• Title/Summary/Keyword: Leaf epidermis

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The Possible Participation of the Mesophyll on Stomatal Opening

  • Lee, Joon-Sang
    • Korean Journal of Environmental Biology
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    • v.19 no.1
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    • pp.1-6
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    • 2001
  • Many researchers have been studied with guard cell protoplasts and detached epidermis as they think that properly stabilized protoplasts and detached epidermis retain many of the properties of intact guard cells. However, some studies have shown that stomata in detached epidermis behave differently, both quantitatively and qualitatively, from those in the intact leaf. Stomata in the intact leaf are very sensitive to environmental factors such as light, $CO_2$ and osmotic stress, but stomata in detached epidermis are less sensitive to these factors than those in the intact leaf. The clearest evidence to suggest the different response between detached epidermis and intact leaf obtained from the experiments with heavy metal, cadmium. 3-weeks old Commelina. communis was transferred to and grown in Hoagland solution in the presence or absence of 5 mM $Cd^{2+}$ for 4 days. The application of $Cd^{2+}$ showed about 70% inhibition of stomatal conductance when measured at various light intensity (100-1,000 $\mu$mole $m^{-2}s^{-1}). However, stomata in detached epidermis floated on an incubation medium containing 100 $\mu$M $Cd^{2+}$ opened to a degree of about 8.38 fm, but the stomata treated with no cadmium opened to 3.74 ${\mu}{\textrm}{m}$. These results were unexpected as the intact leaf grown in a Hoagland solution containing cadmium showed very negative physiological responses. These results showed that stomata in detached epidermis and in the intact leaf could respond reversely. Therefore, it is possible that we now misunderstand how stomata open in real natural condition.

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The Relationship Between Stomatal Opening and Photosynthetic Activity of the Mesophyll in Commelina Communis L.

  • Lee, Joon-Sang
    • Journal of Environmental Science International
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    • v.15 no.12
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    • pp.1109-1117
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    • 2006
  • To investigate the influence of the mesophyll cells on stomatal opening in response to white light, the segments of isolated epidermis were transferred on partly exposed mesophyll cells of a leaf and stomatal apertures were measured. Transferring the isolated epidermis on partly exposed mesophyll cells of a leaf caused a marked increase on stomatal apertures while stomata in isolated epidermis incubated in MES buffer hardly opened. Mesophyll infiltration with photosynthetic inhibitors (DCMU, DCCD, $NaN_3$) was performed to elucidate the correlation between stomatal apertures and the degree of photosynthetic activity. It was found that transferring the isolated epidermis on partly exposed mesophyll cells of a leaf caused an increase of stomatal apertures depending on the degree of photosynthetic activities. In $NaN_3$ infiltrated leaf discs, transferring the fresh isolated epidermis on partly exposed mesophyll cells of a leaf showed no significant effect, but a slight increase on stomatal apertures. Isolated epidermis alone did not respond to the light properly, but if it was closely contacted with mesophyil cells, the stomata regained the ability of the light response. Therefore, it could be suggested that stomatai apertures were related with the degree of photosynthetic activity in the mesophyll cells.

Effect of of Predisposing Temperatures on The Histopathology of The Rice Blast Fungus, pyricularia oryzae ill. Relationship Between Hyphal Growth in The Sheath and Percent Penetration in The Leaf Epidermis (접종전 온도처리가 벼 도열병균의 조직병리학에 미치는 영향 III. 엽초의 균사신전도와 잎의 침입율과의 관계)

  • KIM Chang Kyu;CRILL PAT
    • Korean journal of applied entomology
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    • v.19 no.4 s.45
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    • pp.234-238
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    • 1980
  • The relationships between the mean degree of hyphal growth in the leaf sheath and percent penetration in the leaf epidermis within the same predisposing temperature regime were highly significant. A positive relationship was found between degree of hyphal growth in the leaf sheath and Percent Penetration in the leaf epidermis.

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The Effects of Light and $CO_2$ on the Changes of Electrical Potential Difference in Isolated Epidermis and Intact Leaves of Commeina communis L

