scholarly journals Erect culm internodal anatomy and properties of sun ecotype of Imperata cylindrica (L.) P. Beauv

2015 ◽  
Vol 44 (1) ◽  
pp. 67-72
Author(s):  
SN Sima ◽  
AK Roy ◽  
N Joarder
Keyword(s):  
Vascular Bundle ◽  
Vascular Tissue ◽  
Leaf Sheath ◽  
Imperata Cylindrica ◽  
Vascular Bundles ◽  
Peripheral Vascular ◽  
Phloem Tissue ◽  
Vascular Tissues

Internodal anatomy of Imperata cylindrica (L.) P. Beauv. was described in this paper. Culm internodes were completely encircled by leaf sheath. Peripheral vascular bundles were many in number and small in size. Central bundles were large in size and a few in number. Large bundles were of various sizes and vascular tissues well developed. Each vascular bundle had strong mass of sclerenchyma tissue arching over the phloem in the form of phloem hood. Small bundles were poorly developed in respect of vascular tissue. A small percentage of vascular bundle consisted of phloem tissue only fundamental ground tissues were parenchyma in nature. DOI: http://dx.doi.org/10.3329/bjb.v44i1.22725 Bangladesh J. Bot. 44(1): 67-72, 2015 (March)

scholarly journals Cross-sectional anatomy of leaf blade and leaf sheath of cogon grass (Imperata cylindrica L.)

2018 ◽  
Vol 25 ◽  
pp. 17-26
Author(s):  
SN Sima ◽  
AK Roy ◽  
MT Akther ◽  
N Joarder
Keyword(s):  
Vascular Bundle ◽  
Leaf Blade ◽  
Leaf Sheath ◽  
Bundle Sheath ◽  
Imperata Cylindrica ◽  
Saline Stress ◽  
Vascular Bundles ◽  
Bulliform Cells ◽  
Kranz Anatomy ◽  
Adaxial Epidermis

Histology of leaf blade and sheath of cogon grass (Imperata cylindrica L.) Beauv., indicated typical C4 Kranz anatomy. Cells of adaxial epidermis were smaller and bulliform cells were present on the adaxial epidermis. The shape of bulliform cells was bulbous; 3-7 cells were present in a group and 3-5 folds larger than epidermal cells. Three types of vascular bundles in respect of size and structure were extra large, large and small and they were part of leaf blade histology. These three sizes of vascular bundles were arranged in successive manner from midrib to leaf margin. Leaf sheath bundles were of two types: large and small. Extra large bundles were flanked by five small and four large bundles but small bundles were alternate found to be with large typed bundles. Extra large bundles were of typical monocotyledonous type but the large type had reduced xylem elements and the small typed was found to be transformed into treachery elements. Small be bundles occupied half the thickness of the flat portion of leaf blade topped by large bulliform cells of the adaxial epidermis. Extra large and large bundle had been extended to upper and lower epidermis. Kranz mesophyll completely encircled the bundle sheath and radiated out into ground tissue. Midrib was projected in abaxial direction and had a central vascular bundle with large and small bundles on either side of it along the abaxial regions. The midrib vascular bundle was devoid of chlorenchymatous bundle sheath and was of non-Kranz type. Continuous sub-epidermal sclerenchyma girders were noted as adaxial hypodermis. Anatomical traits exhibited an important adaptive defense against draught and saline stress of the plant. Quantitative measurement of various anatomical traits indicated strong variations among them.J. bio-sci. 25: 17-26, 2017

scholarly journals Anatomy of the Windmill Palm (Trachycarpus fortunei) and Its Application Potential

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1130 ◽  
Author(s):  
Jiawei Zhu ◽  
Jing Li ◽  
Chuangui Wang ◽  
Hankun Wang
Keyword(s):  
Cell Wall ◽  
Vascular Bundle ◽  
Vascular Tissue ◽  
Leaf Sheath ◽  
Indentation Modulus ◽  
Vascular Bundles ◽  
Fibrous Sheath ◽  
Force Microscopy ◽  
Significant Difference ◽  
Tissue Proportion

