Histological Study of Some Echium vulgare, Pulmonaria officinalis and Symphytum officinale Populations

Plants living in different ecological habitats can show significant variability in their histological and phytochemical characters. The main histological features of various populations of three medicinal plants from the Boraginaceae family were studied. Stems, petioles and leaves were investigated by light microscopy in vertical and transverse sections. The outline of the epidermal cells, as well as the shape and cell number of trichomes was studied in leaf surface casts. Differences were measured among the populations of Echium vulgare in the width and height of epidermis cells in the stem, petiole and leaf, as well as in the size of palisade cells in the leaves. Among the populations of Pulmonaria officinalis significant differences were found in the length of trichomes and in the slightly or strongly wavy outline of epidermal radial cell walls. Populations of Symphytum officinale showed variance in the height of epidermal cells in leaves and stems, length of palisade cells and number of intercellular spaces in leaves, and the size of the central cavity in the stem. Boraginaceae bristles were found to be longer in plants in windy/shady habitats as opposed to sunny habitats, both in the leaves and stems of P. officinalis and S. officinale, which might be connected to varying levels of exposure to wind. Longer epidermal cells were detected in the leaves and stems of both E. vulgare and S. officinale plants living in shady habitats, compared with shorter cells in sunny habitats. Leaf mesophyll cells were shorter in shady habitats as opposed to longer cells in sunny habitats, both in E. vulgare and S. officinale. This combination of histological characters may contribute to the plant's adaptation to various amounts of sunshine. The reported data prove the polymorphism of the studied taxa, as well as their ability to adapt to various ecological circumstances.

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Histopathological and ultrastructural comparison of Stemphylium sarcinaeforme and S. botryosum on red clover foliage

Canadian Journal of Botany ◽

10.1139/b78-250 ◽

1978 ◽

Vol 56 (17) ◽

pp. 2097-2108 ◽

Cited By ~ 3

Author(s):

Verna J. Higgins ◽

G. L. Lazarovits

Keyword(s):

Cell Walls ◽

Light And Electron Microscopy ◽

Red Clover ◽

Epidermal Cells ◽

Blue Staining ◽

Mesophyll Cells ◽

Toluidine Blue Staining ◽

Different Types ◽

Wall Appositions ◽

Palisade Cells

As part of a continuing study of non-host resistance, red clover leaves inoculated with the clover pathogen Stemphylium sarcinaeforme, or the closely related alfalfa pathogen S. botryosum, were examined by light and electron microscopy to compare the events occurring in the initial stages of infection. Stemphylium botryosum penetrated leaves primarily via the stomata with resultant death of the guard cells and with varying effects on adjacent epidermal cells. Appressoria were frequently formed, and although they rarely resulted in successful penetrations, the contacted epidermal cells were often markedly affected as judged by toluidine blue staining. Growth of hyphae was intercellular but very limited in its extent. At some infection sites, one to several mesophyll cells underwent extensive plasmolysis and cytoplasmic disruption. Less severely affected mesophyll cells contained large lipid bodies, abundant rough endoplasmic reticulum, and Golgi vesicles and had wall appositions at points of contact with necrotic cells or with hyphae. Stemphylium sarcinaeforme generally penetrated between or directly through the epidermal cells, causing death of the contacted cells. Hyphae grew intercellularly or intracellularly in the palisade tissue and hyphal elongation was considerably more rapid than that of S. botryosum. Palisade cells adjacent to, or containing, the hyphae underwent several different types of cytoplasmic deterioration. Mesophyll cells surrounding these areas showed the same features as comparable cells in tissue infected by S. botryosum. In tissue infected by either fungus, the exterior of host cell walls was coated with a layer of extracellular material.

