• Title/Summary/Keyword: carbohydrate translocation

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Characteristics of phloem translocation of photoassimilates and herbicides (광합성산물과 제초제의 체관이행 기작)

  • Kim, Song-Mun;Hur, Jang-Hyun;Han, Dae-Sung
    • The Korean Journal of Pesticide Science
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    • v.2 no.1
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    • pp.1-11
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    • 1998
  • The generally accepted idea for carbohydrate translocation in plants is an osmotic pressure flow hypothesis. According to the hypothesis, a high concentration of carbohydrate in the phloem of carbohydrate synthesis regions (source) causes a water influx into the phloem. The generated osmotic potential in the phloem is responsible for long distance carbohydrate transport through the positive hydrostatic pressure. In regions of carbohydrate utilization and storage (sink), translocated carbohydrates are continuously metabolized and compartmentalized, generating a concentration gradient between source and sinks. In this system, carbohydrates load into the phloem (phloem loading) and unload out of the phloem (phloem unloading). Phloem-mobile herbicides that are applied to plants are also translocated from the source to sinks. However, some experimental results reveal that the patterns of phloem translocation between carbohydrates and herbicides are different. The differences are due, in part, to the physico-chemical properties of herbicides and to the absence/presence of specific carrier(s) in the phloem.

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Non-classical role of Galectin-3 in cancer progression: translocation to nucleus by carbohydrate-recognition independent manner

  • Kim, Seok-Jun;Chun, Kyung-Hee
    • BMB Reports
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    • v.53 no.4
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    • pp.173-180
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    • 2020
  • Galectin-3 is a carbohydrate-binding protein and regulates diverse functions, including cell proliferation and differentiation, mRNA splicing, apoptosis induction, immune surveillance and inflammation, cell adhesion, angiogenesis, and cancer-cell metastasis. Galectin-3 is also recommended as a diagnostic or prognostic biomarker of various diseases, including heart disease, kidney disease, and cancer. Galectin-3 exists as a cytosol, is secreted in extracellular spaces on cells, and is also detected in nuclei. It has been found that galectin-3 has different functions in cellular localization: (i) Extracellular galectin-3 mediates cell attachment and detachment. (ii) cytosolic galectin-3 regulates cell survival by blocking the intrinsic apoptotic pathway, and (iii) nuclear galectin-3 supports the ability of the transcriptional factor for target gene expression. In this review, we focused on the role of galectin-3 on translocation from cytosol to nucleus, because it happens in a way independent of carbohydrate recognition and accelerates cancer progression. We also suggested here that intracellular galecin-3 could be a potent therapeutic target in cancer therapy.

Effect of Suboptimal Nutritional Status on Mineral Uptake and Carbohydrate Metabolism in Tomato Plants

  • Sung, Jwakyung;Lee, Sangmin;Lee, Suyeon;Kim, Rogyoung;Lee, Yejin;Yun, Hongbae;Ha, Sangkeun;Song, Beomheon
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.5
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    • pp.351-358
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    • 2013
  • A suitable supply of mineral elements into shoot via a root system from growth media makes plants favorable growth and yield. The shortage or surplus of minerals directly affects overall physiological reactions to plants and, especially, strongly influences carbohydrate metabolism as a primary response. We have studied mineral uptake and synthesis and translocation of soluble carbohydrates in N, P or K-deficient tomato plants, and examined the interaction between soluble carbohydrates and mineral elements. Four-weeks-old tomato plants were grown in a hydroponic growth container adjusted with suboptimal N ($0.5mmol\;L^{-1}\;Ca(NO_3)2{\cdot}4H_2O$ and $0.5mmol\;L^{-1}\;KNO_3$), P ($0.05mmol\;L^{-1}\;KH_2PO_4$), and K ($0.5mmol\;L^{-1}\;KNO_3$) for 30 days. The deficiency of specific mineral element led to a significant decrease in its concentration and affected the concentration of other elements with increasing treatment period. The appearance of the reduction, however, differed slightly between elements. The ratios of N uptake of each treatment to that in NPK sufficient tomato shoots were 4 (N deficient), 50 (P deficient), and 50% (K deficient). The P uptake ratios were 21 (N deficient), 19 (P deficient), and 28% (K deficient) and K uptake ratios were 11 (N deficient), 46 (P deficient), and 7% (K deficient). The deficiency of mineral elements also influenced on carbohydrate metabolism; soluble sugar and starch was substantially enhanced, especially in N or K deficiency. In conclusion, mineral deficiency leads to an adverse carbohydrate metabolism such as immoderate accumulation and restricted translocation as well as reduced mineral uptake and thus results in the reduced plant growth.

