Occurrence of transfer cells in vascular parenchyma of Hieracium florentinum roots

1976 ◽  
Vol 54 (13) ◽  
pp. 1458-1471 ◽  
Author(s):  
Linda J. Letvenuk ◽  
R. L. Peterson
Keyword(s):  
Lateral Root ◽  
Secondary Xylem ◽  
Lateral Roots ◽  
Transfer Cells ◽  
Main Root ◽  
Sieve Elements ◽  
Parenchyma Cells ◽  
Vascular Parenchyma ◽  
Xylem Elements ◽  
Root Stele

In the roots of Hieracium florentinum plants grown in hydroponic nutrient cultures, vascular parenchyma cells adjacent to both xylem and phloem conducting elements develop wall ingrowths and become transfer cells. Xylem transfer cells occur around the protoxylem elements and secondary xylem elements at the base of the junction of a lateral root with the main root stele and along the xylem elements of the lateral root for some distance into the lateral root. Phloem transfer cells occur adjacent to sieve elements in the phloem regions of the main root stele which have connections with the lateral root phloem and adjacent to sieve elements in the lateral root. Transfer cells were absent in the vascular parenchyma of the main root stele not associated with lateral roots.

scholarly journals Influence of Root Morphology on Ecological Slope Protection

2020 ◽  
Vol 198 ◽  
pp. 04036
Author(s):  
JI Xiaolei ◽  
XU Lanlan ◽  
YANG Guoping
Keyword(s):  
Root Morphology ◽  
Lateral Root ◽  
Lateral Roots ◽  
Soil Mass ◽  
Soil Reinforcement ◽  
Main Root ◽  
Protection Effect ◽  
Included Angle ◽  
Theoretical Support ◽  
Object Based

Ecological slope protection is of great importance for preventing the water and soil loss on bare slopes, improving the ecological environment, and realizing the sustainable ecosystem development. The root-soil composite slope consisting of homogenous soil mass and oleander root system was taken as the study object. Based on the mechanics principle of soil reinforcement by roots in ecological slope protection, the influences of the lateral root quantity of plants and included angle between main root and lateral root on the slope protection were investigated via the finite element (FE) software ABAQUS. The simulation results show that the larger the quantity of lateral roots, the more obvious the displacement reduction of the soil mass on the slope surface will be. The slope protection effect varies with the root morphology, the included angle between main root and lateral root is an important factor influencing the slope protection effect of plants, and the slope protection effect at included angle of 30° is apparently superior to that at 90°. The research results can provide a theoretical support for the plant selection in the ecological slope protection.

Traumatic Gum-Resin Cavities in the Stem of Ailanthus Excelsa Roxb.

IAWA Journal ◽  
1987 ◽  
Vol 8 (2) ◽  
pp. 167-174 ◽  
Author(s):  
A.M. Babu ◽  
G.M. Nair ◽  
J.J. Shah
Keyword(s):  
Epithelial Cells ◽  
Secondary Xylem ◽  
Ailanthus Excelsa ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Ray Cells ◽  
Cell Layers ◽  
Ethephon Treatment ◽  
Xylem Elements ◽  
Ray Parenchyma Cells

Traumatic gum-resin cavities develop in the secondary xylem of the stem of Ailanthus excelsa Roxb. in response to fungal infection and ethephon treatment. After infection or ethephon treatment, traumatic parenchyma in several cell layers develops instead of normal secondary xylem elements. It consists of unlignified axial and ray parenchyma cells. Vessels and fibres are absent. Gum-resin cavities in one or two tangential rows develop in this tissue by the lysis of its axial parenchyma cells. The cavities are bordered by an epithelium. A few layers of traumatic parenchyma cells adjacent to the epithelial cens become meristematic and appear cambiform. The epithelial cells undergo lysis and they evidently contribute to gum-resin formation. As the lysis of epithelial cens proceeds, the adjacent cambiform cens divide to form additional epithelial cells. The process continues for some time and eventually an the axial cells of the traumatic parenchyma break down forming a tangentially anastomosing network of cavities. The cavities do not traverse the ray cells, and the multiseriate rays remain intact like bridges amidst the ramifying cavities.