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Salinity tolerance in chickpea is associated with the ability to ‘exclude’ Na from leaf mesophyll cells

Journal of Experimental Botany ◽

10.1093/jxb/erz241 ◽

2019 ◽

Vol 70 (18) ◽

pp. 4991-5002 ◽

Cited By ~ 9

Author(s):

Lukasz Kotula ◽

Peta L Clode ◽

Juan De La Cruz Jimenez ◽

Timothy D Colmer

Keyword(s):

Salinity Tolerance ◽

Structural Damage ◽

Leaf Tissue ◽

Cell Types ◽

Epidermal Cells ◽

Salinity Treatment ◽

Mesophyll Cells ◽

X Ray ◽

Leaf Mesophyll ◽

Excessive Accumulation

Abstract Salinity tolerance is associated with Na ‘exclusion’ from, or ‘tissue tolerance’ in, leaves. We investigated whether two contrasting chickpea genotypes, salt-tolerant Genesis836 and salt-sensitive Rupali, differ in leaf tissue tolerance to NaCl. We used X-ray microanalysis to evaluate cellular Na, Cl, and K concentrations in various cell types within leaflets and also in secretory trichomes of the two chickpea genotypes in relation to photosynthesis in control and saline conditions. TEM was used to assess the effects of salinity on the ultrastructure of chloroplasts. Genesis836 maintained net photosynthetic rates (A) for the 21 d of salinity treatment (60 mM NaCl), whereas A in Rupali substantially decreased after 11 d. Leaflet tissue [Na] was low in Genesis836 but had increased markedly in Rupali. In Genesis836, Na was accumulated in epidermal cells but was low in mesophyll cells, whereas in Rupali cellular [Na] was high in both cell types. The excessive accumulation of Na in mesophyll cells of Rupali corresponded to structural damage to the chloroplasts. Maintenance of photosynthesis and thus salinity tolerance in Genesis836 was associated with an ability to ‘exclude’ Na from leaflets and in particular from the photosynthetically active mesophyll cells, and to compartmentalize Na in epidermal cells.

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A histological study of interactions between avirulent races of stem rust and wheat containing resistance genes Sr5, Sr6, Sr8, or Sr22

Canadian Journal of Botany ◽

10.1139/b79-044 ◽

1979 ◽

Vol 57 (4) ◽

pp. 324-331 ◽

Cited By ~ 28

Author(s):

R. Rohringer ◽

W. K. Kim ◽

D. J. Samborski

Keyword(s):

Resistance Genes ◽

Stem Rust ◽

Chinese Spring ◽

Histological Study ◽

Fungal Growth ◽

Triticum Aestivum L ◽

Epidermal Cells ◽

Host Cells ◽

Colony Development ◽

Mesophyll Cells

Primary leaves of wheat (Triticum aestivum L.) with and without resistance genes Sr5, Sr6, Sr8, or Sr22 were inoculated with avirulent races of stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn.) and examined by fluorescence microscopy. In leaves containing the Sr5 gene for resistance, both epidermal and mesophyll cells fluoresced when interacting with the fungus, indicating incompatibility. In leaves containing the Sr6 gene, interacting epidermal cells did not fluoresce and incompatibility was expressed only in mesophyll cells.When the effect of the Sr5 gene was studied in leaves with different genetic backgrounds, it was found that most colonies developed only one or two haustorial mother cells in leaves containing this gene in Prelude, Marquis, or Reliance backgrounds, when examined up to 72 h after incubation. Conversely, in leaves with the Chinese Spring background, one-third of the colonies continued to grow and they produced macroscopically visible lesions. Our observations indicated that the Chinese Spring genotype partially altered the expression of the Sr5 gene in mesophyll but not in epidermal cells. In contrast, the Sr6 gene was more effective in the Chinese Spring background than in the Prelude background.Rust development in leaves with or without the Sr8 gene was the same up to 60 h after incubation, when incompatibility in resistant plants was first detected by the appearance of fluorescing host cells. By 72 h, mean colony size in resistant leaves was smaller than that in susceptible leaves, evidently because growth of runner hyphae was inhibited. Apparently, the P8 gene for avirulence was not expressed until colonies had reached considerable size. In leaves containing the Sr22 gene for resistance, the sequence of histological events was similar to that in leaves containing Sr8, but fluorescing host cells appeared later (72 h) and colony growth was inhibited only at 96 h after incubation. In both of these interactions, fluorescing host cells developed at the periphery of colonies when incompatibility was expressed. The host-parasite interaction in cells invaded before that time remained compatible even at later stages of colony development. In leaves containing the Sr5 or the Sr8 gene, but not in those with the Sr6 gene, the growth of some colonies was inhibited although they were not associated with fluorescing host cells. Evidently, host-cell necrosis was closely associated with reduced fungal growth in interactions involving Sr6, but not in interactions involving the resistance genes Sr5 and Sr8.

