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.

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.

Histo-anatomical leaf variations related to depth in Posidonia oceanica

2015 ◽  
Vol 42 (4) ◽  
pp. 418 ◽  
Author(s):  
Silvia Nicastro ◽  
Anna M. Innocenti ◽  
Nicodemo G. Passalacqua
Keyword(s):  
Anatomical Variation ◽  
Light Availability ◽  
Posidonia Oceanica ◽  
Absorption Efficiency ◽  
Epidermal Cells ◽  
Vascular Bundles ◽  
Terrestrial Plants ◽  
Mesophyll Cells ◽  
Seagrass Meadows ◽  
Functional Efficiency

The purpose of our study is to explore the acclimation of Neptune seagrass (Posidonia oceanica (L.) Delile) to depth by characterising the histo-anatomical leaf modifications. P. oceanica is the dominant seagrass and main habitat constructor of seagrass meadows in the Mediterranean Sea. Meadows play an important biological and ecological role in marine ecosystems, serving as a habitat for a large diversity of species and an efficient erosion protection system for our coasts. Seagrasses are very sensitive to change in light availability and small changes can have significant effects on growth, abundance and distribution. In this study, we analyse changes in P. oceanica leaves collected at –5 m, –15 m and –25 m depth in the Cirella meadow (Tyrrhenian coast, Southern Italy) in order to determine their depth-related histo-anatomical variation. Two main changes were observed at depth: (1) photosynthetic epidermal cells showed smaller chloroplasts but in the same number; and (2) leaves showed smaller epidermal cells and in greater number. Hence, the photosynthetic surface of P. oceanica leaves remains the same at different depths but pigment absorption efficiency can be significantly enhanced with depth. This response supports the differential photoacclimatory response of seagrasses with respect to terrestrial plants previously documented. Mesophyll cells are smaller with depth and more numerous, with a consequent increase in leaf density. The number of vascular bundles also increases, which allows improved functional efficiency of the transport system and solute exchange. Our study is a new contribution to the morpho-functional implications of the histo-anatomy of P. oceanica.

Studies on Graminicolous Species of Phyllachora Fckl. II.. Invasion of the host and development of the fungus

1963 ◽  
Vol 11 (2) ◽  
pp. 131 ◽  
Author(s):  
DG Parbery
Keyword(s):  
Life Cycle ◽  
Close Contact ◽  
Detailed Examination ◽  
Epidermal Cells ◽  
Vascular Bundles ◽  
Mesophyll Cells ◽  
Full Life Cycle ◽  
Full Life ◽  
Made In ◽  
Mechanical Tissue

Infection of grasses by species of Phyllachora Fckl. has been observed, and a detailed examination of the life cycle of two species of this genus has been made on hosts artificially inoculated while growing under glass-house conditions. Gemiiiatiiig ascospores of P. ischaemi and P. parilis prodced appressoria on the leaves of their respective hosts, Ischaemum australe and Paspalurn orbiculare. From each appressorium an infection peg penetrated into the lumen of an epidermal cell and expanded into a normal hypha. Some branches of this hypha invaded adjacent epidermal cells, thus laying the foundations of the clypeus, while other branches invaded the underlying mesophyll cells. At first all hyphae were intracellular and passed from cell to cell by means of fine infection hyphae produced by appressorium-like swellings of the hyphae appressed to the cell wall. Intercellular mycelium was found at a later stage when hyphae were forming perithecium initials. The observation that the clypeus developed independently of the perithecium dispels some existing confusion about its origin. The clypeus developed in the epidermal cells of the host and not as an outgrowth of the ostiolar region of the perithecium. The perithecium initial developed deep in the mesophyll, and in the case of Phyllachora parilis was preceded by the formation of a subclypeal pycnidium containing filiform spores. In each case, the perithecium expanded until its ostiolar region came into close contact with the clypeus. The ostiole then developed right through the ciypeus, and its development is believed to be lysigenous. The mouth of the ostiole remained closed by a membrane which appeared to be the undissolved cuticle. It was noted that asci of all species examined possessed an ascus crown, a structure not previously observed in species of this genus. It has been found that the anatomy of the host can determine the form of some structures of Phyllachora spp. Clypeus thickness is governed by the size of the epidermal cells, while its radial expansion is checked by the mechanical tissue associated with vascular bundles. Similarly, perithecium size and shape are influenced by the amount of mechanical tissue in a leaf. The time for P. ischaemi to complete its life cycle was influenced by seasonal conditions. Colonies arising from infections in April 1961 discharged ascospores in 32 days, whereas infections made 1 month later did not produce sporulating colonies until 54-58 days later. The full life cycle of P. parilis took 62-77 days when inoculations were made in May 196 1.

