• Title/Summary/Keyword: leaf sheath

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Structural Differentiation of Photosynthetic Tissue in Kranz Anatomy of Salsola Species (Salsola속 Kranz구조내 광합성조직의 구조분화)

  • Kim, In-Sun
    • Applied Microscopy
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    • v.31 no.4
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    • pp.367-374
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    • 2001
  • Leaves of two developmental stages of Salsola species, young and mature, were examined to reveal the structural and functional relationships in the photosynthetic tissue using anatomical and ultrastructural criteria. Both young and mature leaves had Kranz anatomy of the Salsolid type with two layers of chlorenchyma on the leaf periphery: an outer layer of palisade mesophyll cells and an inner layer of compact bundle sheath cells with centripetally arranged organelles. The chlorenchyma was continuous in young leaves , while it was discontinuous in mature leaves. The main vascular bundle occupied the central position in the leaf. but the small peripheral vascular bundles were in contact with the chlorenchyma. Structural dimorphism of chloroplasts was obvious in bundle sheath cells of mature leaves exhibiting noticeable grana reduction, whereas mesophyll cell chloroplasts had well developed grana in all cases. Plasmodesmata were less numerous and rather simple in young leaves relative to well-developed secondary plasmodesmata of the later stage. According to the current data, features of two stages of Salsola leaves corresponded to NADP-ME bio-chemical subtype on the basis of photosynthetic cell ultrastructure. Implications of developing such anatomical and ultrastructural data of Sulsola species and biochemical characteristics reported in other C-4 species have been discussed.

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Characterization and Transcriptional Expression of the α-Expansin Gene Family in Rice

  • Shin, Jun-Hye;Jeong, Dong-Hoon;Park, Min Chul;An, Gynheung
    • Molecules and Cells
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    • v.20 no.2
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    • pp.210-218
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    • 2005
  • The rice genome contains at least 28 EXPA (${\alpha}$-expansin) genes. We have obtained near full-length cDNAs from the previously uncharacterized genes. Analysis of these newly identified clones together with the 12 identified earlier showed that the EXPA genes contain up to two introns and encode proteins of 240 to 291 amino acid residues. The EXPA proteins contain three conserved motifs: eight cysteine residues at the N-terminus, four tryptophan residues at the C-terminus, and a histidine-phenylalanine-aspartate motif in the central region. EXPA proteins could be divided into six groups based on their sequence similarity. Most were strongly induced in two-day-old seedlings and in the roots of one-week-old plants. However, only 14 genes were expressed in the aboveground organs, and their patterns were quite diverse. Transcript levels of EXPA7, 14, 15, 18, 21, and 29 were greater in stems, while EXPA2, 4, 5, 6, and 16 were highly expressed in both stem and sheath but not in leaf blade. EXPA1 is leaf blade-preferential, and EXP9 is leaf sheath-preferential. Most of the root-expressed genes were more strongly expressed in the dividing zone. However, the Group 2 EXPA genes were also strongly expressed in both mature and dividing zones, while EXPA9 was preferentially expressed in the elongation zone. Fourteen EXPA genes were expressed in developing panicles, with some being expressed during most developmental stages, others only as the panicles matured. These diverse expression patterns of EXPA genes suggest that in general they have distinct roles in plant growth and development.

Studies on the Development of Branch Patterns and the Electronmicroscopic Structure of Photosynthetic organs in Zoysia japonica Steud. (한국잔디(Zoysia japonica Steud.)의 분지 발달양상과 광합성기관의 전자 현미경적 구조에 관한 연구)

  • 장남기;김형기;유준희;김용진;임채성
    • Asian Journal of Turfgrass Science
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    • v.1 no.1
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    • pp.42-48
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    • 1987
  • This study was carried out to elucidate the physiological and ecological mechamism of the branch pattern and electronmicroscopic structure of photosynthetic organs in Zoysia japonica Steud. The angles between the internodes of rhizome and the branches of Z.iaponica were changed from 0 to 52 degrees. The rhizomes tended to branch from the 3th node to the 10th node. When the terminal bud was damaged by various environmental factors, the initial branching formation was appeared immediately to the 4th node. The internode growth of the rhizome started from the beginning of April and continued to the end of Octobor. It became evident that there is a division labor between two different kinds of photosynthetic cells of mesophyll and bundle sheath tissues in Z.japonica The thick-walled bundle sheath cells surrounds the leaf vascular bundles as the Kranz type and separates them from the mesophyll cells.