  • Lee Joon-Sang
    • Korean Journal of Environmental Biology
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    • v.23 no.3 s.59
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    • pp.221-227
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    • 2005
  • The effects of light and $CO_2$ on the electrophysiological characteristics of guard cells in the intact leaf and isolated epidermis have been investigated. Fast hyperpolarization of guard cell apoplastic PD in the intact leaf was recorded reaching up to around 7 mV and 20 mV in response to light and $CO_2$. Whenever the experiments were attempted with isolated epidermis, there was no response to light and $CO_2$. In order to determine the influence of the mesophyll cells, the apoplastic PD of guard cells in isolated epidermis was measured in the presence of the mesophyll supernatant or the control medium. The apoplastic PD in isolated epidermis was hyperpolarized to -7mV, changing from -22mV to -29mV at 40 min. But, when isolated epidermis was incubated with the supernatant from mesophyll cells incubated in the light, the apoplastic PD in isolated epidermis was hyperpolarized to -19 mV, changing from -22 mV to -40.5 mV. $CO_2$ also caused a change of 0.1 to 0.3 pH unit in the intact leaf. However, this change was absent in isolated epidermis. A vibrating probe was used to detect the change in electrical currents at the surface of excised intact leaves and isolated epidermis. The reading of excised intact leaves in the dark was $0.5\muA\;cm^{-2},$ remaining steady until illuminated. Light increased the current on the surface of excised leaves to about $0.8\muA\;cm^{-2},$. However, light had no effect in the current on the surface of isolated epidermis. Apoplastic pH changes across the stomatal complex in response to light and dark were measured both in the intact leaves and isolated epidermis over the same time period using pH micro-electrodes. The guard cell wall of intact leaf was acidified to 2.5 pH unit, falling from pH 7.5 to pH 5.0 in the first 10 min. in the light. At the same time the guard cell wall pH of isolated epidermis fell from pH 7.5 to pH 7.0 at 10 min. The guard cell wall pH of isolated epidermis incubated in the mesophyll supernatant fell from pH 7.6 to pH 6.7 at 10 min. Likewise, It could be imagined that an electrical signal, chemicals and hormones propagated from the mesophyll in response to light and $CO_2$ could control a fast stomatal response.

Stomata Variation of Rice and Weeds (수도(水稻) 및 잡초(雜草)의 기공형태(氣孔形態)와 분포(分布))

  • Kim, S.C.;Lee, S.K.;Chung, G.S.
    • Korean Journal of Weed Science
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    • v.9 no.1
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    • pp.46-55
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    • 1989
  • Stomatal variation was observed at the Yeongnam Crop Experiment Station in 1988 using 42 rice cultivars and 30 weed species. The shape, density or size of stomata was varied depending on the species. Two general trends, however, were found that more number of stomata was found at lower leaf epidermis than upper leaf epidermis and stomata number was negatively correlated with stomata size. Aneilema japonica and Portulaca oleracea had the least number of stomata having 17-20 stomata per $m^2$ for upper leaf epidermis and 17-54 stomata for lower leaf epidermis while Polygonum conspicuum had the greatest number of stomata (449 for upper leaf epidermis and 511 for lower leaf epidermis). Soybean, Aeschynomene indica, Ludwigia prostrata and Lactuca indica had the smallest in stomata size while the biggest stomata was found at P. oleracea and A. Japonica that had the least number of stomata. Cyperus species such as C. difformis, C. iria and C. serotinus had no stomata at upper leaf epidermis. The stomata were distributed only at lower leaf epidermis for these species. Potamogeton distinctus, on the other hand, had stomata almost at upper leaf epidermis and thus, hardly found the stomata at lower leaf epidermis. Among rice cultivars, Tongil-type had the greatest number of stomata followed by Indica-type and Japonica-type, in order. Cultivars released after 1960 had more stomata than cultivars released before 1960 for Japonica-type cultivars while stomata size had reversed trend. Jinheung had the least number of stomata (${\fallingdotseq}$ 150 per $mm^2$) while Yushin had the greatest number of stomata (350 for upper and 449 for lower leaf epidermis, respectively) among rice cultivars. Other cultivars having more than 350 stomata per $mm^2$ were Samgangbyeo, Milyang 23, Woonbongbyeo, etc.

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A Study of Epidermal Patterns of the Leaf Blades on Korean Sedges, Eriophorum, Fuirena, Kobresia, Rhynchospora and Scirpus(6) (한국산 사초과 식물 잎의 표피형에 대하여(6))

  • 오용자
    • Journal of Plant Biology
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    • v.17 no.2
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    • pp.99-105
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    • 1974
  • Author has studied and reported on taxonomy of Korean sedges, using gross morphology, anatomy and epidermal patterns of the leaf blades(1969, 1971, 1973, 1974). This paper is the 6th report of epidermal patterns of leaf blade on sedges and includes 5 genera, Eriophorum, Fuirena, Kobresia, Rhynchospora and Scirpus. The author proposed to find epidermal patterns of leaf blades as an important taxonomic characteristic of sedges classification. The result of this study, the elements of leaf epidermis, subsidal cells, silica body, cell wall of long cell, prickles, and arrangement of the elements are considered to be significant characteristics for the identification and classification of sedge.

