• Journal of Microbiology and Biotechnology
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• v.21 no.1
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• pp.55-61
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• 2011

Forty yeast strains isolated from soils taken from different locations in Egypt were tested for their P-solubilizing activities on the basis of analyzing the clear zone around colonies growing on a tricalcium phosphate medium after incubation for 5 days at $25^{\circ}C$, denoted as the solubilization index (SI). Nine isolates that exhibited P-solubilization potential with an SI ranging from 1.19 to 2.76 were genetically characterized as five yeasts belonging to the genus Saccharomyces cerevisiae and four non-Saccharomyces, based on a PCR analysis of the ITS1-26S region amplied by SC1/SC2 species-specific primers. The highest P-solubilization efficiency was demonstrated by isolate PSY- 4, which was identified as Saccharomyces cerevisiae by a sequence analysis of the variable D1/D2 domain of the 26S rDNA. The effects of single and mixed inoculations with yeast PSY-4 and Bacillus polymyxa on the P-uptake and growth of corn were tested in a greenhouse experiment using different levels of a phosphorus chemical fertilizer (50, 100, and 200 kg/ha super phosphate 15.5% $P_2O_5$). The results showed that inoculating the corn with yeast PSY-4 or B. polymyxa caused significant increases in the shoot and root dry weights and P-uptake in the shoots and roots. The P-fertilization level also had a significant influence on the shoot and root dry weights and P-uptake in the shoots and roots when increasing the P-level from 50 up to 200 kg/ha. Dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 200 kg/ha gave higher values for the shoot and root dry weights and P-uptake in the shoots and roots, yet these increases were nonsignificant when compared with dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 100 kg/ha. The best increases were obtained from dual inoculation with yeast strain PSY-4 and B. polymyxa at a P-fertilization level of 100 kg/ha, which induced the following percentage increases in the shoot and root dry weights, and P-uptake in the shoots and roots; 16.22%, 46.92%, 10.09%, and 31.07%, respectively, when compared with the uninoculated control (fertilized with 100 kg/ha).

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.65-72
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• 2013

This study was carried out to understand the long-term effects of organic waste treatments on the fate of heavy metals in soils originated from the organic wastes and consequent uptake of heavy metals by plant, together with examination of changes in soil properties and plant growth performance. In this study, the soils treated with three different organic wastes (municipal sewage sludge, alcohol fermentation processing sludge, pig manure compost) at three different rates (12.5, 25.0, 50.0 ton $ha^{-1}yr^{-1}$) for 7 years (1994 - 2000) were used. To see the long-term effect, plant growth study and soil examination were conducted twice in 2000 and 2010, respectively. There was no additional treatments of organic wastes for 10 years after the organic waste treatment for 7 years. Compared to plant growth examination conducted in 2000 using radish (Raphanus sativus cv. sodamaltari), it appeared that height, root length and diameter, fresh weight of radish grown in 2010 decreased in the plots treated with municipal sewage sludge and alcohol fermentation processing sludge and that the extent of decrease was higher with increase of sludge application rates. On the other hand, pig compost treatment increased plant height, root length and diameter, fresh weight with increasing application rates. Cu and Pb concentrations in radish root and leaves increased in 2010 compared to those in 2000 while Ni concentrations in root and leaves decreased. Zn concentration was increased only in the soils treated with pig manure compost. Multiple regression analysis among heavy metal species fractions in soils, soil pH, and metal concentrations in radish root and leaves indicated that the metal uptake by radish was governed mainly by the soil pH and subsequent increase of available heavy metal fractions in soils with organic waste treatments.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.12
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• pp.25-29
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• 1972

This experiment was carried out to investigate the role of Silicon accumlated in rice plant under different conditions of light and humidity, using radioisotopes Ca-45, Mn-54, and P-32. This results obtained in are as follows; 1. Light effect is more severe in phosphate uptake by rice plant than is calcium. Amounts of phosphate uptake in light condition is six times more than in dark conditions, while that of calcium is double. 2. Change of relative humidity affects calcium absorption and transport from root to shoot. It seems not to be influenced in phosphate and manganese uptake by relative humidity. 3. More uptake of each element Ca-45, P-32, or Mn-54 was found in the rice plant applied with silicic acid. It is considered that there must be some relationship between silicon content and ion uptake in rice plant. 4. The transport ratio of nutrient from root to shoot shows a specific pattern that calcium is approximately 1.0 manganese 0.5 and phosphate 0.2 respectively.

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.69-73
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• 2002

Lettuce (Lactuca sativa L.) plants were grown under hydroponic system to characterize the diurnal change of nitrate concentration and nitrate uptake rate and to examine the effect of short term cold treatment to rhizosphere on nitrate concentration and uptake rate in lettuce plant. The nitrate concentrations in midrib were two times higher than those in leaf. Nitrate concentration in the shoot reached to minimum (8.7 mg-N/GDW) at 14:00 and, thereafter, increased continuously until 23:00. During 11:00$\sim$17:00, nitrate uptake by lettuce plant was maximum (4.8 mg-N/GDW-Root/hr). Short term cold treatment reduced nitrate concentration in the shoot by 14$\sim$18%, and nitrate uptake rate by 50$\sim$55%, respectively. These results showed that short term cold treatment before harvest could be applied for the purpose of reduction of nitrate concentration in the leaf under hydroponic culture.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.16-25
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• 1992

