Perimedullary Zone Research Articles

MORPHOLOGICAL ASSESSMENT OF KIDNEY CORTICAL SUBSTANCE DEVELOPMENT IN CHILDHOOD

One of the factors for arterial hypertension development is an increase in the activity of the renin-angiotensin-aldosterone system. It is supposed to be relevant to study the structure of subcortical and perimedullary nephrons in order to identify their morphofunctional characteristics in postnatal ontogenesis.
 The aim of the study was to investigate the age-related characteristics of the renal cortex structure in children of different age groups.
 Materials and Methods. The study was performed on the autopsy renal material obtained from children without any vascular and renoparenchymal diseases, who died at the age of 2 months – 10 years. Six age groups were identified: those who died at the age of 2–4 months, 6–9 months, 10–12 months, 3 years, 6 years, and 10 years. Paraffin microscope slides were prepared according to a standard method and stained with hematoxylin and eosin. The authors determined the number of subcortical and perimedullary renal corpuscles, cortical and perimedullary nephron area, glomeruli area of subcortical and perimedullary nephrons and their average capsule area using the Levenhuk morphometric program.
 Results. In postnatal ontogenesis, uneven maturation of the cortical renal substance is observed. Initially, the nephrons of the subcapsular zone develop faster, with predominant growth of convoluted tubules. Nephron number in the perimedullary zone is lower than in the subcortical one. Active tubule and stroma growth is observed since the age of 3. By the age of 10, the number of subcortical and perimedullary nephrons becomes the same and corresponds to the kidney structure in adults. In ontogenesis, the corpuscles and vascular glomeruli of the pericerebral nephrons are larger than those of the subcapsular ones. However, the urinary space is wider in the subcapsular nephrons, which indicates their earlier involvement in the urination process. A significant development of the vascular glomeruli of the perimedullary nephrons indicates their predominant involvement in the processes of blood pressure regulation through renin synthesis.

Aerial seed bank in a cold desert annual‐ephemeral species: Role of anatomical structure of stem and delayed fruit dehiscence in timing of seed dispersal

AbstractWhy the fruits are retained on dead upright herbaceous plants and how this relates to seed dispersal and timing of germination remain unclear. Stems of the annual Euclidium syriacum (Brassicaceae) with infructescences bearing indehiscent silicles remain upright after plants die in the spring. We investigated the effect of anatomical structures of stem and pedicle and delayed silicle dehiscence on seed dispersal phenology of this species. For comparison, sections were made of the stem of the annual Goldbachia laevigata (Brassicaceae), which has stems that fall over when plants die. Compared to G. laevigata, the stem of E. syriacum has vascular bundles that are closer together, a thicker xylem and phloem, more fibers, a thicker perimedullary zone and a smaller pith diameter:stem diameter ratio. The thickened pedicle did not form an abcission layer. By late October, 5–20% of seeds were dispersed, depending on the position of infructescences on the plant. Snow covered the plants in late autumn and when it melted in mid‐April many of the plants had fallen over, with a high number of seeds germinating in attached silicles; seedlings became rooted in soil. After snowmelt, 14–15% of the silicles on the remaining upright plants contained seeds; all seeds were dispersed by early July. The anatomical structures of the stem and pedicle plus the delayed dehiscence of silicles explain the presence of an aerial seed bank in E. syriacum and delay of germination of many of seeds until spring. Further, pieces of upright plants are broken off and dispersed by wind, which helps to explain the wide distribution of E. syriacum in the cold desert.

On the phenomenological model for potato tuber tissue in relation to its anatomy

AbstractA phenomenological constitutive model based on the principle of hyperelasticity for the perimedullary zone of the potato tuber is presented. The proposed constitutive model is controlled by an internal memory variable that is based on the strain history. Parameter identification is based on stress‐stretch relations obtained from single‐cycle uniaxial compression experiments on samples extracted from the perimedullary zone of potato tubers. The stress‐strain response of the tissue is characterized by a pronounced and reproducible hysteresis. This may be caused by the eviction of intracellular fluid as well as an inelastic cell wall response. Test on single cells from the perimedullary zone are used to identify the cause of hysteresis and plastic deformation as well as to connect the microstructure to the observed stress‐strain response.