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Electrical characteristics of cells from leaves of Lycopersicon

Canadian Journal of Botany ◽

10.1139/b77-060 ◽

1977 ◽

Vol 55 (5) ◽

pp. 497-510 ◽

Cited By ~ 8

Author(s):

John M. Cheeseman ◽

Barbara G. Pickard

Keyword(s):

External Medium ◽

Mean Value ◽

Epidermal Cells ◽

Electrical Characteristics ◽

Mesophyll Cells ◽

Tissue Sections ◽

Nernst Potential ◽

Leaf Mesophyll ◽

Microelectrode Techniques ◽

External Ph

Microelectrode techniques were used to investigate the electrical properties of leaf cells of Lycopersicon esculentum both in excised leaflets and in small tissue sections. Most of the recordings were from epidermal cells of the abaxial midrib.Cells were electrically coupled. Apparent resistivity was lowest shortly after impalement (mean value about 1.8 kΩ cm−2) and increased gradually during most experiments. A fluctuation of resistance and potential occurred during the first 5–10 min of many recordings.Potentials between the vacuole and external medium averaged about −125 mV in all preparations, regardless of the external K+ content. Vacuolar K+ activity averaged about 66 mM. The average Nernst potential for K+ would thus be only about −48 mV for an external concentration of 10 mM. Changes of external pH between 5.6 and 8.6 had little or no effect on the potential, but at 4.6 the cells depolarized to about −50 mV and required about 2 h to recover after the pH was raised to 6.6. The potentials were partially dependent on metabolic activity, since CN− or CN− and SHAM together caused marked depolarization.Darkening and illuminating leaf mesophyll cells elicited reproducible transients; associated with the transient light-induced depolarization was a 10–15 mV spike. Changes in illumination had extremely variable effects on the potential of midrib epidermal cells.

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An analysis of the effects of gibberellic acid on the leaflet structure of dwarf cultivars of pea (Pisum sativum)

Canadian Journal of Botany ◽

10.1139/b79-133 ◽

1979 ◽

Vol 57 (10) ◽

pp. 1089-1092 ◽

Cited By ~ 1

Author(s):

G. F. Israelstam ◽

Erica Davis

Keyword(s):

Pisum Sativum ◽

Gibberellic Acid ◽

Surface Area ◽

Epidermal Cells ◽

Mesophyll Cells ◽

Spongy Mesophyll ◽

Number Of Layers ◽

Dwarf Cultivar ◽

Palisade Cells ◽

Degree Of Differentiation

The effects of gibberellic acid (GA3) on the penultimate leaflets of dwarf and normal cultivars of pea were investigated. In control plants, the leaflets of the dwarf were heavier, thicker, and had a smaller surface area than the normal. Epidermal and palisade cells of the dwarf were longer than those of the normal cultivar and the dwarf had longer spongy mesophyll cells and more layers of spongy mesophyll than the normal, with fewer intercellular spaces.Application of GA3 to dwarf plants increased leaflet surface area and length of epidermal cells, while leaflet weight and thickness and the number of layers of spongy mesophyll cells decreased. No significant changes in the leaflet of the normal cultivar were induced by GA3.The overall effect of GA3 application to the dwarf cultivar was to induce a degree of differentiation in the penultimate leaflets such that they tended to resemble more closely those of the normal cultivar.

