Mesophyll Architecture and Cell Exposure to Intercellular Air Space in Alpine, Desert, and Forest Species

2002 ◽  
Vol 163 (6) ◽  
pp. 937-948 ◽  
Author(s):  
Michèle R. Slaton ◽  
William K. Smith
Keyword(s):  
Forest Species ◽  
Air Space ◽  
Intercellular Air Space

scholarly journals LEAF ANATOMY OF MICROPROPAGATED GRAPE AFFECTED BY REDUCED WATER POTENTIAL

HortScience ◽  
1991 ◽  
Vol 26 (6) ◽  
pp. 725C-725 ◽  
Author(s):  
Imed Dami ◽  
Harrison Hughes
Keyword(s):  
Leaf Anatomy ◽  
Pore Space ◽  
Small Cells ◽  
Layer Formation ◽  
Palisade Layer ◽  
Normal Leaf ◽  
Air Space ◽  
Reduced Water ◽  
Intercellular Air Space

Grape cv. Valiant was micropropagated in an MS medium with and without 2% (W/V) of polyethylene glycol (PEG, MW 8000). Leaf anatomy of control (in vitro, no PEG), treated (in vitro, PEG), field grown and greenhouse grown plants were compared under light microscopy. Cell size, palisade layer formation, relative intercellular air space and apparent chloroplast number varied between the leaves of control and PEG treated (high osmoticum) plantlets. These leaf characteristics in the high osmoticum medium appeared more similar to the leaves of the greenhouse and field grown plants. Leaves from control plantlets contained cells of larger size, lacked normal palisade layer formation, greater intercellular pore spaces and fewer chloroplasts. Leaves of PEG treated plantlets had smaller cells, a more defined palisade layer, reduced intercellular pore spaces and greater number of chloroplasts. Leaves of greenhouse and field grown plants had small cells, a well-defined palisade layer, least intercellular pore space and greatest number of chloroplasts. These results demonstrate that a high osmoticum medium may be used to induce more normal leaf development.

Leaf mass per area predicts palisade structural properties linked to mesophyll conductance in balsam poplar (Populus balsamifera L.)

Botany ◽  
2016 ◽  
Vol 94 (3) ◽  
pp. 225-239 ◽  
Author(s):  
Estefania A. Milla-Moreno ◽  
Athena D. McKown ◽  
Robert D. Guy ◽  
Raju Y. Soolanayakanahally
Keyword(s):  
Structural Features ◽  
Leaf Mass Per Area ◽  
Mesophyll Conductance ◽  
Populus Balsamifera ◽  
Balsam Poplar ◽  
Leaf Mass ◽  
Leaf Physiology ◽  
Air Space ◽  
Pathway Length ◽  
Intercellular Air Space

Modifications to leaf structural components that drive variation in leaf mass per area (LMA) may substantially impact leaf physiology by changing how easily CO2 diffuses through intercellular air space to carboxylation sites in mesophyll tissues. Mesophyll conductance (gm) is inversely proportional to the total pathway length for CO2, including the structural resistances encountered. In balsam poplar (Populus balsamifera L.), gm increases with latitude, paralleled by an increase in LMA. We investigated a family of P. balsamifera (K4×C) with high variation in LMA for different characteristics (tissues, nitrogen content, ultrastructural attributes). We interpreted trait variability using a developmental scale quantified by the leaf plastochron index (LPI). Developmental age significantly affected LMA, but those effects were lost at LPI ≥ 6. We outlined contributions of anatomical components to LMA and found palisade mesophyll properties were the primary drivers of variation in LMA within mature leaves (LPI ≥ 6). Using anatomical data, we derived components corresponding to structural resistances for gm. Perimeters of palisade cells and surface area of palisade exposed to intercellular air space, which may strongly influence CO2 diffusion, were correlated to LMA. Variation in LMA is positively related to differences in structural features expected to increase the conductance to CO2 diffusion within palisade mesophyll.