Ідентифікація статі рослин актинідії гострої (Actinidia arguta (Siebold & Zucc.) Planch. ex Miq.)

Актинідія – це дводомна культура, і для забезпечення високої продуктивності її насаджень на ділянках необхідно одночасно висаджувати чоловічі та жіночі рослини у співвідношенні 1 до 5–7. Сортові жіночі рослини для насаджень одержують лише способом вегетативного розмноження, тоді як чоловічі рослини-запилювачі можуть бути як вегетативного, так і насіннєвого походження. Численні дослідження свідчать, що саме сіянці краще пристосовуються до нових умов зростання, вирізняються вищою адаптивною здатністю, підвищеною стійкістю до негативних чинників навколишнього середовища порівняно з вегетативно розмноженими рослинами. За літературними даними, вихід рослин-запилювачів інколи сягає 90 %, а то й 100 % від загальної маси сіянців. Ефективні методи визначення статі сіянців актинідії до вступу їх у генеративну фазу розвитку (на 5–7-й рік після посіву) нині відсутні, тому питання пошуку критеріїв ранньої діагностики статі рослин актинідії й опрацювання методу її визначення є надзвичайно актуальним і має важливе теоретичне та практичне значення. На основі комплексного вивчення особливостей чоловічих і жіночих рослин Аctinidia arguta (Siebold & Zucc.) Planch. ex Miq. колекції Національного ботанічного саду ім. М. М. Гришка НАН України запропоновано метод діагностики статі сіянців у прегенеративний період їх розвитку. В основу методу ідентифікації статі A.arguta, що пропонують, покладено оброблення рослинних зразків хімічним реагентом, подальший аналіз результатів реакції та встановлення статі рослини за забарвленням зразків. Точність визначення сягає 95 %, що вказує на високу ефективність і перспективність частого використання запропонованого експрес-методу визначення статі у прегенеративному періоді розвитку рослин. Застосування цього методу дає змогу визначити стать рослин уже в 2–3-річному віці.

Permineralized Calamitean Axes from the Upper Permian of Xinjiang, Northwest China and Its Paleoecological Implication

Two anatomically preserved calamitean axes are reported for the first time from the Late Permian Wutonggou Formation in the southern Bogda Mountains, Xinjiang Uygur Autonomous Region, Northwest China. Based on the anatomical features, these axes are assigned to Arthropitys. A new species Arthropitys taoshuyuanensis sp. nov. is established. A. taoshuyuanensis sp. nov. possesses a large pith and comprises large pith cavity and a narrow perimedullary zone at the nodes and diaphragms at the internodes. Carinal canals are circular and surrounded by a single layer of metaxylem tracheids. Secondary xylem is divided into interfascicular rays and fascicular wedges. Interfascicular rays are initially four to five cells wide and taper abruptly centrifugally. Fascicular wedge consists of thick-walled tracheids and thin-walled fascicular ray cells. Radial tracheid walls have uniseriate or biseriate circular pits, or scalariform pits. The absence of growth rings in the Arthropitys specimens indicates that they probably lived in the wetland area under stable annual temperature and water sufficient conditions.

At harvest prediction of the susceptibility of potato varieties to blackspot after impact over long-term storage

The paper presents a prediction method of the susceptibility blackspot damage after impact of potato varieties for three- and seven-month storage of potato tubers at a temperature of 4 °C based on the geometric parameter of the microstructure of tuber parenchyma determined at harvest. Similar sized and shaped potato tubers of twenty eight cultivars harvested in 2012 and 2013 were analysed. Analyses of the tuber parenchyma microstructure were carried out using an optical confocal microscope for ten tubers of each variety. Cylindrical samples with a thickness of 1 mm and a diameter of 10 mm were collected from the perimedullary zone. Microscopic images of the structure were analysed. The size parameter of the cell cross-section surface area was determined two days after harvest, and the susceptibility of each variety to blackspot after impact was assessed after three and seven months of storage. The mean post-harvest size of the tuber parenchyma cells and the susceptibility to blackspot during storage are related. Tubers of varieties with smaller cells of the perimedullary zone tissue exhibited greater blackspot susceptibility during storage.

