• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.910-919
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• 2012

The role of inorganic nitrogen assimilation in the production of amino acids, organic acids and soluble sugars is one of the most important biochemical processes in plants, and, in order to achieve normally, nitrate uptake and assimilation is essential. For this reason, the characterization of nitrate assimilation and metabolite composition from leaves, roots and xylem sap of tomato (Solanum lycopersicum) was investigated under different nitrate levels in media. Tomato plants were grown hydroponically in liquid culture under five different nitrate regimes: deficient (0.25 and 0.75 mM $NO_3{^-}$), normal (2.5 mM $NO_3{^-}$) and excessive (5.0 and 10.0 mM $NO_3{^-}$). All samples, leaves, roots and xylem sap, were collected after 7 and 14 days after treatment. The levels of amino acids, soluble sugars and organic acids were significantly decreased by N-deficiency whereas, interestingly, they remained higher in xylem sap as compared with N-normal and -surplus. The N-excessive condition did not exert any significant changes in metabolites composition, and thus their levels were similar with N-normal. The gene expression and enzyme activity of nitrate reductase (NR), nitrite reductase (NIR) and glutamine synthetase (GS) were greatly influenced by nitrate. The data presented here suggest that metabolites, as a signal messenger, existed in xylem sap seem to play a crucial role to acquire nitrate, and, in addition, an increase in ${\alpha}$-ketoglutarate pathway-derived amino acids under N-deficiency may help to better understand plant C/N metabolism.

• Animal Bioscience
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• v.36 no.7
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• pp.1130-1142
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• 2023

Objective: Cow urine possesses several bioactive properties but the responsible components behind these bioactivities are still far from identified. In our study, we tried to identify the possible components behind the antimicrobial activity of cow urine by exploring the peptidome and metabolome. Methods: We extracted peptides from the urine of Sahiwal cows belonging to three different physiological states viz heifer, lactation, and pregnant, each group consisting of 10 different animals. The peptides were extracted using the solid phase extraction technique followed by further extraction using ethyl acetate. The antimicrobial activity of the aqueous extract was evaluated against different pathogenic strains like Staphylococcus aureus, Escherichia coli, and Streptococcus agalactiae. The safety of urinary aqueous extract was evaluated by hemolysis and cytotoxicity assay on the BuMEC cell line. The urinary peptides were further fractionated using high-performance liquid chromatography (HPLC) to identify the fraction(s) containing the antimicrobial activity. The HPLC fractions and ethyl acetate extract were analyzed using nLC-MS/MS for the identification of the peptides and metabolites. Results: A total of three fractions were identified with antimicrobial activity, and nLC-MS/MS analysis of fractions resulted in the identification of 511 sequences. While 46 compounds were identified in the metabolite profiling of organic extract. The urinary aqueous extract showed significant activity against E. coli as compared to S. aureus and S. agalactiae and was relatively safe against mammalian cells. Conclusion: The antimicrobial activity of cow urine is a consequence of the feeding habit. The metabolites of plant origin with several bioactivities are eliminated through urine and are responsible for their antimicrobial nature. Secondly, the plethora of peptides generated from the activity of endogenous proteases on protein shed from different parts of tissues also find their way to urine. Some of these sequences possess antimicrobial activity due to their amino acid composition.

• Journal of Plant Biotechnology
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• v.38 no.1
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• pp.9-14
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• 2011

To determine whether pattern recognition based on metabolite fingerprinting for whole cell extracts can be used to discriminate cultivars metabolically, leaves of nine commercial Orostachys plants were subjected to Fourier transform infrared spectroscopy (FT-IR). FT-IR spectral data from leaves were analyzed by principal component analysis (PCA) and Partial least square discriminant analysis (PLS-DA). The dendrogram based on hierarchical clustering analysis of these PLS-DA data separated the nine Orostachys species into five major groups. The first group consisted of O. iwarenge 'Yimge', 'Jeju', 'Jeongsun' and O. margaritifolius 'Jinju' whereas in the second group, 'Sacheon' was clustered with 'Busan,' both of which belong to O. malacophylla species. However, 'Samchuk', belong to O. malacophylla was not clustered with the other O. malacophylla species. In addition, O. minuta and O. japonica were separated to the other Orostachys plants. Thus we suggested that the hierarchical dendrogram based on PLS-DA of FT-IR spectral data from leaves represented the most probable chemotaxonomical relationship between commercial Orostachys plants. Furthermore these metabolic discrimination systems could be applied for reestablishment of precise taxonomic classification of commercial Orostachys plants.

