Resistance of hardwood vessels to degradation by white rot Basidiomycetes

1988 ◽  
Vol 66 (9) ◽  
pp. 1841-1847 ◽  
Author(s):  
Robert A. Blanchette ◽  
John R. Obst ◽  
John I. Hedges ◽  
Karen Weliky
Keyword(s):  
Cell Wall ◽  
Secondary Wall ◽  
White Rot ◽  
Fungal Decay ◽  
Acacia Koa ◽  
Monomer Composition ◽  
Lignin Removal ◽  
Vessel Elements ◽  
Parenchyma Cells ◽  
Unusual Type

White stringy rot, an unusual type of selective fungal decay, can be found in wood of some dicotyledonous angiosperms. Stages of advanced decay consist of a mass of vessel elements with only remnants of other cells adhering to the vessel walls. Degradation by various white rot Basidiomycetes causes loss of fibers, fiber tracheids, and parenchyma cells but not vessels. In wood of Acacia koa var. koa with a white pocket rot caused by Phellinus kawakamii, fibers and parenchyma cells were preferentially delignified. After extensive lignin removal the cellulose remaining in the secondary wall was degraded. Large vessel elements remained relatively intact after other cells were completely degraded. The resistance of vessels to degradation appears to be due to their high ligninxarbohydrate ratio, lignin monomer composition, and cell wall morphology.

Lignin Distribution in Coppice Poplar, Linseed and Wheat Straw

Holzforschung ◽  
2001 ◽  
Vol 55 (4) ◽  
pp. 379-385 ◽  
Author(s):  
Lloyd Donaldson ◽  
Jamie Hague ◽  
Rebecca Snell
Keyword(s):  
Wheat Straw ◽  
Secondary Wall ◽  
Middle Lamella ◽  
Laser Scanning Microscopy ◽  
Interference Microscopy ◽  
Confocal Laser ◽  
Lignin Concentration ◽  
Lignin Distribution ◽  
Vessel Elements ◽  
Parenchyma Cells

Summary Lignin distribution was determined by interference microscopy, and by confocal laser scanning microscopy (CLSM) for a range of agricultural residues including coppice poplar, linseed, and wheat straw. Interference microscopy was used to determine the lignin concentration in the middle lamella at the cell corner, and for the secondary wall of libriform fibres in the secondary xylem of poplar and linseed. Wheat was examined in the same way for cortical fibres. In addition the secondary wall of vessel elements was examined for poplar. Confocal microscopy was used to confirm the results from interference microscopy by providing semiquantitative information based on lignin autofluorescence, and by staining with acriflavine. Wheat had the lowest level of lignification, with 31 % lignin in the middle lamella of cortical fibres and 9% lignin in the secondary wall. Poplar had a lignin concentration of 63% in the middle lamella and 6% in the secondary wall of libriform fibres, while linseed had corresponding values of 69 % and 13 %. The secondary wall of poplar vessel elements had a lignin concentration of 25 %. In all three species most of the stem tissue was lignified except for phloem and bark, where present. In linseed the pith was unlignified. In wheat, most of the parenchyma cells were lignified except for a few cells lining the stem cavity. Libriform fibres in poplar and linseed sometimes had an unlignified gelatinous layer in samples containing tension wood. In linseed, lignification was greater in xylem fibres compared to bast fibres. Ray parenchyma cells of poplar and linseed appeared to be lignified to the same extent as xylem fibres.

Certain aspects of xylem differentiation in corn

1972 ◽  
Vol 50 (9) ◽  
pp. 1795-1804 ◽  
Author(s):  
L. M. Srivastava ◽  
A. P. Singh
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Wall Thickening ◽  
Xylem Differentiation ◽  
Cytoplasmic Protein ◽  
Wall Deposition ◽  
Vessel Elements ◽  
Parenchyma Cells ◽  
Vacuolar Membranes

