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.

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.

scholarly journals Comparative Transcriptomic Analysis of Race 1 and Race 4 of Fusarium oxysporum f. sp. cubense Induced with Different Carbon Sources

2017 ◽  
Vol 7 (7) ◽  
pp. 2125-2138 ◽  
Author(s):  
Shiwen Qin ◽  
Chunyan Ji ◽  
Yunfeng Li ◽  
Zhenzhong Wang
Keyword(s):  
Gene Expression ◽  
Cell Wall ◽  
Fusarium Oxysporum ◽  
Host Cell ◽  
Expression Profiles ◽  
Cell Wall Polysaccharide ◽  
Host Cell Wall ◽  
Race 1 ◽  
Race 4 ◽  
Banana Cultivar

Abstract The fungal pathogen Fusarium oxysporum f. sp. cubense causes Fusarium wilt, one of the most destructive diseases in banana and plantain cultivars. Pathogenic race 1 attacks the “Gros Michel” banana cultivar, and race 4 is pathogenic to the Cavendish banana cultivar and those cultivars that are susceptible to Foc1. To understand the divergence in gene expression modules between the two races during degradation of the host cell wall, we performed RNA sequencing to compare the genome-wide transcriptional profiles of the two races grown in media containing banana cell wall, pectin, or glucose as the sole carbon source. Overall, the gene expression profiles of Foc1 and Foc4 in response to host cell wall or pectin appeared remarkably different. When grown with host cell wall, a much larger number of genes showed altered levels of expression in Foc4 in comparison with Foc1, including genes encoding carbohydrate-active enzymes (CAZymes) and other virulence-related genes. Additionally, the levels of gene expression were higher in Foc4 than in Foc1 when grown with host cell wall or pectin. Furthermore, a great majority of genes were differentially expressed in a variety-specific manner when induced by host cell wall or pectin. More specific CAZymes and other pathogenesis-related genes were expressed in Foc4 than in Foc1 when grown with host cell wall. The first transcriptome profiles obtained for Foc during degradation of the host cell wall may provide new insights into the mechanism of banana cell wall polysaccharide decomposition and the genetic basis of Foc host specificity.

Histopathology of Fusarium wilt of staghorn sumac (Rhus typhina) caused by Fusarium oxysporum f. sp. callistephi race 3. III. Host cell and tissue reactions

2006 ◽  
Vol 87 (1) ◽  
pp. 17-27 ◽  
Author(s):  
Guillemond B. Ouellette ◽  
Mohamed Cherif ◽  
Marie Simard
Keyword(s):  
Cell Wall ◽  
Fusarium Oxysporum ◽  
Host Cell ◽  
Cross Wall ◽  
Tissue Proliferation ◽  
Host Cytoplasm ◽  
Transmission Electron ◽  
Host Cell Wall ◽  
Tissue Reactions ◽  
Rhus Typhina

Abstract Various cell reactions occurred in staghorn sumac plants inoculated with Fusarium oxysporum f. sp. callistephi. Light and transmission electron microscopy observations and results of cytochemical tests showed: 1) increased laticifers and latex production in the phloem; 2) tylosis formation; 3) host cell wall modifications, including appositions or other cell wall thickenings; and 4) unusual cross wall formation in some cells, and cell hypertrophy and hyperplasia. Tylosis walls labelled for pectin and cellulose and many displayed inner suberin-like layers. These layers were also noted in cells of the medullary sheath and in many cells with dense content and thickened walls in the barrier zones that had formed. These zones also contained fibres with newly-formed gelatinous-like layers. In the vicinity of these cells, host cell walls were frequently altered, associated with opaque matter. Many small particles present in chains also occurred in some of these cells, which contained only remnants of host cytoplasm. Light microscopy observations showed that pronounced tissue proliferation and aberrant cells occurred in the outer xylem in the infected plants. Unusual neoplasmic tissue also formed from cells surrounding the pith and medullary sheath, and it spanned directly across the pre-existing xylem tissue and burst as large mounds on the stems.

scholarly journals Characterizing Hyperspectral Microscope Imagery for Classification of Blueberry Firmness with Deep Learning Methods

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 85
Author(s):  
Bosoon Park ◽  
Tae-Sung Shin ◽  
Jeong-Seok Cho ◽  
Jeong-Ho Lim ◽  
Ki-Jae Park
Keyword(s):  
Cell Wall ◽  
Deep Learning ◽  
Cell Adhesion ◽  
Spectral Characteristics ◽  
Parenchyma Cell ◽  
Life Quality ◽  
Intercellular Spaces ◽  
Parenchyma Cells ◽  
Cell Shapes ◽  
Cell To Cell Adhesion