Deactivation of aquaporins decreases internal conductance to CO2 diffusion in tobacco leaves grown under long-term drought

2008 ◽  
Vol 35 (7) ◽  
pp. 553 ◽  
Author(s):  
Shin-Ichi Miyazawa ◽  
Satomi Yoshimura ◽  
Yuki Shinzaki ◽  
Masayoshi Maeshima ◽  
Chikahiro Miyake
Keyword(s):  
Water Permeability ◽  
Abaxial Epidermis ◽  
Tobacco Leaves ◽  
Surface Areas ◽  
Co2 Diffusion ◽  
Internal Conductance ◽  
Air Space ◽  
Leaf Tissues ◽  
Intercellular Air Space

We compared the diffusion conductance to CO2 from the intercellular air space to the chloroplasts (internal conductance (g i)) between tobacco leaves acclimated to long-term drought (drought-acclimated (DA)) and those grown under sufficient irrigation (well-watered (WW)), and analysed the changes in g i in relation to the leaf anatomical characteristics and a possible CO2 transporter, aquaporin. The g i, which was estimated by combined analyses of CO2 gas exchange with chlorophyll fluorescence, in the DA plants was approximately half of that in the WW plants. The mesophyll and chloroplast surface areas exposing the intercellular air space, which potentially affect g i, were not significantly different between the WW and DA plants. The amounts of plasma membrane aquaporins (PIP), immunochemically determined using radish PIP antibodies, were unrelated to g i. After treatment with HgCl2, an aquaporin inhibitor, the water permeability of the leaf tissues (measured as the weight loss of fully-turgid leaf disks without the abaxial epidermis in 1 m sorbitol) in WW plants decreased with an increase in HgCl2 concentration. The g i in the WW plants decreased to similar levels to the DA plants when the detached leaflets were fed with 0.5 mm HgCl2. In contrast, both water permeability and g i were insensitive to HgCl2 treatments in DA plants. These results suggest that deactivation of aquaporins is responsible for the significant reduction in g i observed in plants growing under long-term drought.

scholarly journals Firmness Decline in `Gala' Apple during Fruit Development

2003 ◽  
Vol 128 (6) ◽  
pp. 797-802 ◽  
Author(s):  
Richard K. Volz ◽  
F. Roger Harker ◽  
Sandy Lang
Keyword(s):  
Packing Density ◽  
Fruit Development ◽  
Developmental Changes ◽  
Cortical Tissue ◽  
Full Bloom ◽  
Malus Sylvestris ◽  
Air Space ◽  
Puncture Force ◽  
Intercellular Air Space ◽  
Space Cell

Puncture force was measured in `Gala'apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] fruit from 16 to 175 days after full bloom over 2 years using a range of circular flat-tipped probes (1 to 11 mm diameter) to test the firmness of each fruit. The area-dependent (Ka) and perimeter-dependent (Kp) coefficients of puncture force were determined and were used to calculate the indicative puncture force approximating a standard 11.1-mm-diameter Effegi/Magness-Taylor probe for even the smallest fruit. Ka declined exponentially throughout fruit development with much greater changes occurring closer to bloom. In contrast, maximum Kp occurred at 107 to 119 days after full bloom before declining progressively. Estimated firmness (using a 11.1-mm-diameter probe) declined constantly from 16 days after full bloom. Ka was associated with developmental changes in cortical tissue intercellular air space, cell volume and cell packing density although relationships changed throughout fruit growth. However seasonal change in Kp was not associated with any obvious anatomical change in the cortex.

Quantitative Microscopic Comparison of the Organization of the Lung in Transgenic Mice Expressing Transforming Growth Factor-α (TGF-α)

1996 ◽  
Vol 54 ◽  
pp. 14-15
Author(s):  
C. G. Plopper ◽  
C. Helton ◽  
A. J. Weir ◽  
J. A. Whitsett ◽  
T. R. Korfhagen
Keyword(s):  
Growth Factor ◽  
Pulmonary Fibrosis ◽  
Transgenic Mice ◽  
Blood Vessels ◽  
Lung Parenchyma ◽  
Lung Maturation ◽  
Alveolar Air ◽  
Parenchymal Tissue ◽  
Air Space ◽  
Conducting Airways