• Korean Journal of Environmental Agriculture
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• v.16 no.3
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• pp.207-211
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• 1997

Laboratory experiments were conducted to the potential ability of bioremediation with bentazon such as determining the absorption, translocation, and metabolism of $^{14}C-Bentazon$ in minari after foliar applications. The absorption and translocation of $^{14}C-bentazon$ were compared when applied to foliar of minari. In foliar applications, 21% was observed in treated leaves, 66% remained in water extracts of leaf surfaces, and 13% was found in the epicuticular wax layer after 2d. Translocation of the herbicide from treated leaves to roots was very low(79 to 9%). Analysis of methanol-soluble extracts of $^{14}C$ indicated that more than 60% of the foliarapplied herbicide was metabolized in all plant sections after 2d. However, 77% or more of the bentazon was degraded in roots and shoots 2d after root absorption. The major metabolite in these experiments was an unknown compound that was less polar than bentazon and 6- and 8-hydroxy bentazon.

• Journal of Microbiology and Biotechnology
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• v.34 no.5
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• pp.1029-1039
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• 2024

This study explores beneficial bacteria isolated from the roots and rhizosphere soil of Khao Rai Leum Pua Phetchabun rice plants. A total of 315 bacterial isolates (KK001 to KK315) were obtained. Plant growth-promoting traits (phosphate solubilization and indole-3-acetic acid (IAA) production), and antimicrobial activity against three rice pathogens (Curvularia lunata NUF001, Bipolaris oryzae 2464, and Xanthomonas oryzae pv. oryzae) were assessed. KK074 was the most prolific in IAA production, generating 362.6 ± 28.0 ㎍/ml, and KK007 excelled in tricalcium phosphate solubilization, achieving 714.2 ± 12.1 ㎍/ml. In antimicrobial assays using the dual culture method, KK024 and KK281 exhibited strong inhibitory activity against C. lunata, and KK269 was particularly effective against B. oryzae. In the evaluation of antimicrobial metabolite production, KK281 and KK288 exhibited strong antifungal activities in cell-free supernatants. Given the superior performance of KK281, taxonomically identified as Bacillus sp. KK281, it was investigated further. Lipopeptide extracts from KK281 had significant antimicrobial activity against C. lunata and a minimum inhibitory concentration (MIC) of 3.1 mg/ml against X. oryzae pv. oryzae. LC-ESI-MS/MS analysis revealed the presence of surfactin in the lipopeptide extract. The crude extract was non-cytotoxic to the L-929 cell line at tested concentrations. In conclusion, the in vitro plant growth-promoting and disease-controlling attributes of Bacillus sp. KK281 make it a strong candidate for field evaluation to boost plant growth and manage disease in upland rice.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.568-571
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• 2000

Cepacidine A was previously isolated as a novel antifungal antibiotic from the culture broth of Pseudomonas cepacia AF2001. It exhibits a potent in vitro antifungal activity against various plant pathogenic fungi, such as Plasmopora veticola on grapes, Septoria nodorum and Fusarium culmorum on wheat, as well as Colletotrichum lagenarium on cucumbers. Accordingly, this study was conducted to evaluate the potential crop protection activity of strain P. cepacia AF2001. The strain was tested in semi-greenhouse biocontrol assays, and showed an excellent biological activity against Pythium ultimum in cotton and cucumbers; however, only a minor activity against Rhizoctonia aolani in cotton was observed. Furthermore, the nematodes Haemonchus contortus and Trichostrongylus only exhibited a moderated activity in the in vitro larval development assay with no activity in the in vivo animal model.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.417-420
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• 2005

