Effects of Shading on the Anatomy and Ultrastructure of the Leaf Mesophyll and Vascular Bundles of Itchgrass (Rottboellia exaltata)

Weed Science ◽  
1980 ◽  
Vol 28 (2) ◽  
pp. 216-224 ◽  
Author(s):  
Rex N. Paul ◽  
David T. Patterson

A study of the C4plant itchgrass (Rottboellia exaltataL.f.) grown under 100%, 60%, 25% and 2% sunlight revealed differences in the anatomy and cytology of the foliar mesophyll and vascular bundles associated with shading. In the bundle sheath, shading caused a reduction in thickness of the cell walls, shrinkage of plastids, rearrangement of plastid thylakoids, a reduction in starch deposits and vacuolization of the cytoplasm. In general, plastids and mitochondria retained membrane integrity but underwent stromal deterioration. Shading effects on cytoplasm were similar for mesophyll and bundle sheath cells. Mesophyll chloroplasts lost starch grains and the peripheral reticulum tended to decrease with greater shading. Grana were well developed at all irradiances, although the chloroplasts themselves decreased in size with shading. Movement of mesophyll chloroplasts away from bundle sheath-mesophyll borders was pronounced at 60% sunlight and was progressively greater at the two lower irradiances. These observations suggest that the structural relationships thought to be necessary for the intercellular transfer of C4acids and the functioning of the C4photosynthetic pathway were disrupted by shading.

1969 ◽  
Vol 47 (1) ◽  
pp. 15-21 ◽  
Author(s):  
T. Bisalputra ◽  
W. J. S. Downton ◽  
E. B. Tregunna

The ultrastructure of the chlorenchymatous tissues around the vascular bundles of three different types of grass leaves is described. In the temperate grass leaf, as exemplified by wheat, the inner mestom sheath contains proplastids. Normal chloroplasts are found only within the mesophyll cells. Smaller chloroplasts occur in cells of the ill-defined parenchymatic bundle sheath. This type of leaf has the photosynthetic pathway described by Calvin and a high carbon dioxide compensation value. In the tropical grasses, Sorghum and Aristida, the new photosynthetic pathway proposed by Hatch et al. and low carbon dioxide compensation are correlated with development of the parenchymatic bundle sheath. Cytological evidence indicates that cells of the bundle sheath are much more active than the surrounding mesophyll tissue. The specialized chloroplasts of the bundle sheath cells may be responsible for the physiological and biochemical differences between leaves of tropical and temperate grasses.


1995 ◽  
Vol 73 (6) ◽  
pp. 827-842 ◽  
Author(s):  
John Kuo ◽  
Joan G. Stewart

The leaf anatomy and ultrastructure of the North American Phyllospadix species P. serrulatus Rupt. ex Aschers., P. scouleri Hook, and P. torreyi Watson are described. The unique anatomical and ultrastructural features of these species are compared with those of other seagrasses and their possible functional significance is discussed. All three species have ultrastructures similar to those in other members of the family Zosteracae. Subcuticular cavities, wall ingrowths, and numerous mitochondria and chloroplasts with well-developed grana are present in the blade epidermal cells and the adaxial sheath epidermal cells, indicating that these cells may play a major role in photosynthesis, osmoregulation, and absorption. Plasmodesmata are present occasionally between adjacent epidermal cells, and also between epidermal and mesophyll cells, suggesting that solutes can be transferred symplastically between these tissues. The vascular bundle sheath cells are not easy to recognize, as cell walls are thin and not suberized. The phloem contains both normal and nacreous-walled sieve tubes that may be functional. The walls of the phloem parenchyma cells facing nacreous-walled sieve tubes possess weak wall ingrowths, leading to speculation that these parenchyma cells may play an important role in solute translocation. The absence of suberin lamella in bundle sheath cells and the presence of a small xylem element in each vascular bundle suggest that the water flow in xylem elements in these seagrasses may be limited and that water is taken directly from the water column by leaf epidermal cells and is transported apoplastically along cell walls. The three North American Phyllospadix species can be separated by anatomical characters such as number of vascular bundles, the shape of epidermal cells in both transverse sectional and surface views, and the distribution of fibre bundles. It is proposed that P. serrulatus is taxonomically more closely related to the Japanese P. iwatensis Makino than to P. scouleri and P. torreyi and that there is no detectable hybrid species occurring between P. scouleri and P. torreyi. Key words: anatomy, ultrastructure, seagrasses, Phyllospadix, North America.


