The Study of Stalk Rot and Causal Organisms via Scanning Electron Microscopy

Cooperative SIU Research Includes: A. J. Pappelis, W. E. Schmid, O. Myers, Jr. (Botany); J. N. Bemiller, C. Hinckley (Chemistry); and J. Murphy (Center for Electron Microscopy).Stalk rot of corn is a disease costing millions of dollars annually. Because of the economic importance of this disease, many studies have been undertaken on the nature of resistance to stalk rot, host-parasite interactions, as well as studies of the various pathogens causing stalk rot.In studying the number of mechanisms for stalk rot resistance, A. J. Pappelis discovered a positive correlation between stalk rot susceptibility to Diplodia maydis and the pattern of natural cell death of parenchyma cells in the stalk and a positive correlation between disease resistance and the presence of living cells in that tissue.

Morphological and Structural Characters of Trichomes on Various Organs of Rosa roxburghii

HortScience ◽

10.21273/hortsci13485-18 ◽

2019 ◽

Vol 54 (1) ◽

pp. 45-51 ◽

Cited By ~ 1

Author(s):

Dao-Jing Wang ◽

Jing-Wen Zeng ◽

Wen-Tao Ma ◽

Min Lu ◽

Hua-Ming An

Keyword(s):

Electron Microscopy ◽

Glandular Trichomes ◽

Economic Importance ◽

Horticultural Crops ◽

Parenchyma Cells ◽

Morphology And Structure ◽

Rosa Roxburghii ◽

Square Cells ◽

Rosa roxburghii Tratt (Rosaceae) of various organ surfaces are widely existing trichomes. Certain varieties have fruits that are thickly covered with macroscopic trichomes. R. roxburghii Tratt (RR) and R. roxburghii Tratt. f. esetosa Ku (RRE) are important commercial horticultural crops in China because of their nutritional and medicinal values. RRE is generally considered a smooth-fruit variant that arose from RR. Despite their economic importance, the morphological and anatomic features of organ trichomes have not been explored in detail for these two rose germplasms. In this research, we investigated the distribution, morphology, and structure of trichomes distributed on the stem, pedicel, fruit, sepal, and marginal lobule sepals (MLS) of RR as well as RRE. This was accomplished using scanning electron microscopy (SEM). There are various shapes of trichomes distributed on the surfaces of stems, pedicels, fruits, and sepals of the two germplasms. Binate prickles arose on the stem nodes in both germplasms, but acicular trichomes, papillary trichomes, and ribbon trichomes were present only on the surfaces of pedicels in RR. Likewise, flagelliform trichomes were present only on the surfaces of pedicels in RRE. Furthermore, a transection of stems shows that thorns in the two germplasms are composed of epidermis, meristematic layer, and parenchyma cells. The trichome epidermis and meristematic layer in stems of RR are composed of round cells, whereas RRE exhibits square cells in the same layers. Trichomes on the fruit of RR were macroscopic and of single flagelliform and acicular shape. RRE exhibited polymorphic trichomes of flagelliform, triangular, capitate glandular, and elliptic glandular shapes on the pericarp. On the surfaces of RR sepals, there are thick macroscopic acicular trichomes. In contrast, RRE sepals presented flagelliform trichomes and capitate glandular trichomes. It is interesting that no trichomes were found on the surfaces of the MLS in the two germplasms; however, stomata were densely packed on the MLS of RRE when compared with RR. For RR, the trichomes on both sepal and fruit are composed of an epidermis layer and parenchyma cells; however, the epidermis cells of sepal trichomes are polygon-shaped, in contrast to the round epidermis cells in fruit. These results suggest that the two rose germplasms are good candidates for understanding the trichome ontogeny in the genus and for further breeding of the smooth organ trait in this rose species.

Examination of Schistosome Cercariae and Schistosomules by Scanning Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100062154 ◽

1969 ◽

Vol 27 ◽

pp. 50-51

Author(s):

D. Johnson ◽

P. Moriearty

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

Light Microscopy ◽

Surface Structure ◽

Extensive Study ◽

Scanning Microscopy ◽

Host Parasite ◽

Conventional Electron Microscopy ◽

Since several species of Schistosoma, or blood fluke, parasitize man, these trematodes have been subjected to extensive study. Light microscopy and conventional electron microscopy have yielded much information about the morphology of the various stages; however, scanning electron microscopy has been little utilized for this purpose. As the figures demonstrate, scanning microscopy is particularly helpful in studying at high resolution characteristics of surface structure, which are important in determining host-parasite relationships.

