38 results on '"Khanh TD"'
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2. Methods to determine allelopathic potential of crop plants for weed control
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Xuan Tran Dang, Eiji, T., Shinkichi, T., and Khanh, Td
3. Identification of potential allelochemicals from Kava (Piper methysticum L.) root
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Xuan Tran Dang, Eiji, T., Hiroyuki, T., Mitsuhiro, M., and Khanh, Td
4. Generation of parthenocarpic tomato plants in multiple elite cultivars using the CRISPR/Cas9 system.
- Author
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Nguyen CC, Van Vu T, Shelake RM, Nguyen NT, Khanh TD, Kim WY, and Kim JY
- Abstract
Tomato ( Solanum lycopersicum L.) is one of the most important crops in the world for its fruit production. Advances in cutting-edge techniques have enabled the development of numerous critical traits related to the quality and quantity of tomatoes. Genetic engineering techniques, such as gene transformation and gene editing, have emerged as powerful tools for generating new plant varieties with superior traits. In this study, we induced parthenocarpic traits in a population of elite tomato (ET) lines. At first, the adaptability of ET lines to genetic transformation was evaluated to identify the best-performing lines by transforming the SlANT1 gene overexpression cassette and then later used to produce the SlIAA9 knockout lines using the CRISPR/Cas9 system. ET5 and ET8 emerged as excellent materials for these techniques and showed higher efficiency. Typical phenotypes of knockout sliaa9 were clearly visible in G0 and G1 plants, in which simple leaves and parthenocarpic fruits were observed. The high efficiency of the CRISPR/Cas9 system in developing new tomato varieties with desired traits in a short period was demonstrated by generating T-DNA-free homozygous sliaa9 knockout plants in the G1 generation. Additionally, a simple artificial fertilization method was successfully applied to recover seed production from parthenocarpic plants, securing the use of these varieties as breeding materials., Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01452-1., Competing Interests: Conflict of interestThe authors declare no competing interests., (© The Author(s), under exclusive licence to Springer Nature B.V. 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)
- Published
- 2024
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5. Salinity Treatments Promote the Accumulations of Momilactones and Phenolic Compounds in Germinated Brown Rice.
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Hasan M, Quan NV, Anh H, Khanh TD, and Xuan TD
- Abstract
This is the first investigation, conducted in a completely randomized design (CRD), to determine the effects of different salinity levels (75 and 150 mM) and germination periods (3, 4, and 5 days) on momilactone and phenolic accumulations in germinated brown rice (GBR) var. Koshihikari. Particularly, the identification of bioactive compounds was confirmed using electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) spectroscopy (
1 H and13 C). Momilactone A (MA) and momilactone B (MB) amounts were determined by ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS), whereas other compounds were quantified by spectrophotometry and high-performance liquid chromatography (HPLC). Accordingly, GBR under B2 treatment (75 mM salinity for 4 days) showed the greatest total phenolic and flavonoid contents (14.50 mg gallic acid and 11.06 mg rutin equivalents, respectively, per g dry weight). GBR treated with B2 also accumulated the highest quantities of MA, MB, ρ -coumaric, ferulic, cinnamic, salicylic acids, and tricin (18.94, 41.00, 93.77, 139.03, 46.05, 596.26, and 107.63 µg/g DW, respectively), which were consistent with the strongest antiradical activities in DPPH and ABTS assays (IC50 = 1.58 and 1.78 mg/mL, respectively). These findings have implications for promoting the value of GBR consumption and rice-based products that benefit human health.- Published
- 2023
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6. Self-Repairing and Energy-Harvesting Triboelectric Sensor for Tracking Limb Motion and Identifying Breathing Patterns.
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Meena JS, Khanh TD, Jung SB, and Kim JW
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- Humans, Amides, Carbamates, Motion, Physical Phenomena, Movement, Urethane
- Abstract
The increasing prevalence of health problems stemming from sedentary lifestyles and evolving workplace cultures has placed a substantial burden on healthcare systems. Consequently, remote health wearable monitoring systems have emerged as essential tools to track individuals' health and well-being. Self-powered triboelectric nanogenerators (TENGs) have exhibited significant potential for use as emerging detection devices capable of recognizing body movements and monitoring breathing patterns. However, several challenges remain to be addressed in order to fulfill the requirements for self-healing ability, air permeability, energy harvesting, and suitable sensing materials. These materials must possess high flexibility, be lightweight, and have excellent triboelectric charging effects in both electropositive and electronegative layers. In this work, we investigated self-healable electrospun polybutadiene-based urethane (PBU) as a positive triboelectric layer and titanium carbide (Ti
3 C2 Tx ) MXene as a negative triboelectric layer for the fabrication of an energy-harvesting TENG device. PBU consists of maleimide and furfuryl components as well as hydrogen bonds that trigger the Diels-Alder reaction, contributing to its self-healing properties. Moreover, this urethane incorporates a multitude of carbonyl and amine groups, which create dipole moments in both the stiff and the flexible segments of the polymer. This characteristic positively influences the triboelectric qualities of PBU by facilitating electron transfer between contacting materials, ultimately resulting in high output performance. We employed this device for sensing applications to monitor human motion and breathing pattern recognition. The soft and fibrous-structured TENG generates a high and stable open-circuit voltage of up to 30 V and a short-circuit current of 4 μA at an operation frequency of 4.0 Hz, demonstrating remarkable cyclic stability. A significant feature of our TENG is its self-healing ability, which allows for the restoration of its functionality and performance after sustaining damage. This characteristic has been achieved through the utilization of the self-healable PBU fibers, which can be repaired via a simple vapor solvent method. This innovative approach enables the TENG device to maintain optimal performance and continue functioning effectively even after multiple uses. After integration with a rectifier, the TENG can charge various capacitors and power 120 LEDs. Moreover, we employed the TENG as a self-powered active motion sensor, attaching it to the human body to monitor various body movements for energy-harvesting and sensing purposes. Additionally, the device demonstrates the capability to recognize breathing patterns in real time, offering valuable insights into an individual's respiratory health.- Published
- 2023
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7. Fulvic Acid Improves Salinity Tolerance of Rice Seedlings: Evidence from Phenotypic Performance, Relevant Phenolic Acids, and Momilactones.
