scholarly journals RADIOAUTOGRAPHIC STUDY OF CELL WALL DEPOSITION IN GROWING PLANT CELLS

1967 ◽  
Vol 35 (3) ◽  
pp. 659-674 ◽  
Author(s):  
Peter M. Ray

Segments cut from growing oat coleoptiles and pea stems were fed glucose-3H in presence and absence of the growth hormone indoleacetic acid (IAA). By means of electron microscope radioautography it was demonstrated that new cell wall material is deposited both at the wall surface (apposition) and within the preexisting wall structure (internally). Quantitative profiles for the distribution of incorporation with position through the thickness of the wall were obtained for the thick outer wall of epidermal cells. With both oat coleoptile and pea stem epidermal outer walls, it was found that a larger proportion of the newly synthesized wall material appeared to become incorporated within the wall in the presence of IAA. Extraction experiments on coleoptile tissue showed that activity that had been incorporated into the cell wall interior represented noncellulosic constituents, mainly hemicelluloses, whereas cellulose was deposited largely or entirely by apposition. It seems possible that internal incorporation of hemicelluloses plays a role in the cell wall expansion process that is involved in cell growth.

1989 ◽  
Vol 67 (7) ◽  
pp. 1938-1943 ◽  
Author(s):  
Kimberly D. Gwinn ◽  
Margaret E. Daub ◽  
Pi-Yu Huang

Freshly isolated protoplasts of Cercospora nicotianae and Neurospora crassa are equally sensitive to the toxin, cercosporin. After a 12-h regeneration period C. nicotianae cells are resistant, but N. crassa cells remain sensitive. Production of cell wall material by both C. nicotianae and N. crassa was monitored by transmission electron microscopy and fluorescence microscopy. Freshly isolated protoplasts lacked cell wall material as shown by observation with electron microscopy and inability to bind the fluorescent brightener Tinopal 5BM. After a 12-h incubation, electron micrographs of regenerating protoplasts showed well-developed cell walls for N. crassa, whereas C. nicotianae displayed variations in wall structure. Ability to bind Tinopal 5BM was acquired very early by regenerating cells of both fungi. Percentages of cells that could bind Concanavalin A did not differ between the two fungi at any time after protoplast isolation. Ability to bind wheat germ agglutinin and Bandeiraea simplicifolia agglutinin II was detected earlier in C. nicotianae than in N. crassa. These data demonstrate the presence of cell wall materials in both C. nicotianae and N. crassa at the time that differential sensitivity to cercosporin is observed. These results suggest that components in the C. nicotianae cell wall may play a role in cercosporin resistance.


1969 ◽  
Vol 47 (12) ◽  
pp. 1873-1877 ◽  
Author(s):  
L. C. Fowke ◽  
George Setterfield

Applied auxin caused cells of artichoke tuber slices to expand and deposit significant amounts of new wall material while cells in slices held on water remained essentially inert in both respects. Cells in all physiological treatments showed multivesicular structures at the plasma membrane (plasmalemmasomes, lomasomes), within the cytoplasm and within the central vacuoles. The number of plasmalemmasomes was considerably greater in cells not depositing wall than in cells treated with auxin to stimulate wall synthesis. Multivesicular structures showed no relation to Golgi bodies, which increase in number and apparent activity in response to auxin treatment. It is concluded that plasmalemmasomes are not involved in cell wall deposition. Multivesicular structures in plant cells could have several origins and it is suggested that some may represent artifactual reorganization of plasmalemma and tonoplast membranes during cytological processing. Such reorganization would presumably be sensitive to the physiological state of the tissue.


2018 ◽  
Vol 15 (8) ◽  
pp. 513
Author(s):  
Ewen Silvester ◽  
Annaleise R. Klein ◽  
Kerry L. Whitworth ◽  
Ljiljana Puskar ◽  
Mark J. Tobin

Environmental contextSphagnum moss is a widespread species in peatlands globally and responsible for a large fraction of carbon storage in these systems. We used synchrotron infrared microspectroscopy to characterise the acid-base properties of Sphagnum moss and the conditions under which calcium uptake can occur (essential for plant tissue integrity). The work allows a chemical model for Sphagnum distribution in the landscape to be proposed. AbstractSphagnum is one the major moss types responsible for the deposition of organic soils in peatland systems. The cell walls of this moss have a high proportion of carboxylated polysaccharides (polygalacturonic acids), which act as ion exchangers and are likely to be important for the structural integrity of the cell walls. We used synchrotron light source infrared microspectroscopy to characterise the acid-base and calcium complexation properties of the cell walls of Sphagnum cristatum stems, using freshly sectioned tissue confined in a flowing liquid cell with both normal water and D2O media. The Fourier transform infrared spectra of acid and base forms are consistent with those expected for protonated and deprotonated aliphatic carboxylic acids (such as uronic acids). Spectral deconvolution shows that the dominant aliphatic carboxylic groups in this material behave as a monoprotic acid (pKa=4.97–6.04). The cell wall material shows a high affinity for calcium, with a binding constant (K) in the range 103.9–104.7 (1:1 complex). The chemical complexation model developed here allows for the prediction of the chemical environment (e.g. pH, ionic content) under which Ca2+ uptake can occur, and provides an improved understanding for the observed distribution of Sphagnum in the landscape.


2021 ◽  
Author(s):  
Žiga Pandur ◽  
Matevž Dular ◽  
Rok Kostanjšek ◽  
David Stopar

1986 ◽  
Vol 62 (6) ◽  
pp. 1703-1712 ◽  
Author(s):  
H. G. Jung ◽  
K. P. Vogel

2006 ◽  
Vol 41 (16) ◽  
pp. 5122-5126 ◽  
Author(s):  
Steffen Orso ◽  
Ulrike G. K. Wegst ◽  
Eduard Arzt

Weed Science ◽  
1968 ◽  
Vol 16 (3) ◽  
pp. 344-347 ◽  
Author(s):  
Walter E. Splittstoesser

Barley (Hordeum vulgareL. var. Trail) root growth was inhibited at lower concentrations of 1-(2-methylcyclohexyl)-3-phenylurea (siduron) than was shoot growth. The influence of siduron upon root metabolism was assessed with excised roots grown in 0 or 5 ppm siduron. More glucose-U-14C and leucine-U-14C were degraded to CO2and less were incorporated into cell wall material and protein by roots grown in siduron. However, roots grown in siduron incorporated more adenine-8-14C into nucleic acids and degraded less adenine to CO2than roots grown in water. It was suggested that siduron disrupted the normal nucleic acid metabolism of barley roots which was necessary for protein and cell wall synthesis.


2021 ◽  
Vol 289 ◽  
pp. 110304 ◽  
Author(s):  
Eden Eran Nagar ◽  
Liora Berenshtein ◽  
Inbal Hanuka Katz ◽  
Uri Lesmes ◽  
Zoya Okun ◽  
...  

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