Differentiation of vessel elements in corn is accompanied by marked changes in nearly all organelles except plastids. The young cells increase in volume and apparently synthesize new cytoplasmic protein. The initiation of wall thickening is accompanied by an aggregation of microtubules in specific locations and an increase in the number of mitochondria and dictyosomes. During the period of active wall deposition, the endoplasmic reticulum (ER) shows a highly elaborate form, harbors intralamellar tubules, and nearly blankets those parts of the wall which remain unthickened. Dictyosomes seem to produce at least two types of vesicles, one of which may serve as a carrier of lignin precursors. The final autolysis involves a progressive removal of vacuolar membranes, plastids, dictyosomes, vesicles associated with secretion of noncellulosic polysaccharides, microtubules, and finally plasmalemma, parts of cell wall, and cytoplasm. Mitochondria and ribosomes are degenerated. The ER probably plays an important role in this autolysis. The parenchyma cells associated with vessel elements are rich in mitochondria.

Ultrastructural and cytochemical study of colonization of xylem vessel elements of susceptible and resistant Dianthus caryophyllus by Fusarium oxysporum f.sp. dianthi

1999 ◽  
Vol 77 (5) ◽  
pp. 644-663 ◽  
Author(s):  
G B Ouellette ◽  
R P Baayen ◽  
M Simard ◽  
D Rioux
Keyword(s):  
Cell Wall ◽  
Fusarium Oxysporum ◽  
Host Cell ◽  
Parenchyma Cell ◽  
Dianthus Caryophyllus ◽  
Vessel Element ◽  
Cytochemical Study ◽  
Secondary Invasion ◽  
Vessel Elements ◽  
Parenchyma Cells

The colonization processes of the xylem in the susceptible carnation cv. Early Sam and the resistant cv. Novada were studied ultrastructurally following inoculation with Fusarium oxysporum f.sp. dianthi. Samples from 1 to 3 cm above the incision were collected over 5 weeks and processed following conventional procedures as well as with probes for cellulose, N-acetyl-glucosamine, and pectin. The fungus grew profusely in the vessel lumina of the susceptible cultivar. Some of the colonized vessels were lined with coating material connected to the fungal cell wall and extending into the host cell wall through microfilamentous-like structures. Coatings did not label for pectin or cellulose. The pathogen crossed from one vessel element to another (and at times to parenchyma cells) usually directly through pit membranes; often the invading structures of the fungus appeared to be either only membrane-bound or formed solely of microfilamentous-like entities. The fungus subsequently invaded extensively, generally by means of microhyphae, the vessel intercalary walls from the pit membranes and vessel wall junctures. Microhyphae had thin or imperceptible walls and contained only some of the normal cytoplasmic components. Initially, the invading hyphae dislocated the host cell walls, apparently mechanically more than by lysis; however, more pronounced lysis occurred following general tissue invasion. Host parenchyma cells seemed relatively unaffected, even after the surrounding walls had undergone severe degradation. Colonization of resistant plants was restricted. Degradation of tissues did not occur and microhyphae were not observed. Inoculated vessel elements in the 'Novada' plants contained numerous fungal cells and little occluding material, whereas the surrounding vessels were almost completely occluded. The initially invaded xylem became tangentially compartmentalized by parenchyma cell wall thickenings and by hyperplastic parenchyma. Occasionally, hyperplastic tissues were slightly re-invaded, forming secondary invasion pockets. Vessel-occluding material varied in structure and opacity, not only from vessel to vessel but also within the same vessel, and contained microfilamentous-like structures and other types of fine fibrillar material. Some vessel elements in or near the secondary invasion pockets contained only the finer fibrils that reacted strongly with an antibody specific for pectin. Vessel elements rarely contained tyloses.Key words: cellulose, chitin, Dianthus caryophyllus, Fusarium wilt, gels and gums, host wall degradation, microhyphae, pectin, tyloses.

scholarly journals Anatomy and cell wall ultrastructure of sunflower stalk rind

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Lizhen Wang ◽  
Hao Ren ◽  
Shengcheng Zhai ◽  
Huamin Zhai
Keyword(s):  
Cell Wall ◽  
Middle Lamella ◽  
Transmission Electron ◽  
Vessel Elements ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Phloem Fibers ◽  
Ray Parenchyma Cells ◽  
Xylem Fibers ◽  
Anatomy And Ultrastructure