Firmness is an important quality indicator of blueberries. Firmness loss (or softening) of postharvest blueberries has posed a challenge in its shelf-life quality control and can be delineated with its microstructural changes. To investigate spatial and spectral characteristics of microstructures based on firmness, hyperspectral microscope imaging (HMI) was employed for this study. The mesocarp area with 20× magnification of blueberries was selectively imaged with a Fabry–Perot interferometer HMI system of 400–1000 nm wavelengths, resulting in 281 hypercubes of parenchyma cells in a resolution of 968 × 608 × 300 pixels. After properly processing each hypercube of parenchyma cells in a blueberry, the cell image with different firmness was examined based on parenchyma cell shape, cell wall segment, cell-to-cell adhesion, and size of intercellular spaces. Spectral cell characteristics of firmness were also sought based on the spectral profile of cell walls with different image preprocessing methods. The study found that softer blueberries (1.96–3.92 N) had more irregular cell shapes, lost cell-to-cell adhesion, loosened and round cell wall segments, large intercellular spaces, and cell wall colors that were more red than the firm blueberries (6.86–8.83 N). Even though berry-to-berry (or image-to-image) variations of the characteristics turned out large, the deep learning model with spatial and spectral features of blueberry cells demonstrated the potential for blueberry firmness classification with Matthew’s correlation coefficient of 73.4% and accuracy of 85% for test set.

Wound Effects on Cytodifferentiation in Hardwood Xylem

IAWA Journal ◽  
1985 ◽  
Vol 6 (2) ◽  
pp. 107-118 ◽  
Author(s):  
Keiko Kuroda ◽  
Ken Shimaji
Keyword(s):  
Vascular System ◽  
Parenchyma Cell ◽  
Vessel Element ◽  
Tissue Formation ◽  
Vessel Elements ◽  
Wound Reaction ◽  
Ray Parenchyma Cells ◽  
Mother Cells ◽  
Ray Cell ◽  
Wound Tissue

The wound effects on cytodifferentiation in hardwood xylem were studied by means of periodical observation of wound tissue formation after a pin insertion into the stem of poplar. The mitotic reactivation of ray parenchyma cells was similar to that in conifers. These ray cell derivatives easily invaded other cells creating the impression of septate fibres. Conspicuous abnormalities were found in the differentiation of those fusiform cells which were situated in the zone of xylem mother cells at the time of wounding and those originating from cambial initials for several days after wounding. In the former zone, fusiform cells were prevented from differentiating into vessel elements after dividing transversely several times in the zone adjacent to the injury ; fusiform cells in the area extending several millimetres longitudinally were variously modified morphologically after the frequent transverse divisions in the xylem mother cell zone: they showed various transitional patterns from vessel element-like through tracheid-like, and axial parenchyma-cell-like to fibre-like. These observations suggest that the direction of cytodifferentiation is determined in the cambial initials or the neighbouring xylem mother cells, and is controlled by certain substances, which may change in concentration through the wounding stimulus, bringing about the modification in cytodifferentiation. Wound reaction of hardwood (i .e., woody dicotyledons) was thus completely different from the regeneration of vascular system in injured herbaceous dicotyledons.

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.

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.

Peculiar ultrastructural characteristics of fungal cells and of other elements apposed to and in vessel walls in plants of a susceptible carnation cultivar, infected with Fusarium oxysporum f.sp. dianthi race 2

2005 ◽  
Vol 85 (3) ◽  
pp. 121-138 ◽  
Author(s):  
Guillemond B. Ouellette ◽  
Robert P. Baayen ◽  
Danny Rioux ◽  
Marie Simard
Keyword(s):  
Fusarium Oxysporum ◽  
Host Cell ◽  
Outer Layer ◽  
Cell Walls ◽  
Vessel Elements ◽  
Tissue Degradation ◽  
Ultrastructural Characteristics ◽  
Vessel Walls ◽  
Race 2

Abstract Ultrastructural characteristics and cytochemical reactions of unusual, irregular elements (IE) in vessel elements in susceptible carnation plants infected with Fusarium oxysporum are reported. As revealed by labelling for chitin, fungal cells in contact with host cell walls or content had altered or defective lucent layers, and labelling was frequently associated with their outer, opaque layer or matter located outside the cells. Coating matter on vessel walls occurred at all stages of infection, and IEs only in later stages. IEs were delineated by opaque, often folded bands, some contouring pit borders, and contained membranous and vesicular structures mixed with other fine components. Only then, IEs were strongly but not uniformly labelled for chitin. Coating, IE-delineating bands, and the opaque outer layer of typical fungal cells were texturally similar, not labelled for chitin or cellulose, except where they impinged upon host walls. Both probes for chitin and cellulose strongly attached to vessel secondary walls. IEs were often confluent with coating, and with fungal cells connected to them by means of microfilamentous structures. Similar microfilamentous structures and opaque bands connected to IEs, the coating, and the microhyphae, or protruding from fungal cells reached into host walls, associated with alterations of these walls. The possible malleable IEs might be a counterpart of the coating, and although they do not occur in the initial stages of the disease, they could play an important role in the final stages of tissue degradation.

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