Amount Of Intercellular Space Research Articles

Identification of Piper species that are resistant to Phytophthora capsici, Meloidogyne incognita, and waterlogging in Vietnam

AbstractBlack pepper (Piper nigrum) is a spice commonly used in kitchens throughout the world. Black pepper production is devastated by a range of pathogenic agents, including Phytophthora capsici and Meloidogyne incognita. Many efforts have been directed towards finding black pepper cultivars that are resistant to these pathogens. In this work, a 39‐accession germplasm panel of species in the Piper family collected throughout Vietnam was described. Preliminary tests using P. capsici inoculation onto leaves were carried out to identify potentially resistant accessions. Next, candidate plants were inoculated with P. capsici mycelial suspension and survival rates were assessed 15, 30 and 45 days postinoculation. In addition, Piper plants were challenged with M. incognita by adding larvae/juveniles to growing pots. Resistance to M. incognita was determined by the number of root galls and the percentage of plants with yellow leaves 1, 2 and 4 months after treatment. Piper accessions were also subjected to a 4‐day waterlogged treatment. Two accessions (HUIB_PH30 and HUIB_PD36) demonstrated high levels of resistance to all biological and water stresses. Micromorphological characterizations revealed that the amount of intercellular spaces in the root cortex correlated with the resistance to P. capsici and waterlogging tolerance. Hence, the abundance of intercellular spaces can serve as a guide for further selection of black pepper accessions that are resistant to common diseases and tolerant to waterlogged conditions.

Anatomical responses to waterlogging in Chrysanthemum zawadskii

The purpose of this study was to investigate the anatomical adaptations of Chrysanthemum zawadskii to waterlogged conditions. Compared with the comparable tissues prior to waterlogging treatments, waterlogging caused the thicknesses of the upper epidermis, lower epidermis, leaf, palisade parenchyma, and spongy parenchyma to increase by 27.1%, 67.6%, 33.8%, 47.7%, and 12.4%, respectively. After waterlogging, the ratio of the thickness of the palisade mesophyll to the thickness of the spongy mesophyll, palisade cell length, and palisade cell width increased by 40.0%, 62.2% and 15.9%, respectively. However, after 10d of exposure to waterlogged conditions, stomatal aperture decreased to 44.4% of that observed in control plants. The stomatal density increased initially after the onset of exposure to waterlogged conditions, reaching levels 126.8% higher than those in control plants after 6d of exposure to waterlogged conditions, after which it decreased. The amount of intercellular space in root cortex tissue increased 8.9-fold over the course of a 10-d waterlogging treatment. The area of aerenchyma in the stem increased 4.5-fold over the course of a 10-d waterlogging treatment. These substantial changes in leaf anatomy following prolonged immersion come at the cost of reduced rates of photosynthesis. The nature of the changes in leaf, root and stem anatomy suggest that C. zawadskii exhibits anatomical adaptations to cope with waterlogged conditions.

The relationship between gas transport properties and the histology of apple

AbstractThe relation between skin resistance to gas diffusion, diffusivity and several histological characteristics of apple cvs Braeburn and Jonica was investigated. Large discrepancies were found between the skin resistance values measured by the efflux method and a diffusion method. It is believed that these discrepancies are due to the invalidity of Graham's law in tightly packed tissue, the existence of internal gas gradients and the types of tissue measured in the two methods. The differences between cultivars in diffusivity of O2 and CO2 in the same tissue were related to differences in intercellular space volume and cell size. The spatial pattern of the diffusivity of oxygen and carbon dioxide could be linked to the number of cells, the cell area, the cell perimeter and the internal free space volume. The considerably lower diffusivity in the skin was believed to be caused by both the skin and the very dense tissue of the outer cortex. Changes in diffusivity during storage coincided with changes in the amount of intercellular space and in the shape of the cells. Copyright © 2004 Society of Chemical Industry

A comparative study on fine structure of inflammatory and neoplastic dysplasia of the esophagus

To clarify the fine structure of esophageal dysplasia, desmosomes and nuclei were evaluated numerically and morphologically using the electron microscope. Thirteen punch biopsies were taken from patients with esophageal dysplasia ascertained by iodine staining and showing up as unstained or faintly stained areas. We conducted a morphological study of two types of esophageal dysplasia, one with reactive immature epithelium (RIE) and the other classified as an intra-epithelial neoplastic lesion (INL). The ultrastructural differences observed between the RIE and INL were the degree of the cellular or nuclear atypia, the number of desmosomes or hemidesmosomes, and the amount of intercellular space. The nucleocytoplasmic ratio in INL was higher than in RIE. In the cells of RIE, the number of desmosomes was smaller than in normal epithelium, but larger than in INL. The hemidesmosomes were found predominantly between the RIE cells and basal laminae, but were very few or absent in INL and tumor cells.

