Activités ATPasiques du nœud cotylédonaire et du bourgeon cotylédonaire du pois inhibé, réactivé ou soumis à la fusicoccine

1983 ◽  
Vol 61 (1) ◽  
pp. 119-134 ◽  
Author(s):  
Arlette Nougarède ◽  
Pierre Landré ◽  
Jacques Rembur
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Outer Surface ◽  
Cotyledonary Node ◽  
Transfer Cells ◽  
Intact Plant ◽  
High Concentration ◽  
Sieve Elements ◽  
Cell Specificity ◽  
Activity Of Enzymes

The activity of enzymes which hydrolyse ATP at neutral pH was demonstrated cytochemically in the cotyledonary node and in three types of cotyledonary buds (inhibited, released from dominance, treated with fusicoccin). In the intact plant, the transfer cells of the cotyledonary node showed a very strong Mg2+-dependent, ouabaïne-insensitive ATPase activity, essentially located on the outer surface of the plasmalemma. A high concentration of K+ stimulated the ATPase activity of the plasmalemma of transfer cells and sieve elements. ATPase activity was even more specifically detected along mitochondrial cristae and the tonoplast of the phloem transfer cells and along the reticular membranes of the xylem transfer cells. All these activities which were not modified by decapitation increased after a fusicoccin treatment. In the inhibited bud the same pattern of ATPase activity occurred along the plasma membrane but with a lesser intensity. At the base of the first-bud internodes the phloem transfer cells were the only ones with a high ATPase activity. Decapitation induced, without cell specificity, an increase in the ATPase activity of the plasmalemma for the entire bud, while after fusicoccin treatment, the increase extended to the tonoplast. Proper controls eliminate the possibility of artifactual reactions or interactions with other enzymes.

scholarly journals ATPase in mature and differentiating phloem and xylem.

1980 ◽  
Vol 28 (4) ◽  
pp. 375-377 ◽  
Author(s):  
J Cronshaw
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Atpase Activity ◽  
Plasma Membranes ◽  
Transfer Cells ◽  
Cytochemical Study ◽  
Sieve Elements ◽  
Xylem Element ◽  
P Proteins ◽  
Atpase Localization

A cytochemical study using a lead precipitation technique has been made of the distribution of adenosine triphosphatase (ATPase) in mature and differentiating phloem and xylem cells of Nicotiana tabacum and Pisum sativum. The sites of ATPase localization in tobacco phloem were the plasma membrane, endoplasmic reticulum, mitochondria, dictyosomes, plasmodesmata, and the dispersed P proteins of mature sieve elements. In pea phloem sieve elements ATPase was localized in the endoplasmic reticulum, but was not associated with the P proteins or plasma membranes at any stage of their differentiation. In pea transfer cells ATPase activity was associated with the endoplasmic reticulum at all stages of their differentiation and with the plasma membrane of transfer cells that had formed wall ingrowths. In xylem cells of both tobacco and pea the patterns of ATPase activity was similar. At early stages of differentiation ATPase activity was associated with the plasma membrane and the endoplasmic reticulum. At intermediate stages of differentiation ATPase activity continued to be associated with the endoplasmic reticulum, but was no longer associated with the plasma membrane. At later stages of xylem element differentiation ATPase activity was associated with disintegrating organelles and with the hydrolyzing cell walls.

scholarly journals Cytochemical localization of ecto-ATPases in rat neurohypophysis.

1996 ◽  
Vol 44 (2) ◽  
pp. 103-111 ◽  
Author(s):  
S Thirion ◽  
J D Troadec ◽  
G Nicaise
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Atpase Activity ◽  
Outer Surface ◽  
Nerve Endings ◽  
Glutaraldehyde Fixation ◽  
Cytochemical Localization ◽  
Cytochemical Method ◽  
Ca Pump ◽  
Dependent Atpase

We studied the distribution of Ca(2+)- or Mg(2+)-dependent ATPase activity in rat neurohypophysis using the lead cytochemical method of Ando et al. In electron microscopy, precipitates were found lining the outer surface of the plasma membrane surrounding nerve endings and pituicytes. These precipitates were believed to represent the activity of ecto-ATPases (as opposed to Ca pump ATPases) for the following reasons: there was equal activation by Ca2+ in the absence of Mg2+ or Mg2+ in the absence of Ca2+; the effects of the two ions were not additive; there was activation by ATP or GTP; and there was resistance to glutaraldehyde fixation, to high (10 mM) Ca2+ concentrations, and to various inhibitors such as NEM, vanadate, oligomycin, quercetin, p-chloromercuribenzoate, ouabain, and levamisole. Cytosolic activity observed in certain nerve endings in the same conditions of incubation but more sensitive to NEM is also described and discussed.