- Author
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Jesmin A, Anh H, Mai NP, Khanh TD, and Xuan TD
- Abstract
Salinity is a severe stress that causes serious losses in rice production worldwide. This study, for the first time, investigated the effects of fulvic acid (FA) with various concentrations of 0.125, 0.25, 0.5, and 1.0 mL/L on the ability of three rice varieties, Koshihikari, Nipponbare, and Akitakomachi, to cope with a 10 dS/m salinity level. The results show that the T3 treatment (0.25 mL/L FA) is the most effective in stimulating the salinity tolerance of all three varieties by enhancing their growth performance. T3 also promotes phenolic accumulation in all three varieties. In particular, salicylic acid, a well-known salt-stress-resistant substance, is found to increase during salinity stress in Nipponbare and Akitakomachi treated with T3 by 88% and 60%, respectively, compared to crops receiving salinity treatment alone. Noticeably, the levels of momilactones A (MA) and B (MB) fall in salt-affected rice. However, their levels markedly rise in rice treated with T3 (by 50.49% and 32.20%, respectively, in Nipponbare, and by 67.76% and 47.27%, respectively, in Akitakomachi), compared to crops receiving salinity treatment alone. This implies that momilactone levels are proportional to rice tolerance against salinity. Our findings suggest that FA (0.25 mL/L) can effectively improve the salinity tolerance of rice seedlings even in the presence of a strong salt stress of 10 dS/m. Further studies on FA application in salt-affected rice fields should be conducted to confirm its practical implications.
- Published
- 2023
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8. Benzimidazole Derivatives Suppress Fusarium Wilt Disease via Interaction with ERG6 of Fusarium equiseti and Activation of the Antioxidant Defense System of Pepper Plants.
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El-Nagar A, Elzaawely AA, El-Zahaby HM, Xuan TD, Khanh TD, Gaber M, El-Wakeil N, El-Sayed Y, and Nehela Y
- Abstract
Sweet pepper ( Capsicum annuum L.), also known as bell pepper, is one of the most widely grown vegetable crops worldwide. It is attacked by numerous phytopathogenic fungi, such as Fusarium equiseti , the causal agent of Fusarium wilt disease. In the current study, we proposed two benzimidazole derivatives, including 2-(2-hydroxyphenyl)-1-H benzimidazole (HPBI) and its aluminum complex (Al-HPBI complex), as potential control alternatives to F. equiseti . Our findings showed that both compounds demonstrated dose-dependent antifungal activity against F. equiseti in vitro and significantly suppressed disease development in pepper plants under greenhouse conditions. According to in silico analysis, the F. equiseti genome possesses a predicted Sterol 24-C-methyltransferase ( FeEGR6 ) protein that shares a high degree of homology with EGR6 from F. oxysporum ( FoEGR6 ). It is worth mentioning that molecular docking analysis confirmed that both compounds can interact with FeEGR6 from F. equiseti as well as FoEGR6 from F. oxysporum. Moreover, root application of HPBI and its aluminum complex significantly enhanced the enzymatic activities of guaiacol-dependent peroxidases (POX), polyphenol oxidase (PPO), and upregulated four antioxidant-related enzymes, including superoxide dismutase [Cu-Zn] ( CaSOD-Cu ), L-ascorbate peroxidase 1, cytosolic ( CaAPX ), glutathione reductase, chloroplastic ( CaGR ), and monodehydroascorbate reductase ( CaMDHAR ). Additionally, both benzimidazole derivatives induced the accumulation of total soluble phenolics and total soluble flavonoids. Collectively, these findings suggest that the application of HPBI and Al-HPBI complex induce both enzymatic and nonenzymatic antioxidant defense machinery.
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- 2023
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9. Isolation and Identification of Constituents Exhibiting Antioxidant, Antibacterial, and Antihyperuricemia Activities in Piper methysticum Root.
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Minh TN, Van TM, Khanh TD, and Xuan TD
- Abstract
The aqueous extract of kava ( Piper methysticum ) root is known as a traditional beverage for daily intake in the Western Pacific Islands, such as Fiji, Tonga, and Vanuatu, to induce relaxation and health-beneficial effects. In this study, the antioxidant, anti-hyperuricemia, and antibacterial properties of kava root were investigated through the isolation and purification of bioactive compounds in ten fractions separated by column chromatography (CC). They included six flavonoids, 5-hydroxy-4',7-dimethoxyflavanone ( C1 ), matteucinol ( C2 ), isosakuranetin ( C3 ), 5,7- dimethoxyflavanone ( C4 ), 2',4'-dihydroxy-6'-methoxydihydrochalcone (in MC5 ) and alpinetin ( C10 ), and seven kavalactones, 5,6-dehydrokawain (DK) (in MC5 and C6 ), kavain (in MC7 ), yangonin (in MC7 and C8 ), dihydro-5,6-dehydrokavain (DDK) (in MC9 ), 7,8-dihydromethysticin (in MC9 ), dihydromethysticin (in MC9 ), methysticin (in MC9 ). The chemical structures of the compounds were illustrated by the analyses of gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), nuclear magnetic resonance (
1 H and13 C-NMR), and X-ray diffraction. The evaluation of the free radical scavenging activity of the isolated substances via the DPPH and ABTS assays revealed that C3 (IC50 : ABTS = 76.5; DPPH = 74.8 µg/mL) possessed the strongest antioxidant property. In terms of anti-hyperuricemia activity evaluated via the xanthine oxidase inhibitory in vitro assay, the compound C10 was the most promising inhibitor, revealing an IC50 of 134.52 µg/mL. The two kavalactone mixtures in MC5 and a pure compound C6 inhibited the growth of bacteria Listeria monocytogenes , while MC7 can constrain the development of Klebsiella pneumoniae. This is the first study to isolate, purify, and identify the flavonoids isosakuranetin, 2',4'-dihydroxy-6'-methoxydihydrochalcone and alpinetin in kava root and report their pharmaceutical potential. The identified bioactive compounds showed potent antioxidant, anti-hyperuricemia, and antibacterial activity and thus can enhance the value of beverages and foods derived from kava root.- Published
- 2022
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10. Cytotoxic Mechanism of Momilactones A and B against Acute Promyelocytic Leukemia and Multiple Myeloma Cell Lines.
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Anh H, Lam VQ, Takami A, Khanh TD, Quan NV, and Xuan TD
- Abstract
This is the first study clarifying the cytotoxic mechanism of momilactones A (MA) and B (MB) on acute promyelocytic leukemia (APL) HL-60 and multiple myeloma (MM) U266 cell lines. Via the MTT test, MB and the mixture MAB (1:1, w / w ) exhibit a potent cytotoxicity on HL-60 (IC
50 = 4.49 and 4.61 µM, respectively), which are close to the well-known drugs doxorubicin, all-trans retinoic acid (ATRA), and the mixture of ATRA and arsenic trioxide (ATRA/ATO) (1:1, w / w ) (IC50 = 5.22, 3.99, and 3.67 µM, respectively). Meanwhile MB, MAB, and the standard suppressor doxorubicin substantially inhibit U266 (IC50 = 5.09, 5.59, and 0.24 µM, respectively). Notably, MB and MAB at 5 µM may promote HL-60 and U266 cell apoptosis by activating the phosphorylation of p-38 in the mitogen-activated protein kinase (MAPK) pathway and regulating the relevant proteins (BCL-2 and caspase-3) in the mitochondrial pathway. Besides, these compounds may induce G2 phase arrest in the HL-60 cell cycle through the activation of p-38 and disruption of CDK1 and cyclin B1 complex. Exceptionally, momilactones negligibly affect the non-cancerous cell line MeT-5A. This finding provides novel insights into the anticancer property of momilactones, which can be a premise for future studies and developments of momilactone-based anticancer medicines.- Published
- 2022
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11. Challenges and Priorities of Municipal Solid Waste Management in Cambodia.