The occurrence and ontogeny of transfer cells associated with lateral roots and root nodules in Leguminosae

1979 ◽  
Vol 57 (23) ◽  
pp. 2583-2602 ◽  
Author(s):  
William Newcomb ◽  
R. L. Peterson
Keyword(s):  
Nitrogen Fixation ◽  
Rhizobium Leguminosarum ◽  
Root Nodules ◽  
Lateral Roots ◽  
Transfer Cells ◽  
Xylem Parenchyma ◽  
Cortical Cells ◽  
Nitrogenous Compounds ◽  
Wall Ingrowths ◽  
Xylem Elements

Xylem parenchyma transfer cells are present in the stele of the root tissue adjacent to emergent effective root nodules of garden pea (Pisum sativum), red kidney bean (Phaseolus vulgaris), broad bean (Vicia faba), soybean (Glycine max), and mung bean (Vigna radiata), two types of ineffective pea nodules, and emergent lateral roots of pea. The xylem parenchyma transfer cells contain many polyribosomes and mitochondria near the wall ingrowths which are located adjacent to pits in the xylem elements. Pericycle transfer cells also occur in the three types of pea nodules. In effective pea nodules wall ingrowths begin to form in the pericycle cells 5 days after inoculation with Rhizobium leguminosarum; at this stage rhizobia are only present in the root hair but the cortical cells have enlarged and some have undergone mitosis. The wall ingrowths begin to form in the xylem parenchyma cells 7–8 days after inoculation or the approximate time that rhizobia begin to be released from the infection thread. In both instances the wall ingrowths begin to form before the onset of dinitrogen reduction although previous workers have suggested that a flux of nitrogenous compounds (containing fixed N) induces their formation. The development of wall ingrowths in ineffective pea nodules also occurs independently of nitrogen fixation. Similarly, the wall ingrowths located near soybean nodules also begin to develop before the onset of nitrogen fixation.

Variability in the Distribution of Middle Lamella Lignin in Secondary Vascular Tissues of Kenaf Stems

IAWA Journal ◽  
2014 ◽  
Vol 35 (1) ◽  
pp. 61-68
Author(s):  
Seung Gon Wi ◽  
Kwang Ho Lee ◽  
Hyeun Jong Bae ◽  
Byung Dae Park ◽  
Adya P. Singh
Keyword(s):  
Cell Walls ◽  
Secondary Xylem ◽  
Middle Lamella ◽  
Hibiscus Cannabinus ◽  
Secondary Phloem ◽  
Xylem Parenchyma ◽  
Vascular Tissues ◽  
Transmission Electron ◽  
Parenchyma Cells ◽  
Xylem Elements

Lignin in the middle lamella of the secondary xylem of angiosperms appears to be inhomogeneously distributed, based on studies where the focus is on a close examinantion of the middle lamella region of fibre cell walls by transmission electron microscopy (TEM). This is in contrast to the secondary xylem of gymnosperms which often display a more uniform distribution of lignin in the middle lamella of secondary xylem elements. The aim of our study was to undertake TEM examination of kenaf (Hibiscus cannabinus L.), an angiosperm plant mainly cultivated for its high quality secondary phloem fibres, to investigate lignin distribution in the middle lamella of secondary vascular tissues, including secondary phloem fibres. The middle lamella displayed considerable heterogeneity in the distribution of lignin in all lignified secondary vascular tissues, including xylem and phloem fibres, vessels and axial xylem parenchyma cells. The results provided evidence of lignin inhomogeneity in the secondary phloem fibres as well as in other lignified elements of kenaf vascular tissues, extending previous observations which were confined only to fibre cells.

