6,359 research outputs found
A Systematic Approach for the Determination of B-Group Vitamins in Multivitamin Dietary Supplements by High Performance Liquid Chromatography with Diode-Array Detection and Mass Spectrometry
No full textThis paper describes a practical approach using an LC diode-array detector (DAD) and MS for the quantitation of B-group vitamins (thiamine, riboflavin, nicotinamide, pantothenic acid, pyridoxine, biotin, folic acid, and cyanocobalamin) in multivitamin supplements. The purpose of this study was to optimize the extraction and chromatographic conditions without application of internal standards to determine B-group vitamins in multivitamins. Chromatographic separation on a C18 column was optimized on the basis of chromatographic behavior depending on pH variation of the mobile phase. The optimized methods showed good r values, with RSD values lower than 2.44 and 3.09% for most of the B-group vitamins (except cyanocobalamin) using LC DAD and LC-MS, respectively. The methods were also proved to be reproducible, with RSD values of 0.96 and 2.48% being obtained with LC DAD and LC-MS, respectively. In addition, the developed analytical methods for B-group vitamins were validated using certified reference materials and were applied to commercially available multivitamin tablet
Physiological and molecular processes associated with long duration of ABA treatment
No full textPlants need to respond to various environmental stresses such as abiotic stress for proper development and growth. The responses to abiotic stress can be biochemically demanding, resulting in a trade-off that negatively affects plant growth and development. Thus, plant stress responses must be fine-tuned depending on the stress severity and duration. Abscisic acid, a phytohormone, plays a key role in responses to abiotic stress. Here, we investigated time-dependent physiological and molecular responses to long-term ABA treatment in Arabidopsis as an approach to gain insight into the plant responses to long-term abiotic stress. Upon ABA treatment, the amount of cellular ABA increased to higher levels, reaching to a peak at 24 h after treatment (HAT), and then gradually decreased with time whereas ABA-GE was maintained at lower levels until 24 HAT and then abruptly increased to higher levels at 48 HAT followed by a gradual decline at later time points. Many genes involved in dehydration stress responses, ABA metabolism, chloroplast biogenesis, and chlorophyll degradation were strongly expressed at early time points with a peak at 24 or 48 HAT followed by gradual decreases in induction fold or even suppression at later time points. At the physiological level, long-term ABA treatment caused leaf yellowing, reduced chlorophyll levels, and inhibited chloroplast division in addition to the growth suppression whereas short-term ABA treatment did not affect chlorophyll levels. Our results indicate that the duration of ABA treatment is a crucial factor in determining the mode of ABA-mediated signaling and plant responses: active mobilization of cellular resources at early time points and suppressive responses at later time points. © 2018 Wang, Lee, Choi, Park, Sim, Kim and Hwan
An Alcohol Dehydrogenase Gene from Synechocystis sp Confers Salt Tolerance in Transgenic Tobacco
No full textSynechocystis salt-responsive gene 1 (sysr1) was engineered for expression in higher plants, and gene construction was stably incorporated into tobacco plants. We investigated the role of Sysr1 [a member of the alcohol dehydrogenase (ADH) superfamily] by examining the salt tolerance of sysr1-overexpressing (sysr1-OX) tobacco plants using quantitative real-time polymerase chain reactions, gas chromatography-mass spectrometry, and bioassays. The sysr1-OX plants exhibited considerably increased ADH activity and tolerance to salt stress conditions. Additionally, the expression levels of several stress-responsive genes were upregulated. Moreover, airborne signals from salt-stressed sysr1-OX plants triggered salinity tolerance in neighboring wild-type (WT) plants. Therefore, Sysr1 enhanced the interconversion of aldehydes to alcohols, and this occurrence might affect the quality of green leaf volatiles (GLVs) in sysr1-OX plants. Actually, the Z-3-hexenol level was approximately twofold higher in sysr1-OX plants than in WT plants within 1-2 h of wounding. Furthermore, analyses of WT plants treated with vaporized GLVs indicated that Z-3-hexenol was a stronger inducer of stress-related gene expression and salt tolerance than E-2-hexenal. The results of the study suggested that increased C-6 alcohol (Z-3-hexenol) induced the expression of resistance genes, thereby enhancing salt tolerance of transgenic plants. Our results revealed a role for ADH in salinity stress responses, and the results provided a genetic engineering strategy that could improve the salt tolerance of crops.