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Assessment of the Nutritive Value of Whole Corn Stover and Its Morphological Fractions

  • Li, H.Y.;Xu, L.;Liu, W.J.;Fang, M.Q.;Wang, N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.2
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    • pp.194-200
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    • 2014
  • This study investigated the chemical composition and ruminal degradability of corn stover in three maize-planting regions in Qiqihaer, Heilongjiang Province, China. The whole stover was separated into seven morphological fractions, i.e., leaf blade, leaf sheath, stem rind, stem pith, stem node, ear husk, and corn tassel. The assessment of nutritive value of corn stover and its fractions was performed based on laboratory assays of the morphological proportions, chemical composition, and in situ degradability of dry matter (DM), neutral detergent fiber (NDF), and acid detergent fiber (ADF). The chemical composition of corn stover was significantly different from plant top to bottom (p<0.05). Among the whole corn stover and seven morphological fractions, leaf blade had the highest crude protein (CP) content and the lowest NDF and ADF contents (p<0.05), whereas stem rind had the lowest CP content and the highest ADF and acid detergent lignin (ADL) contents (p<0.05). Ear husk had significantly higher NDF content and relatively lower ADL content than other corn stover fractions. Overall, the effective degradability of DM, NDF, and ADF in rumen was the highest in leaf blade and stem pith, followed by ear husk. The results indicate that leaf blade, ear husk, and stem pith potentially have higher nutritive values than the other fractions of corn stover. This study provides reference data for high-efficiency use of corn stover in feeding ruminants.

Effect of Defoliation on Seed Development of Rye and Triticale Cultivar (전엽이 팔당호밀과 신기호밀의 종실발육에 미치는 영향)

  • 노창우;차영훈;김태수;권규칠;박연규
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.35 no.3
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    • pp.211-217
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    • 1990
  • This study was carried out to elucidate the effect of different time and severity of defoliation on the dry matter accumulation in grain of rye (cv, Paldanghomil) and triticale (cv, Sinkihomil). The weight of the 2nd leaf blade was the greatest and this was followed by the 3rd and flag leaf in that order. The chlorophyll content in leaf blade and sheath were decreased at lower leaf position (flag > 2nd > 3rd). The average chlorophyll content of rye was higher than that of triticale. The earlier and severer defoliation was made, the more grain weight was its was decreased. As the time of defoliation was made later and the degree of its was small, 1,000 grain weight was increased. The results showed that the effect of defoliation on 1,000 grain weight followed the order of the flag, the 2nd and the 3rd leaf. The greatest 1,000 grain weight was observed at the middle part of panicle, which followed by the top and bottom part in that order.

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Physiological and Ecological Response of Agronomic Characters Related to Source and Sink in Rice (벼의 Source와 Sink 관련형질의 생리생태적 반응)

  • 최수일
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.34 no.3
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    • pp.239-245
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    • 1989
  • This experiment was conducted to study the physiological and ecological responses of agronomic characters related to source and sink relation in rice. Standard deviation and coefficient of variability of agronomic characters by individual tiller were greatly influenced by the lower internodes in the length of internode, flag leaf in the leaf blade, lower leaf blade in the leaf width, and the number and spikelets of secondary rachis branch in panicle. In relation to the parts of source and sink of rice plant and the number of spikelet in panicle, the number of spikelet was significantly correlated with the length and leaf area of second leaf blade, the length of second internode, and culm diameter of third internode. The correlation of the length of panicle with the length of internode and leaf blade was greatly influenced by the length of second leaf blade and second internode. The number of spikelet was increased with increasing the second rachis branch rather than first rachis branch. The content of total inorganic nutrients was greatest at leaf blade followed by leaf sheath and internode, and panicle.

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Effect of Dust Mite Incidence on Grain Filling and Quality in Rice (벼먼지응애 발생이 등숙 및 미질에 미치는 영향)

  • Kim, Deog-Su;Lee, Moon-Hee;Im, Dae-Joon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.46 no.3
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    • pp.180-183
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    • 2001
  • This study was conducted to find out the effect of ripened grain and rice quality by the breeding of rice dust mite (Steneotarsonemus spinki). Growth temperature of sample (Suwon 441 and Ilpumbyeo) was maintained from 22$^{\circ}C$ (during night) to 26$^{\circ}C$ (during day) in a controlled phytotron. Plant hight and number of panicle could not showed the difference by the discoloration degree of leaf sheath. But number of spikelet was reduced affected by discoloration degree of leaf sheath. Ratio discoloration of grain was increased according to circumstances more discoloration degree of leaf sheath in Suwon 441 then Ilpumbyeo. The perfect rice grain was observed to similar Suwon 441 and Ilpumbyeo in the IV degree of ratio discoloration of grain, but less Suwon 441 than Ilpumbyeo in III and II, in such a case comparison between coloration and discoloration.