The windmill palm (Trachycarpus fortunei (Hook.) H. Wendl.) is widely distributed and is an important potential source of lignocellulosic materials. The lack of knowledge on the anatomy of the windmill palm has led to its inefficient use. In this paper, the diversity in vascular bundle types, shape, surface, and tissue proportions in the leaf sheaths and stems were studied with digital microscopy and scanning electron microscope (SEM). Simultaneously, fiber dimensions, fiber surfaces, cell wall ultrastructure, and micromechanics were studied with atomic force microscopy (AFM) and a nanoindenter. There is diversity among vascular bundles in stems and leaf sheaths. All vascular bundles in the stems are type B (circular vascular tissue (VT) at the edge of the fibrous sheath (FS)) while the leaf sheath vascular bundles mostly belong to type C (aliform (VT) at the center of the (FS), with the wings of the (VT) extending to the edge of the vascular bundles). In addition, variation among the vascular bundle area and tissue proportion in the radial direction of the stems and different layers of the leaf sheaths is also significant. Microscopically, the fibers in the stem are much wider and longer than that in the leaf sheath. The secondary walls of stem fibers are triple layered while those in the leaf sheath are double layered. The indentation modulus and hardness of the cell wall of leaf sheath fibers are higher than that of the stem. An independent sample t-test also showed a significant difference between stems and leaf sheaths. All this indicates that windmill palm stems and leaf sheaths are two different materials and have different application prospects.

Early ontogeny defines the diversification of primary vascular bundle systems in angiosperms

2020 ◽  
Author(s):  
Regine Claßen-Bockhoff ◽  
Doris Franke ◽  
Hansjörg Krähmer
Keyword(s):  
Vascular Bundle ◽  
Vascular Tissue ◽  
Three Dimensional ◽  
Early Ontogeny ◽  
Leaf Primordia ◽  
Dimensional System ◽  
Vascular Bundles ◽  
Histological Data ◽  
Molecular Aspects ◽  
The One

Abstract Understanding vascular bundle systems in angiosperms is a challenge. On the one hand, the vascular tissue is extremely important in reconstructing the evolution and survivability of plants, but on the other hand, it forms a complicated three-dimensional system of controversially discussed phylogenetic and ontogenetic origin. To increase clarity, in this paper we briefly summarize histological, phylogenetic and molecular aspects of primary vascular bundle formation in angiosperms, adding histological data on early stages of vascular bundle formation, proposing a concept combining the different views and providing simplified illustrations to improve the understanding of primary vascular systems in angiosperms. Based on the auxin hypothesis, vascular bundle formation is stimulated by the development of leaf primordia. Provascular domains appear at the base of the leaf primordia and develop into two directions (leaf, internode). The low vs. high number of internodal bundles, their circular vs. scattered arrangement and the open vs. closed bundle construction in eudicots vs. monocots can be deduced to be due to processes below the shoot apical meristem. The most important processes distinguishing monocots from eudicots are the isolated bundle initiation outside the primary meristem, the enormous expansion of the leaf bases associated with a high number of vascular bundles and the early onset of primary thickening passively dislocating vascular bundles.

Influence, chez le Manihot esculenta, du développement de la lame du limbe sur celui du pétiole et de l'entre-noeud sous-jacent

1992 ◽  
Vol 70 (10) ◽  
pp. 2053-2065 ◽  
Author(s):  
R. Médard ◽  
J. M. N. Walter ◽  
P. Barnola
Keyword(s):  
Key Words ◽  
Vascular Bundle ◽  
Manihot Esculenta ◽  
Vascular Development ◽  
Vascular Bundles ◽  
Mechanical Pressure ◽  
Vascular Tissues ◽  
Growth Area

Within each internode and about four plastochrons after its formation, an intercalary growth area appears, leading to a continued lengthening due essentially to anticline mitoses. It temporarily looks like a cambium. The blade of the leaf which is directly above the internode is absolutely necessary for the formation of this growth area. Xylem integrity of the cauline vascular bundle connected with this leaf is also required. Within each leaf, the presence of the blade and the integrity of vascular bundles are also indispensable for the lengthening of the petiole, whose mitotic system resembles the internode's. The hypothesis of a blade influence on the mitotic lengthening system through mechanical pressure due to the vascular development is discussed. Key words: internode, petiole, blade, vascular tissues, Manihot esculenta, intercalary growth.