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Pheakdey DV, Quan NV, Khanh TD, and Xuan TD
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- Cambodia, Cities, Humans, Incineration, Solid Waste analysis, Waste Disposal Facilities, Refuse Disposal, Waste Management
- Abstract
Municipal solid waste (MSW) management is one of the utmost challenges for Cambodia's city and district centers. The unsound management of MSW has detrimentally affected the environment and human health. In the present study, an attempt has been made to provide a comprehensive insight into the generation and characteristics, policies and legislation frameworks, management arrangement, collection, treatment, and disposal of MSW. The experience of developed and developing countries and the challenges and priorities of MSW management in Cambodia are also highlighted. In Cambodia, about 4.78 million tons of MSW were generated in 2020, with a 0.78 kg/capita/day generation rate. Only 86% of cities and districts have access to MSW collection services. The current practice of MSW management is reliance on landfill (44%). There are 164 landfills operating countrywide, receiving about 5749 tons of MSW per day. Recycling, incineration, and composting share 4%, 4%, and 2% of MSW generation, respectively. In 2021, the total revenue that was recovered from recyclables was USD 56M. The study concludes several major challenges and proposes valuable suggestions, which may be beneficial for the improvement of the current system to support the sustainable management of MSW in Cambodia.
- Published
- 2022
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12. Genomic regions and candidate genes selected during the breeding of rice in Vietnam.
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Higgins J, Santos B, Khanh TD, Trung KH, Duong TD, Doai NTP, Hall A, Dyer S, Ham LH, Caccamo M, and De Vega J
- Abstract
Vietnam harnesses a rich diversity of rice landraces adapted to a range of conditions, which constitute a largely untapped source of diversity for the continuous improvement of cultivars. We previously identified a strong population structure in Vietnamese rice, which is captured in five Indica and four Japonica subpopulations, including an outlying Indica-5 group. Here, we leveraged that strong differentiation and 672 native rice genomes to identify genomic regions and genes putatively selected during the breeding of rice in Vietnam. We identified significant distorted patterns in allele frequency (XP-CLR) and population differentiation scores ( F
ST ) resulting from differential selective pressures between native subpopulations, and later annotated them with QTLs previously identified by GWAS in the same panel. We particularly focussed on the outlying Indica-5 subpopulation because of its likely novelty and differential evolution, where we annotated 52 selected regions, which represented 8.1% of the rice genome. We annotated the 4576 genes in these regions and selected 65 candidate genes as promising breeding targets, several of which harboured alleles with nonsynonymous substitutions. Our results highlight genomic differences between traditional Vietnamese landraces, which are likely the product of adaption to multiple environmental conditions and regional culinary preferences in a very diverse country. We also verified the applicability of this genome scanning approach to identify potential regions harbouring novel loci and alleles to breed a new generation of sustainable and resilient rice., Competing Interests: The authors declare no conflicts of interest., (© 2022 The Authors. Evolutionary Applications published by John Wiley & Sons Ltd.)- Published
- 2022
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13. Effects of In Vitro Digestion on Anti-α-Amylase and Cytotoxic Potentials of Sargassum spp.
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Un S, Quan NV, Anh H, Lam VQ, Takami A, Khanh TD, and Xuan TD
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- Digestion, Hypoglycemic Agents pharmacology, Phytochemicals, alpha-Amylases, Sargassum chemistry, Seaweed
- Abstract
This is the first study to examine the effects of in vitro digestion on biological activities of Sargassum spp., a broadly known brown seaweed for therapeutic potential. Three fractions (F1-F3) were obtained from hexane extract by column chromatography. Under in vitro simulated digestion, the anti-α-amylase capacity of F1 in oral and intestinal phases increases, while it significantly decreases in the gastric phase. The α-amylase inhibition of F2 promotes throughout all digestive stages while the activity of F3 significantly reduces. The cytotoxic activity of F1 against U266 cell-line accelerates over the oral, gastric, and intestinal stages. The fractions F2 and F3 exhibited the declined cytotoxic potentialities in oral and gastric phases, but they were strengthened under intestinal condition. Palmitic acid and fucosterol may play an active role in antidiabetic and cytotoxic activity against multiple myeloma U266 cell line of Sargassum spp. However, the involvement of other phytochemicals in the seaweed should be further investigated.
- Published
- 2022
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14. Anti-Diabetes, Anti-Gout, and Anti-Leukemia Properties of Essential Oils from Natural Spices Clausena indica , Zanthoxylum rhetsa , and Michelia tonkinensis .
- Author
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Quan NV, Anh H, Lam VQ, Takami A, Teschke R, Khanh TD, and Xuan TD
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- Humans, Oils, Volatile chemistry, Antineoplastic Agents therapeutic use, Clausena chemistry, Gout Suppressants therapeutic use, Hypoglycemic Agents therapeutic use, Leukemia drug therapy, Magnoliaceae chemistry, Oils, Volatile therapeutic use, Zanthoxylum chemistry
- Abstract
Essential oils (EOs) of Clausena indica fruits, Zanthoxylum rhetsa fruits, and Michelia tonkinensis seeds were analyzed for their phytochemical profiles and biological activities, including anti-diabetes, anti-gout, and anti-leukemia properties. Sixty-six volatile compounds were identified by gas chromatography-mass spectrometry (GC-MS), in which, myristicin (68.3%), limonene (44.2%), and linalool (49.3%) were the most prominent components of EOs extracted from C. indica , Z. rhetsa , and M. tonkinensis , respectively. In addition, only EOs from C. indica inhibited the activities of all tested enzymes comprising α-amylase (IC
50 = 7.73 mg/mL), α-glucosidase (IC50 = 0.84 mg/mL), and xanthine oxidase (IC50 = 0.88 mg/mL), which are related to type 2 diabetes and gout. Remarkably, all EOs from C. indica , Z. rhetsa (IC50 = 0.73 mg/mL), and M. tonkinensis (IC50 = 1.46 mg/mL) showed a stronger anti-α-glucosidase ability than acarbose (IC50 = 2.69 mg/mL), a known anti-diabetic agent. Moreover, the growth of leukemia cell Meg-01 was significantly suppressed by all EOs, of which, the IC50 values were recorded as 0.32, 0.64, and 0.31 mg/mL for EOs from C. indica , Z. rhetsa , and M. tonkinensis , respectively. As it stands, this is the first report about the inhibitory effects of EOs from C. indica and Z. rhetsa fruits, and M. tonkinensis seeds on the human leukemia cell line Meg-01 and key enzymes linked to diabetes and gout. In conclusion, the present study suggests that EOs from these natural spices may be promising candidates for pharmaceutical industries to develop nature-based drugs to treat diabetes mellitus or gout, as well as malignant hematological diseases such as leukemia.- Published
- 2022
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15. Resequencing of 672 Native Rice Accessions to Explore Genetic Diversity and Trait Associations in Vietnam.