© 2017 Yi, Ku, Sim, Kim, Park, Lyu, So, Choi, Kim, Ahn, Kim, Park,
Jeong, Lim, Min and Liu. This is an open-access article distributed under the terms
of the Creative Commons Attribution License (CC BY). The use, distribution or
reproduction in other forums is permitted, provided the original author(s) or licensor
are credited and that the original publication in this journal is cited, in accordance
with accepted academic practice. No use, distribution or reproduction is permitted
which does not comply with these terms
Spatial regulation of ABCG25, an ABA exporter, is an important component of the mechanism controlling cellular aba levels
No full textThe phytohormone abscisic acid (ABA) plays crucial roles in various physiological processes, including responses to abiotic stresses, in plants. Recently, multiple ABA transporters were identified. The loss-of-function and gain-of-function mutants of these transporters show altered ABA sensitivity and stomata regulation, highlighting the importance of ABA transporters in ABA-mediated processes. However, how the activity of these transporters is regulated remains elusive. Here, we show that spatial regulation of ATP BINDING CASETTE G25 (ABCG25), an ABA exporter, is an important mechanism controlling its activity. ABCG25, as a soluble green fluorescent protein (sGFP) fusion, was subject to posttranslational regulation via clathrin-dependent and adaptor protein complex-2-dependent endocytosis followed by trafficking to the vacuole. The levels of sGFP:ABCG25 at the plasma membrane (PM) were regulated by abiotic stresses and exogenously applied ABA; PMlocalized sGFP:ABCG25 decreased under abiotic stress conditions via activation of endocytosis in an ABA-independent manner, but increased upon application of exogenous ABA via activation of recycling from early endosomes in an ABAdependent manner. Based on these findings, we propose that the spatial regulation of ABCG25 is an important component of the mechanism by which plants fine-tune cellular ABA levels according to cellular and environmental conditions. © 2016 American Society of Plant Biologists. All rights reserve
TAR-18-100_R1_Supplementary_tables – Supplemental material for Clinical outcomes of patients receiving prolonged extracorporeal membrane oxygenation for respiratory support
No full textSupplemental material, TAR-18-100_R1_Supplementary_tables for Clinical outcomes of patients receiving prolonged extracorporeal membrane oxygenation for respiratory support by Soo Jin Na, Jae-Seung Jung, Sang-Bum Hong, Woo Hyun Cho, Sang-Min Lee, Young-Jae Cho, Sunghoon Park, So-My Koo, Seung Yong Park, Youjin Chang, Byung Ju Kang, Jung-Hyun Kim, Jin Young Oh, So Hee Park, Jung-Wan Yoo, Yun Su Sim and Kyeongman Jeon in Therapeutic Advances in Respiratory Disease</p
Dual functionality of natural mixtures of bacterial volatile compounds on plant growth
No full textBacteria emit volatile compounds that modulate plant growth. Previous studies reported the impacts of bacterial volatile compounds on plant growth; however, the results varied depending on bacterial nutrient availability. We investigated whether the effects of plant growth-inhibiting volatiles (PGIVs) and plant growth-promoting volatiles (PGPVs) depended on the perceived dose by evaluating the growth of Arabidopsis thaliana seedlings placed at 7, 14, and 21 cm away from Bacillus amyloliquefaciens GB03 colonies growing in rich medium. A large bacterial colony (500 mu l inoculum) inhibited plant growth at 7 cm and promoted growth at 21 cm, whereas a small bacterial colony (100 mu l inoculum) induced the opposite pattern of response. We identified pyrazine and 2,5-dimethylpyrazine as candidate PGIVs that significantly reduced plant growth at a distance of 7 cm. PGIV effects were validated by exposing plants to synthetic 2,5-dimethylpyrazine and bacteria emitting PGPVs, which showed that PGIVs overwhelm PGPVs to rapidly increase salicylic acid content and related gene expression. This is referred to as the defence-growth trade-off. Our results indicate that high PGIV concentrations suppress plant growth and promote immunity, whereas low PGPV concentrations promote growth. This study provides novel insights into the complex effects of bacterial volatile mixtures and fine-tuning of bacteria-plant interactions.11Nsciescopu