Functional leaf anatomy and ultrastructure in a marine angiosperm, Syringodium isoetifolium (Aschers.) Dandy (Cymodoceaceae)

1993 ◽  
Vol 44 (1) ◽  
pp. 59 ◽  
Author(s):  
J Kuo
Keyword(s):  
Vascular Bundle ◽  
Leaf Blade ◽  
Small Region ◽  
Total Surface Area ◽  
Epidermal Cells ◽  
Secretory Cells ◽  
Vascular Bundles ◽  
Mesophyll Cells ◽  
Vascular Tissues ◽  
Syringodium Isoetifolium

The terete leaf blade of Syringodium isoetifolium (Aschers.) Dandy from south-western Australia has uniformly small epidermal cells and a few large secretory cells. Mesophyll tissues contain several air lacunae, a central longitudinal vascular bundle, and eight to twelve peripheral longitudinal vascular bundles, but no fibre bundles. The total volume of air lacunae is about 10% that of the leaf blades, but the total surface area of air lacunae is similar to that of leaf blades. The leaf cuticle appears as a thin, electron-transparent layer. Leaf-blade epidermal cells have a large central vacuole and peripheral cytoplasm containing many chloroplasts that lack starch grains. Wall ingrowths are absent. However, the small region between the walls and the plasmalemma could play an important role in nutrient absorption. Plasmodesmata appear to be absent between adjacent epidermal cells, and also between epidermal and mesophyll cells, suggesting that there is only an apoplastic pathway for the transport of photosynthate to the vascular tissues. Each vascular bundle is surrounded by a layer of sheath cells, which are characterized by the presence of suberized lamellae in their walls. These may act to reduce the apoplastic exchange of solutes and water between the mesophyll and vascular tissues. Xylem elements, represented by large lumens and intensely hydrolysed walls, may not be present in all peripheral vascular bundles. Two types of sieve elements occur in S. isoetifolium leaf blades: normal thin-walled ones with large lumens, and thick-walled ones with reduced lumens, representing the photophloem and the metaphloem, respectively.

scholarly journals BdERECTA controls vasculature patterning and phloem-xylem organization in Brachypodium distachyon

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kaori Sakai ◽  
Sylvie Citerne ◽  
Sébastien Antelme ◽  
Philippe Le Bris ◽  
Sylviane Daniel ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Vascular Tissue ◽  
Vascular System ◽  
Brachypodium Distachyon ◽  
Premature Stop Codon ◽  
Vascular Network ◽  
Vascular Bundles ◽  
Large Set ◽  
Vascular Tissues ◽  
Tissue Organization

Abstract Background The vascular system of plants consists of two main tissue types, xylem and phloem. These tissues are organized into vascular bundles that are arranged into a complex network running through the plant that is essential for the viability of land plants. Despite their obvious importance, the genes involved in the organization of vascular tissues remain poorly understood in grasses. Results We studied in detail the vascular network in stems from the model grass Brachypodium distachyon (Brachypodium) and identified a large set of genes differentially expressed in vascular bundles versus parenchyma tissues. To decipher the underlying molecular mechanisms of vascularization in grasses, we conducted a forward genetic screen for abnormal vasculature. We identified a mutation that severely affected the organization of vascular tissues. This mutant displayed defects in anastomosis of the vascular network and uncommon amphivasal vascular bundles. The causal mutation is a premature stop codon in ERECTA, a LRR receptor-like serine/threonine-protein kinase. Mutations in this gene are pleiotropic indicating that it serves multiple roles during plant development. This mutant also displayed changes in cell wall composition, gene expression and hormone homeostasis. Conclusion In summary, ERECTA has a pleiotropic role in Brachypodium. We propose a major role of ERECTA in vasculature anastomosis and vascular tissue organization in Brachypodium.