Bothalia ◽  
1990 ◽  
Vol 20 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Evangelina Sanchez ◽  
Mirta O. Arriaga ◽  
Roger P. Ellis

The transectional anatomy of photosynthetic flowering culms of Arundinella berteroniana (Schult.) Hitchc. Chase and A. hispida (Willd.) Kuntze from South America and A.  nepalensis Trin. from Africa is described and illustrated. The vascular bundles are arranged in three distinct rings, the outermost being external to a continuous sclerenchymatous band. Each of these peripheral bundles is surrounded by two bundle sheaths, a complete mestome sheath and an incomplete, outer, parenchymatous Kranz sheath, the cells of which contain large, specialized chloroplasts. Kranz bundle sheath extensions are also present. The chlorenchyma tissue is also located in this narrow peripheral zone and is interrupted by the vascular bundles and their associated sclerenchyma. Dispersed throughout the chlorenchyma are small groups of Kranz distinctive cells, identical in structure to the outer bundle sheath cells. No chlorenchyma cell is. therefore, more than two cells distant from a Kranz cell. The structure of the chlorenchyma and bundle sheaths indicates that the C4 photosynthetic pathway is operative in these culms. This study clearly demonstrates the presence of the peculiar distinctive cells in the culms as well as in the leaves of Arundinella. Also of interest is the presence of an inner bundle sheath in the vascular bundles of the culm whereas the bundles of the leaves possess only a single sheath. It has already been shown that Arundinella is a NADP-me C4 type and the anatomical predictor of a single Kranz sheath for NADP-me species, therefore, either does not hold in the culms of this genus or the culms are not NADP-me. This is only the second reported breakdown of this association between MS anatomy and the NADP-me biochemical C4 type.


1990 ◽  
Vol 68 (6) ◽  
pp. 1222-1232 ◽  
Author(s):  
Nancy G. Dengler ◽  
Ronald E. Dengler ◽  
Douglas J. Grenville

The C4 grass Arundinella hirta is characterized by unusual leaf blade anatomy: photosynthetic carbon reduction takes place both within the chlorenchymatous bundle sheath cells of the longitudinal veins and within longitudinal strands of "distinctive cells" that form part of the leaf mesophyll and are often completely isolated from vascular tissue. Although they are equivalent physiologically, these two cell types have different ontogenetic origins: bundle sheath cells are delimited from procambium early in leaf development, whereas distinctive cells differentiate from ground meristem at a later developmental stage. Although the two cell types share numerous cytological features (large chloroplasts with reduced grana, thick cell walls with a suberin lamella), we also found significant differences in cell lengths, length to width ratios, cell cross-sectional areas, organelle numbers per cell cross section, phenol content of the cell walls, and numbers of pit fields in the longitudinal cell walls. The size and shape of bundle sheath cells are likely a direct consequence of procambial origin. The thicker walls of bundle sheath cells (in major veins) and their greater lignification may reflect the inductive effect of cell differentiation in the proximity of sclerenchyma and vascular tissues. Differences between major and minor vein bundle sheath cells may reflect differences in the timing of initiation of procambial strands. Our analysis of cell wall characteristics has also shown the presence of numerous primary pit fields in the transverse walls between adjacent distinctive cells in a file; plasmodesmata in these pit fields form a pathway for longitudinal symplastic transport not previously known to exist.


2003 ◽  
Vol 15 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Maria Luiza Carvalho Carelli ◽  
Rachel Benetti Queiroz-Voltan ◽  
Joel Irineu Fahl ◽  
Paulo César Ocheuze Trivelin

Possible presence of vascular bundle sheath cells and its relation to photosynthetic pathway, leaf anatomy and carbon isotope composition (delta13C) were examined in six species of genus Coffea: C. arabica (cvs. Catuaí Vermelho, Mundo Novo, Bourbon Vermelho and Icatu Amarelo), C. canephora (cvs. Apoatã and Guarini), C. liberica, C. dewevrei, C. salvatrix and C. stenophylla. In all genotypes, the vascular bundle was surrounded by a layer of cells with numerous chloroplasts in a centrifugal position. Visually no differences could be seen between the spongy parenchyma cells and the bundle sheath cells, neither in size nor in chloroplast number. The leaf delta13C values ranged between a maximum of - 26.2 ‰ in C. salvatrix and a minimum of -29.7 ‰ in C. liberica. A strong correlation (r = 0.972, p = 0.001) between delta13C and anatomical characteristics was observed in coffee species. C. salvatrix exhibited the highest delta13C values and the most compact mesophyll, with more palisade and spongy parenchyma cells in contact with the vascular bundle sheath.


1990 ◽  
Vol 68 (8) ◽  
pp. 1803-1811 ◽  
Author(s):  
InSun Kim ◽  
David G. Fisher