Plants generally produce secondary metabolites in nature as a defense mechanism against pathogenic and insect attack. In this study, we applied several abiotic elicitors in order to enhance growth and ginseng saponin biosynthesis in the hairy roots of P. ginseng. Generally, elicitor treatments were found to inhibit the growth of the hairy roots, although simultaneously enhancing ginseng saponin biosynthesis. The addition of selenium at inoculum time did not significantly affect ginseng saponin biosynthesis. However, when 0.5 mM selenium was added as an elicitor after 21 days of culture, ginseng saponin content and productivity increased to about 1.31 and 1.33 times control levels, respectively. These results suggest that processing time for the generation of ginseng saponin in a hairy root culture can be reduced via the application of an elicitor.

• Proceedings of the Botanical Society of Korea Conference
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• 2002.04a
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• pp.73-82
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• 2002

The committing step in Met and S-adenosyl-L-methionine (SAM) synthesis is catalyzed by cystathionine ${\gamma}$ -synthase (CGS). Transgenic Arabidopsis thaliana overexpressing CGS under control of 35S promoter show increased soluble Met and its metabolite S-methylmethionine, but only at specific stages of development. CGS-overexpressing seedlings are resistant to ethionine. Similar results were obtained with transgenic potato plants overexpressing Arabidopsis CGS. Several of the transgenic lines show silencing of CGS resulting in deformed p]ants with a reduced capacity for reproductive growth similar as transgenic plants by antisense RNA (CGS[-]). Exogenous feeding of Met to the CGS[-] and CGS[+] silenced plants partially restores their growth. Similar morphological deformities are observed in plants cosuppressed for SAM synthetase, even though such plants accumulate 250 fold more soluble Met than wild type and they overexpress CGS. The results suggest that the abnormalities associated with CGS and SAM synthetase silencing are due in part to a reduced ability to produce SAM, and that SAM may be a regulator of CGS expression.

• KSBB Journal
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• v.10 no.4
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• pp.358-369
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• 1995

A mathematical model using local thermodynamic equilibrium isotherms for adsorption in encapsulated adsorbent is proposed in order to optimize the design parameters in situ bioproduct separation process. The model accurately follows the experimental data on the adsorption of berberine, secondary metabolite produced in Thaictrum rugosum plant cell culture. The adsorption rate on encapsulated adsorbent is compared with that on alginate-entrapped adsorbent. The result shows that the higher loading capacity in encapsulated adsorbent is mainly due to the increase in the maximum solid phase concentration. Based on the adsorption rate and loading capacity, the encapsulated adsorbent would be more useful than the entrapped adsorbent when used in situ bioproduct separation process. Design parameters in situ bioproduct separation process, such as the size of the capsule, membrane thickness, the ratio of capsule volume to bulk volume, the ratio of single capsule volume to total capsule volume and the adsorbent content in the capsule, are evaluated by using the model. The ratio of single capsule volume to total capsule volume is the most effective parameter for adsorption of berberine on encapsulated adsorbent.

• Molecules and Cells
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• v.39 no.4
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• pp.310-315
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• 2016

Coumarin is a phenolic compound that mainly affects the liver due to its metabolization into a toxic compound. The deterrent and ovicidal activities of coumarin in insect models such as Drosophila melanogaster have been reported. Here we explore the molecular mechanisms by which these insects protect themselves and their eggs from this toxic plant metabolite. Coumarin was fatal to the flies in a dosage-dependent manner. However, coumarin feeding could be inhibited through activation of the aversive gustatory receptor neurons (GRNs), but not the olfactory receptor neurons. Furthermore, three gustatory receptors, GR33a, GR66a, and GR93a, functioned together in coumarin detection by the proboscis. However, GR33a, but not GR66a and GR93a, was required to avoid coumarin during oviposition, with a choice of the same substrates provided as in binary food choice assay. Taken together, these findings suggest that anti-feeding activity and oviposition to avoid coumarin occur via separate mechanisms.