• 한국초지조사료학회지
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• 제42권3호
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• pp.137-145
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• 2022

Aluminum (Al) is one of the major factors adversely affects crop growth and productivity in acidic soils. In this study, the effect of Al on plants in soil was investigated by comparing the protein expression profiles of alfalfa roots exposed to Al stress treatment. Two-week-old alfalfa seedlings were exposed to Al stress treatment at pH 4.0. Total protein was extracted from alfalfa root tissue and analyzed by two-dimensional gel electrophoresis combined with MALDI-TOF/TOF mass spectrometry. A total of 45 proteins differentially expressed in Al stress-treated alfalfa root tissues were identified, of which 28 were up-regulated and 17 were down-regulated. Of the differentially expressed proteins, 7 representative proteins were further confirmed for transcript accumulation by RT-PCR analysis. The identified proteins were involved in several functional categories including disease/defense (24%), energy (22%), protein destination (9%), metabolism (7%), transcription (5%), secondary metabolism (4%), and ambiguous classification (29%). The identification of key candidate genes induced by Al in alfalfa roots will be useful to elucidate the molecular mechanisms of Al stress tolerance in alfalfa plants.

• Journal of Microbiology and Biotechnology
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• 제31권9호
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• pp.1231-1240
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• 2021

Members of the genus Bacillus are known to play an important role in promoting plant growth and protecting plants against phytopathogenic microorganisms. In this study, 21 isolates of Bacillus spp. were obtained from the root micro-ecosystem of Suaeda glauca. Analysis of the 16S rRNA genes indicated that the isolates belong to the species Bacillus amyloliquefaciens, Bacillus velezensis, Bacillus subtilis, Bacillus pumilus, Bacillus aryabhattai and Brevibacterium frigoritolerans. One of the interesting findings of this study is that the four strains B1, B5, B16 and B21 are dominant in rhizosphere soil. Based on gyrA, gyrB, and rpoB gene analyses, B1, B5, and B21 were identified as B. amyloliquefaciens and B16 was identified as B. velezensis. Estimation of antifungal activity showed that the isolate B1 had a significant inhibitory effect on Fusarium verticillioides, B5 and B16 on Colletotrichum capsici (syd.) Butl, and B21 on Rhizoctonia cerealis van der Hoeven. The four strains grew well in medium with 1-10% NaCl, a pH value of 5-8, and promoted the growth of Arabidopsis thaliana. Our results indicate that these strains may be promising agents for the biocontrol and promotion of plant growth and further study of the relevant bacteria will provide a useful reference for the development of microbial resources.

• 한국토양비료학회지
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• 제47권6호
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• pp.563-570
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• 2014

The shortage or surplus of minerals directly affects overall physiological metabolism of plants; especially, it strongly influences carbohydrate metabolism as a primary response. We have studied mineral uptake, synthesis and partitioning of soluble carbohydrates, and the relationship between them in N, P or K-excessive 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 excessive N ($20.0mmol\;L^{-1}$ $Ca(NO_3)2{\cdot}4H_2O$ and $20.0mmol\;L^{-1}$ $KNO_3$), P ($2.0mmol\;L^{-1}$ $KH_2PO_4$), and K ($20.0mmol\;L^{-1}$ $KNO_3$), respectively, for 30 days. Shoot growth rates were significantly influenced by excessive N or K, but not by excessive P. The concentrations of water soluble N (nitrate and ammonium), P and K were clearly different with each tissue of tomato plants as well as the mineral conditions. The NPK accumulation in all treatments was as follows; fully expanded leaves (48%) > stem (19%) = roots (16%) = petioles (15%) > emerging leaves (1). K-excessive condition extremely contributed to a remarkable increase in the ratio, which ranged from 2.79 to 10.34, and particularly potassium was dominantly accumulated in petioles, stem and roots. Fresh weight-based soluble sugar concentration was the greatest in NPK-sufficient condition ($154.8mg\;g^{-1}$) and followed by K-excessive (141.6), N-excessive (129.2) and P-excessive (127.7); whereas starch was the highest in K-excessive ($167.0mg\;g^{-1}$) and followed by P-excessive (146.1), NPK-sufficient (138.2) and N-excessive (109.7). Soluble sugar showed positive correlation with dry weight-based total N content (p<0.01) whereas was negatively correlated with soluble P (p<0.01) and dry weight-based total P (p<0.01). On the other hand, starch production was negatively influenced by total N (p<0.001), but, it showed positive relation with total K concentration (p<0.05). This study shows that uptake pattern of NPK and production and partitioning of soluble carbohydrate were substantially different from each mineral, and the relationship between water soluble- and dry weight-based-mineral was positive.