AbstractThe anatomy and ultrastructure of sunflower stalk rind are closely related to its conversion and utilization. We studied systematically the anatomy and ultrastructure of the stalk rind using light, scanning electron, transmission electron and fluorescence microscopy. The results showed that the stalk rind consisted of phloem fibers (PF), xylem fibers (XF), vessel elements (V), ground parenchyma cells (GPC), axial parenchyma cells (APC), xylem ray parenchyma cells (XRPC), and pith ray parenchyma cells (PRPC). These cell walls were divided into the middle lamella, primary wall, and secondary wall (S). It was found that the S of PF, XF and V was further divided into three layers (S1–S3), while the S of APC, GPC, XRPC and PRPC showed a non-layered cell wall organization or differentiated two (S1, S2) to seven layers (S1–S7). Our research revealed the plasmodesmata characteristics in the pit membranes (PMs) between parenchyma cells (inter-GPCs, inter-XRPCs, and inter-PRPCs). The morphology of the plasmodesmata varied with the types of parenchyma cells. The thickness and diameter of PMs between the cells (inter-Vs, V–XF, V–APC, and V–XRPC) were greater than that of PMs between parenchyma cells. The cell corners among parenchyma cells were intercellular space. The lignification degree of vessels was higher than that of parenchyma cells and fibers. The results will provide useful insights into the biological structure, conversion and utilization of sunflower stalk rind.

Development and Structure of Pit Membranes in the Rhizome of the Woody Fern Botrychium Dissectum

IAWA Journal ◽  
1998 ◽  
Vol 19 (4) ◽  
pp. 429-441 ◽  
Author(s):  
Angela C. Morrow ◽  
Roland R. Dute
Keyword(s):  
Cell Wall ◽  
Secondary Wall ◽  
Matrix Material ◽  
Parenchyma Cell ◽  
Pit Membrane ◽  
Parenchyma Cells ◽  
Combined Features ◽  
Early Fall ◽  
Secondary Wall Formation ◽  
Parenchyma Cell Wall

Botrychium dissectum Sprengel rhizomes were examined at monthly intervals from February 1993 through December 1994. Sampies taken ranged from those with an inactive cambium and only mature tracheids to those having an active cambium and immature tracheids. The vascular cambium became activated in the early fall prior to maturation of the leaf and fertile spike complex. Intertracheid pit membranes with tori were present in all sampies, although the morphology of the torus varied. The presence of tori was first observed in a tracheid that had just initiated its secondary wall formation. As the pit membrane matured, matrix material was hydrolyzed first from the margo area, then from the torus, and eventually the pit membrane was represented only by a very thin network of microfibrils. In addition, studies confirmed that tracheids bordering parenchyma cells developed a torus thickening, aIthough no thickening of the parenchyma cell wall occurred. Torus ontogeny in B. dissectum combined features previously described for angiosperms and gymnosperms.

Unusual cell wall layers in elm parenchyma of secondary xylem

1978 ◽  
Vol 56 (17) ◽  
pp. 2109-2113 ◽  
Author(s):  
G. B. Ouellette
Keyword(s):  
Cell Wall ◽  
Secondary Wall ◽  
Secondary Xylem ◽  
Protective Layers ◽  
American Elm ◽  
Additional Layer ◽  
Parenchyma Cells ◽  
Ray Parenchyma

Multilayering of secondary wall layers in American elm parenchyma cells is described. This includes one additional layer like S1–S3 and protective layers each in vasicentric parenchyma and up to two additional such layers in ray parenchyma. These extra layers are comparable with those mentioned by a few other workers, but they are not necessarily related to tylosis formation as implied by some of these.