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Anatomical Traits Associated With Pod Rot Resistance in Peanut1

Peanut Science ◽

10.3146/pnut.12.2.0008 ◽

1985 ◽

Vol 12 (2) ◽

pp. 77-82 ◽

Cited By ~ 5

Author(s):

R Godoy ◽

O. D Smith ◽

R. A Taber ◽

R. E Pettit

Keyword(s):

Leaf Blade ◽

Cell Number ◽

Genotypic Differences ◽

Total Width ◽

Mesophyll Cells ◽

Cell Width ◽

Disease Reaction ◽

Lignin Distribution ◽

Low Efficiency ◽

Palisade Cells

Abstract Peanut (Arachis hypogaea L.) cultivars resistant to Pythium myriotylum Drechs. and Rhizoctonia solani Kuhn, are needed for effective management of pod rotting diseases. The low efficiency of field screening for disease reaction in breeding for resistance has emphasized the need for improved evaluation methods. Anatomical examinations of roots, stems, leaves, pegs, and shells were made of six genotypes (TxAG-3, PI 341885, Toalson, Starr, Florunner, and Goldin I) with various degrees of resistance to pod rots in search of traits that might be used effectively in screening for disease reaction. The palisade mesophyll cells of 50-day old plants were arranged more compactly in pod rot resistant than in susceptible genotypes. An index representing total width (μm) of palisade cells/mm leaf blade was more discriminative in distinguishing among genotypes than average of either cell width or cell number alone. The distribution of lignin in peanut shells was correlated with pod rot resistance. The cell walls in the epicarp and sclerenchymatous mesocarp were thicker and more lignified in the resistant than in the susceptible genotypes. Genotypic differences in lignin distribution were readily apparent at 100x when shell sections were stained with phloroglucinol. Associations between anatomical traits of stems, pegs, roots, or juvenile plant leaflets and field pod rot reaction were not consistent among all genotypes. However, lignin-distribution in pods, and an index representing μm of palisade cells/mm of leaf blade individually or in combination, might be used effectively to supplement field evaluations in screening breeding lines for pod disease reaction.

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Leaf structural adaptations of two Limonium miller (Plumbaginales, Plumbaginaceae) taxa

Zbornik Matice srpske za prirodne nauke ◽

10.2298/zmspn1325043z ◽

2013 ◽

pp. 43-54 ◽

Cited By ~ 4

Author(s):

Lana Zoric ◽

Goran Anackov ◽

Dunja Karanovic ◽

Jadranka Lukovic

Keyword(s):

Epidermal Cells ◽

High Dimensions ◽

Salt Glands ◽

Abaxial Epidermis ◽

Mesophyll Cells ◽

Saline Habitats ◽

Flat Cell ◽

Palisade Cells ◽

Limonium Gmelinii ◽

Structural Adaptations

Limonium gmelinii (Willd.) O. Kuntze 1891 subsp. hungaricum (Klokov) So? is Pannonian endemic subspecies that inhabits continental halobiomes, while Limonium anfractum (Salmon) Salmon 1924 is one of the indicators of halophyte vegetation of marine rocks and its distribution is restricted to the southern parts of Mediterranean Sea coast. In this work, micromorphological and anatomical characters of leaves of these two Limonium taxa were analyzed, in order to examine their adaptations to specific environmental conditions on saline habitats. The results showed that both taxa exhibited strong xeromorphic adaptations that reflected in flat cell walls of epidermal cells, thick cuticle, high palisade/spongy tissue ratio, high index of palisade cells, the presence of sclereid idioblasts in leaf mesophyll and mechanical tissue by phloem and xylem. Both taxa are crynohalophytes and have salt glands on adaxial and abaxial epidermis for excretion of surplus salt. Relatively high dimensions of mesophyll cells, absence of non-glandular hairs and unprotected stomata slightly increased above the level of epidermal cells, are also adaptations to increased salinity.

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