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Epidermal Features of the Nelumbo nucifera Tissues and Lotus Effect (연꽃식물 조직의 표피 특성과 연잎효과)

  • Kim, In-Sun
    • Applied Microscopy
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    • v.42 no.2
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    • pp.95-103
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    • 2012
  • The cell surface sculpture of the plant epidermis has received great interest recently. It has also been an active area of research, as the biological microstructures of the surface, such as papillae and waxes, exhibit several unique properties, including self-cleaning character; namely the "Lotus effect" first described in the leaves of the lotus, Nelumbo nucifera. The Lotus effect is the phenomenon in which the super-hydrophobic and water-repellent nature of lotus leaves allow water drops to run off easily on the surface in a rolling and sliding motion thereby facilitating the removal of dirt particles. It is well-known that surface roughness on the micro- and nanoscale is a primary characteristic allowing for the Lotus effect. This effect is common among plants and is of great technological importance, since it can be applied industrially in numerous fields. In the present study, Nelumbo nucifera leaf and stem epidermal surfaces have been examined with a focus on the features of papillae and wax crystalloids. Both young and mature Nelumbo nucifera leaf epidermis demonstrated the Lotus effect on their entire epidermal surface. The central area of the upper epidermis, in particular, formed extremely papillose surfaces, with an additional wax layer, enabling greater water repellency. Despite the presence of wax crystalloids, epidermal surfaces of the lower leaf and stem lacking papillae, were much more easily wetted.

Anatomical study of Atractylodes japonica Koidz. ex Kitam. and A. macrocephaza Koidz. (삽주(Atractylodes japonica Koidz. ex Kitam.)와 큰꽃삽주(A. macrocephala Koidz.)의 해부학적 연구)

  • 정규영;김미숙
    • Korean Journal of Plant Resources
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    • v.14 no.3
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    • pp.188-195
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    • 2001
  • The anatomical characteristics of rhizome, lateral root, stem, leaf, petiole, ovary and leaf epidermis about Atractylodes japonica Koidz. ex Kitam. and A. macrocephala Koidz. were investigated to estimate these taxonomic values. The cross sections of stem and ovary were very similar to two species, therefore these characters were not useful for delimitation of two species, but the size and distribution numbers per 100${\mu}{\textrm}{m}$$^2$of oil cavites in rhizome, the shape of leaf and petiole in cross section, the size of leaf epidermal cell and distribution numbers per 100 ${\mu}{\textrm}{m}$$^2$of stomata were differ from two species, therefore these were thought to be useful characters for delimitation of two species.

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Taxonomic Studies of Korean Tripterospermum japonicum (Max.) Max. and Pterygocalyx volubilis Max. (한국산 덩굴용담과 좁은잎덩굴용담의 분류학적 재검토)

  • 백원기
    • Korean Journal of Plant Resources
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    • v.16 no.1
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    • pp.61-73
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    • 2003
  • External and anatomical characters such as stem, leaf, ovary, calyx lobe, ultrastructure of stigma epidermis of leaf blade and midvein, corolla lobe, seed coat and pollen were examined on Pterygocalyx volubilis and Tripterospermum japonicum of Korean Gentianaceae. Fruit characters(capsule and berry), absent or not of corona and pollen characters(reticulate and striate) has been used by identification characters of two taxa. But study results, external characters(root, leaf, calyx lobe, stigma, anther), internal characters(calyx love, ovary) and ultrastructure characters(epidermis o leaf blade and midvein, corolla lobe, seed coat) were useful for species identification. Taxonomic relationships among problematic taxa were discussed.

Trichome Type and Development in Leaves of Althaea rosea (접시꽃 (Althaea rosea) 엽육표피에서의 모용의 분화 발달)

  • Kim, In-Sun;Lee, Seung-Hee
    • Applied Microscopy
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    • v.35 no.2
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    • pp.97-104
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    • 2005
  • Plant epidermis consists of relatively unspecialized cells and more specialized cells of various structure and function. Trichomes are specialized cells originated from the epidermis and much attention has been paid to the plants developing trichomes with peculiar structure and function. The present study has been undertaken to examine the trichome type noticed in the leaf epidermis of Althaea rosea using scanning electron microscopy. Four types, namely simple, short-and long-tufted, and glandular hairs, were detected in their epidermis. Their Distribution, frequency and structure varied by the development and epidermal surface. The most frequently distinguished type was the tufted ones growing in young leaves of the abaxial epidermis, while the simple hairs were rare throught the examination. The short-tufted hairs branched up to seven times having each branchlet about $160{\sim}210{\mu}m$ in length at maturity. The long-tufted hairs exhibited up to ten branchlets, where branchlets could reach up to $900{\sim}1,000{\mu}m$ long when fully expanded. Glandular trichome was the peltate type comprising $1{\sim}2$ secretory head cells, 2 stalk cells and a basal cell. The short peltate glandular hairs, usually not exceeding $40{\mu}m$, differentiated more along the areoles in the adaxial epidermis. The function of these trichomes in A. rosea has been still obscure, but it has been speculated that they probably play a role in protection; non-glandular ones possibly providing a defense against insects and secretory glandular type participating in chemical defense. Structural features of these trichomes at cellular level will be discussed in the following study of transmission electron microscopy.