with 1000 µМ B, the distribution of B between different shoot organs was preferentially directed to the readily transpiring ones. Thus, B distribution in sunflower plants seems to be mainly influenced by transpiration and does not act as a B tolerance mechanism in sunflower. As a second possible mechanism for B tolerance, the compartmentation of B between water insoluble residue (i.e. cell wall) and cell sap (i.e. symplasm) was determined. Additional binding of B in the cell wall in response to excess B supply for 6 h was very low in leaves and negligible in roots. Thus, a substantial contribution of the cell wall in detoxification of excess B can be ruled out. In an additional experiment with a B supply of 1 µМ (marginal) to 1000 µМ (moderately toxic), the compartmentation of B between the apoplasmic fluid and the cell sap was investigated. The B concentration in the apoplasmic fluid was always lower than that in the symplasm. Thus, B was not excluded from the symplasm, but accumulated within it. The apoplasmic fluid did not contribute substantially to the detoxification of excess B in the leaf.

Localisation of aluminium in root apex cells of two Australian perennial grasses by X-ray microanalysis

1998 ◽  
Vol 25 (4) ◽  
pp. 427 ◽  
Author(s):  
Simon A. Crawford ◽  
Alan T. Marshall ◽  
Sabine Wilkens
Keyword(s):  
Significant Positive Correlation ◽  
Root Apex ◽  
Root Cap ◽  
Perennial Grasses ◽  
Elemental Distribution ◽  
X Ray ◽  
Positive Correlation ◽  
Distribution Maps ◽  
Meristematic Cells ◽  
Root Apices

To determine if an increased aluminium (Al) sensitivity is the result of greater accumulation of Al in root apices, the quantity and distribution of Al in root apex cells of Danthonia linkii Kunth and Microlaena stipoides (Labill.) R.Br. was investigated by X-ray microanalysis. Seedlings were grown in nutrient solution with 0, 185 and 370 µM total Al for 24 h after which the terminal 5 mm of the roots were excised, rapidly frozen and embedded using freeze-substitution. Elemental distribution maps of root apices showed that Al had accumulated in the nuclei of root cap and meristematic cells in Al-stressed roots of D. linkii but not in M. stipoides. Al appeared to be co-localised with phosphorous (P) in the nuclei of these cells. Quantitation of Al revealed that Al-stressed root apex cells of D. linkiiaccumulated significantly more Al than M. stipoides. Exposure of D. linkii roots to Al resulted in substantial increases in the P content of root apex cells, and a significant positive correlation was found between Al and P in both root cap and meristematic cells. Analysis of intracellular structures showed that the majority of Al had accumulated in the nuclei of cells. A significant positive correlation was found between Al and P in the nuclei, but not in the cytoplasm or cell walls. No positive correlation was found between Al and P in root apex cells of M. stipoides.

The effect of low concentrations of sodium on potassium uptake and growth of wheat

2000 ◽  
Vol 27 (2) ◽  
pp. 175 ◽  
Author(s):  
Sally Box ◽  
Daniel P. Schachtman
Keyword(s):  
Plant Biomass ◽  
Wheat Root ◽  
Terrestrial Plants ◽  
Short Term ◽  
Root Cells ◽  
Light Levels ◽  
Low Concentrations ◽  
Na Uptake

Sodium is a beneficial mineral for some plant species when external concentrations are low. The role of Na+ in energising K+ acquisition in terrestrial plants has recently been suggested because of evidence demonstrating that wheat root cells express a high-affinity Na+-energised K+ symporter. To determine whether low concentrations of Na+ improve the K+ nutrition and growth of wheat, long-term growth and short-term tracer flux experiments were conducted. Long-term growth experiments were conducted over a range of K+ concentrations, at acidic and alkaline pH, with and without 500 µM NaCl. Plant biomass and tissue Na+ and K+ content was measured. Short-term experi-ments were conducted using tracers to determine whether low concentrations of Na+ or K+ stimulate Rb+ or Na+ uptake, respectively. Sodium stimulated the growth of wheat only at low (20 µM) external K+ in one of the long-term experiments, but not in two other experiments. Na+ did not stimulate Rb+ uptake, but K+ stimulated Na+ uptake in short-term tracer flux experiments. The results suggest that low concentrations of Na+ do not increase K+ uptake to a large extent, and only when light levels are low does Na+ have a beneficial effect on the growth of wheat.

scholarly journals Lysozyme and Penicillin Inhibit the Growth of Anaerobic Ammonium-Oxidizing Planctomycetes

2013 ◽  
Vol 79 (24) ◽  
pp. 7763-7769 ◽  
Author(s):  
Ziye Hu ◽  
Theo van Alen ◽  
Mike S. M. Jetten ◽  
Boran Kartal
Keyword(s):  
Cell Wall ◽  
Continuous Cultivation ◽  
Penicillin G ◽  
Anammox Bacteria ◽  
Short Term ◽  
Content Type ◽  
Genome Data ◽  
Wall Structures ◽  
Anammox Activity

ABSTRACTAnaerobic ammonium-oxidizing (anammox) planctomycetes oxidize ammonium in the absence of molecular oxygen with nitrite as the electron acceptor. Although planctomycetes are generally assumed to lack peptidoglycan in their cell walls, recent genome data imply that the anammox bacteria have the genes necessary to synthesize peptidoglycan-like cell wall structures. In this study, we investigated the effects of two antibacterial agents that target the integrity and synthesis of peptidoglycan (lysozyme and penicillin G) on the anammox bacteriumKuenenia stuttgartiensis. The effects of these compounds were determined in both short-term batch incubations and long-term (continuous-cultivation) growth experiments in membrane bioreactors. Lysozyme at 1 g/liter (20 mM EDTA) lysed anammox cells in less than 60 min, whereas penicillin G did not have any observable short-term effects on anammox activity. Penicillin G (0.5, 1, and 5 g/liter) reversibly inhibited the growth of anammox bacteria in continuous-culture experiments. Furthermore, transcriptome analyses of the penicillin G-treated reactor and the control reactor revealed that penicillin G treatment resulted in a 10-fold decrease in the ribosome levels of the cells. One of the cell division proteins (Kustd1438) was downregulated 25-fold. Our results suggested that anammox bacteria contain peptidoglycan-like components in their cell wall that can be targeted by lysozyme and penicillin G-sensitive proteins were involved in their synthesis. Finally, we showed that a continuous membrane reactor system with free-living planktonic cells was a very powerful tool to study the physiology of slow-growing microorganisms under physiological conditions.

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