Leaf anatomy of tropical fern rheophytes, with its evolutionary and ecological implications

1992 ◽  
Vol 70 (1) ◽  
pp. 165-174 ◽  
Author(s):  
Masahiro Kato ◽  
Ryoko Imaichi
Keyword(s):  
Leaf Anatomy ◽  
Cell Expansion ◽  
Mesophyll Cells ◽  
Running Water ◽  
Unit Leaf ◽  
Flood Resistance ◽  
Stream Beds ◽  
Ecological Specificity ◽  
Wax Deposits ◽  
Cuticular Layer

Rheophytes are restricted to stream beds that are regularly flooded by swift-running water after rains and are morphologically characterized by having narrow, (ob)lanceolate leaves – leaflets (stenophylls) and other features that are adapted to the unique habitat, decreasing resistance to the swift-running water. The present study characterized anatomically the leaves of fern rheophytes. Generally, the mesophyll cells of rheophytes are less expanded, and therefore their intercellular spaces are smaller than those of related dryland species. Furthermore, frequency of occurrence of stomata per unit leaf area is greater, the cuticular layer is thicker, and the epicuticular wax deposits on the leaf epidermis are denser in at least some rheophytes than in related dryland species. It can be assumed that the stenophylls of the rheophytes are produced by developmental events, including weaker cell expansion than in dryland species, and that a phylogenetic decrease in cell expansion in leaves was involved in the origin of stenophylls from broader leaves of ancestral dryland species. The leaf anatomical features are discussed in relation to the ecological specificity of the rheophytes. Key words: evolution, flood resistance, intercellular space, leaf anatomy, rheophytic ferns, stenophyll.

scholarly journals Leaf anatomy and micromorphology of six Posoqueria Aublet species (Rubiaceae)

Rodriguésia ◽  
2010 ◽  
Vol 61 (3) ◽  
pp. 505-518 ◽  
Author(s):  
Rosani do Carmo de Oliveira Arruda ◽  
Doria Maria Saiter Gomes ◽  
Aline Carvalho de Azevedo ◽  
Michelle Lima Magalhães ◽  
Mario Gomes
Keyword(s):  
Leaf Anatomy ◽  
Leaf Blade ◽  
Vascular System ◽  
Glandular Trichomes ◽  
Atlantic Rain Forest ◽  
Leaf Margin ◽  
Anticlinal Wall ◽  
Wax Deposition ◽  
Palisade Parenchyma ◽  
Cuticular Layer

Abstract The present study deals with the leaf anatomy and leaf surface of Posoqueria acutifolia Mart., P. latifolia Mart., P. longiflora Aublet, P. macropus Mart., P. palustris (Rudge) Roem. and Posoqueria sp., collected in fragments of Atlantic rain forest, Rio de Janeiro, Brazil. The epicuticular wax may occur in the form of filaments, granules or crusts. The leaves are covered by a thick cuticular layer that may be smooth or striated. Paracytic stomata, and non-glandular trichomes are limited to the abaxial surface; the latter are numerous in P. palustris, and rare in P. longiflora and P. latifolia. Leaves have a dorsiventral structure, with only one layer of palisade parenchyma and varied amounts of spongy parenchyma. Idioblasts containing crystalliferous sand were observed, and were more abundant in P. latifolia. The leaf blade vascular system is formed by collateral bundles with a parenchymatous sheath, associated with fibers. The vascular system of the petiole and the leaf blade forms an arch. Some of the anatomical features observed can be used to distinguish the species studied. Anatomical leaf characters could be used in the recognition of six species of Posoqueria studied, such as anticlinal wall of epidermal cells, wax deposition, trichomes and shape of the leaf margin.

Leaf Ultrastructure and δ13C Values of Three Seagrasses from the Great Barrier Reef

1976 ◽  
Vol 3 (1) ◽  
pp. 9 ◽  
Author(s):  
ME Doohan ◽  
EH Newcomb
Keyword(s):  
Great Barrier Reef ◽  
Leaf Anatomy ◽  
Co2 Assimilation ◽  
Land Plants ◽  
Vascular Bundles ◽  
Barrier Reef ◽  
Thalassia Hemprichii ◽  
Mesophyll Cells ◽  
Δ13c Values ◽  
Abundant Cytoplasm