Microscopie de la mycoflore des aiguilles de Sapin blanc (Abies alba). IV. Décomposition de la cuticule, de l'hypoderme et de l'épiderme

1989 ◽  
Vol 67 (3) ◽  
pp. 933-939 ◽  
Author(s):  
François Gourbière ◽  
Régis Pépin ◽  
Dominique Bernillon
Keyword(s):  
Cell Wall ◽  
Light And Electron Microscopy ◽  
Abies Alba ◽  
Soft Rot ◽  
Fungal Species ◽  
White Rot ◽  
Type I ◽  
Parenchyma Cells ◽  
Coniferous Needles ◽  
Stage 1

Degradation of protective tissues of coniferous needles (Abies alba Mill.) was examined by light and electron microscopy. Cuticle and hypodermis were destroyed at the beginning of the F1 stage, 1 year after needle fall. Hyphae from the superficial mycelium penetrated and colonized the cuticle, giving rise to numerous cavities throughout the cuticular layers. At the same time the cell wall of the hypodermis was invaded by soft rot fungi (type I) and hyphae grew within cavities within the secondary wall. During the F2 stage the epidermis was also destroyed by formation of cavities in the cell wall. At this time the remaining cuticle gave a typical wrinkled appearance to the needle surface. Hypotheses about the fungal species implicated in these activities are discussed. These processes do not affect residual cytoplasm of parenchyma cells and appear to be strongly different from white rot degradation of litter.

scholarly journals MYB Transcription Factors and Its Regulation in Secondary Cell Wall Formation and Lignin Biosynthesis during Xylem Development

2021 ◽  
Vol 22 (7) ◽  
pp. 3560
Author(s):  
Ruixue Xiao ◽  
Chong Zhang ◽  
Xiaorui Guo ◽  
Hui Li ◽  
Hai Lu
Keyword(s):  
Cell Wall ◽  
Transcription Factors ◽  
Secondary Wall ◽  
Secondary Cell Wall ◽  
Lignin Biosynthesis ◽  
Cell Wall Formation ◽  
Long Distance ◽  
Secondary Cell Wall Formation ◽  
Myb Transcription Factors ◽  
Wall Formation

The secondary wall is the main part of wood and is composed of cellulose, xylan, lignin, and small amounts of structural proteins and enzymes. Lignin molecules can interact directly or indirectly with cellulose, xylan and other polysaccharide molecules in the cell wall, increasing the mechanical strength and hydrophobicity of plant cells and tissues and facilitating the long-distance transportation of water in plants. MYBs (v-myb avian myeloblastosis viral oncogene homolog) belong to one of the largest superfamilies of transcription factors, the members of which regulate secondary cell-wall formation by promoting/inhibiting the biosynthesis of lignin, cellulose, and xylan. Among them, MYB46 and MYB83, which comprise the second layer of the main switch of secondary cell-wall biosynthesis, coordinate upstream and downstream secondary wall synthesis-related transcription factors. In addition, MYB transcription factors other than MYB46/83, as well as noncoding RNAs, hormones, and other factors, interact with one another to regulate the biosynthesis of the secondary wall. Here, we discuss the biosynthesis of secondary wall, classification and functions of MYB transcription factors and their regulation of lignin polymerization and secondary cell-wall formation during wood formation.

Phenological Comparison of the Onset of Vessel Formation Between Ring-Porous and Diffuse-Porous Deciduous Trees in a Japanese Temperate Forest

IAWA Journal ◽  
1996 ◽  
Vol 17 (4) ◽  
pp. 431-444 ◽  
Author(s):  
Mitsuo Suzuki ◽  
Kiyotsugu Yoda ◽  
Hitoshi Suzuki
Keyword(s):  
Secondary Wall ◽  
Leaf Expansion ◽  
Vessel Element ◽  
Early Maturation ◽  
Vessel Formation ◽  
Wall Deposition ◽  
Water Conduction ◽  
Vessel Elements ◽  
Secondary Wall Deposition ◽  
Diffuse Porous

Initiation of vessel formation and vessel maturation indicated by secondary wall deposition have been compared in eleven deciduous broadleaved tree species. In ring-porous species the first vessel element formation in the current growth ring was initiated two to six weeks prior to the onset of leaf expansion, and secondary wall deposition on the vessel elements was completed from one week before to three weeks after leaf expansion. In diffuse-porous species, the first vessel element formation was initiated two to seven weeks after the onset of leaf expansion, and secondary wall deposition was completed four to nine weeks after leaf expansion. These results suggest that early maturation of the first vessel elements in the ring-porous species will serve for water conduction in early spring. On the contrary, the late maturation of the first vessel elements in the diffuse-porous species indicates that no new functional vessels exist at the time of the leaf expansion.

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