- Author
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Higgins J, Santos B, Khanh TD, Trung KH, Duong TD, Doai NTP, Khoa NT, Ha DTT, Diep NT, Dung KT, Phi CN, Thuy TT, Tuan NT, Tran HD, Trung NT, Giang HT, Nhung TK, Tran CD, Lang SV, Nghia T, Van Giang N, Xuan TD, Hall A, Dyer S, Ham LH, Caccamo M, and De Vega JJ
- Abstract
Background: Vietnam possesses a vast diversity of rice landraces due to its geographical situation, latitudinal range, and a variety of ecosystems. This genetic diversity constitutes a highly valuable resource at a time when the highest rice production areas in the low-lying Mekong and Red River Deltas are enduring increasing threats from climate changes, particularly in rainfall and temperature patterns., Results: We analysed 672 Vietnamese rice genomes, 616 newly sequenced, that encompass the range of rice varieties grown in the diverse ecosystems found throughout Vietnam. We described four Japonica and five Indica subpopulations within Vietnam likely adapted to the region of origin. We compared the population structure and genetic diversity of these Vietnamese rice genomes to the 3000 genomes of Asian cultivated rice. The named Indica-5 (I5) subpopulation was expanded in Vietnam and contained lowland Indica accessions, which had very low shared ancestry with accessions from any other subpopulation and were previously overlooked as admixtures. We scored phenotypic measurements for nineteen traits and identified 453 unique genotype-phenotype significant associations comprising twenty-one QTLs (quantitative trait loci). The strongest associations were observed for grain size traits, while weaker associations were observed for a range of characteristics, including panicle length, heading date and leaf width., Conclusions: We showed how the rice diversity within Vietnam relates to the wider Asian rice diversity by using a number of approaches to provide a clear picture of the novel diversity present within Vietnam, mainly around the Indica-5 subpopulation. Our results highlight differences in genome composition and trait associations among traditional Vietnamese rice accessions, which are likely the product of adaption to multiple environmental conditions and regional preferences in a very diverse country. Our results highlighted traits and their associated genomic regions that are a potential source of novel loci and alleles to breed a new generation of low input sustainable and climate resilient rice.
- Published
- 2021
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16. LED Lights Promote Growth and Flavonoid Accumulation of Anoectochilus roxburghii and Are Linked to the Enhanced Expression of Several Related Genes.
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Gam DT, Khoi PH, Ngoc PB, Linh LK, Hung NK, Anh PTL, Thu NT, Hien NTT, Khanh TD, and Ha CH
- Abstract
Anoectochilus roxburghii is a wild edible species and has been traditionally used for a wide range of diseases in many countries. Our research aims to find the optimal light-emitting diode (LED) lighting conditions to improve the growth and development of A. roxburghii seedling at the acclimation stage. Two-month-old explants were cultured under the various lighting conditions including red (R), blue (B), BR (one blue: four red), BRW151 (one blue: five red: one white), BRW142 (one blue: four red: two white), and fluorescent lamp (FL). The results showed that the lighting conditions not only affect the growth and morphology of plants but also the accumulation of total flavonoids. Single wavelengths (B or R LED) inhibited the growth and secondary biosynthesis of A. roxburghii , while the BR LED showed an enhancement in both growth and biomass accumulation. A. roxburghii plants were grown under BR LED light has average plant height (7.18 cm), stem diameter (17.6mm), number of leaves (5.78 leaves/tree), leaf area (4.67 cm
2 ), fresh weight (0.459 g/tree), dry matter percentages (11.69%), and total flavonoid (1.811 mg/g FW) is considered to be superior to FL lamps and other LEDs in the experiment. This indicates that both blue and red wavelengths are required for the normal growth of A. roxburghii . To learn more about how light affects flavonoid biosynthesis, we evaluated the expression of genes involved in this process ( pal , chs , chi , and fls ) and found that BR LED light enhances the expression level of chi and fls genes compared to fluorescent lamps (1.18 and 1.21 times, respectively), leading to an increase in the flavonoid content of plant. Therefore, applying BR LED during in vitro propagation of A. roxburghii could be a feasible way to improve the medicinal value of this plant.- Published
- 2020
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17. Mapping-by-Sequencing via MutMap Identifies a Mutation in ZmCLE7 Underlying Fasciation in a Newly Developed EMS Mutant Population in an Elite Tropical Maize Inbred.
- Author
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Tran QH, Bui NH, Kappel C, Dau NTN, Nguyen LT, Tran TT, Khanh TD, Trung KH, Lenhard M, and Vi SL
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- Chromosome Mapping methods, Edible Grain genetics, Ethyl Methanesulfonate, Hybrid Vigor, Plant Breeding methods, Plant Proteins genetics, Promoter Regions, Genetic, Sequence Analysis, DNA methods, Zea mays growth & development, Chromosomes, Plant genetics, Mutation, Zea mays genetics
- Abstract
Induced point mutations are important genetic resources for their ability to create hypo- and hypermorphic alleles that are useful for understanding gene functions and breeding. However, such mutant populations have only been developed for a few temperate maize varieties, mainly B73 and W22, yet no tropical maize inbred lines have been mutagenized and made available to the public to date. We developed a novel Ethyl Methanesulfonate (EMS) induced mutation resource in maize comprising 2050 independent M2 mutant families in the elite tropical maize inbred ML10. By phenotypic screening, we showed that this population is of comparable quality with other mutagenized populations in maize. To illustrate the usefulness of this population for gene discovery, we performed rapid mapping-by-sequencing to clone a fasciated-ear mutant and identify a causal promoter deletion in ZmCLE7 (CLE7) . Our mapping procedure does not require crossing to an unrelated parent, thus is suitable for mapping subtle traits and ones affected by heterosis. This first EMS population in tropical maize is expected to be very useful for the maize research community. Also, the EMS mutagenesis and rapid mapping-by-sequencing pipeline described here illustrate the power of performing forward genetics in diverse maize germplasms of choice, which can lead to novel gene discovery due to divergent genetic backgrounds.