The translocation of photosynthetically assimilated 14C in corn

1969 ◽  
Vol 47 (9) ◽  
pp. 1435-1442 ◽  
Author(s):  
G. Hofstra ◽  
C. D. Nelson
Keyword(s):  
Vascular Bundle ◽  
Leaf Blade ◽  
Vascular Bundles ◽  
Lateral Movement ◽  
Cutting Out ◽  
Corn Plants

A detailed study was made of translocation of photosynthetically assimilated 14C in 3- to 6-week-old corn plants. Corn assimilated 14C via malate and aspartate, and incorporated most of the 14C into sucrose, the only translocation compound. Lowering the temperature from 26° to 8 °C delayed the incorporation of 14C into sucrose, but had no effect on the distribution of 14C among the intermediates. Recent 14C assimilate was translocated very rapidly from the fed area, the amount remaining in the fed area decreasing logarithmically with time. The translocate moved down the vascular bundle it entered in the fed area, with no detectable lateral movement. The logarithmic profile in the leaf blade appeared to be the result of a temporary accumulation of the labelled pulse in the separate vascular bundles. This accumulation of sucrose in the veins could be eliminated by cutting out the fed area. Between 80 and 90% of the assimilated 14C was translocated from the fed area of the leaf in 24 hours with 50% moved out in the first 30 minutes. Both the rate of translocation and the total amount moved out of the fed area increased as the temperature was changed over the range 7 to 26 °C. Each leaf of young corn plants both imported assimilates from and exported assimilates to all other parts of the plant.

scholarly journals The utility of Bambusoideae (Poaceae, Poales) leaf blade anatomy for identification and systematics

2016 ◽  
Vol 76 (3) ◽  
pp. 708-717 ◽  
Author(s):  
T. D. Leandro ◽  
R. T. Shirasuna ◽  
T. S. Filgueiras ◽  
V. L. Scatena
Keyword(s):  
Vascular Bundle ◽  
Leaf Blade ◽  
Sympatric Species ◽  
Subsidiary Cell ◽  
Vascular Bundles ◽  
Diagnostic Features ◽  
Bulliform Cells ◽  
Herbaceous Bamboos ◽  
Stomatal Apparatus ◽  
Woody Bamboos

Abstract Bambusoideae is a diverse subfamily that includes herbaceous (Olyreae) and woody (Arundinarieae and Bambuseae) bamboos. Species within Bambusae are particularly difficult to identify due to their monocarpic lifecycle and the often long durations between mass flowering events; whereas the herbaceous bamboos are pluricarpic, but often are found with no reproductive structures. The leaf blade anatomy of 16 sympatric species of native Brazilian bamboos (Olyreae and Bambuseae) from the Atlantic Rainforest was studied in order to detect useful features for their identification. All the studied species share the following features: epidermis with a single stratum of cells; adaxial bulliform cells; mesophyll with arm cells, rosette cells, and fusoid cells; and collateral vascular bundles. Herbaceous bamboos share two features: papillae scattered on the abaxial surface and parallel-sided arrays of bulliform cells; whereas woody bamboos share: centrally organized papillae and fan-shaped arrays of bulliform cells. Also within the woody bamboos, intercostal fibers and a midrib with only one vascular bundle (simple midrib) characterize the subtribe Arthrostylidiinae; whereas a midrib with more than one vascular bundle (complex midrib) and a stomatal apparatus with two pappilae per subsidiary cell characterize the subtribe Chusqueinae. There are also diagnostic features for the sampled species, such as: papillae shape, and the outline and structure of the midrib. An identification key for all the studied species is provided based on the anatomical features.