Leaf anatomy, ultrastructure and 13C/12C ratios were studied in three species of seagrasses collected on the Great Barrier Reef: Cymodocea rotundata Ehrenb. & Hempr., C. serrulata (R. Br.) Aschers. & Magnus, and Thalassia hemprichii (Ehrenb.) Aschers. Although they belong to two different mono- cotyledonous families, the three species are quite similar in the characteristics studied. Cells of the epidermal layer of the leaves are extremely thick-walled and have abundant cytoplasm with large chloroplasts and numerous mitochondria. The chloroplast-microbody profile ratio is c. 4-5 : 1 and the mitochondrion-microbody ratio 10-15 : 1. The epidermal cells resemble transfer cells in having a pronounced development of ingrowths on the radial walls. The mesophyll cells have thin walls, a large central vacuole and a thin layer of cytoplasm with relatively few organelles. There is no specialization of mesophyll cells around the vascular bundles. The δ13C values for the three sea- grasses range from -6.90, to - 12.40, and thus are characteristic of C4 land plants, although the seagrasses do not conform to the C4 syndrome in leaf anatomy or ultrastructure. It is not possible to place the seagrasses in either the C3, C4 or crassulacean acid metabolism category of land plants, but whether they constitute yet a fourth group with respect to characteristics related to CO2 assimilation is not clear.

scholarly journals Are thick leaves, large mesophyll cells and small intercellular air spaces requisites for CAM?

2020 ◽  
Vol 125 (6) ◽  
pp. 859-868 ◽  
Author(s):  
Ana Herrera
Keyword(s):  
Cell Density ◽  
Leaf Anatomy ◽  
Isotopic Ratio ◽  
Leaf Thickness ◽  
Cell Area ◽  
Mesophyll Cells ◽  
Carbon Isotopic ◽  
Δ 13C ◽  
Cam Species ◽  
Nocturnal Acid Accumulation

Abstract Background and Aims It is commonly accepted that the leaf of a crassulacean acid metabolism (CAM) plant is thick, with large mesophyll cells and vacuoles that can accommodate the malic acid produced during the night. The link between mesophyll characteristics and CAM mode, whether obligate or C3/CAM, was evaluated. Methods Published values of the carbon isotopic ratio (δ 13C) as an indicator of CAM, leaf thickness, leaf micrographs and other evidence of CAM operation were used to correlate cell density, cell area, the proportion of intercellular space in the mesophyll (IAS) and the length of cell wall facing the intercellular air spaces (Lmes/A) with CAM mode. Key Results Based on 81 species and relatively unrelated families (15) belonging to nine orders, neither leaf thickness nor mesophyll traits helped explain the degree of CAM expression. A strong correlation was found between leaf thickness and δ 13C in some species of Crassulaceae and between leaf thickness and nocturnal acid accumulation in a few obligate CAM species of Bromeliaceae but, when all 81 species were pooled together, no significant changes with δ 13C were observed in cell density, cell area, IAS or Lmes/A. Conclusions An influence of phylogeny on leaf anatomy was evidenced in a few cases but this precluded generalization for widely separate taxa containing CAM species. The possible relationships between leaf anatomy and CAM mode should be interpreted cautiously.

scholarly journals Leaf Anatomy and Stomatal Morphology of Greenhouse Roses Grown at Moderate or High Air Humidity

2003 ◽  
Vol 128 (4) ◽  
pp. 598-602 ◽  
Author(s):  
Sissel Torre ◽  
Tove Fjeld ◽  
Hans Ragnar Gislerød ◽  
Roar Moe
Keyword(s):  
Leaf Anatomy ◽  
Structural Changes ◽  
Vascular Tissue ◽  
Postharvest Quality ◽  
Water Control ◽  
Mesophyll Cells ◽  
Single Node ◽  
Stomatal Morphology ◽  
Reduced Density ◽  
Response To Water

Single node cuttings with one mature leaf were taken from Rosa ×hybrida `Baroness' and rooted in water culture. The plants were subjected to either 90% (high) or 70% (moderate) relative humidity (RH) in climate chambers. Single stem roses with intact roots were transferred to 40% (low) RH to investigate the stomatal response to water stress. Moderate RH plants showed decreasing leaf conductance from day 1 to day 3 during both light and dark phases, in contrast to high RH roses, which showed almost similar leaf conductances during the 3 days. Leaf samples were studied with a light microscope (LM) and a scanning electron microscope (SEM) to quantify morphological and structural changes. Epidermal imprints showed a significantly higher number of stomata and longer stomata, as well as a wider stomatal apertures on roses grown at high RH. The high RH leaves showed a reduced density of vascular tissue and thinner leaves when compared to moderate RH leaves. Enlarged intercellular air-space (ICA) was found due to a reduced number of spongy and palisade mesophyll cells. No obvious difference in shape, size, undulation or the structure of the epicuticular wax was observed in SEM between high and moderate RH grown leaves. In conclusion, roses subjected to high RH showed differences in leaf anatomy, stomatal morphology and stomatal function, which may explain the loss of water control of these plants. Stomatal ontogenesis should occur at RH conditions below 85% to secure roses with a high postharvest quality potential.

scholarly journals Prospects for enhancing leaf photosynthetic capacity by manipulating mesophyll cell morphology