The origin and development of root buds in Asclepias syriaca

1982 ◽  
Vol 60 (10) ◽  
pp. 2119-2125 ◽  
Author(s):  
Patricia L. Polowick ◽  
M. V. S. Raju
Keyword(s):  
Lateral Root ◽  
Early Stage ◽  
Lateral Roots ◽  
Cambial Activity ◽  
Root Anatomy ◽  
Main Root ◽  
Asclepias Syriaca ◽  
Bud Development ◽  
Vascular Connections ◽  
Root Buds

The persistence of Asclepias syriaca L. as a weed is related to its ability to propagate vegetatively by the development of adventitious buds on roots. These root buds arise on the main root and upper lateral roots within 25 days of the establishment of seedlings and are generally associated with the bases of lateral roots. A study of root anatomy shows that the origin of these buds is endogenous, in the pericycle and (or) its derivatives. No root buds are initiated until after lateral roots have developed and some cambial activity has begun. Vascular connections from the bud to the stele of the parent root, or an associated lateral root, are made at an early stage of bud development.

Ontogeny of phloem transfer cells in Hieracium floribundum

1975 ◽  
Vol 53 (23) ◽  
pp. 2745-2758 ◽  
Author(s):  
R. L. Peterson ◽  
E. C. Yeung
Keyword(s):  
Cell Types ◽  
Transfer Cells ◽  
Vascular Cambium ◽  
Secondary Phloem ◽  
Sieve Elements ◽  
Wall Ingrowths ◽  
Wall Ingrowth ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Cambium Activity

The primary phloem system in the rhizome of Hieracium floribundum has transfer cells that have developed from companion cells and parenchyma cells, which are adjacent to sieve elements. In both cell types changes occur in the cytoplasmic organelles at the time of wall ingrowth formation. Dicytosomes and polyribosomes become more numerous and 'boundary formations' and other multivesiculated structures appear. Few microtubules were found in the cytoplasm at this time. After the wall ingrowths become obvious, the transfer cells develop numerous mitochondria and an enlarged nucleus. The phloem transfer cells become vacuolated with age and the wall ingrowths become less numerous. This may be associated with a change in the translocation pattern in the phloem after the inception of vascular cambium activity. Parenchyma cells in the secondary phloem usually become rather vacuolated and develop few wall ingrowths.

scholarly journals Phenotyping Root System Architecture of Cotton (Gossypium barbadense L.) Grown Under Salinity

2017 ◽  
Vol 63 (4) ◽  
pp. 142-150 ◽  
Author(s):  
Shady A. Mottaleb ◽  
Essam Darwish ◽  
Menna Mostafa ◽  
Gehan Safwat
Keyword(s):  
Root System ◽  
System Architecture ◽  
Root Length ◽  
Lateral Root ◽  
Lateral Roots ◽  
Root System Architecture ◽  
Gossypium Barbadense ◽  
Shoot Biomass ◽  
Peat Moss ◽  
Main Root

Abstract Soil salinity causes an annual deep negative impact to the global agricultural economy. In this study, the effects of salinity on early seedling physiology of two Egyptian cotton (Gossypium barbadense L.) cultivars differing in their salinity tolerance were examined. Also the potential use of a low cost mini-rhizotron system to measure variation in root system architecture (RSA) traits existing in both cultivars was assessed. Salt tolerant cotton cultivar ‘Giza 90’ produced significantly higher root and shoot biomass, accumulated lower Na+/K+ ratio through a higher Na+ exclusion from both roots and leaves as well as synthesized higher proline contents compared to salt sensitive ‘Giza 45’ cultivar. Measuring RSA in mini-rhizotrons containing solid MS nutrient medium as substrate proved to be more precise and efficient than peat moss/sand mixture. We report superior values of main root growth rate, total root system size, main root length, higher number of lateral roots and average lateral root length in ‘Giza 90’ under salinity. Higher lateral root density and length together with higher root tissue tolerance of Na+ ions in ‘Giza 90’ give it an advantage to be used as donor genotype for desirable root traits to other elite cultivars.