A wide variety of growth factors are thought to be involved in the regulation of pre- and postnatal lung maturation, including factors which bind to the epidermal growth factor receptor. Marked pulmonary fibrosis and enlarged alveolar air spaces have been observed in lungs of transgenic mice expressing human TGF-α under control of the 3.7 KB human SP-C promoter. To test whether TGF-α alters lung morphogenesis and cellular differentiation, we examined morphometrically the lungs of adult (6-10 months) mice derived from line 28, which expresses the highest level of human TGF-α transcripts among transgenic lines. Total volume of lungs (LV) fixed by airway infusion at standard pressure was similar in transgenics and aged-matched non-transgenic mice (Fig. 1). Intrapulmonary bronchi and bronchioles made up a smaller percentage of LV in transgenics than in non-transgenics (Fig. 2). Pulmonary arteries and pulmonary veins were a smaller percentage of LV in transgenic mice than in non-transgenics (Fig. 3). Lung parenchyma (lung tissue free of large vessels and conducting airways) occupied a larger percentage of LV in transgenics than in non-transgenics (Fig. 4). The number of generations of branching in conducting airways was significantly reduced in transgenics as compared to non-transgenic mice. Alveolar air space size, as measured by mean linear intercept, was almost twice as large in transgenic mice as in non-transgenics, especially when different zones within the lung were compared (Fig. 5). Alveolar air space occupied a larger percentage of the lung parenchyma in transgenic mice than in non-transgenic mice (Fig. 6). Collagen abundance was estimated in histological sections as picro-Sirius red positive material by previously-published methods. In intrapulmonary conducting airways, collagen was 4.8% of the wall in transgenics and 4.5% of the wall in non-transgenic mice. Since airways represented a smaller percentage of the lung in transgenics, the volume of interstitial collagen associated with airway wall was significantly less. In intrapulmonary blood vessels, collagen was 8.9% of the wall in transgenics and 0.7% of the wall in non-transgenics. Since blood vessels were a smaller percentage of the lungs in transgenics, the volume of collagen associated with the walls of blood vessels was five times greater. In the lung parenchyma, collagen was 51.5% of the tissue volume in transgenics and 21.2% in non-transgenics. Since parenchyma was a larger percentage of lung volume in transgenics, but the parenchymal tissue was a smaller percent of the volume, the volume of collagen associated with parenchymal tissue was only slightly greater. We conclude that overexpression of TGF-α during lung maturation alters many aspects of lung development, including branching morphogenesis of the airways and vessels and alveolarization in the parenchyma. Further, the increases in visible collagen previously associated with pulmonary fibrosis due to the overexpression of TGF-α are a result of actual increases in amounts of collagen and in a redistribution of collagen within compartments which results from morphogenetic changes. These morphogenetic changes vary by lung compartment. Supported by HL20748, ES06700 and the Cystic Fibrosis Foundation.

Reenacting Migration, Past and Present

Transfers ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 127-130
Author(s):  
Mariana C. Françozo
Keyword(s):  
Maritime History ◽  
Christopher Columbus ◽  
Exhibition Space ◽  
European Capital Of Culture ◽  
Air Space ◽  
History Of ◽  
The City

Located at the old harbor of the city of Genoa, the modern Galata Museo del Mare was inaugurated as part of the commemoration of Genoa as the 2004 European Capital of Culture. Only twelve years later, the museum proudly welcomes 200,000 visitors annually into its twenty-eight galleries, organized in an impressive exhibition space of 10,000 square meters, showcasing 4,300 objects. While the aim of the museum is to tell the maritime history of Genoa—ranging from Christopher Columbus to an open-air space showcasing the story of the Genoese shipyard—it is the exhibition on migration to and from Italy that will truly impress the visitor.

Steigende Bestandszahlen bei Spechten und anderen Vogelarten dank Zunahme von Totholz? | An increase in the population of woodpeckers and other bird species thanks to an increase in the quantities of deadwood?

2009 ◽  
Vol 160 (11) ◽  
pp. 334-340 ◽  
Author(s):  
Pierre Mollet ◽  
Niklaus Zbinden ◽  
Hans Schmid
Keyword(s):  
Forest Inventory ◽  
Bird Species ◽  
National Forest Inventory ◽  
Population Increase ◽  
National Forest ◽  
Forest Species ◽  
Breeding Populations ◽  
Willow Tit ◽  
Middle Spotted Woodpecker ◽  
Important Habitat

Results from the monitoring programs of the Swiss Ornithological Institute show that the breeding populations of several forest species for which deadwood is an important habitat element (black woodpecker, great spotted woodpecker, middle spotted woodpecker, lesser spotted woodpecker, green woodpecker, three-toed woodpecker as well as crested tit, willow tit and Eurasian tree creeper) have increased in the period 1990 to 2008, although not to the same extent in all species. At the same time the white-backed woodpecker extended its range in eastern Switzerland. The Swiss National Forest Inventory shows an increase in the amount of deadwood in forests for the same period. For all the mentioned species, with the exception of green and middle spotted woodpecker, the growing availability of deadwood is likely to be the most important factor explaining this population increase.

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