Seven species of Portulaca growing in Hawaii can be divided into two groups based on the morphology, anatomy, and ultrastructure of their leaves. Portulaca oleracea, P. molokiniensis, P. lutea, forming group A, have spatulate to obovate leaves, paradermal minor veins, and mesophyll cells that completely encircle the minor veins. The chloroplasts in their bundle sheath cells are larger than those in the mesophyll cells and have well-developed grana and reduced peripheral reticulum. Bundle sheath mitochondria are larger and more numerous than those in the mesophyll, and chloroplasts in the mesophyll cells have well-developed grana and peripheral reticulum. Portulaca pilosa, P. villosa, P. sclerocarpa, and P. "ulupalakua," forming group B, have lanceolate to oblong–oblanceolate leaves, peripheral minor veins, and incomplete wreaths of mesophyll cells. The choroplasts in their bundle sheath cells are about the same size as those in the mesophyll and have reduced grana and well-developed peripheral reticulum. The bundle sheath mitochondria are about the same in size and number as those in the mesophyll, and the mesophyll chloroplasts have well-developed grana and reduced peripheral reticulum. Groups A and B may be equivalent, respectively, to types ii and i of R. C. Carolin, S. W. L. Jacobs, and M. Vesk (Aust. J. Bot. 26: 683–698, 1978) and to coronary subtypes B and A of E. V. Voznesenskaya and Y. V. Gamalei (Bot. Zh. Leningrad, 71: 1291–1306, 1986), which constitute groupings of Portulaca species studied by those authors.


1989 ◽  
Vol 67 (5) ◽  
pp. 1429-1433 ◽  
Author(s):  
Nels R. Lersten ◽  
Curt L. Brubaker

Paraveinal mesophyll is described from leaves of a common goldenrod species, Solidago canadensis L. (tribe Astereae). This is the first report of paraveinal mesophyll from the Asteraceae. It is a uniseriate middle layer consisting of horizontally lobed cells that form a lacy meshwork between veins. It abuts the tightly cylindrical bundle sheath at the level of the xylem in all vascular bundles. Vein endings, however, differ from other vascular bundles in two ways: sieve tube members may extend to the vein tip, end at an intermediate point, or be absent, and lateral bundle sheath cells distal to the terminal sieve tube member swell greatly or protrude horizontally and interdigitate with adjacent paraveinal mesophyll cells. Cells of both paraveinal mesophyll and bundle sheath have fewer and smaller chloroplasts than other mesophyll cells; the chloroplasts mostly lie adjacent to intercellular spaces. During leaf development, the paraveinal mesophyll layer differentiates before other mesophyll layers. Solidago canadensis paraveinal mesophyll resembles the well-studied paraveinal mesophyll of Glycine max, except for differences in its anatomical relationship to minor veins and vein endings.


1970 ◽  
Vol 18 ◽  
pp. 66-73 ◽  
Author(s):  
N Joarder ◽  
AK Roy ◽  
SN Sima ◽  
K Parvin

Context: Kranz anatomy of locally developed sugarcane cultivars were studied in relation to C4 vascular arrangement.   Objective: The objective of this study was to make gross cross-sectional anatomy and quantitative assessment of the anatomic traits of the leaf-blade and midrib of the sugarcane cultivars.   Materials and Methods: Leaf blade and leaf sheath of two sugarcane cultivars Ishurdi 20 and Ishurdi 32 were used as the materials. Free hand section with appropriate stain were used. Sections were studied using an advanced biological system microscope fitted with motic camera. Anatomic traits were studied through motic image plus J 1.0 software using Macintosh computer.   Results: Three sized vascular bundles and significant differences in distance between those vascular bundles were noted. Ishurdi 32 possessed two sized vascular bundles. Large vascular bundles characters by two large metaxylem vessels on either side of protoxylem. Phloem well developed. Intermediate and small bundles lack metaxylem vessels and protoxylem, but have metaphloem with thick and thin walled sieve tubes. Bundle sheaths have extended to upper and lower epidermis but for small bundle it is extended to abaxial epidermis. Vascular bundles are almost completely surrounded by chlorenchymatous bundle sheath and associated with hypodermal sclerenchyma on both abaxially and adaxially except small blade bundles which associated with the abaxial sclerenchyma. Bundle sheath cells were smaller in large and larger in other two types of vascular bundle. An inner mestome sheath with thickened walls is always present round the phloem and metaxylem around all or part of the xylem in large and intermediate bundles. In small bundles mestome sheath is altogether absent. Bulliform cells with varied area were present on the adaxial epidermis opposite to small vascular bundles. Midrib anatomy consists of central large vascular bundles lacking bundle sheath cells pushed deep inside parenchymatous hypodermis from abaxial hypodermal sclerenchyma girders. Lack of Kranz traits, and bundle sheath cells have transformed into sclerenchymatous bundle cover. Central mid-rib large bundle flanked by 3-10 small bundles on either side of midrib which have Kranz system of anatomy. Midrib region have continuous hypodermis consists of sclerenchyma cells and it is few layer (Ishurdi 32) to multilayer (Ishurdi 20).   Conclusion: Kranz system with well developed bundle sheath associated with Kranz mesophil in the leaf blade were observed but Kranz tissue absent in midrib region. Large and small vascular bundles alternate all alone the leaf blade. Bulliform cell well develop indicates zeric adaptation. Two cultivars differ in respect of quantitative expression of Kranz tissue.   Keywords: Sugarcane cultivar; Kranz tissue; bulliform cells; mestome sheath. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8778 JBS 2010; 18(0): 66-73


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