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

Anatomical changes induced by triazoles in wheat seedlings

1988 ◽  
Vol 66 (6) ◽  
pp. 1178-1185 ◽  
Author(s):  
J. Gao ◽  
G. Hofstra ◽  
R. A. Fletcher
Keyword(s):  
Triticum Aestivum L ◽  
Chlorophyll Synthesis ◽  
Epidermal Cells ◽  
Vascular Bundles ◽  
Mesophyll Cells ◽  
Wheat Seedlings ◽  
Anatomical Changes ◽  
Subsidiary Cells ◽  
Wheat Leaves ◽  
Stimulation Of

The triazoles triadimefon and S-3307, applied as seed treatments at two concentrations each (0.1 and 1.0, and 0.001 and 0.01 g active ingredient/kg of seed, respectively), increased epicuticular wax and reduced the length but increased the width and thickness of wheat leaves (Triticum aestivum L. cv. Glenlea). Mesophyll cells of treated leaves were thicker than those of controls and there were more layers of cells around the median and lateral vascular bundles of leaves treated with the higher concentration of S-3307. The length of epidermal cells was reduced and the width was increased by both triazoles; the depth of epidermal cells was increased by the higher concentration of triadimefon only. S-3307 increased the number of vascular bundles, whereas triadimefon at the higher concentration increased their diameter. Both concentrations of S-3307 reduced the length of trichomes. The two triazoles increased chloroplast size along both the long and short axes. Compared with those of controls, the stomata in the triadimefon-treated leaves were constricted and sunken, whereas in S-3307 treated leaves the subsidiary cells were wider. The effects of the triazoles observed in this study may account in part for several plant growth regulatory activities reported earlier, including growth retardation, stimulation of chlorophyll synthesis, and protection against injury from water stress.

Leaf anatomy of the South African Danthonieae (Poaceae). V. Merxmuellera macowanii, M. davyi and M. aureocephala

Bothalia ◽  
1981 ◽  
Vol 13 (3/4) ◽  
pp. 493-500
Author(s):  
R. P. Ellis
Keyword(s):  
Light Microscopy ◽  
South African ◽  
Vascular Bundle ◽  
Leaf Anatomy ◽  
Related Species ◽  
Leaf Blade ◽  
Vascular Bundles ◽  
The South ◽  
Species Groups

Transverse sections and abaxial epidermal scrapes, of herbarium and freshly fixed leaf blade material, of Merxmuellera macowanii (Stapf) Conert, M. davyi (C. E. Hubb.) Conert and M. aureocephala (J. G. Anders.) Conert, were examined using light microscopy. The leaf anatomy o f these three species is very similar in all respects with the exception o f certain  M. aureocephala specimens. In addition, the anatomy indicates a relationship between these three species and M. disticha (Nees) Conert. This group of species differs anatomically from M. stricta (Schrad.) Nees, and related species such as  M. drakensbergensis (Schweick.) Conert and  M. stereophylla (J. G. Anders.) Conert, in the sequence of vascular bundles along the width of the leaf blade and associated characters. However, the M. aureocephala specimens, not having the  M. disticha type of vascular bundle arrangement, anatomically resemble the M. stricta group of species, and M. aureocephala appears to be intermediate between these two species groups.resemble the M. stricta group of species, and M. aureocephala appears to be intermediate between these two species groups.

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)

Foliar anatomy of the subfamily Myrtoideae (Myrtaceae)

2009 ◽  
Vol 57 (2) ◽  
pp. 148 ◽  
Author(s):  
C. M. V. Cardoso ◽  
S. L. Proença ◽  
M. G. Sajo
Keyword(s):  
Vascular Bundle ◽  
Vascular System ◽  
Diagnostic Value ◽  
Bundle Sheath ◽  
Epidermal Cells ◽  
Vascular Bundles ◽  
Palisade Parenchyma ◽  
Surface Features ◽  
Foliar Anatomy ◽  
Secretory Cavities

The foliar structure of 44 species of Myrtoideae Nied. (Myrtaceae) was described to characterise the anatomy of the leaves in this subfamily and also to recognise particular features in each genus and/or subtribe. In the present study, nine genera of the subtribe Myrtinae, five genera of the subtribe Myrciinae and eight genera of the subtribe Eugeniinae were examined. All of them have dorsiventral and hypostomatic leaves, with stomata slightly protruded in relation to other epidermal cells; the leaves also present secretory cavities, idioblasts containing druses and vascular bundles with phloem on both adaxial and abaxial sides. Some surface features have diagnostic value for all genera of these three subtribes, such as the percentage of palisade parenchyma, the presence or absence of an adaxial hypodermis, the occurrence of an extension to the vascular bundle sheath, and the shape and position of the vascular system of the midrib. These features are described for each of the species studied and the results are discussed in a taxonomical context.

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