Apoplastic Phloem Loading of Photoassimilate (광합성산물의 아포플라스트 체관부적재 기작)

  • Kim, Song-Mun;Hur, Jang-Hyun;Han, Dae-Sung
    • Korean Journal of Weed Science
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    • v.17 no.4
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    • pp.345-361
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    • 1997
  • Photoassimilates translocate from regions of carbohydrate synthensis(source) to regions of carbohydrate utilization or storage(sink). In the source, assimilate loads into the phloem for long-distance transport. Current evidence suggests that there are twig loading mechanisms : one involves assimilate transfer via the apoplasm and then load into the phloem by carrier-mediated proton-sucrose cotransport, while the other involves movement through the continuous symplastic connections between the mesophyll cells and the phloem. Inspite of problems associated with the interpretation of experiments, the evidence for apoplastic loading remains convincing because the apoplastic loading systems explains well the observed accumulation capacity arid the selectivity of assimilate uptake by tile phloem.

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Nitrate Metabolism Affected by Osmotic Stress and Nitrate Supply Level in Relation to Osmoregulation

  • Kim, Tae-Hwan
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.20 no.2
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    • pp.77-84
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    • 2000
  • Eight-week old perennial ryegrass (Lolium perenne L. cv. Reveille) plants were exposed to different NO3-concentrations or osmotic stress with NaCI. Previously labeled "N was chased during 14 days of non-labeled'NO3 feeding in order to investigate NO3 metabolism in relation to osmoregulation. The short termmeasurement of osmotic potential showed that the extemal concentration of Nos- had not great effect on theosmotic potential, but that osmotic adjustment was observed in NaCl-treated plants. Total uptake of NO 3 - waslargely increased by increasing supply level of NO3 while it was depressed by exposing to osmotic stress.Nitrate reduction increased to more than 29% by increasing extemal NO,- concentration from 1 mM to 10mM. When osmotically stressed with NaCI, nitrate reduction was depressed to about 37% as compared to thecontrol. The decrease in translocation of reduced N into leaves was also observed in NaCl exposed plants. Inthe medium exposed to 10 mM NO,., osmotic contribution of nitrate to cumulative osmotic potential wasdecreased, and it was osmotically compensated with soluble carbohydrate. When osmotically stressed withNaC1, the contribution of chloride was much higher than that of nitrate. The present data indicate that N03-in plant tissues, factually affected by the assimilation of this ion, plays an active role in osmotic regulation incorrelation with other osmotica such carbohydrate and chloride.(Key words : Nitrate metabolism, Osmotic stress, Nitrate supply level, Osmoregulation)ate supply level, Osmoregulation)

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Effect of high temperature on mineral uptake, Soluble carbohydrates partitioning and cucumber yield