Elemental Analysis of Phloem Tissue in Lemna Minor Root Tips

1980 ◽  
Vol 38 ◽  
pp. 798-799
Author(s):  
Patrick Echlin ◽  
Thomas Hayes ◽  
Clifford Lai ◽  
Greg Hook
Keyword(s):  
Vascular Tissue ◽  
Lemna Minor ◽  
Atomic Weight ◽  
Companion Cell ◽  
Root Tips ◽  
Phloem Tissue ◽  
Cell Stage ◽  
Phloem Parenchyma ◽  
Parenchyma Cells ◽  
Xylem Element

Studies (1—4) have shown that it is possible to distinguish different stages of phloem tissue differentiation in the developing roots of Lemna minor by examination in the transmission, scanning, and optical microscopes. A disorganized meristem, immediately behind the root-cap, gives rise to the vascular tissue, which consists of single central xylem element surrounded by a ring of phloem parenchyma cells. This ring of cells is first seen at the 4-5 cell stage, but increases to as many as 11 cells by repeated radial anticlinal divisions. At some point, usually at or shortly after the 8 cell stage, two phloem parenchyma cells located opposite each other on the ring of cells, undergo an unsynchronized, periclinal division to give rise to the sieve element and companion cell. Because of the limited number of cells involved, this developmental sequence offers a relatively simple system in which some of the factors underlying cell division and differentiation may be investigated, including the distribution of diffusible low atomic weight elements within individual cells of the phloem tissue.

The potential digestibility of cellulose in grasses and its relationship with chemical and anatomical parameters

1972 ◽  
Vol 78 (3) ◽  
pp. 457-464 ◽  
Author(s):  
R. J. Wilkins
Keyword(s):  
Floral Development ◽  
Lignin Content ◽  
Leaf Sheath ◽  
Vascular Bundles ◽  
Cellulose Digestibility ◽  
Wimmera Ryegrass ◽  
Rate Of Decline ◽  
The Relationship ◽  
Anatomical Parameters

SUMMARYPotential cellulose digestibility, measured by incubation in vitrofor 6 days, decreased during floral development in perennial ryegrass, Wimmera ryegrass, cocksfoot, oat and tall fescue. The rate of decline was slower than for cellulose digestibility measured after incubation in vitro for 2 days only. Morphological fractions ranked in order of descending potential cellulose digestibility – leaf blade, inflorescence, leaf sheath and stem.Lignin content was determined chemically by the method of Van Soest (1963) and lignified tissue was assessed by staining transverse sections of leaf blades and leaf sheaths with safranin and fast green. Both lignin and lignified tissue increased with maturity. Lignified tissue increased mainly through increase in the number of scleren-chyma cells, but was also affected by the formation of lacunae or cavities between the vascular bundles in leaf blades of cocksfoot and in leaf sheaths of all species studied. For 19 samples of leaf blades and leaf sheaths, potential cellulose digestibility had significant negative correlations with both lignin content (r = -0·862) and lignified tissue (r = -0·905). Limitations to the techniques used to assess lignification and further factors which may affect the relationship between lignification and potential cellulose digestibility are discussed.

scholarly journals Knockout of Auxin Response Factor SlARF4 Improves Tomato Resistance to Water Deficit

2021 ◽  
Vol 22 (7) ◽  
pp. 3347
Author(s):  
Mengyi Chen ◽  
Xiaoyang Zhu ◽  
Xiaojuan Liu ◽  
Caiyu Wu ◽  
Canye Yu ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Vascular Bundle ◽  
Plant Resistance ◽  
Quantitative Polymerase Chain Reaction ◽  
Photochemical Efficiency ◽  
Differentially Expressed ◽  
Vascular Bundles ◽  
Aba Signaling ◽  
Auxin Response