2018 ◽  
Author(s):  
Tao Ren ◽  
Sarathi M Weraduwage ◽  
Thomas D. Sharkey
Keyword(s):  
Cell Morphology ◽  
Leaf Anatomy ◽  
Target Genes ◽  
Photosynthetic Capacity ◽  
Control Cell ◽  
Mesophyll Cell ◽  
Light Distribution ◽  
Potential Target ◽  
Unit Leaf ◽  
Physiological Processes

AbstractLeaves are beautifully specialized organs designed to maximize the use of light and CO2 for photosynthesis. Engineering leaf anatomy therefore brings great potential to enhance photosynthetic capacity. Here we review the effect of the dominant leaf anatomical traits on leaf photosynthesis and confirm that a high chloroplast surface area exposed to intercellular airspace per unit leaf area (Sc) is critical for efficient photosynthesis. The possibility of improving Sc through appropriately increasing mesophyll cell density is further analyzed. The potential influences of modifying mesophyll cell morphology on CO2 diffusion, light distribution within the leaf, and other physiological processes are also discussed. Some potential target genes regulating leaf mesophyll cell proliferation and expansion are explored. Indeed, more comprehensive research is needed to understand how manipulating mesophyll cell morphology through editing the potential target genes impact leaf photosynthetic capacity and related physiological processes. This will pinpoint the targets for engineering leaf anatomy to maximize photosynthetic capacity.HighlightCell morphology in leaves affects photosynthesis by controlling CO2 diffusion and light distribution. Recent work has uncovered genes that control cell size, shape, and number paving the way improved photosynthesis.

scholarly journals Water stress-induced changes in morphology and anatomy of flag leaf of spring wheat

2014 ◽  
Vol 63 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Barbara Zagdańska ◽  
Janusz Kozdój
Keyword(s):  
Water Stress ◽  
Leaf Anatomy ◽  
Flag Leaf ◽  
Decisive Role ◽  
Mesophyll Cells ◽  
Flag Leaves ◽  
Leaf Area And Thickness ◽  
Total Cell Volume ◽  
Simultaneous Decrease ◽  
Induced Changes

Flag leaves of wheat (drought hardened and non-hardened) were examined by light microscopy to determine whether the differences in leaf anatomy could be related to the known differences in dehydration tolerance. Plants exposure to water stress during tissue differentiation of flag leaves resulted in an irreversible reduction of leaf area and thickness, increased frequencies of stomata and higher number of bulliform cells with simultaneous decrease in number of intermediate veins and an increase in the share of the cell walls in total cell volume. The smaller leaf thickness was due to a diminished number of mesophyll layers and a decreased size of mesophyll cells. Such altered leaf anatomy indicated development of leaf xerophily. It was found that the irreversible changes in anatomy of wheat flag leaves play a decisive role in acquiring drought tolerance during wheat acclimation to drought.

Leaf anatomy of ocotillo (Fouquieria splendens; Fouquieriaceae), especially vein endings and associated veinlet elements

1974 ◽  
Vol 52 (9) ◽  
pp. 2017-2021 ◽  
Author(s):  
Nels R. Lersten ◽  
Kathryn A. Carvey
Keyword(s):  
North America ◽  
Leaf Anatomy ◽  
Sieve Tube ◽  
Bundle Sheath ◽  
Mesophyll Cells ◽  
Spongy Mesophyll ◽  
Short Period ◽  
Bundle Sheath Cells ◽  
And Function ◽  
Sheath Cells

Leaves of ocotillo, a shrub of southwestern North America, lack xeromorphic features. After rain, a few leaves at each node expand and function for a short period, then abscise. This cycle may be repeated several times each year. Palisade layers occur interior to both epidermal surfaces, and the spongy mesophyll is reduced. Venation is camptodromous, with many vein endings. In the distal lamina half, sclerified bundle sheath cells ("veinlet elements") become increasingly common in minor veins and vein endings. Near the leaf tip, adjacent mesophyll cells also become sclerified, to such an extent that some areoles appear filled with these cells ("accessory veinlet elements"). Phloem is conspicuous because it stains intensely and occupies more volume than xylem in most bundles. In minor veins and vein endings, sieve tube members become increasingly more slender than associated phloem cells, and xylem frequently changes its position, becoming parallel with, or even abaxial to, the phloem. Phloem mostly ends before, less commonly with, the xylem.