• 한국토양비료학회지
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• 제17권2호
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• pp.82-89
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• 1984

논토양(土壤)에 볏짚을 시용(施用)하고 투수조건(透水條件)으로 수도(水稻)를 재배(栽培)하면서 경시적(經時的)으로 질소대식(窒素代識)에 관여(關與)하는 미생물(微生物)의 소장(消長)과 토양성분(土壤成分)의 변화(變化)를 조사(調査)하여 얻어진 결과(結果)는 다음과 같다. 토양중(土壤中) Eh는 경시적(經時的)으로 저하(低下)했으며 볏짚시용구(施用區)의 Eh가 더욱 낮다. pH는 상층(上層)이 하층(下層)보다 약간 높았다. 이가철(二價鐵)은 함량(含量)이 볏짚시용(施用)으로 증가(增加)되었으며 경시적(經時的)으로 증가(增加)하는 경향(傾向)이었다. $NH_4$-N는 생육초기(生育初期)에 볏짚시용구(施用區)가 함량(含量)이 낮고 $NO_3$-N는 거의 검출(檢出)되지 않았다. 탈실균(脫室菌)은 담수초기(湛水初期)에 상층(上層)에서 높았으며 볏짚시용(施用)으로 생육초기(生育初期)에 약간 균수증가(菌數增加)가 있었다. 경시적(經時的)으로 탈질균(脫窒菌)은 감소(減少)하는 경향(傾向)이었으며 질산환원균(窒酸還元菌)은 증가(增加)하였다. 암모니아 산화균(酸化菌)은 상층(上層)의 균수(菌數)가 하층(下層)보다 많았다. 아질산산화균(亞窒酸酸化菌)은 경시적(經時的)으로 감소(減少)하고 볏짚시용(施用)으로 균수(菌數)가 더욱 감소(減少)되었다. 토양중(土壤中) 이가철함량(二價鐵含量)과 탈질균(脫窒菌)과는 부(負)의 상관(相關)이 비교적 높으며 질산환원균(窒酸還元菌)과는 정(正)의 상관(相關)은 있으나 유의성(有意性)은 없었다. 암모니아산화균(酸化菌)과 그 이가철함량(二價鐵含量)과는 일정(一定)한 상관관계(相關關係)를 나타내지 못하고 있으며 $NH_4$-N 함량(含量)과도 뚜렷한 유의상관(有意相關)이 없었다.

• Journal of Ginseng Research
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• 제21권2호
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• pp.91-97
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• 1997

In order to elucidate the mechanism of red-colored phenomena(RCP) in ginseng(Panax ginseng C.A. Meyer), distribution of inorganic elements of ginseng root and its surrounding soil, and microflora in the soil were investigated. Red brown colored-substances were accumulated in the cell wall of epidermis at early stage of red-colored ginseng (RCG). Cell wall of the late stage of RCG was disordered and microorganisms were shown in the disordered cell wall. Al, Si and Fe contents among inorpanic elements in the epidermis of RCG were higher at two or three times than that of healthy ginseng. On the other hand, K content was higher at three times in healthy ginseng than that of RCG. Especially, Fe content was higher at three times in lateral roots of RCG than that of healthy ginseng. Total 21 strains of microorganisms were isolated on the 523 medium from surface soil, surrounding soil of both healthy and RCG, and RCG. Six strains of microorganisms among them were resistant to 2 mM Fe. Two species in Bacillus app. and Lactobacillus app. , and one species in Micrococcus sp. and Npisseria sp. respectively were identified. It seemed that RCP was closely related with the distribution and uptake of inorganic elements, was also correlated Fe-independent metabolism of microorganisms.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.340-343
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• 2003

Soils contaminated by hazardous hydrophobic organic compounds, such as polycyclic aromatic hydrocarbons (PAHs), have become a major environmental issue due to toxic and carcinogenic properties of those compounds. In this work, we investigated effects of various metabolic inducers on phenanthrene biodegradation. Biodegradation tests were peformed with two different Pseudomonads: Pseudononrdia hydrocarboxydans (Gram positive) and Pseudomonas putida (Gram negative). Intermediates of phenanthrene metabolism (1-hydroxy-2-naphthoate, salicylate, catechol, phthalate and protocatechuate) were selected as inducers. The tests indicated that 1-hydroxy-2-naphthoate was the most effective inducer and enhanced the phenanthrene degradation rate up to 5.7 times, even though all the others also had induction ability to some extent. The effective induction could be achieved even at a low concentration of 1-hydroxy-2-naphthoate. Addition of metabolic inducers would be an attractive trick for the successful bioremediation of PAH-contaminated soil.