Palynological analysis of five selected Onosma taxa

Biologia ◽

10.2478/s11756-008-0026-y ◽

2008 ◽

Vol 63 (2) ◽

Cited By ~ 4

Author(s):

Filippo Maggi ◽

Vladislav Kolarčik ◽

Pavol Mártonfi

Keyword(s):

Electron Microscopy ◽

Chromosome Number ◽

Pollen Grains ◽

Pollen Size ◽

Palynological Analysis ◽

Positive Correlation ◽

Pollen Characters ◽

AbstractPollen size and exine structure of the following five Onosma L. species from Slovakia and Italy were studied by light and scanning electron microscopy: Onosma echioides, O. tornensis, O. visianii, O. arenaria, and O. pseudoarenaria. Among the taxa studied, O. echioides has the smallest pollen grains in average (10.5–17.5 × 8.0–14.5 µm), and O. pseudoarenaria the largest grains in average (15.3–20.5 × 12.3–16.3 µm). Pollen grains of all 5 species are small sized, 3-syncolporate, subprolate, heteropolar, with ovate equatorial outlines and circular to rounded triangular polar outlines; the tectum is microechinate. A positive correlation is found between pollen size and chromosome number. The value of pollen characters for taxonomic purposes and the position of the taxa studied within the genus Onosma are discussed.

Host-Parasite Relations in a Mycoparasite. VII. Light and Scanning Electron Microscopy of Interactions of Piptocephalis Virginiana with Host and Nonhost Species

Mycologia ◽

10.1080/00275514.1981.12021426 ◽

1981 ◽

Vol 73 (5) ◽

pp. 976-987 ◽

Cited By ~ 2

Author(s):

M. S. Manocha ◽

Roya Golesorkhi

Keyword(s):

Electron Microscopy ◽

Host Parasite ◽

Cytinus under the Microscope: Disclosing the Secrets of a Parasitic Plant

Plants ◽

10.3390/plants10010146 ◽

2021 ◽

Vol 10 (1) ◽

pp. 146

Author(s):

Enrico Sanjust ◽

Andrea C. Rinaldi

Keyword(s):

Food Production ◽

Current Knowledge ◽

Biological Activities ◽

Parasitic Plants ◽

Common Species ◽

Economic Importance ◽

Adaptive Traits ◽

Host Parasite Interactions ◽

Main Representative ◽

Host Parasite

Well over 1% of all flowering plants are parasites, obtaining all or part of the nutrients they need from other plants. Among this extremely heterogeneous assemblage, the Cytinaceae form a small group of holoparasites, with Cytinus as the main representative genus. Despite the small number of known species and the fact that it doesn’t attack crops or plants of economic importance, Cytinus is paradigmatic among parasitic plants. Recent research has indeed disclosed many aspects of host–parasite interactions and reproductive biology, the latter displaying a vast array of adaptive traits to lure a range of animal pollinators. Furthermore, analysis of biological activities of extracts of the most common species of Cytinus has provided evidence that this plant could be a valuable source of compounds with high potential in key applicative areas, namely food production (nutraceuticals) and the development of antimicrobial therapeutics. This article offers a complete overview of our current knowledge of Cytinus.

Surface ultrastructure and elasticity in growing tips and mature regions of Aspergillus hyphae describe wall maturation

Microbiology ◽

10.1099/mic.0.28328-0 ◽

2005 ◽

Vol 151 (11) ◽

pp. 3679-3688 ◽

Cited By ~ 54

Author(s):

Hui Ma ◽

Laelie A. Snook ◽

Susan G. W. Kaminskyj ◽

Tanya E. S. Dahms

Keyword(s):

Electron Microscopy ◽

Tip Growth ◽

Living Cells ◽

Surface Ultrastructure ◽

Force Microscopy ◽

Atomic Force ◽

Young Branch ◽

Hyphal Tip ◽

Cryo Scanning Electron Microscopy ◽

This study reports the first direct, high-resolution physical and structural evidence of wall changes during hyphal tip growth, visualized by atomic force microscopy (AFM) in Aspergillus nidulans. Images from AFM and cryo-scanning electron microscopy provided comparable information, but AFM was also able to image and physically probe living cells. AFM images showed changes in the surface ultrastructure of A. nidulans hyphae, from newly deposited walls at hyphal tips to fully mature walls, as well as additional changes at young branches arising from mature walls. Surface architecture during wall maturation correlated with changes in the relative viscoelasticity (compliance per unit applied force) of walls measured by force spectroscopy (FS) in growing A. nidulans hyphae. Growing tips showed greater viscoelasticity than mature walls, despite equal support from turgor. Branch tips had comparable viscoelasticity to hyphal tips, unlike the mature wall from which they grew. FS also revealed differences in surface hydrophilicity between newly deposited and mature walls, with the tips being more hydrophilic. The hydrophilicity of young branch tips was similar to that of hyphal tips, and different from that of mature walls. Taken together, AFM images and FS data suggest that the A. nidulans wall matures following deposition at the hyphal tip.

Structure of nectaries of Malus sylvestris (L.) Mill.

