scholarly journals Resistance of the S1 layer in kempas heartwood fibers to soft rot decay

IAWA Journal ◽  
2018 ◽  
Vol 39 (1) ◽  
pp. 37-42
Author(s):  
Adya P. Singh ◽  
Andrew H.H. Wong ◽  
Yoon Soo Kim ◽  
Seung Gon Wi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Walls ◽  
Middle Lamella ◽  
Wood Decay ◽  
Soft Rot ◽  
Normal Wood ◽  
Fibre Cell ◽  
Utility Pole ◽  
Transmission Electron

Naturally durable heartwoods, where available, continue to be used as support structures in environments considered hazardous, particularly in ground contact. However, durability of heartwoods against wood decay microorganisms varies. Therefore, it is important to evaluate heartwood products for their in-service performance in order to maximise benefits derived from this valuable natural resource of limited supply. In the work presented, wood pieces from a kempas (Koompassia malaccensis) utility pole that had been placed in service in an acidic soil in Malaysia, and in time had softened at the ground-line position, were examined by light and transmission electron microscopy to evaluate the cause of deterioration.Light microscopy (LM) provided evidence of extensive attack on fibre cell walls by cavity-producing soft rot fungi. Transmission electron microscopy (TEM) revealed in greater detail the distribution and micromorphologies of cavities as well as their relationships to the fine structure of fibre cell walls, which consisted of a highly electron dense middle lamella, a moderately dense S1 layer and a multilamellar S2 layer with variable densities, reflecting differences in lignin concentration. The resistance of the moderately dense S1 layer to soft rot was a feature of particular interest and is the main focus of the work presented. The resistance appeared to be correlated with high lignification of the outermost region of the S2 wall, interfacing with the S1 layer, an unusual cell wall feature not previously described for normal wood.

scholarly journals Investigation of the internal structure of flax fibre cell walls by transmission electron microscopy

Cellulose ◽  
2015 ◽  
Vol 22 (6) ◽  
pp. 3521-3530 ◽  
Author(s):  
Anthony Thuault ◽  
Bernadette Domengès ◽  
Isabel Hervas ◽  
Moussa Gomina
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Internal Structure ◽  
Cell Walls ◽  
Flax Fibre ◽  
Fibre Cell ◽  
Transmission Electron

Electron microscopic and chemical study of degraded Pinus radiata wood from a marine pile

1991 ◽  
Vol 69 (12) ◽  
pp. 2762-2771 ◽  
Author(s):  
A. P. Singh ◽  
M. E. Hedley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Analysis ◽  
Light Microscopy ◽  
Pinus Radiata ◽  
Cellulose Degradation ◽  
Middle Lamella ◽  
Soft Rot ◽  
Minor Role ◽  
Transmission Electron

During an inspection of marine piles, 12 years after installation, severe degradation was noted on one of them in the vicinity of a corroded eyebolt. The wood was dark brown in colour and tended to crumble easily. Wood fragments were examined by light microscopy and scanning and transmission electron microscopy and were also analyzed for carbohydrates and lignin. Light microscopy indicated numerous cracks in tracheid walls resulting in delamination at the middle lamella – S1 and S1–S2 boundaries and also in fractures across the tracheid wall. Chemical analysis showed extensive loss of both hemicellulose and cellulose. Observations with polarized light microscopy supported the data from chemical analysis on cellulose degradation, indicating a loss of crystallinity. Although presence of microbial flora in the lumen of wood cells was revealed by scanning electron microscopy, transmission electron microscopy showed only occasional soft rot decay zones in the S2 layer. The degradation of Pinus radiata wood from this sample appears to have been caused primarily by brown rot attack and (or) iron corrosion products, soft rot attack playing a minor role. Key words: Pinus radiata wood, marine pile, wood cell wall degradation, electron microscopy.

Colonization of Sphagnum cells by Lyophyllum palustre

1985 ◽  
Vol 63 (4) ◽  
pp. 757-761 ◽  
Author(s):  
E. Untiedt ◽  
K. Müller
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Host Cell ◽  
Cell Walls ◽  
Transmission Electron ◽  
Scanning Electron

Lyophyllum palustre (Peck) Singer, a basidiomycete (Tricholomataceae) parasitizing Sphagnum, was examined for points of contact between hyphae and Sphagnum cells with the help of light microscopy, scanning electron microscopy, and transmission electron microscopy. Results indicate that the fungus attacks Sphagnum cells by penetrating cell walls and altering host cell protosplasm. In addition, the formation of additional partitioning cell walls in attacked living Sphagnum cells was observed.