- Published
- 2020
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18. Momilactones A, B, and Tricin in Rice Grain and By-Products are Potential Skin Aging Inhibitors.
- Author
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Quan NV, Thien DD, Khanh TD, Tran HD, and Xuan TD
- Abstract
We previously reported the inhibitory potentials of momilactones A (MA) and B (MB) against key enzymes related to type 2 diabetes and obesity. In this study, antioxidant and anti-skin-aging activities of MA and MB were investigated and compared with tricin, a well-known antioxidant and antiaging flavonoid in rice. MA, MB, and tricin were purified from rice husk by column chromatography and their biological activities were subsequently assayed by in vitro trials. The contents of MA, MB, and tricin of different commercial rice cultivars in Japan were quantified and confirmed by ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS) and high-performance liquid chromatography (HPLC) analyses. The antioxidant assays revealed a synergistic activity of the mixture MA and MB (MAB, 1:1, v/v ). In addition, in 2,2'-azino-bis (ABTS) assay, IC
50 values of MAB (0.3 mg/mL) and tricin (0.3 mg/mL) was 4-fold and 9-fold greater than that of individual MB (1.3 mg/mL) or MA (2.8 mg/mL), respectively. The in vitro enzymatic assays on pancreatic elastase and tyrosinase indicated that MA and MB were potential to relief skin wrinkles and freckles. In detail, MA exerted higher inhibition on both enzymatic activities (30.9 and 37.6% for elastase and tyrosinase inhibition, respectively) than MB (18.5 and 12.6%) and MAB (32.0 and 19.7%) at a concentration of 2.0 mg/mL. Notably, MA and the mixture MAB exhibited stronger inhibitions on elastase and tyrosinase in comparison with tricin and vanillin. MA, MB, and tricin in rice are potential to develop cosmetics as well as supplements for skin aging treatments., Competing Interests: The authors declare no conflict of interest.- Published
- 2019
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19. Cordycepin Isolated from Cordyceps militaris : Its Newly Discovered Herbicidal Property and Potential Plant-Based Novel Alternative to Glyphosate.
- Author
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Quy TN, Xuan TD, Andriana Y, Tran HD, Khanh TD, and Teschke R
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- Glycine analogs & derivatives, Glyphosate, Cordyceps chemistry, Deoxyadenosines chemistry, Deoxyadenosines isolation & purification, Deoxyadenosines pharmacology, Herbicides chemistry, Herbicides isolation & purification, Herbicides pharmacology, Raphanus growth & development
- Abstract
There is currently much interest in finding new phytochemicals among plants and fungi as nature-based alternatives to replace problematic herbicides such as glyphosate, which are preferentially used in agricultural production n. We discovered striking herbicidal potency in Cordyceps militaris (L.) and identified cordycepin as its principal plant growth inhibitor. Cordycepin obtained as an ethyl acetate extract was subjected to column chromatography and evaluated for its bioassay-guided phytotoxic capacity against Raphanus sativus (radish), showing a maximum inhibition on germination and growth of radish (IC
50 = 0.052-0.078 mg/mL). Gas chromatography-mass spectrometry (GC-MS) ( m / z : 251.2) and liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) ([M + Na]+ m / z : 274.1; [M + H]+ m / z : 252.1) analyses confirmed cordycepin as the major component of the tested column fraction (55.38%). At 0.04 mg/mL, cordycepin showed 3.8-5.9- and 3.3-3.7-fold greater inhibition of the germination and growth of radish than benzoic acid (BA) and glyphosate, respectively. Compared with BA, isolated cordycepin reduced plant chlorophyll and carotenoid contents (2.0-9.5 -fold), while proline, total phenolic and total flavonoid contents were increased 1.2-1.8-fold. Finally, cordycepin promoted electrolyte leakage and malondialdehyde accumulation in radish aerial parts. Thus, cordycepin successfully isolated from Cordyceps militaris is a highly potent plant growth inhibitor with pending worldwide patent and may become a potential plant-based novel alternative to the disputed glyphosate., Competing Interests: The authors declare no conflict of interest.- Published
- 2019
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20. Allelochemicals and Signaling Chemicals in Plants.
- Author
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Kong CH, Xuan TD, Khanh TD, Tran HD, and Trung NT
- Subjects
- Crops, Agricultural chemistry, Herbivory, Pest Control, Pheromones pharmacology, Phytochemicals chemistry, Phytochemicals pharmacology, Plant Breeding, Allelopathy, Pheromones chemistry, Plant Physiological Phenomena, Plants chemistry
- Abstract
Plants abound with active ingredients. Among these natural constituents, allelochemicals and signaling chemicals that are released into the environments play important roles in regulating the interactions between plants and other organisms. Allelochemicals participate in the defense of plants against microbial attack, herbivore predation, and/or competition with other plants, most notably in allelopathy, which affects the establishment of competing plants. Allelochemicals could be leads for new pesticide discovery efforts. Signaling chemicals are involved in plant neighbor detection or pest identification, and they induce the production and release of plant defensive metabolites. Through the signaling chemicals, plants can either detect or identify competitors, herbivores, or pathogens, and respond by increasing defensive metabolites levels, providing an advantage for their own growth. The plant-organism interactions that are mediated by allelochemicals and signaling chemicals take place both aboveground and belowground. In the case of aboveground interactions, mediated air-borne chemicals are well established. Belowground interactions, particularly in the context of soil-borne chemicals driving signaling interactions, are largely unknown, due to the complexity of plant-soil interactions. The lack of effective and reliable methods of identification and clarification their mode of actions is one of the greatest challenges with soil-borne allelochemicals and signaling chemicals. Recent developments in methodological strategies aim at the quality, quantity, and spatiotemporal dynamics of soil-borne chemicals. This review outlines recent research regarding plant-derived allelochemicals and signaling chemicals, as well as their roles in agricultural pest management. The effort represents a mechanistically exhaustive view of plant-organism interactions that are mediated by allelochemicals and signaling chemicals and provides more realistic insights into potential implications and applications in sustainable agriculture.
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- 2019
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21. Contribution of momilactones A and B to diabetes inhibitory potential of rice bran: Evidence from in vitro assays.