Correlation between cell size and blackspot of potato tuber parenchyma tissue after storage

Mechanical injuries are the main cause of damage and loss of quality of plant raw materials. Potatoes are susceptible to external and internal pressures, which cause bruising and fracture in soft tissues. The paper shows research concerning the relationship between geometrical parameters of the microstructure of potato tuber tissue and susceptibility of potatoes to blackspot damage after six months of storage. Twenty eight potato varieties from 2011 and 2012 crops in Poland were used in the experiment. The tubers had a similar size and shape. A TRSLM confocal microscope was used to study the microstructure of soft tissue in potato tubers and microscope images of the perimedullary zone of the tissue were analyzed.The study shows that there is a correlation between the size of perimedullary tissue cells in potato tubers and blackspot damage. Potato tubers with smaller cells of the perimedullary zone show higher susceptibility to blackspot damage, described by the blackspot index BIP, in comparison with potatoes with larger cells which were stored for six months.

Pharmacobotanical study of Baccharis pentaptera

Baccharis L. sect. Caulopterae, Asteraceae, comprises thirty species in Brazil that show stems represented by cladodes, which are very similar in morphology. These species are popularly known as “carqueja” in Brazil and Argentina and are used in popular medicine as diuretic and stomachic. The aim of this work was to examine the morpho-anatomical characters of cladodes of Baccharis pentaptera (Less.) DC. for diagnosis purposes. The plant material was prepared by light and scanning electron microscopy. B. pentaptera shows opposite and spread wings in the two-winged cladode axis and irregular arrangement in the three-winged cladode. The wings have a uniseriate epidermis with palisade parenchyma next to both sides of epidermis. The spongy parenchyma crossed by minor collateral vascular bundles is observed in the central region of wings. The glandular trichomes are capitate and biseriate and the non-glandular trichomes are uniseriate and flagelliform with 2–3 cells that extend from the base. In caulinar axis, there are uniseriate epidermis, chlorenchyma alternating with angular collenchyma and perivascular fiber caps adjoining the phloem which is outside the xylem. Prismatic and styloid crystals are verified in the perimedullary zone. These combined characters can assist the diagnosis of Baccharis species sect. Caulopterae.

Temporally and spatially controlled death of parenchyma cells is involved in heartwood formation in pith regions of branches of Robinia pseudoacacia var. inermis

Focussing on four types of parenchyma cell around pith regions of branches of Robinia pseudoacacia L. var. inermis, we examined the timing and role of cell death during heartwood formation. Large parenchyma cells that were located in the inner part of the pith died within a year. By contrast, other parenchyma cells died within 4 years, with the timing of cell death depending on the type of cell. Axial parenchyma cells of the xylem close to the pith died first. Then, small parenchyma cells died in the perimedullary zone in the outer part of the pith. Finally, ray parenchyma cells in the xylem close to the pith died. Variations in the autofluorescence of cell walls, which might have been due to deposition of heartwood substances, were observed first in xylem ray parenchyma cells and small parenchyma cells in the perimedullary zone. Our results indicate that the initiation of heartwood formation occurs within 4 years in pith regions of branches in Robinia pseudoacacia L. var. inermis. Moreover, it appears that not only xylem ray parenchyma cells but also small parenchyma cells in the perimedullary zone might be involved in the synthesis of heartwood substances.

The distribution of mechanical resistance in potato tuber tissues

The distribution of mechanical resistance in relation to the type of tissue for potato cultivars of different technological uses (cooking, French fries and potato chip production) was examined. A puncture test performed both perpendicularly and parallel to the long axis of the tubers was used and the mechanical resistance expressed by puncture force (N) and puncture energy (mJ). The results showed statistically significant differences in mechanical resistance between the cultivars, with those designed for potato chip production having the highest mechanical resistance. The mechanical resistance of the morphological elements of all examined cultivars could be ordered as follows (according to increasing values): (1) perimedullary zone, (2) pith and (3) cortex. Distribution of puncture resistance within the tuber volume was not uniform—puncture force and energy values were usually higher near the stem end of the tuber for all morphological elements. The values of puncture forces measured perpendicularly to the length of the tuber axis were always lower than those measured parallel to the long axis. The opposite was true for puncture energy.