Acta Agrobotanica ◽

10.5586/aa.2006.004 ◽

2012 ◽

Vol 59 (1) ◽

pp. 41-48

Author(s):

Agata Konarska

Keyword(s):

Electron Microscopy ◽

Middle Part ◽

Epidermal Cells ◽

Secretory Cells ◽

Floral Nectary ◽

Malus Sylvestris ◽

Parenchyma Cells ◽

Nectariferous Tissue ◽

The structure of floral nectary of <i>Malus sylvestris</i> was examined using light and scanning electron microscopy. Nectaries in <i>M. sylvestris</i> flowers were situated on the adaxial surface of the receptacle, between the style and the base of filaments. The middle part of the nectary was covered epidermal cells with striated cuticle. The remaining part of the nectary was covered with smooth cuticle. Open and modified nectarostomata were situated at the same level as epidermal cells. The nectariferous tissue was formed by densely packed small parenchyma cells (secretory cells) with dark protoplasts.

Low-voltage field-emission scanning electron microscopy applications in nematology

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104169 ◽

1988 ◽

Vol 46 ◽

pp. 420-421

Author(s):

William P. Wergin ◽

Richard M. Sayre ◽

Terrence W. Reilly

Keyword(s):

Electron Microscopy ◽

Field Emission ◽

Low Voltage ◽

Structural Information ◽

Parasitic Nematodes ◽

Objective Lens ◽

New Information ◽

Host Parasite ◽

Conventional scanning electron microscopy (CSEM) has long been used to gain structural information on the taxonomy, morphology, host-parasite relationships and predators of plant parasitic nematodes. Although a significant amount of new information has accumulated during the past few years, further gains in structural detail will be hampered because CSEMs have resolutions of 40-70A, 5-20kV accelerating voltages are normally required to excite adequate secondary electrons, and current preparation techniques require specimen coatings of 200-300A.Recently a new SEM, the Hitachi S900, combined a condensor-objective lens system with a field emission electron source. This instrument, known as a field emission (FE) SEM, has a resolution of about 5A or 10 times greater than that of CSEMs, can be used to observe specimens with little or no coating and operates at accelerating voltages as low as 1 or 2 kV while producing electron densities nearly 1000 times brighter than those of CSEMs.

The role of cortical orientation in the control of the direction of ciliary beat in Paramecium.

The Journal of Cell Biology ◽

10.1083/jcb.64.1.98 ◽

1975 ◽

Vol 64 (1) ◽

pp. 98-112 ◽

Cited By ~ 39

Author(s):

S L Tamm ◽

T M Sonneborn ◽

R V Dippell

Keyword(s):

Electron Microscopy ◽

Living Cells ◽

Swimming Behavior ◽

Directional Response ◽

Metachronal Waves ◽

Direction Opposite ◽

Normal Cortex ◽

The swimming behavior of many ciliate protozoans depends on graded changes in the direction of the ciliary effective stroke in response to depolarizing stimuli (i.e., the avoiding reaction of Paramecium). We investigated the problem of whether the directional response of cilia with a variable plane of beat is related to the polarity of the cell as a whole or to the orientation of the cortical structures themselves. To do this, we used a stock of Paramecium aurelia with part of the cortex reversed 180 degrees. We determined the relation of the orientation of the kineties (ciliary rows) to the direction of beat in these mosaic paramecia by cinemicrography of particle movements near living cells and by scanning electron microscopy of instantaneously fixed material. We found that the cilia of the inverted rows always beat in the direction opposite to that of normally oriented cilia during both forward and backward swimming. In addition, metachronal waves of ciliary coordination were present on the inverted patch, travelling in the direction opposite to those on the normal cortex. The reference point for the directional response of Paramecium cilia to stimuli thus resides within the cilia or their immediate cortical surroundings.

Eocronartium muscicola: a basidiomycetous moss parasite exploiting gametophytic transfer cells

Canadian Journal of Botany ◽

10.1139/b88-113 ◽

1988 ◽

Vol 66 (4) ◽

pp. 762-770 ◽

Cited By ~ 13

Author(s):

E. W. A. Boehm ◽

D. J. McLaughlin

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Transfer Cells ◽

Transmission Electron ◽

Host Parasite ◽

Relationship Of ◽

The Relationship ◽

Gain Access ◽

The host–parasite interface in Eocronartium muscicola, Auriculariales sensu lato, was examined histologically for 6 of the 21 reported moss hosts, using light microscopy, scanning electron microscopy, and transmission electron microscopy. A unique mode of fungal biotrophy was encountered in 5 of the 6 mosses analyzed, in which E. muscicola exploits gametophytic host transfer cells concomitant with varying degrees of supplantation of the moss sporophyte. Basidiocarps are restricted in these mosses to postfertilized archegonia, in which they are seen to associate with the sporophyte foot region, where they gain access to the host transfer cell nutritional interface. Basidiocarp ontogeny is presented as it relates to the development of the host–parasite interface. The relationship of E. muscicola to other simple-septate auricularioid taxa and the the Uredinales is discussed.