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Quan NV, Xuan TD, Tran HD, Ahmad A, Khanh TD, and Dat TD
- Abstract
This study was the first to detect the presence of the two compounds momilactone A (MA) and momilactone B (MB) in rice bran using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). By in vitro assays, both MA and MB exhibited potent inhibitory activities on pancreatic α-amylase and α-glucosidase which were significantly higher than γ-oryzanol, a well-known diabetes inhibitor. Remarkably, MA and MB indicated an effective inhibition on trypsin with the IC
50 values of 921.55 and 884.03 µg/mL, respectively. By high-performance liquid chromatography (HPLC), quantities of MA (6.65 µg/g dry weight) and MB (6.24 µg/g dry weight) in rice bran were determined. Findings of this study revealed the α-amylase, α-glucosidase and trypsin inhibitors MA and MB contributed an active role to the diabetes inhibitory potential of rice bran.- Published
- 2019
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22. Isolation and Purification of Bioactive Compounds from the Stem Bark of Jatropha podagrica .
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Minh TN, Xuan TD, Tran HD, Van TM, Andriana Y, Khanh TD, Quan NV, and Ahmad A
- Subjects
- Anti-Bacterial Agents isolation & purification, Anti-Bacterial Agents pharmacology, Antioxidants isolation & purification, Antioxidants pharmacology, Benzothiazoles chemistry, Biphenyl Compounds chemistry, Biphenyl Compounds pharmacology, Cell Proliferation drug effects, Coumarins chemistry, Coumarins pharmacology, Gallic Acid analogs & derivatives, Gallic Acid chemistry, Gallic Acid pharmacology, Humans, Microbial Sensitivity Tests, Picrates chemistry, Plant Bark chemistry, Plant Stems chemistry, Spectrometry, Mass, Electrospray Ionization, Staphylococcus aureus pathogenicity, Sulfonic Acids chemistry, Antioxidants chemistry, Jatropha chemistry, Plant Extracts chemistry, Staphylococcus aureus drug effects
- Abstract
This paper reports the successive isolation and purification of bioactive compounds from the stem bark of Jatropha podagrica , a widely known medicinal plant. The ethyl acetate extract of the stem bark exhibited the strongest antioxidant activity assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP) assays (IC
50 = 46.7, 66.0, and 492.6, respectively). By column chromatography (CC) with elution of hexane and ethyl acetate at 8:2, 7:3, and 6:4 ratios, the isolation of this active extract yielded five fractions ( C1 ⁻ C5 ). Chemical structures of the constituents included in C1 ⁻ C5 were elucidated by gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) and resolved as methyl gallate ( C1 , C2 , C3 , C4 ), gallic acid ( C1 , C2 ), fraxetin ( C2 , C3 , C4 , C5 ), and tomentin ( C3 ). Mixture C2 (IC50 DPPH and ABTS = 2.5 µg/mL) and C3 (IC50 FRAP = 381 µg/mL) showed the highest antioxidant properties. Among the isolated fractions, C4 was the most potential agent in growth inhibition of six bacterial strains including Staphylococcus aureus , Escherichia coli , Klebsiella pneumoniae, Listeria monocytogenes, Bacillus subtilis , and Proteus mirabilis (MIC = 5, 20, 30, 20, 25, and 20 mg/mL, respectively). All identified constituents exerted an inhibitory activity on the growth of Lactuca sativa , of which the mixture C3 performed the maximal inhibition on shoot (IC50 = 49.4 µg/mL) and root (IC50 = 47.1 µg/mL) growth. Findings of this study suggest that gallic acid, methyl gallate, fraxetin, and tomentin isolated from J. podagrica possessed antioxidant, antibacterial, and growth inhibitory potentials.- Published
- 2019
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23. Phytochemical Analysis and Potential Biological Activities of Essential Oil from Rice Leaf.
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Minh TN, Xuan TD, Van TM, Andriana Y, Viet TD, Khanh TD, and Tran HD
- Subjects
- Gas Chromatography-Mass Spectrometry, Lactuca drug effects, Phytochemicals pharmacology, Plant Leaves chemistry, Plant Roots chemistry, Raphanus drug effects, Ricinoleic Acids chemistry, Seedlings drug effects, Spectrometry, Mass, Electrospray Ionization, Xanthine Oxidase chemistry, alpha-Linolenic Acid chemistry, Antioxidants chemistry, Oils, Volatile chemistry, Oryza chemistry, Phytochemicals chemistry
- Abstract
Although many investigations on phytochemicals in rice plant parts and root exudates have been conducted, information on the chemical profile of essential oil (EO) and potent biological activities has been limited. In this study, chemical compositions of rice leaf EO and in vitro biological activities were investigated. From 1.5 kg of fresh rice leaves, an amount of 20 mg EO was obtained by distillation and analyzed by gas chromatography-mass spectrometry (GC-MS), electrospray ionization (ESI), and atmospheric pressure chemical ionization (APCI) to reveal the presence of twelve volatile constituents, of which methyl ricinoleate (27.86%) was the principal compound, followed by palmitic acid (17.34%), and linolenic acid (11.16%), while 2-pentadecanone was the least (2.13%). Two phytoalexin momilactones A and B were first time identified in EO using ultra-performance liquid chromatography coupled with electrospray mass spectrometry (UPLC/ESI-MS) (9.80 and 4.93 ng/g fresh weight, respectively), which accounted for 7.35% and 3.70% of the EO, respectively. The assays of DPPH (IC
50 = 73.1 µg/mL), ABTS (IC50 = 198.3 µg/mL), FRAP (IC50 = 700.8 µg/mL) and β-carotene oxidation (LPI = 79%) revealed that EO possessed an excellent antioxidant activity. The xanthine oxidase assay indicated that the anti-hyperuricemia potential was in a moderate level (IC50 = 526 µg/mL) as compared with the standard allopurinol. The EO exerted potent inhibition on growth of Raphanus sativus, Lactuca sativa , and two noxious weeds Echinochloa crus-galli , and Bidens pilosa , but in contrast, the growth of rice seedlings was promoted. Among the examined plants, the growth of the E. crus-galli root was the most inhibited, proposing that constituents found in EO may have potential for the control of the problematic paddy weed E. crus-galli . It was found that the EO of rice leaves contained rich phytochemicals, which were potent in antioxidants and gout treatment, as well as weed management. Findings of this study highlighted the potential value of rice leaves, which may provide extra benefits for rice farmers.- Published
- 2019
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24. Momilactones A and B Are α-Amylase and α-Glucosidase Inhibitors.