  • Sung, Jwakyung;Lee, Suyeon;Lee, Yejin;Ha, Sangkeun;Sonn, Yeonkyu
    • Korean Journal of Agricultural Science
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    • v.41 no.4
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    • pp.291-298
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    • 2014
  • Plastic film houses are directly associated with increases in plant growth and yield of vegetable crops through a year round cultivation, however, at the same time temperature stresses are one of fates which are difficult to avoid during crop growth. The objective of this study was to examine the translocation and distribution of minerals (N, P, K) and carbohydrates as well as seasonal fluctuation of mineral uptake and carbohydrate production in cucumber plant grown under moderately high temperature. The temperature treatments consisted of 2-layers film houses (optimal temp.) and 3-layers (high temp.). Shoot growth of cucumber plants were linearly increased until 14 weeks after transplanting (WAT) without any significant difference between both temperatures, and the slowdown was observed from 16 WAT. The level of soluble sugar and starch was slightly greater in optimal temperature compared to the high. Cumulative accumulation of soluble sugar was significantly different before and after 12 WAT in both treatments, whereas starch level represented a constant increase. Monthly production of soluble sugar reached the peak between 12 to 16 WAT, and starch peaked between 4 to 8 WAT and 12 to 16 WAT. Total uptake of N, P and K in optimal and high temperature conditions was $18.4g\;plant^{-1}$ and 17.6 for N, 4.7 and 5.1 for P, and 37.7 and 36.2 for K, respectively, and the pattern of monthly N uptake between optimal and high temperatures was greater in early growth stage, whereas was greater in mid growth stage in both P and K. Thus, this study suggests that moderately high temperature influences much greater to photosynthesis and carbohydrate production than plant biomass and mineral uptake. On the basis of the present result, it is required to indentify analysis of respiration rates from plant and soil by constantly increasing temperature conditions and field studies where elevated temperatures are monitored and manipulated.

Varietal Difference in Protein, Carbohydrate, P,K,Ca and Mg Content of Naked Barley (과맥품종별 단백질(蛋白質) 탄수화물(炭水化物) 및 P.K.Ca 및 Mg 함량(含量))

  • Park, Hoon
    • Applied Biological Chemistry
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    • v.19 no.1
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    • pp.31-35
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    • 1976
  • Fifteen naked barley cultivars including radiation breeding lines from three places were analized for crude protein, carbohydrates, P, K, Ca, Mg and tested protein by dye binding method and biuret method. Their content and simple correlation analyses among them were as follows. 1. Protein content was 7.67 for average (max. 10.3 in Baegdong, min. 6.0 in Bangju) that was lower than in milled barley and had significant (at p=0.01) correlation with dye binding capacity (r=0.769) and biuret absorbance (r=0.616). 2. Protein content also had significant correlation with $P_2O_5$(r=0.607, p=0.01) and with MgO(r=0.498, p=0.05). 3. There was great difference in protein content among radiation breeding lines(max. 8.40, min. 6.75%). 4. Naked barley appeared to be lower in carbohydrate content but higher in crude ash to compare with milled barley. 5. There was significant correlation(r=0.560, p=0.01) between Ca and K, indicating competition in uptake or translocation to grain. 6. Carbohydrate content showed the highest negative correlation with protein content but it was not significant. 7. The low protein variety (Bangju) showed higher yield than the high protein one (Baegdong) both with (16%) and without (48%) fertilizers.

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Changes of Organic Solutes and Antioxidative Enzyme Activity in Rice Seedling under Salt Stress

  • Park So-Hyeon;Sung Jwa-Kyung;Lee Su-Yeon;Lee Ju-Young;Jang Byoung-Choon;Song Beom-Heom;Kim Tae-Wan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.5
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    • pp.325-331
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    • 2005
  • Seedlings of two rice genotyopes, cvs. Ilpumbyeo and Gancheokbyeo, were exposed to 0, 50 and 100 mM NaCl in nutrient solution for nine days. Plants were collected at the interval of 3 days and organic and inorganic solutes in leaves and roots and antioxidative enzyme activity in leaves were determined. Under salinity, the accumulation of soluble sugars occurred considerably in the older leaves of stressed seedlings compared to younger leaves and roots. The endogenous Na+ contents markedly increased at higher NaCl concentration in leaves and roots of seedlings, though it was higher accumulated in roots. Salinity resulted in an excessive proline accumulation in the stressed plants. A more pronounced increase was observed in Gancheokbyeo leaves. SOD activity in Impumbyeo cannot found any remarkable change, whereas, in Gancheokbyeo, its activity was rapidly decreased. CAT and POD activities increased with an increase in NaCl concentration in both genotypes. In sum­mary, the high capacity of rice seedlings to overcome an unfavorable growth condition such salt stress appears to be related to an adequate partition of organic solutes between shoots and roots and to changes in absorption, transport and re-translocation of salts.