The paraveinal mesophyll: a specialized path for intermediary transfer of assimilates in legume leaves

2000 ◽  
Vol 27 (9) ◽  
pp. 757 ◽  
Author(s):  
Alexis J. Lansing ◽  
Vincent R. Franceschi
Keyword(s):  
Vascular System ◽  
Phloem Loading ◽  
Assimilate Transport ◽  
Vascular Bundles ◽  
Transport Pathway ◽  
Mesophyll Cells ◽  
Diffusion Limitations ◽  
Unit Leaf ◽  
Paraveinal Mesophyll ◽  
Leaf Surface Area

This paper originates from a presentation at the International Conference on Assimilate Transport and Partitioning, Newcastle, NSW, August 1999 The distance between sites of synthesis of assimilates and the site of phloem loading can be large, and specialized leaf cell layers such as the paraveinal mesophyll (PVM) might act to enhance the efficiency of transport. A number of techniques were used to analyse PVM of legume leaves with respect to a hypothesized function in transfer of assimilates between tissues. Of 39 legume species examined, PVM was found in 22. Leaves of all PVM-containing species had multiple palisade parenchyma layers, while non-PVM species generally had only one distinct palisade layer. Morphometric analysis identified a significant correlation between PVM presence and greater numbers of palisade cells per unit leaf surface area. Comparison of photosynthetic rates of four PVM and four non-PVM species showed the PVM species had higher rates on a leaf area basis than all but one of the non-PVM species. Microautoradiography of 14CO2 pulse–chase studies in soybean demonstrated PVM is an intermediary tissue in transfer of assimilates to vascular bundles. In addition, PVM cells but not mesophyll cells, were enriched in a sucrose binding protein previously found to be associated with sucrose-transporting tissues. The structural, positional and transport data support the hypothesis that the PVM acts as a transport pathway between the vascular system and photoassimilatory cells of the leaf, and has probably evolved to overcome diffusion limitations imposed by multiple palisade layers.

The distribution and ultrastructure of chloroplasts in leaves differing in photosynthetic carbon metabolism. II. Atriplex rosea and Atriplex hastata (Chenopodiaceae)

1969 ◽  
Vol 47 (6) ◽  
pp. 915-919 ◽  
Author(s):  
W. J. S. Downton ◽  
T. Bisalputra ◽  
E. B. Tregunna
Keyword(s):  
Leaf Anatomy ◽  
Carbon Metabolism ◽  
Chloroplast Development ◽  
Bundle Sheath ◽  
Mesophyll Cells ◽  
Bundle Sheath Cells ◽  
Photosynthetic Carbon ◽  
Changing Roles ◽  
Photosynthetic Carbon Metabolism ◽  
Maximum Development

Some aspects of chloroplast development for parenchymatic bundle sheath cells and mesophyll cells of Atriplex rosea leaves are described. The mesophyll chloroplasts begin to degenerate when the bundle sheath chloroplasts have reached a stage of maximum development. These events are related to the changing roles of the two types of chloroplasts in carbon dioxide assimilation. Leaves of Atriplex rosea are similar to those of tropical grasses in leaf anatomy, photosynthetic carbon metabolism, and CO2 compensation value. Atriplex hastata differs from A. rosea in leaf anatomy and is photosynthetically similar to the temperate grasses. There is a lack of parenchymatic sheath development and the chloroplasts which surround the vascular bundle are ultrastructurally identical with those in the rest of the mesophyll.

Carbon dioxide compensation—its relation to photosynthetic carboxylation reactions, systematics of the Gramineae, and leaf anatomy

1968 ◽  
Vol 46 (3) ◽  
pp. 207-215 ◽  
Author(s):  
W. J. S. Downton ◽  
E. B. Tregunna
Keyword(s):  
Carbon Dioxide ◽  
Leaf Anatomy ◽  
Rapid Determination ◽  
High Concentration ◽  
Mesophyll Cells ◽  
Biochemical Status ◽  
Carbon Dioxide Compensation Concentration ◽  
Carboxylation Pathway ◽  
Compensation Concentration

The carbon dioxide compensation concentration of members of the Gramineae and a few other plants was determined with an infrared CO2 analyzer. These results were then considered in relation to the new photosynthetic carboxylation pathway proposed by Hatch et al., rates of photosynthesis, grass systematics, leaf anatomy, and distribution of starch in the leaf. Plants possessing the new carboxylation pathway had low compensation values whereas those having the Calvin carboxylation reaction had high values. Low compensation plants also had a well-developed parenchyma bundle sheath containing a high concentration of chloroplasts which accumulated large amounts of starch. Little or no starch was present in the mesophyll cells. Cyperus was exceptional in that it also formed appreciable starch in the mesophyll. Those low compensation members of the Gramineae tested belonged either to the chloridoid–eragrostoid or the panicoid lines of evolution. A literature survey indicated that low compensation grasses have photosynthetic rates that are about double those of plants with photorespiration correlated with a temperature optimum for photosynthesis of about 35 °C. Those plants with photorespiration have optima within the range 10–25 °C. Some simple assay procedures proposed on the basis of the above correlations allow rapid determination of the physiological and biochemical status of plants with respect to photosynthesis.

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