• 한국환경농학회지
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• 제26권4호
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• pp.351-363
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• 2007

The scientific articles using radio labelled insecticides performed by Korean researchers were reviewed. The research works were divided into 4 categories such as soil, plant, animal and insect. All researches used $^{14}C$-labelled chemicals, and the $^{14}C$-carbofuran was widely used among them. Fate of insecticides, bound-residues and metabolic process were staple concerning area in soil study. And the uptake and translocation, metabolism and metabolites also a major interests in plant study. As well as the degradation, metabolic pathway and metabolites, and distribution of chemicals in animal tissue were another point of consideration in animal study. And finally, the penetration ratio into body and resistant mechanism were the major concerning views of study with insects.

• Environmental Engineering Research
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• 제22권4호
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• pp.347-355
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• 2017

This study investigated how the combined changes in environmental conditions and nitrogen (N) deposition influence the mineralization processes and carbon (C) dynamics of wetland soil. For this objective, we conducted a growth chamber experiment to examine the effects of combined changes in environmental conditions and N deposition on the anaerobic decomposition of organic carbon and the emission of greenhouse gases from wetland soil. A chamber with elevated $CO_2$ and temperature showed almost twice the reduction of total decomposition rate compared to the chamber with ambient atmospheric conditions. In addition, $CO_2$ fluxes decreased during the incubation under the conditions of ambient $CO_2$ and temperature. The decrease in anaerobic microbial metabolism resulted from the presence of vegetation, which influences the litter quality of soils. This can be supported by the increase in C/N ratio over the experimental duration. Principle component analysis results demonstrated the opposite locations of loadings for the cases at the initial time and after three months of incubation, which indicates a reduction in the decomposition rate and an increasing C/N ratio during the incubation. From the distribution between the decomposition rate and gas fluxes, we concluded that anaerobic decomposition rates do not have a significantly positive relationship with the fluxes of greenhouse gas emissions from the soil.

• Journal of Forest and Environmental Science
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• 제40권1호
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• pp.43-52
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• 2024

Cadmium (Cd) is non-essential heavy metal that negatively affects plant metabolism. Nitric oxide (NO) is an increasingly important molecule for plant metabolism that makes signaling. In this study, it was aimed to investigate the alleviating effect of sodium nitroprusside (SNP) application as NO donor in white poplar (Populus alba) under Cd stress conditions. SNP and without SNP treatments increased the Cd accumulation in root tissue. While photosynthetic pigments (Chl a, Chl b, Chl a+b, and carotenoid) content decreased by only Cd application, SNP+Cd application decreased the rate of photosynthetic pigments reduction. When the results of Cd and Cd+SNP applications were evaluated for mineral (Fe, Zn, Mn and Cu) uptake, it was found that the positive effect of SNP was heterogeneously affected. Depending on SNP application, it was found that malondialdehyde (MDA) amount decreased in leaf in 100 µM Cd applications while hydrogen peroxide (H₂O₂) amount decreased in 100 and 500 µM Cd applications. When antioxidant enzyme activities were examined, it was found that catalase (CAT) and ascorbate peroxidase (APX) enzyme activities increased with 100 µM SNP applications under all Cd applications. As a result, it was found that SNP application under Cd stress generally supports physiological processes positively in white poplar, suggesting that NO molecule plays important alleviating roles in plant metabolism.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.223-229
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• 1994

The metabolic fate of methionine in rumen bacteria was studied by intraruminal administration of $^{15}N$ and $1-^{13}C$ labeled methionine in goats. Time course changes in isotopic abundance of amino acids in the rumen bacteria were determined with a computer-controlled gas-chromatograph mass spectrometer. The results from the transition of peak isotopic abundance in amino acids indicated that in rumen bacteria the $^{15}N$ or $^{13}C$ isotope in the methionine molecule was transferred rapidly to into bacteria, methionine administered intraruminally may not be retained as it is, but would be converted quickly to other metabolites in the bacteria.