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Quan NV, Tran HD, Xuan TD, Ahmad A, Dat TD, Khanh TD, and Teschke R
- Subjects
- Amylases antagonists & inhibitors, alpha-Glucosidases metabolism, Diterpenes pharmacology, Glycoside Hydrolase Inhibitors chemistry, Lactones pharmacology, Oryza chemistry, alpha-Amylases antagonists & inhibitors
- Abstract
Momilactones A (MA) and B (MB) are the active phytoalexins and allelochemicals in rice. In this study, MA and MB were purified from rice husk of Oryza sativa cv. Koshihikari by column chromatography, and purification was confirmed by high-performance liquid chromatography, thin-layer chromatography, gas chromatography-mass spectrometry, liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS), and ¹H and
13 C nuclear magnetic resonance analyses. By in vitro assays, both MA and MB exerted potent inhibition on α-amylase and α-glucosidase activities. The inhibitory effect of MB on these two key enzymes was greater than that of MA. Both MA and MB exerted greater α-glucosidase suppression as compared to that of the commercial diabetic inhibitor acarbose. Quantities of MA and MB in rice grain were 2.07 ± 0.01 and 1.06 ± 0.01 µg/dry weight (DW), respectively. This study was the first to confirm the presence of MA and MB in refined rice grain and reported the α-amylase and α-glucosidase inhibitory activity of the two compounds. The improved protocol of LC-ESI-MS in this research was simple and effective to detect and isolate MA and MB in rice organs.- Published
- 2019
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25. Heavy Metal Accumulation in Water, Soil, and Plants of Municipal Solid Waste Landfill in Vientiane, Laos.
- Author
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Vongdala N, Tran HD, Xuan TD, Teschke R, and Khanh TD
- Subjects
- Environmental Pollutants metabolism, Environmental Pollutants standards, Food Contamination analysis, Laos, Metals, Heavy metabolism, Metals, Heavy standards, Soil chemistry, Waste Disposal Facilities standards, Water chemistry, Environmental Monitoring, Environmental Pollutants analysis, Metals, Heavy analysis, Plants metabolism, Solid Waste analysis, Waste Disposal Facilities statistics & numerical data
- Abstract
The municipal solid waste (MSW) landfill in Vientiane, Laos, which receives > 300 tons of waste daily, of which approximately 50% is organic matter, has caused serious environmental problems. This study was conducted to investigate the accumulated levels of heavy metals (HMs) (cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn)) in water (surface and groundwater), soil, and plants between dry and wet seasons according to the standards of the Agreement on the National Environmental Standards of Laos (ANESs), Dutch Pollutant Standards (DPSs), and the World Health Organization (WHO), respectively. Although no impact of pollution on the surface water was observed, the levels of Cr and Pb in the groundwater significantly exceeded the basics of ANESs and WHO in both seasons. The pollution caused by Cd and Cu reached the eco-toxicological risk level in the landfill soils and its vicinity. The vegetable Ipomoea aquatica , which is consumed by the nearby villagers, was seriously contaminated by Cr, Pb, Cu, and Zn, as the accumulation of these toxic metals was elevated to much greater levels as compared to the WHO standards. For the grass Pennisetum purpureum (elephant grass), the quantities of HMs in all plant parts were extreme, perhaps due to the deeper growth of its rhizome than I. aquatica . This study is the first to warn of serious HM pollution occurring in the water, soil, and plants in the MSW landfill of Vientiane, Laos, which requires urgent phytoremediation. The indication of what sources from the MSW principally cause the pollution of HMs is needed to help reduce the toxicological risks on Lao residents and the environment in Vientiane as well.
- Published
- 2018
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26. Allelopathic Responses of Rice Seedlings under Some Different Stresses.
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Khanh TD, Anh H, Nghia T, Huu Trung K, Bich Hien P, Minh Trung D, and Dang Xuan T
- Abstract
The objective of this study was to evaluate the allelopathic responses of rice seedlings under submergence stress at different temperatures (10, 25, 32, and 37 °. The results showed that a wide range of allelopathic responses of rice seedlings depended on varieties and stress conditions, with temperature was being a key factor. It showed that the extracts of rice seedlings induced significant suppression on lettuce and radish seedling germination, but had negligible allelopathic effects on growth of barnyardgrass, whilst the emergence and growth of natural weeds was stimulated. In contrast, the root exudates of Koshihikari rice seedlings (K32) at 32 °C reduced the number of total weeds by ≈60.0% and the total dry weight of weeds by 93.0%; i.e., to a greater extent than other root exudates. Among the 13 identified phenolic acids, p- hydroxybenzoic, vanillic, syringic, sinapic and benzoic acids—at concentrations of 0.360, 0.045, 3.052, 1.309 and 5.543 μg/mL might be involved in allelopathic responses of K32, inhibiting the growth of barnyardgrass and natural weeds. Findings of the present study may provide useful information on allelopathic responses of rice under environmental stresses and thus further understand of the competitive relationships between rice and weeds under natural conditions.
- Published
- 2018
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27. Association and Expression of Virulence from Plasmids of the Group B Strain in Pseudomonas syringae pv. eriobotryae.
- Author
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Khanh TD and Xuan TD
- Abstract
Pseudomonas syringae pv. eriobotryae causes serious stem canker in loquat ( Eriobotrya japonica ) trees. This study was conducted to determine whether plasmids are involved with its virulence. The strain NAE89, which belonged to the B group, harbored two plasmids at approximately 6.2 and 50 Mdal that caused stem canker and halo leaf spots on loquat plants. Following digestion with Bam HI and ligation into the Bam HI cloning site of the broad range host cosmid pLAFR3, four DNA fragments at 3.8, 6.6, 12.3, and 22.8 kb were generated. Although the plasmid-encoded virulence gene psv A was undigested with the Bam HI, the halo leaf spot gene may be adjacent to the psv A gene was digested. A pLAFR3 cosmid clone was introduced into the non-pathogenic PE0 and NAE89-1 strains by triparental matings and the pathogenicity was recovered. As a result, the pLAFR3 cosmid clone was introduced into the largest size DNA fragment of 22.8 kb and determined to be the causal agent of canker on the stem of the loquat. This study revealed that the psv A gene, previously found in the 50 Mdal plasmid, was also observed in the 22.8 kb DNA fragment., Competing Interests: The authors declare no conflict of interests.
- Published
- 2018
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28. An Overview of Chemical Profiles, Antioxidant and Antimicrobial Activities of Commercial Vegetable Edible Oils Marketed in Japan.
- Author
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Xuan TD, Gangqiang G, Minh TN, Quy TN, and Khanh TD
- Abstract
This study analyzed chemical components and investigated the antioxidant and antimicrobial activities of fourteen vegetable edible oils marketed in Japan. High-performance liquid chromatography (HPLC) was used to identify and quantify principal phenolic acids and flavonoids. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, sunflower, safflower, canola, soybean, Inca inchi, sesame, and rice bran showed markedly greater activity, whilst the percentage of lipid peroxidation inhibition (LPI%) in sunflower, canola, cotton, grape, flax, perilla, Inca inchi, perillartine, and rice bran were significantly higher than other oils. Maximum total phenol content (TPC) was recorded in flax, followed by perillartine, rice bran, and perilla, whereas total flavonoid content (TFC) was the greatest in Inca inchi and sesame. Benzoic acid was the most common constituent, followed by vanillic acid, p -hydroxybenzoic acid, ferulic acid, and p -coumaric acid. On the other hand, luteolin was the most abundant flavonoid, followed by esculetin, myricetin, isoquercetin, and kaempferol, while fisetin was detected only in sunflower. In general, all of the edible oils showed antimicrobial activity, but the growth inhibition of Staphylococcus aureus and Escherichia coli of cotton, grape, chia, sesame, and rice bran were greater than other oils., Competing Interests: The authors declare no conflict of interest.