Systemic immunity requires SnRK2.8-mediated nuclear import of NPR1 in arabidopsis
No full textIn plants, necrotic lesions occur at the site of pathogen infection through the hypersensitive response, which is followedby induction of systemic acquired resistance (SAR) in distal tissues. Salicylic acid (SA) induces SAR by activatingNONEXPRESSER OF PATHOGENESIS-RELATED GENES1 (NPR1) through an oligomer-to-monomer reaction. However, SAbiosynthesis is elevated only slightly in distal tissues during SAR, implying that SA-mediated induction of SAR requiresadditional factors. Here, we demonstrated that SA-independent systemic signals induce a gene encoding SNF1-RELATEDPROTEIN KINASE 2.8 (SnRK2.8), which phosphorylates NPR1 during SAR. The SnRK2.8-mediated phosphorylation of NPR1 isnecessary for its nuclear import. Notably, although SnRK2.8 transcription and SnRK2.8 activation are independent of SAsignaling, the SnRK2.8-mediated induction of SAR requires SA. Together with the SA-mediated monomerization of NPR1,these observations indicate that SA signals and SnRK2.8-mediated phosphorylation coordinately function to activate NPR1via a dual-step process in developing systemic immunity in Arabidopsis thaliana. © American Society of Plant Biologists119221sciescopu
Boeremia parva sp. nov., a novel species of the family Didymellaceae isolated from soil
No full textDas, Kallol, Ten, Leonid N., Ban, Jae-Ho, Lee, Seung-Yeol, Jung, Hee-Young (2021): Boeremia parva sp. nov., a novel species of the family Didymellaceae isolated from soil. Phytotaxa 518 (1): 25-35, DOI: 10.11646/phytotaxa.518.1.
Aspects of Korean music and culture: an exhibition of material from the Monash University Library, Rare Book Collection, 27 May - 26 June 2002
No full textThe exhibition was held in the Rare Books Exhibition space, Sir Louis Matheson Library, Monash University from 27 May - 26 June 2002.<p>The exhibition includes editions of musical scores rarely seen outside Korea. Recordings of traditional, folk and contemporary art music were on display as well as a collection of modern Korean objects.<br>Exhibition organized by the Monash University School of Music-Conservatorium, in association with Korean Studies, School of Languages, Cultures and Linguistics; the Monash Asia Institute; and Monash University Library. Special thanks to Jung-Sim Kim, and Aline Scott-Maxwell, Asian Studies Research Library, Richard Overell and Lorraine David, Rare Books Collection, and Georgina Binns, Music Library.</p
Aspects of Korean music and culture: an exhibition of material from the Monash University Library, Rare Book Collection, 27 May - 26 June 2002
No full textThe exhibition was held in the Rare Books Exhibition space, Sir Louis Matheson Library, Monash University from 27 May - 26 June 2002. The exhibition includes editions of musical scores rarely seen outside Korea. Recordings of traditional, folk and contemporary art music were on display as well as a collection of modern Korean objects. Exhibition organized by the Monash University School of Music-Conservatorium, in association with Korean Studies, School of Languages, Cultures and Linguistics; the Monash Asia Institute; and Monash University Library. Special thanks to Jung-Sim Kim, and Aline Scott-Maxwell, Asian Studies Research Library, Richard Overell and Lorraine David, Rare Books Collection, and Georgina Binns, Music Library
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