Effects of direct contact of Pinusresinosa seeds and young seedlings with N-dimethylamino succinamic acid, (2-chloroethyl)trimethylammonium chloride, or maleic hydrazide

Critical concentrations of two growth retardants, N-dimethylamino succinamic acid (Alar) and (2-chloroethyl)trimethylammonium chloride (CCC), and one growth inhibitor, maleic hydrazide, applied continuously to Pinusresinosa seedlings in the cotyledon stage greatly suppressed seedling growth and development and killed many seedlings. Both Alar and CCC arrested the elongation of stems, roots, cotyledons, and primary needles, inhibited the expansion of mesophyll cells, and decreased the amount of intercellular space in the cotyledons and cortex. Growth was inhibited by lower concentrations of CCC than of Alar. Maleic hydrazide reduced the growth of shoots, roots, cotyledons, and primary needles, with growth inhibited by much lower concentrations than those of Alar or CCC. Cell expansion was stimulated by maleic hydrazide at concentrations below 2500 ppm and inhibited by concentrations at or above 2500 ppm. Maleic hydrazide at 100 ppm caused chlorosis and induced wall thickening of ground tissue cells in the hypocotyl and cotyledons. The greater reduction of root growth than of shoot growth as well as the inhibition of the growth of primary needles by nonlethal concentrations of Alar, CCC, or maleic hydrazide will increase the mortality risk of Pinusresinosa seedlings in the cotyledon stage of development.

Intercellular space and hydrogen diffusion in pea and lupin root nodules

The amount and distribution of intercellular space was examined in pea and lupin root nodules. It was found that the amount of intercellular space was just over 1% for both species which were not significantly different in this respect. Within the cortex a layer of cells was found which had little or no intercellular space. It was shown that there is no connection of gaseous phase from the outside to the interior of the nodule. Intercellular spaces in the active infected tissue were discrete so that there was no continuity of gas filled space in this tissue. A mathematical model, based on these findings, shows that, with the nitrogenase activity found in pea root nodules, hydrogen evolved from the nitrogenase could build up to inhibitory levels. It is proposed that hydrogen inhibition of nitrogenase is the cause of the high proportion of hydrogen evolved to nitrogen fixed found in many root nodules.

Development of the embryonic chick otic placode. II. Electron microscopic analysis.

AbstractThe otic placode takes its origin from surface ectoderm. Prior to the arrival of neural crest cells, surface epithelial cells adjacent to the neural folds are squamous in shape and synthesize primarily interstitial bodies. However, by 26 hours of development, neural crest cells, using the undersurface of the epithelium as a substratum, migrate away from the neural tube. Cells of surface epithelium above the neural crest cells assume a columnar shape, and the amount of intercellular space between adjacent epithelial cells is consequently reduced. Placode cells show extensive interdigitation apically as they pseudostratify and invaginate, while it appears that many of the basal cells contribute components to the underlying extracellular matrix. This extracellular matrix interface between surface epithelium and neural crest cells is distinctly fibrillar and less granular than that found between ordinary head ectoderm and primary mesenchymal cells. Just prior to complete invagination as an otocyst, otic placode cells in a region near the ventrolateral wall of the hindbrain extend cell processes through discontinuities in the basal lamina and leave the otocyst. These are likely to be the cells which contribute to the formation of the acoustico‐facialis ganglion. These observations support the hypothesis that the development of the otic placode is the result of a tissue interaction between surface epithelium and neural crest cells.

A quantitative comparison between normal and carcinomatous squamous epithelia of the uterine cervix.

The object of this study was to measure some of the differences between normal squamous epithelial cells and cells from invasive squamous carcinoma of the uterine cervix. A total of 107 patients were studied; only those specimens which when assessed by a histopathologist were thought to show classic normal features or undoubted invasive carcinoma were included in the quantitative analysis. In addition, any specimens which at the electron microscope level, showed faulty sampling or preparation were discarded, leaving us with 16 carcinoma and 15 normal specimens for detailed study.The nuclei of tumour cells had a greater area than those of normal cells; histograms of the size distribution of nuclei showed a distinctly different pattern in the 2 groups. Tumour cells had fewer ribosomes in each cubic micron of cytoplasm than had the normal cells and showed a reduction in the amount of intercellular space; in addition, the malignant cells had a smaller surface density and fewer tonofibrils in their cytoplasm. Some tumour cells had a smaller percentage of cell membrane specialized as desmosomes than the corresponding normal cells but all tumour cells had desmosomes of shorter length than normal.Discriminatory analysis, carried out with the help of a computer, allowed all of these variables to be assessed with respect to each other in order to arrive at a numerical score for each specimen. When expressed graphically, these scores showed that the populations of normal and carcinomatous cells fell into 2 separate groups. The significance of these results is discussed.

Nodal and leaf anatomy of Xanthophyllum (Polygalaceae)

The nodal anatomy of Xanthophyllum is unilacunar with a single broad trace departing the cauline stele. The “stipular glands” or extra floral nectaries of some species are vascularized by bundles originating from the base of the leaf trace. Considerable variation exists among species in petiole vasculature with siphonosteles, steles with medullary bundles and simple, flat traces present. The lamina also shows variation in the presence or absence of a hypodermis, nature of vein sheathing, presence or absence of abaxial epidermal papillae, amount of intercellular spaces, and mature stomatal patterns which range from anisocytic and paracytic to those in which no subsidiary cells are discernible. Of nearly uniform occurrence throughout the genus are extraordinary tracheoid foliar idioblasts, which are confined to the veins in terminal or subterminal positions. The large amount of variation in leaf anatomy is shown to be taxonomically significant within the genus.