Bacteriocin-like substance inhibits potato soft rot caused by Erwinia carotovora

2006 ◽  
Vol 52 (6) ◽  
pp. 533-539 ◽  
Author(s):  
Florencia Cladera-Olivera ◽  
Geruza R Caron ◽  
Amanda S Motta ◽  
André A Souto ◽  
Adriano Brandelli
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Bacillus Licheniformis ◽  
Membrane Lipids ◽  
Erwinia Carotovora ◽  
Soft Rot ◽  
Bactericidal Effect ◽  
Potato Tubers ◽  
Transmission Electron ◽  
Bacterial Surfaces

Soft rot is a major problem encountered in potatoes during postharvest storage. The soft rot bacterium Erwinia carotovora was inhibited by a novel bacteriocin-like substance (BLS) produced by Bacillus licheniformis P40. The BLS caused a bactericidal effect on E. carotovora cells at 30 µg mL–1. Transmission electron microscopy showed that BLS-treated cells presented wrinkled bacterial surfaces and shrinkage of the whole cell, indicating plasmolysis. Erwinia carotovora cells treated with BLS were analyzed by FTIR showing differences in the 1390 cm–1 and 1250–1220 cm–1 bands, corresponding to assignments of membrane lipids. BLS was effective in preventing E. carotovora spoilage on potato tubers, reducing the symptoms of soft rot at 240 µg mL–1 and higher concentrations. Soft rot development was completely blocked at 3.7 mg mL–1. This BLS showed potential to protect potato tubers during storage. Key words: bacteriocin, plant pathogen, potato, soft rot, storage.

Immunolocalization of a proteinase of the sap-staining fungus Ophiostoma piceae using antibodies to proteinase K

1995 ◽  
Vol 73 (10) ◽  
pp. 1604-1610 ◽  
Author(s):  
C. Hoffert ◽  
S. Gharibian ◽  
C. Breuil ◽  
D. L. Brown
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Walls ◽  
Polyclonal Antibodies ◽  
Immunogold Labelling ◽  
Proteinase K ◽  
Igg Antibodies ◽  
Extracellular Proteinase ◽  
Ophiostoma Piceae ◽  
Transmission Electron

Polyclonal antibodies were raised against proteinase K and were used to immunolocalize the major extracellular proteinase of the sap-staining fungus Ophiostoma piceae (Münch) H. and P. Sydow. Immunodot blotting showed that the IgG antibodies recognized both enzymes but reacted more strongly with proteinase K than with the O. piceae proteinase. Immunogold labelling and transmission electron microscopy revealed that the O. piceae proteinase was localized in the cell walls of O. piceae grown either in liquid media or wood. Key words: Ophiostoma piceae, proteinase, immunogold labelling, transmission electron microscopy, antibody, proteinase K.

Ultrastructural Changes in the Compound Middle Lamella of Pinus thunbergii During Lignification and Lignin Removal

Holzforschung ◽  
2000 ◽  
Vol 54 (3) ◽  
pp. 234-240 ◽  
Author(s):  
Jonas Hafrén ◽  
Takeshi Fujino ◽  
Takao Itoh ◽  
Ulla Westermark ◽  
Noritsugu Terashima
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Middle Lamella ◽  
Pinus Thunbergii ◽  
Ultrastructural Changes ◽  
Woody Tissue ◽  
Compound Middle Lamella ◽  
Lignin Removal ◽  
Transmission Electron ◽  
Early Phases

SummaryThe structure of the middle lamella inPinus thunbergiihas been studied by the rapid-freeze deep-etching (RFDE) technique in combination with transmission electron microscopy (TEM). The ultrastructure of the compound middle lamella was studied in the early phases of the development of woody tissue in the cambial and differentiating xylem, before the heavy incrustation with lignin had occurred. Lignified middle lamella in the xylem was studied both directly and after delignification. It was found that the structure of the unlignified middle lamella in the cambium/developing xylem consists of a fine irregular network probably containing pectin and hemicellulose. As a result of lignin incrustation, the middle lamella becomes increasingly dense and the surface structure of the fully lignified middle lamella appeared to be compact and partly covered with globular structures. After delignification of the lignified middle lamella a thin network with a different structure was revealed. This network probably mainly consists of hemicellulose. No microfibrils of the type that occurs in the primary and secondary walls were found in the middle lamella.