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The peduncle-specific expression during floral transition by high-throughput transcriptome analysis in wheat

  • Lee, Cheol Won;Seo, Yong Weo
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.87-87
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    • 2017
  • Flowering time of either early or late is one of the crucial parameters that determine the crop productivity. Therefore, elucidation of regulatory mechanisms of flowering time should contribute to breeding for yield enhancement. However, comprehensive explanation on molecular mechanism of flowering has not yet been reported in hexaploidy common wheat (Triticum asetivum L.). The mechanism of flowering in wheat has been studied mostly using flag leaf or floral meristem. The exposed peduncle, which is a shoot part between bottom of the spike and flag leaf, could be an important tissue that is responsible for flowering through various molecules expressing. To clarify for transcriptomic dynamics in the wheat peduncle that was uncovered by leaf sheath of flag leaf, RNA sequencing and transcriptomic analysis were conducted. With this, we also analyzed other transcriptomic results deposited in the public DB to identify genes specially expressed in peduncle tissue at transition from vegetative to reproductive phase. The obtained results will provide valuable information to understand the role of peduncle for flowing regulation in wheat aimming for elucidation of the regulatory mechanism of wheat flowering.

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Ultrastructure of the Epiphytic Sooty Mold Capnodium on Walnut Leaves

  • Kim, Ki Woo
    • 한국균학회소식:학술대회논문집
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    • 2015.11a
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    • pp.14-14
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    • 2015
  • Cellular aspects of sooty mold on walnut leaves were investigated by using light and electron microscopy. A black coating developed on the adaxial leaf surface of a walnut tree. No infestations were found on the abaxial leaf surface with peltate glandular trichomes. Light microscopy showed that fungal complexes from the leaf surface were composed of brown conidia and hyphae. Conidia, with longitudinal and transverse septa, were variable in length ranging from 10 to $30{\mu}m$, and commonly found in clusters, forming microsclerotia. Neither epidermal penetration nor hyphal entrance to host tissues was observed. Based on their morphological characteristics, the fungal complexes were assumed to be Capnodium species. An electron-dense melanized layer was present on the cell wall of multi-celled conidia. Concentric bodies in the fungal cytoplasm had an electron-translucent core surrounded by an electron-dense margin with a fibrillar sheath. Chloroplasts without starch granules in the palisade mesophyll cells of sooty leaves had electron-dense stromata and swollen plastoglobuli. These results suggest that the epiphytic growth of fungal complexes can be attributed to the melanized layer and concentric bodies against a water-deficient environment on the leaf surface. Ultrastructural characteristics of the sooty leaves indicate typical features of dark-adapted and non-photosynthetic shade leaves.

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Morphological Characteristics of Medium-Leaf Type Zoysiagrasses (Zoysia spp.) and Their Classification Using RAPDs (중엽형 한국잔디(Zoysia spp.)류의 형태적 특성과 RAPDs를 이용한 분류)

  • Choi, Joon-Soo
    • Asian Journal of Turfgrass Science
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    • v.24 no.2
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    • pp.88-96
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    • 2010
  • Zoysiagrass, especially Jungji implicating medium-leaf type zoysiagrass has been widely used in South Korea recently. This study was carried out to classify 36 selected medium-leaf type zoysiagrass accessions compared to 5 basic zoysiagrass species using RAPDs. Morphological characteristics such as leaf width, leaf angle, leaf sheath length, existance of trichomes and stolon color were measured as useful characteristics for identification of species in Zoysia genus. Nineteen RAPD markers were identified using 8 selected random primers. The dissimilarity coefficient of variants ranged from 0 to 0.736. Three zoysiagrass groups were clustered by dissimilarity coefficient analysis. Group 1 consisted of Z. japonica and some US varieties including 'Zenith' and 'Meyer'. Group 2 consisted of Z. sinica, Z. macrostachya and Korean commercial varieties such as 'Anyang', 'Samdeock', and 'Pyeongdong' medium-leaf type grasses. Group 3 was genetically distinct from Group 1 and Group 2, and included Z. matrella and Z. tenuifolia. 'Anyang', 'Samdeock', and 'Pyeongdong' medium-leaf type zoysiagrasses showed very close genetic relationship with Z. sinica and Z. macrostachya.