The fine structure of corn phloem

1972 ◽  
Vol 50 (4) ◽  
pp. 839-846 ◽  
Author(s):  
A. P. Singh ◽  
L. M. Srivastava
Keyword(s):  
Fine Structure ◽  
Long Distance ◽  
Sieve Elements ◽  
Long Distance Transport ◽  
P Protein ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Vascular Parenchyma ◽  
Predominant Orientation ◽  
Distance Transport

The differentiation of sieve elements, companion cells, and vascular parenchyma in leaf bundles of corn is described. The sieve elements have plastids with distinctive crystalline inclusions, lack P-protein, and have nacreous walls in which the predominant orientation of microfibrils seems to be at right angles to the length of the cell. The companion and vascular parenchyma cells have numerous, well-developed mitochondria. These and other results are discussed in relation to long distance transport in the sieve elements.

scholarly journals Development of Successive Cambia and Structure of Secondary Xylem of Ipomoea Obscura (Convolvulaceae)

2014 ◽  
Vol 59 (1) ◽  
pp. 55-61 ◽  
Author(s):  
Kishore S. Rajput ◽  
Bharat D. Chaudhary ◽  
Vidya S. Patil
Keyword(s):  
Secondary Xylem ◽  
Vascular Bundles ◽  
Growth Rings ◽  
Sieve Elements ◽  
Companion Cells ◽  
Parenchyma Cells ◽  
Ray Parenchyma ◽  
Thin Walled ◽  
Ray Parenchyma Cells ◽  
Ipomoea Obscura

Abstract Stems of Ipomoea obscura Ker Gawl., increase in thickness by forming multiple rings of cambia. Stems 5-6 mm thick produce parenchymatous derivatives which divide repeatedly to form small arcs of cambium. Several such small arcs initiate simultaneously and form a ring of small cambial arcs. After the formation of a few xylem and phloem elements, all these arcs are interconnected by transdifferentiation of parenchyma cells present between the cambial arcs and constitute a complete cambial cylinder. This newly formed cambium is functionally bidirectional: earlier- formed arcs produce xylem centripetally and phloem centrifugally, while later-formed segments exclusively produce thin-walled parenchyma cells on either side. Young stems are circular in cross section but as stem thickness increases they become oval to elliptic or lobed and dumbbell-shaped. Xylem rays are mostly uni- or biseriate and thin-walled, but multiseriate rays characteristic for a climbing habit are observed occasionally. In thick stems, the marginal ray parenchyma in most of the samples becomes meristematic and develops ray cambia which exclusively produce sieve elements. Similarly, parenchyma cells produced from later-formed cambial segments give rise to several irregularly oriented vascular bundles. The secondary xylem is diffuse porous, with indistinct growth rings and is composed of fibriform and wider vessels, fibres, and axial and ray parenchyma cells, while phloem consists of sieve elements, companion cells, and axial and ray parenchyma cells.

Localization of phenols and polyphenol oxidase in 'Jewel' sweet potatoes (Ipomoea batatas 'Jewel')

1981 ◽  
Vol 59 (10) ◽  
pp. 1961-1967 ◽  
Author(s):  
W. E. Schadel ◽  
W. M. Walter Jr.
Keyword(s):  
Phenolic Compounds ◽  
Polyphenol Oxidase ◽  
Ipomoea Batatas ◽  
Secondary Xylem ◽  
Root Tissue ◽  
Secondary Phloem ◽  
Sweet Potatoes ◽  
Parenchyma Cells ◽  
Histochemical Tests ◽  
Xylem Elements

Histochemical tests for phenols and polyphenol oxidase were performed on fresh root tissue of Ipomoea batatas (L.) Lam. 'Jewel.' The phenolic compounds were localized in the phellem, phellogen, and phelloderm, in approximately 1 mm (ca. 10–15 cells) of the tissue directly beneath the periderm, in the latex of laticifers, in the phloem, in the cambium which separates the secondary phloem from the secondary xylem, in the anomalous secondary cambia of the central core, in the parenchyma cells adjacent to the xylem elements, and in the walls of the xylem elements. Polyphenol oxidase was localized primarily in the phellogen and phelloderm and most prominently in the latex of laticifers.

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