Effect of Zinc Sulfate and Boric Acid on the Hormonal Status of Potato Plants in Relation to Tuberization

Potato (Solanum tuberosum L.) plants were grown in a greenhouse using zinc- and boron-deficient soil. The effects of seed-tuber treatment with 3 mM zinc sulfate and 8 mM boric acid on the content and ratio of phytohormones in the leaves and mature tubers, the indices of photosynthetic activity, the rate and NaF-sensitivity of respiration, and the tuber growth were studied. Zinc-sulfate treatment shifted the hormonal balance toward a substantial increase in the cytokinin content and the cytokinin/ABA ratio, as well as a decrease in the IAA/cytokinin ratio. Boric-acid treatment resulted in an increase in the IAA content and IAA/cytokinin ratio. Zinc-sulfate treatment abolished the apical dominance and increased the tuber weight due to their increased number and the number of phellem (cork) cell layers. Boric-acid treatment increased cell diameter in the tuber perimedullary zone; an increase in tuber weight per plant was related to tuber growth. A relationship between changes in the plant hormonal status induced by zinc-sulfate and boric-acid treatments and the activity of physiological processes is discussed.

A new species of the sphenopsid stem Arthropitys from Late Permian volcaniclastic sediments of China

Anatomically preserved calamitean stems are described from a previously unknown Late Permian locality in Sichuan Province, China, where they are preserved in volcaniclastic tuffs. Stems possess a large pith with secretory cells and pith cavity, and a narrow perimedullary zone. Primary xylem strands have poorly developed carinal canals whereas the secondary xylem is divided into parenchymatous interfascicular zones and fascicular wedges of tracheids and secondary rays, with the tracheids of the inner part of the secondary xylem having nearly the same size and shape with the interfascicular rays. Interfascicular rays taper abruptly centrifugally. Tracheids of the secondary xylem have scalariform thickenings and cross-fields possess oval–elongate scalariform pits. Secondary rays are parenchymatous and narrow, usually uni- to biseriate and less frequently organized in three to four seriates. The cortex is divided into an inner and outer zone, and primary xylem strands alternate at the nodal region. These stems conform to the features of the genus Arthropitys Geoppert and are most similar to Arthropitys lineata from the Early Permian of Europe; they also are similar to Arthropitys communis and Arthropitys hirmeri var. intermedia from Late Carboniferous coal balls in Europe and North America. However, the Chinese specimens are distinct in a number of ways including characters of the cells surrounding the carinal canals, the carinal canals themselves, features of the secondary xylem and also in their tracheid morphology, leading to the creation of a new species, Arthropitys junlianensis sp. nov. Implications of A. junlianensis on sphenopsid taxonomy, phylogeny and distribution are discussed, and the nearly identical morphology of this new sphenopsid to those of the Late Paleozoic coal swamps of Europe and North America is considered.

Sensitive detection of potato spindle tuber viroid using RT-PCR and identification of a viroid variant naturally infecting pepino plants

A reverse-transcription polymerase chain reaction (RT-PCR) method was developed to detect full length potato spindle tuber viroid (PSTVd) using primer pair 5'-CCCTGAAGCGCTCCTCCGAG-3' (complementary to PSTVd nucleotides 69-88) and 5'ATCCCCGGGGAAACCTGGAGCGAAC-3' (homologous to PSTVd nucleotides 89-113). A full-length amplified PSTVd cDNA was detected using RT-PCR in GeneReleaser-treated nucleic acid extracts of potato tuber tissues taken from tuber periderm, cortical parenchyma, external phloem, xylem ring, perimedullary zone containing internal phloem, perimedullary starch-storage parenchyma or pith regions. The viroid was also detected using RT-PCR from total nucleic acid or GeneReleaser-treated sap extracts of true potato seed (TPS), and pollen. PSTVd detection from total nucleic acid extracts of TPS can be achieved without further treatment with GeneReleaser or after further purification. GeneReleaser-treated sap extracts of as little as five pollen grains were sufficient to yield an amplified full-length PSTVd cDNA by this method. A one-step short version of RT-PCR was shown to detect PSTVd from infected tomato leaf nucleic acids. The RT-PCR protocol was successful in detecting a naturally occurring variant of PSTVd from pepino (Solanum muricatum) plants that consists of 357 nucleotides and differs from the prototype 359 nucleotide PSTVd isolate in five positions.