Auxin response factors (ARFs) play important roles in various plant physiological processes; however, knowledge of the exact role of ARFs in plant responses to water deficit is limited. In this study, SlARF4, a member of the ARF family, was functionally characterized under water deficit. Real-time fluorescence quantitative polymerase chain reaction (PCR) and β-glucuronidase (GUS) staining showed that water deficit and abscisic acid (ABA) treatment reduced the expression of SlARF4. SlARF4 was expressed in the vascular bundles and guard cells of tomato stomata. Loss of function of SlARF4 (arf4) by using Clustered Regularly Interspaced Short Palindromic Repeats/Cas 9 (CRISPR/Cas 9) technology enhanced plant resistance to water stress and rehydration ability. The arf4 mutant plants exhibited curly leaves and a thick stem. Malondialdehyde content was significantly lower in arf4 mutants than in wildtype plants under water stress; furthermore, arf4 mutants showed higher content of antioxidant substances, superoxide dismutase, actual photochemical efficiency of photosystem II (PSII), and catalase activities. Stomatal and vascular bundle morphology was changed in arf4 mutants. We identified 628 differentially expressed genes specifically expressed under water deficit in arf4 mutants; six of these genes, including ABA signaling pathway-related genes, were differentially expressed between the wildtype and arf4 mutants under water deficit and unlimited water supply. Auxin responsive element (AuxRE) elements were found in these genes’ promoters indicating that SlARF4 participates in ABA signaling pathways by regulating the expression of SlABI5/ABF and SCL3, thereby influencing stomatal morphology and vascular bundle development and ultimately improving plant resistance to water deficit.

Acute effects of caffeine ingestion at rest in humans with impaired epinephrine responses

1996 ◽  
Vol 80 (3) ◽  
pp. 999-1005 ◽  
Author(s):  
M. Van Soeren ◽  
T. Mohr ◽  
M. Kjaer ◽  
T. E. Graham
Keyword(s):  
Blood Pressure ◽  
Adenosine Receptors ◽  
Vascular Tissue ◽  
Physiological Responses ◽  
Acute Effects ◽  
Peripheral Vascular ◽  
Direct Stimulation ◽  
Spinal Cord Lesions ◽  
Caffeine Ingestion ◽  
Stimulation Of

Caffeine ingestion has been demonstrated to increase circulating epinephrine (Epi) and norepinephrine (NE), elevate free fatty acids (FFAs), and alter heart rate, blood pressure (BP), and ventilation in humans. Whether these physiological responses are a result of caffeine acting through direct stimulation of specific tissues via adenosine receptors or secondary to Epi increases is not known. In the present experiment, six tetraplegics (level of spinal cord lesions C4-C6) were tested at rest for 3 h to investigate the effects of 6 mg/kg caffeine in capsule form on subjects with impaired Epi responses. Ventilatory, cardiovascular, metabolic, and hormonal data were collected every 15-20 min after caffeine ingestion. There were no significant (P > 0.05) increases in plasma Epi after caffeine ingestion [0.19 +/- 0.04 (SE) nM (preingestion); 0.20 +/- 0.04 nM (80 min postingestion)] or in plasma NE [0.53 +/- 0.16 nM (preingestion); 0.49 +/- 0.09 nM (80 min postingestion; P > 0.05)]. However, significant increases were found in serum FFAs [0.53 +/- 0.08 nM (preingestion); 1.03 +/- 0.20 mM (40 min postingestion; P < 0.05] and in glycerol. These concentrations remained elevated throughout the experiment. BP increased in the first hour postingestion. These data demonstrate that caffeine in physiological doses directly stimulates specific tissues, i.e., adipose and peripheral vascular tissue, and these effects are not secondary to increases in Epi after caffeine ingestion.

Sign in / Sign up

Export Citation Format

Share Document