Localisation des activités de la p-nitrophénylphosphatase et de la phosphatase alcaline dans les cellules de transfert du noeud cotylédonaire du pois nain

1983 ◽  
Vol 61 (5) ◽  
pp. 1476-1490
Author(s):  
A. Nougarède ◽  
P. Landré ◽  
J. Rembur
Keyword(s):  
Alkaline Phosphatase ◽  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Cotyledonary Node ◽  
Ultrastructural Localization ◽  
Transfer Cells ◽  
The Other ◽  
Reaction Products ◽  
Weak Reaction ◽  
Phosphatase Alcaline

The ultrastructural localization of the K+-dependent nitrophenylphosphatase (NPPase) and alkaline phosphatase (ALPase) activities were determined in the transfer cells of the pea cotyledonary node. These two types of activities were generally associated and located essentially on the plasma membrane. NPPase and ALPase activities were also detected along the nuclear membrane of the xylem and phloem transfer cells and along the endoplasmic reticulum profiles (internal face) of phloem transfer cells. Mitochondrial NNPase activity was confined to the outer membrane and cristae. The partial inhibition of the NPPase reaction products by L-p-bromotetramisole and cysteine, the weak reaction observed after deletion of K+, and the suppression of the reaction in the presence of L-p-bromotetramisole are best explained by the concomitant activity of a K+-dependent NPPase and of an ALPase partially inhibited by K+. On the basis of sensitivity to inhibitors, two plasma membrane ALPase isoenzymes were detected. One, extramembranous, was bromotetramisole and cysteine insensitive but inhibited by L-phenylalanine; the other, intramembranous, was bromotetramisole and cysteine sensitive, but insensitive to L-phenylalanine. The other sites of ALPase activities were substantially inhibited by all treatments.

Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

1972 ◽  
Vol 30 ◽  
pp. 230-231
Author(s):  
James Cronshaw ◽  
Jamison E. Gilder
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Higher Plants ◽  
High Surface ◽  
Root Tip ◽  
Animal Cells ◽  
Physiological Processes ◽  
Tip Cells ◽  
Atpase Localization

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.

The Fine Structure of Phloem Cells

1985 ◽  
Vol 43 ◽  
pp. 632-635
Author(s):  
James Cronshaw
Keyword(s):  
Structural Studies ◽  
High Concentration ◽  
Long Distance ◽  
Phloem Tissue ◽  
Sieve Elements ◽  
Long Distance Transport ◽  
P Protein ◽  
Companion Cells ◽  
Electron Microscopical ◽  
Distance Transport

Long distance transport in plants takes place in phloem tissue which has characteristic cells, the sieve elements. At maturity these cells have sieve areas in their end walls with specialized perforations. They are associated with companion cells, parenchyma cells, and in some species, with transfer cells. The protoplast of the functioning sieve element contains a high concentration of sugar, and consequently a high hydrostatic pressure, which makes it extremely difficult to fix mature sieve elements for electron microscopical observation without the formation of surge artifacts. Despite many structural studies which have attempted to prevent surge artifacts, several features of mature sieve elements, such as the distribution of P-protein and the nature of the contents of the sieve area pores, remain controversial.

scholarly journals Potassium depletion increases proton pump (H+-ATPase) activity in intercalated cells of cortical collecting duct

2000 ◽  
Vol 279 (1) ◽  
pp. F195-F202 ◽  
Author(s):  
Randi B. Silver ◽  
Sylvie Breton ◽  
Dennis Brown
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Collecting Duct ◽  
Proton Pumps ◽  
Intercalated Cells ◽  
Cortical Collecting Duct ◽  
Collecting Ducts ◽  
Acid Load ◽  
Collecting Tubules ◽  
Atpase Staining

Intercalated cells (ICs) from kidney collecting ducts contain proton-transporting ATPases (H+-ATPases) whose plasma membrane expression is regulated under a variety of conditions. It has been shown that net proton secretion occurs in the distal nephron from chronically K+-depleted rats and that upregulation of tubular H+- ATPase is involved in this process. However, regulation of this protein at the level of individual cells has not so far been examined. In the present study, H+-ATPase activity was determined in individually identified ICs from control and chronically K+-depleted rats (9–14 days on a low-K+ diet) by monitoring K+- and Na+-independent H+ extrusion rates after an acute acid load. Split-open rat cortical collecting tubules were loaded with the intracellular pH (pHi) indicator 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein, and pHiwas determined by using ratiometric fluorescence imaging. The rate of pHi recovery in ICs in response to an acute acid load, a measure of plasma membrane H+-ATPase activity, was increased after K+ depletion to almost three times that of controls. Furthermore, the lag time before the start of pHirecovery after the cells were maximally acidified fell from 93.5 ± 13.7 s in controls to 24.5 ± 2.1 s in K+-depleted rats. In all ICs tested, Na+- and K+-independent pHi recovery was abolished in the presence of bafilomycin (100 nM), an inhibitor of the H+-ATPase. Analysis of the cell-to-cell variability in the rate of pHi recovery reveals a change in the distribution of membrane-bound proton pumps in the IC population of cortical collecting duct from K+-depleted rats. Immunocytochemical analysis of collecting ducts from control and K+-depleted rats showed that K+-depletion increased the number of ICs with tight apical H+ATPase staining and decreased the number of cells with diffuse or basolateral H+-ATPase staining. Taken together, these data indicate that chronic K+ depletion induces a marked increase in plasma membrane H+ATPase activity in individual ICs.

Plasma membrane H+ -ATPase activity is involved in adaptation of tomato calli to NaCl

2001 ◽  
Vol 111 (4) ◽  
pp. 483-490 ◽  
Author(s):  
Loubna Kerkeb ◽  
Juan Pedro Donaire ◽  
María Pilar Rodríguez-Rosales
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity
Sign in / Sign up

Export Citation Format

Share Document