Ultrastructure of hyperparasitism of Coniothyrium minitans on sclerotia of Sclerotinia sclerotiorum

1987 ◽  
Vol 65 (12) ◽  
pp. 2483-2489 ◽  
Author(s):  
H. C. Huang ◽  
E. G. Kokko
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Sclerotinia Sclerotiorum ◽  
Cell Walls ◽  
Chemical Activity ◽  
Coniothyrium Minitans ◽  
Medullary Tissue ◽  
Transmission Electron

Transmission electron microscopy revealed that hyphae of the hyperparasite Coniothyrium minitans invade sclerotia of Sclerotinia sclerotiorum, resulting in the destruction and disintegration of the sclerotium tissues. The dark-pigmented rind tissue is more resistant to invasion by the hyperparasite than the unpigmented cortical and medullary tissues. Evidence from cell wall etching at the penetration site suggests that chemical activity is required for hyphae of C. minitans to penetrate the thick, melanized rind walls. The medullary tissue infected by C. minitans shows signs of plasmolysis, aggregation, and vacuolization of cytoplasm and dissolution of the cell walls. While most of the hyphal cells of C. minitans in the infected sclerotium tissue are normal, some younger hyphal cells in the rind tissue were lysed and devoid of normal contents.

Parental Stress and Prechilling Effects on Pennsylvania Smartweed (Polygonum pensylvanicum) Achenes

Weed Science ◽  
1982 ◽  
Vol 30 (3) ◽  
pp. 243-248 ◽  
Author(s):  
James L. Jordan ◽  
David W. Staniforth ◽  
Catalina M. Jordan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Zea Mays ◽  
Parental Stress ◽  
Cell Walls ◽  
Lipid Bodies ◽  
Transmission Electron ◽  
Polygonum Pensylvanicum ◽  
Scanning Electron

Pennsylvania smartweed (Polygonum pensylvanicum L.) achenes were harvested from plants growing either free from competition or in competition with corn (Zea mays L. ‘Pioneer 3780′) plants. Seeds were dormant when harvested. After 15 weeks of prechilling, 4 and 35% of the seeds germinated from plants with and without corn competition, respectively; after 30 weeks of prechilling, more than 92% of all seeds germinated. Scanning electron microscopy revealed that the carpel walls of achenes from plants with corn competition were porous with many channels. Carpel walls of achenes from plants without corn competition were without pores and channels. Transmission electron microscopy showed more lipid bodies in the embryo epidermal cells of seeds from plants with corn competition. Cell walls of embryos from non-prechilled seeds from plants with corn competition contained lipoidosomes that traversed cell walls. Lipoidosomes did not occur in cells of prechilled seeds.

Ultrastructural studies on infection of sclerotia of Sclerotinia sclerotiorum by Talaromyces flavus

1989 ◽  
Vol 67 (7) ◽  
pp. 2199-2205 ◽  
Author(s):  
D. L. McLaren ◽  
H. C. Huang ◽  
S. R. Rimmer ◽  
E. G. Kokko
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sclerotinia Sclerotiorum ◽  
Cell Walls ◽  
Ultrastructural Studies ◽  
Transmission Electron ◽  
Talaromyces Flavus

Talaromyces flavus is a destructive hyperparasite capable of infecting sclerotia of Sclerotinia sclerotiorum. Examinations of sclerotia by transmission electron microscopy at 3, 7, and 12 days after inoculation revealed that hyphae of T. flavus penetrated the rind cell walls directly. Etching of the cell walls at the penetration site was evident. This suggests that wall-lysing enzymes may be involved in the process of infection. Hyphae of T. flavus grew both intercellularly and intracellularly throughout the rind, cortical, and medullary tissues. Ramification of the hyperparasite in the sclerotium resulted in destruction and collapse of sclerotial tissues.

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