Sugar and starch in leaf-sheaths and internode of Jinheung and IR667 rice under various ripening environments (진흥(振興)과 IR 667의 엽초(葉鞘) 및 절간(節間)의 당(糖) 및 전분함량(澱粉含量)과 등숙환경(登熟環境))

  • Park, Hoon;Kwon, Hang Gwang;Mok, Sung Kyun
    • Korean Journal of Soil Science and Fertilizer
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    • v.7 no.2
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    • pp.99-105
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    • 1974
  • According to the content of sugar and starch of each positional leaf sheath and internode at heading and 4 weeks after it using IR667-Suwon 214 (high yielding var. having tropical Indica parantage) and Jinheung (local leading var. temperate Japonica) rice grown in various cultivation seasons the suitability of grouping into the high sugar type (sugar>starch), sugar, tendency (increasing tendency in sugar content), high starh type (starch>sugar) and starch tendency (increasing tendency in starch) in carbohydrate metabolism was reexamined as follows. 1. Sugar tendency appeared strongly in IR667 than Jinheung, internode than leaf sheath, late season cultivation than early season, 4 weeks after than heading and high temperature than low temperature. Thus at heading, leaf sheath and internode of Jinheung in early and late season cultivation were high starch type, and lower internode in early season cultiattion and leaf sheath and internode in late season for IR667 were high sugar type. In very late season all internodes of both varieties except 1st internode of Jinheung at heading were high starch type. At four week after heading all leaf sheaths except 1st and 4th one of Jinheung and all internodes were high sugar type. High sugar type was intensified 4 weeks after heading in leaf sheaths than in internodes of IR667 in early season and of both varieties in late season. 2. The upper three leaf sheaths and internodes seem to work in the same way for carbohydrate translocation. Among them upper ones showed sugar tendency at heading and starch tendency 4 weeks after heading and it was clear in Jinheung. 3. The later the cultivation season, the higher the carbohydrate content (sugar+starch), and such tendency was clear 4 weeks after heading and in IR667, suggesting teanslocation inhibition by low temperature. 4. Grain filling rate (weight increase per day) was more rapid in early season cultivation and IR667 took shorter days to reach maximum rate. 5. The later the cultivation season, the greater the percent contribution of carbohydrate before heading to yield and it was always greater in IR667, a leaf sheath type. 6. Sugar and starch ratio appears to be determined principally by metabolic characteristics of variety according to growth process and secondly but considerably by environmental factors.

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Effect of Leaf Blade-cutting on Ripening of Rice (수도(水滔)에 있어 전엽(剪葉)이 등숙(登熟)에 미치는 영향(影響)(예보(豫報)))

  • Park, J.K.;Kim, Y.S.;Lee, J.K.
    • Korean Journal of Soil Science and Fertilizer
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    • v.1 no.1
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    • pp.125-128
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    • 1968
  • The effect of number of leaf after heading time on the growth of residual part and translocation of carbohydrates were investigated with water culture condition. Mutual shading and root rot were prevented. The results may be summerized as follows; 1. The ratio of ripened grain in the plot of no-leaf, flag leaf, two-leaf(flag and 2nd leaf) and three-leaf (flag, 2nd and 3rd leaf) was 38.8, 74.7, 83.9 and 87.0% respectively. The thousand grain weight was 21.3g, as the lowest value in no-leaf plot and was 28.7g in all other plots. 2. The accumulation of carbohydrate translocated in culm was increased by increment of leave-cutting, whereas the weight of culm was decreased. 3. It was suggested that healthy flag and 2nd leaf can keep the ratio of ripened grain around 80 percent.

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