A pot experiment was conducted to understand effect of soil temperaute on soybean shoot and root growth, and its relations to nutrient uptake including phosporus and potassium. Pregerminated soybean seedlings, Paldal cultivar, were planted for 43 days on the pots with Ihyeon silt loam and Samgag sandy loam in the temperature controled water baths at 17, 25 and $32^{\circ}C$. Shoot and root samples were taken at four times and analyzed. Shoot and root dry matter weights were heavier as higher soil temperaure. The root dry matter increased faster than shoot at earlier period. Shoot dry matter weights grown at 17 and $25^{\circ}C$ showed little difference between two soils, however, those grown in silt loam at $32^{\circ}C$ were heavier than sandy loam. The total lengths of roots were longer as higher soil temperature, and longer in silt loam than sandy loam. The roots grown in sandy loam at low temperature were thicker than the roots grown in silt loam at high temperature. The uptakes of phosphorus and potassium were higher as higher tempeature with same trend with dry matter. The uptake rate of unit root surface area was higher in sandy loam soil than silt loam. The uptake rates showed strong dependence on soil temperature as well as dependence of water uptake rate. Based on Dalton and Gardner model, at high temperature the dependence trend of phosphorus and potassium on soil temperature showed with active uptake model, while at low temperature the dependence showed without active uptake model.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.295-297
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• 2006

Potassium (K) distribution in rice (Oryza sativa L.) root was studied by confocal laser microscopy, using potassium sensitive fluorescent dye potassium-binding benzofuran isophthalate (PBFI). Significantly high intensity of K-specific fluorescence was detected at the root cap region followed by meristematic and basal regions. A negligible or fainted fluorescence was observed at the root hairs area. These results suggest that K is heavily distributed in the apical area of rice root, which may be required in higher concentration for division and extension of cells, as it is the rapidly growing region of the root, moreover, may also be involved in water uptake by creating osmotic gradient across membranes.

• Korean journal of food and cookery science
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• v.7 no.2
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• pp.25-40
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• 1991

Five-brown-rice-variety, Akibare, Odaebyeo, Taebaegbyeo, Nonglim Na 1 and Hankangchalbyeo, was prepared and examinated the hydration kinetics and the cooking qualities. Before the hydration the L/W ratio of raw Taebaegbyeo was the biggest value among the five brown rices. The water uptake was directly proportional to the square root of soaking time. During the hydration water uptake of high yielding brown rices was bigger than those of traditional brown rices among the nonglutenious varieties but waxy brown rices were not. Generally volume increase constant was directly proportional to the water uptake constant, which were different a little with brown rices was hydrated which was inversed proportional to the water uptake degree. According to the instrumental result using the rheometer of cooked brown rice with increased soaking times that was decreased the hardness and was increased the adhesiveness. The sensory evaluation test indicated that the hardness and the stickiness value of cooked brown rices were proper after 15-hour-soaking time and it was identical result to the instrumental result using the rheometer.

• Molecules and Cells
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• v.37 no.8
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• pp.575-584
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• 2014

Potassium is a macronutrient that is crucial for healthy plant growth. Potassium availability, however, is often limited in agricultural fields and thus crop yields and quality are reduced. Therefore, improving the efficiency of potassium uptake and transport, as well as its utilization, in plants is important for agricultural sustainability. This review summarizes the current knowledge on the molecular mechanisms involved in potassium uptake and transport in plants, and the molecular response of plants to different levels of potassium availability. Based on this information, four strategies for improving potassium use efficiency in plants are proposed; 1) increased root volume, 2) increasing efficiency of potassium uptake from the soil and translocation in planta, 3) increasing mobility of potassium in soil, and 4) molecular breeding new varieties with greater potassium efficiency through marker assisted selection which will require identification and utilization of potassium associated quantitative trait loci.

• Journal of the Korean Society of Visualization
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• v.8 no.4
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• pp.48-53
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• 2010

Water-uptake through roots, is an essential process of the water flow in plants. Its visualization is very useful for understanding sap flow dynamics at whole plant level. In this study, the tips of Arabidopsis' root hairs were excised and exposed to repeated dehydration and rehydration processes. The water-refilling through individual xylem vessels was visualized using the synchrotron X-ray micro-imaging technique. The high temporal resolution ($2\;{\mu}m$) and beam intensity of the X-ray source allowed to acquisition of consecutive X-ray images of the water-refilling process up to 10 frames/sec. Various flow patterns were observed and the ascending speed of the water-air interfaces was analyzed. The relation between the water-rising height and ascending speed was also analyzed. The present results would provide better alternative for investigating sap flows in roots.

• Mycobiology
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• v.46 no.4
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• pp.388-395
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• 2018

Radionuclides were deposited at forest areas in eastern parts of Japan following the Fukushima Daiichi Nuclear Power Plant incident in March 2011. Ectomycorrhizal (EM) fungi have important effects on radiocaesium dynamics in forest ecosystems. We examined the effect of colonization by the EM fungus Astraeus hygrometricus on the uptake of cesium (Cs) and potassium (K) by Pinus densiflora seedlings. Pine seedlings exhibited enhanced growth after the EM formation due to the colonization by A. hygrometricus. Additionally, the shoot Cs concentration increased after the EM formation when Cs was not added to the medium. This suggests that A. hygrometricus might be able to solubilize Cs fixed to soil particles. Moreover, the shoot K concentration increased significantly after the EM formation when Cs was added. However, there were no significant differences in the root K concentration between EM and non-EM seedlings. These results suggest that different mechanisms control the transfer of Cs and K from the root to the shoot of pine seedlings.