Effect of cyproterone acetate on adrenal cortex of castrated mice

Castrated adult male C57BL/6J mice displayed a wide perimedullary zone (secondary X-zone) whose cells were characterized by proliferated rough and smooth endoplasmic reticulum and elongated mitochondria with lamellar cristae. Castrated mice which received 0.08 mg/g of cyproterone acetate showed a much inhibited secondary X-zone at the light microscopic level, while at the ultrastructural level the perimedullary cells lacked the proliferated rough and smooth endoplasmic reticulum as well as the elongated mitochondria. Cyproterone acetate may inhibit the steroidogenic parameters of the androgen-producing cell population of the adrenal cortex without testicular mediation.

Sampling of potato tubers – a method based on a mathematical interpretation of gross potato tuber anatomy

SummaryEvidence is presented to support the observation that within potato tubers, the mean solids concentration gradient in the perimedullary zone within the xylem ‘ring’ is linearly related to its mean spatial distance from the xylem ‘ring’. Within any tuber the point most remote from the xylem ‘ring’, irrespective of tuber shape, is its geometric centre. If, for any tuber, this point is taken as the zero mean radius, then data obtained by a concentric peeling technique (vide Appendix I) may be used to construct a mathematical model of the mean solids concentration from the geometric centre to the periderm. A sampling technique is proposed whereby the mathematical parameters describing the tuber may be used to transform quantitative data from discrete tissue samples to values representative of whole tubers.

Relationships of hollow heart in Irish potatoes to carbohydrate reabsorption and growth rate of tubers

Tubers of Irish Cobbler that were hollow grew faster than non-hollow tubers on the same plant. However, tubers of varieties without hollow heart grew just as rapidly as tubers of the variety with hollow heart. Therefore tuber growth rate was related to hollow heart occurring within a variety but could not account for differences between varieties. When plant foliage was pruned the C-14 label from sucrose was translocated from the tuber to the top of the plant. Our studies suggest hollow heart can occur in small tubers under the following conditions: (i) moisture stress in the tubers resulting in conversion of starch to sugar, followed by a rapid influx of water into the tuber resulting in rapid enlargement of the perimedullary zone and a separation in the pith that later develops into hollow heart, and/or (ii), following injury to some cells in the tuber due to reabsorption of minerals and carbohydrates or depletion of food reserves followed by tuber enlargement. It seems probable however that hollow heart that is initiated in large tubers is only associated with excessively rapid tuber enlargement without the involvement of reabsorption or depletion of food reserves.

Tensile properties of potato tubers

Mechanical properties of Kennebec and Russet Burbank potato tubers were computed from Force-elongation data on specimens cut from the tuber and tested in tension. Specimens cut from three locations in fresh and stored tubers were tested at varying strain rates at 70 F (21 C) and at 42 F (6 C). Results were analyzed for significant differences. Tests were conducted in 1964 and 1966. In spite of some differences in tuber condition and test and analysis methods, there was good agreement of results between the years. Mean values of properties for all tests were: tensile strength, 98 psi; strain at failure, 0.193 in./in.; and failure modulus (stiffness), 727 psi. Properties varied greatly with location in the tuber. The pith, in the center, is stronger and stiffer than the perimedullary zone surrounding it, and the skin-cortex exhibits different properties than either of these two. Storage affected properties at the skin and in the center much more than in the perimedullary zone. As strain rate increased, tensile strength and stiffness generally increased, and strain at failure decreased. Stiffness generally increased when temperature decreased. Effect of variety was mixed. One of the greatest problems in designing and using potato handling and processing equipment is damage to the potatoes. This lowers their market value and increases their susceptibility to disease and deterioration in storage. Various investigators, by dropping or hitting tubers experimentally or by following them through normal hanlling operations, have determined the external causes of damage to whole tubers and conditions that promote it. These experiments have yielded much needed information, but they tell little about the properties of th tubers that make them so susceptible to injury. Finney (2) and Timbers (7) have attempted to determine some of the mechanical properties of potato tubers and report them in engineering terms. This type of approach is necessary for an understanding of the behavior of potatoes in handling and processing operations. The purpose of this study is to determine mechanical properties of potato tuber tissue and report them in terms that will be usable by people who do further work in this area. Because at least some cracks in potatoes are caused by failure in tension, and because no record of tests on potato tissue in tension was found, these tests were conducted on specimens of potato tuber in tension.

