Cytological comparison of early stages of wall regeneration of Cercospora nicotianae and Neurospora crassa protoplasts

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.

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Ultrastructure of forming and dormant chlamydospores of Fusarium solani in soil

Canadian Journal of Microbiology ◽

10.1139/m76-240 ◽

1976 ◽

Vol 22 (11) ◽

pp. 1634-1642 ◽

Cited By ~ 6

Author(s):

W. H. Van Eck

Keyword(s):

Electron Microscopy ◽

Cell Wall ◽

Fusarium Solani ◽

Wall Material ◽

Cell Wall Material

Chlamydospores of Fusarium solani f. sp. cucurbitae, F. solani f. sp. phaseoli and F. solani f. sp. pisi formed in soil were recovered at intervals and examined by electron microscopy. Cell wall material outside the newly formed chlamydospore cell wall gradually disintegrated. Protoplasts of chlamydospore cells lyse without prior penetration of the cell wall by microorganisms. The mechanisms of lysis of chlamydospores of F. solani in soil are discussed.

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Electron microscopy of the conidial protoplasts of Neurospova crassa

Canadian Journal of Botany ◽

10.1139/b68-216 ◽

1968 ◽

Vol 46 (12) ◽

pp. 1561-1564 ◽

Cited By ~ 8

Author(s):

M. S. Manocha

Keyword(s):

Electron Microscopy ◽

Endoplasmic Reticulum ◽

Cell Wall ◽

Conidial Germination ◽

Cell Wall Structure ◽

Wall Material ◽

Wall Structure ◽

Protoplast Formation ◽

Small Pore ◽

Similarities And Differences

Micromorphology of conidia resembles that of young hyphae except for the details of the cell wall structure, which is thicker and prominently developed in unhydrated conidia. Although mitochondria and endoplasmic reticulum are present in ungerminated conidia, these organelles increase greatly during germination, and vacuoles increase in size and number. Naked protoplasts protrude through a small pore in the partially digested wall of the conidium. Free protoplasts synthesize new wall material when incubated in a regenerative mixture. Similarities and differences between conidial germination and protoplast formation and regeneration are noted.

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RADIOAUTOGRAPHIC STUDY OF CELL WALL DEPOSITION IN GROWING PLANT CELLS

The Journal of Cell Biology ◽

10.1083/jcb.35.3.659 ◽

1967 ◽

Vol 35 (3) ◽

pp. 659-674 ◽

Cited By ~ 85

Author(s):

Peter M. Ray

Keyword(s):

Cell Wall ◽

Indoleacetic Acid ◽

Plant Cells ◽

Outer Wall ◽

Wall Material ◽

Wall Structure ◽

Cell Wall Material ◽

Expansion Process ◽

Cell Wall Deposition ◽

Cell Wall Expansion

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.

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Effect of Exogenously Applied 24-Epibrassinolide and Brassinazole on Xylogenesis and Microdistribution of Cell Wall Polymers in Leucaena leucocephala (Lam) De Wit

Journal of Plant Growth Regulation ◽

10.1007/s00344-021-10313-6 ◽

2021 ◽

Author(s):

S. Pramod ◽

M. Anju ◽

H. Rajesh ◽

A. Thulaseedharan ◽

Karumanchi S. Rao

Keyword(s):

Electron Microscopy ◽

Cell Wall ◽

Leucaena Leucocephala ◽

Higher Plants ◽

Lignin Content ◽

Wood Quality ◽

Wall Structure ◽

Vessel Element ◽

Xylem Differentiation ◽

Cell Wall Polymers

AbstractPlant growth regulators play a key role in cell wall structure and chemistry of woody plants. Understanding of these regulatory signals is important in advanced research on wood quality improvement in trees. The present study is aimed to investigate the influence of exogenous application of 24-epibrassinolide (EBR) and brassinosteroid inhibitor, brassinazole (BRZ) on wood formation and spatial distribution of cell wall polymers in the xylem tissue of Leucaena leucocephala using light and immuno electron microscopy methods. Brassinazole caused a decrease in cambial activity, xylem differentiation, length and width of fibres, vessel element width and radial extent of xylem suggesting brassinosteroid inhibition has a concomitant impact on cell elongation, expansion and secondary wall deposition. Histochemical studies of 24-epibrassinolide treated plants showed an increase in syringyl lignin content in the xylem cell walls. Fluorescence microscopy and transmission electron microscopy studies revealed the inhomogenous pattern of lignin distribution in the cell corners and middle lamellae region of BRZ treated plants. Immunolocalization studies using LM10 and LM 11 antibodies have shown a drastic change in the micro-distribution pattern of less substituted and highly substituted xylans in the xylem fibres of plants treated with EBR and BRZ. In conclusion, present study demonstrates an important role of brassinosteroid in plant development through regulating xylogenesis and cell wall chemistry in higher plants.

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Synchrotron infrared microspectroscopy reveals the response of Sphagnum cell wall material to its aqueous chemical environment

Environmental Chemistry ◽

10.1071/en18120 ◽

2018 ◽

Vol 15 (8) ◽

pp. 513

Author(s):

Ewen Silvester ◽

Annaleise R. Klein ◽

Kerry L. Whitworth ◽

Ljiljana Puskar ◽

Mark J. Tobin

Keyword(s):

Cell Wall ◽

Cell Walls ◽

Chemical Environment ◽

Wall Material ◽

Organic Soils ◽

Cell Wall Material ◽

Acid Base ◽

Widespread Species ◽

Flowing Liquid ◽

Infrared Microspectroscopy

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.

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