Anatomy and compositional variation within potatoes II. Phenolics, enzymes and other minor components

Minor components, including principal phenolics and certain enzymes, are distributed within the potato tuber according to patterns that are significant to many practical problems in the growing, handling, and utilization of potatoes. Chlorogenic acid is much more concentrated in outer than in inner tissue zones; is also highly concentrated in the phloem and phloem parenchyma tissues of both cortex and perimedullary zone. Tyrosine is generally distributed but is more concentrated in the stem end than in the bud end of the tuber and probably is also more concentrated in central than in outer tissues. Results of histochemical tests on distribution of these phenolics agree in general with quantitative analytical results. Phenolases and peroxidase also show characteristic patterns of distribution. Peroxidase affects tissue differentiation and specialization and shows strong histochemical relationship with cell-wall specializations. Phenolases show association with distributions of phenolic substrates and usually are associated with cell contents. Distribution patterns are reviewed for other minor constituents, such as, iron, copper, ascorbic acid, thiamine and solanin.

Anatomy and compositional variation within potatoes

Re-examination of the histological development of the potato tuber supports Artschwager’s view that tuber growth is predominantly due to enlargement of the perimedullary zone and is of procambial origin. Pith (medulla) and cortical regions are differentiated from the ground or fundamental meristem derived from the apical meristem of the stolon apex, even before tuberization has been initiated. The procambium gives rise to external phloem, primary xylem, internal phloem and associated parenchyma, and likewise to interfascicular parenchyma. Those parenchyma cells so formed inwardly to the xylem “ring” contribute to the growth of the perimedullary zone. The sequence of tissue origins is diagrammed and discussed from the viewpoint of modern concepts of histogenesis.

Histological Aspects of the Changes from a Vegetative to a Flowering State

Previous articleNext article No AccessSymposium: Reproduction in PlantsHistological Aspects of the Changes from a Vegetative to a Flowering StateB. Esther StruckmeyerB. Esther Struckmeyer Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The American Naturalist Volume 84, Number 815Mar. - Apr., 1950 Published for The American Society of Naturalists Article DOIhttps://doi.org/10.1086/281616 Views: 3Total views on this site Citations: 5Citations are reported from Crossref PDF download Crossref reports the following articles citing this article:H. A. Borthwick, S. B. Hendricks, James A. Lockhart, H. Mohr., Ursula Brodführer Franzgrote, J. E. Gunckel, A. H. Sparrow, J. Reinert Effects of radiation on growth and development, (Jan 1961): 299–617.https://doi.org/10.1007/978-3-662-11209-0_2Anton Lang Entwicklungsphysiologie, (Jan 1954): 400–475.https://doi.org/10.1007/978-3-642-94624-0_22Erwin Bünning Die inneren Faktoren der Differenzierung, (Jan 1953): 156–298.https://doi.org/10.1007/978-3-642-87328-7_4Erwin Bünning Determinierende Hormone, (Jan 1953): 231–247.https://doi.org/10.1007/978-3-662-02138-5_18AUBREY W. NAYLOR Physiology of Reproduction in Plants, (Jan 1952): 259–300.https://doi.org/10.1016/B978-1-4832-0001-9.50011-7