- Published
- 2018
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29. Weed Suppressing Potential and Isolation of Potent Plant Growth Inhibitors from Castanea crenata Sieb. et Zucc.
- Author
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Tuyen PT, Xuan TD, Tu Anh TT, Mai Van T, Ahmad A, Elzaawely AA, and Khanh TD
- Subjects
- Germination drug effects, Molecular Structure, Plant Extracts chemistry, Plant Extracts pharmacology, Plant Roots drug effects, Seedlings drug effects, Fagaceae chemistry, Herbicides chemistry, Herbicides pharmacology, Plant Weeds drug effects, Weed Control
- Abstract
This study isolated, determined, and quantified plant growth inhibitors in Japanese chestnut ( Castanea crenata Sieb. et Zucc), a deciduous species native to Japan and Korea. In laboratory assays, C. crenata leaves showed strong inhibition on germination and seedling growth of Echinochloa crus-galli (barnyardgrass), Lactuca sativa (lettuce), and Raphanus sativus (radish). Laboratory and greenhouse trials showed that leaves of C. crenata appeared as a promising material to manage weeds, especially the dicot weeds. By GC-MS and HPLC analyses, gallic, protocatechuic, p -hydroxybenzoic, caffeic, ferulic, ellagic, and cinnamic acids were identified and quantified, of which ellagic acid was present in the highest quantity (2.36 mg/g dried leaves). By column chromatography and spectral data (¹H- and
13 C-NMR, IR, and LC-MS) analysis, a compound identified as 2α,3β,7β,23-tetrahydroxyurs-12-ene-28-oic acid ( 1 ) was purified from the methanolic leaf extract of C. crenata (0.93 mg/g dried leaves). This constituent showed potent inhibition on growth of E. crus-galli , a problematic weed in agricultural practice. The inhibition of the compound 1 (IC50 = 2.62 and 0.41 mM) was >5 fold greater than that of p -hydroxybenzoic acid (IC50 = 15.33 and 2.11 mM) on shoot and root growth of E. crus-galli , respectively. Results suggest that the isolated the compound 1 has potential to develop natural herbicides to manage E. crus-galli . This study is the first to isolate and identify 2α,3β,7β,23-tetrahydroxyurs-12-ene-28-oic acid in a plant and report its plant growth inhibitory potential., Competing Interests: The authors declare no conflict of interest.- Published
- 2018
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30. Potential Use of Plant Waste from the Moth Orchid (Phalaenopsis Sogo Yukidian "V3") as an Antioxidant Source.
- Author
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Minh TN, Tuyen PT, Khang DT, Quan NV, Ha PTT, Quan NT, Andriana Y, Xinyan F, Van TM, Khanh TD, and Xuan TD
- Abstract
This research was conducted to exploit the waste of used plant parts from the widely marketed moth orchid cultivar ( Phalaenopsis Sogo Yukidian "V3"). Various extracts of roots, stems, and leaves were evaluated for total phenolics, total flavonoids, and antioxidant capacity. The bound extract from stems contained the highest total phenolics (5.092 ± 0.739 mg GAE (gallic acid equivalent)/g DW (dry weight)). The maximum total flavonoids (2.218 ± 0.021 mg RE (rutin equivalent)/g DW) were found in the hexane extract of leaves. Ethyl acetate extract from roots showed the greatest antioxidant activity compared to other extracts. Of these extracts, the IC
50 values of these samples were 0.070 mg/mL, and 0.450 mg/mL in a free radical 1,-diphenyl-picryl-hydrazyl (DPPH) assay and reducing power method, respectively. The lipid peroxidation inhibition (LPI) was found to be 94.2% using the β-carotene bleaching method. Five phenolic compounds including caffeic acid, syringic acid, vanillin, ellagic acid, and cinnamic acid were quantified by high performance liquid chromatography (HPLC). It is suggested that the roots of the hybrid Phalaenopsis Sogo Yukidian "V3" cultivar may be exploited as an effective source of antioxidants., Competing Interests: The authors declare no conflict of interest.- Published
- 2017
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31. Whole Genome Sequencing Reveals the Islands of Novel Polymorphisms in Two Native Aromatic Japonica Rice Landraces from Vietnam.
- Author
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Trung KH, Nguyen TK, Khuat HBT, Nguyen TD, Khanh TD, Xuan TD, and Nguyen XH
- Subjects
- Breeding, Oryza classification, Vietnam, Whole Genome Sequencing, Genome, Plant, Oryza genetics, Polymorphism, Genetic
- Abstract
Elucidation of the rice genome will not only broaden our understanding of genetic characterization of the agronomic characteristics but also facilitate the rice genetic improvement through marker assisted breeding. However, the genome resources of aromatic rice varieties are largely unexploited. Therefore, the whole genome of two elite aromatic traditional japonica rice landraces in North Vietnam, Tam Xoan Bac Ninh (TXBN), and Tam Xoan Hai Hau (TXHH), was sequenced to identify their genome-wide polymorphisms. Overall, we identified over 40,000 novel polymorphisms in each aromatic rice landrace. Although a discontinuous 8-bp deletion and an A/T SNP just upstream the 5-bp deletion in exon 7 of BADH2 gene were present in both rice landraces, the number of SNP high resolution regions of TXBN was six times higher than that of TXHH. Furthermore, several hot spot regions of novel SNPs and indels were found in both genomes, providing their potential gene pools related to aroma formation. The genomic information of two aromatic rice landraces described in this study will facilitate the identification of fragrance-related genes and the genetic improvement of rice., (© The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.)
- Published
- 2017
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32. Whole-Genome Characteristics and Polymorphic Analysis of Vietnamese Rice Landraces as a Comprehensive Information Resource for Marker-Assisted Selection.
- Author
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Trinh H, Nguyen KT, Nguyen LV, Pham HQ, Huong CT, Xuan TD, Anh H, Caccamo M, Ayling S, Diep NT, Nguyen C, Trung KH, and Khanh TD
- Abstract
Next generation sequencing technologies have provided numerous opportunities for application in the study of whole plant genomes. In this study, we present the sequencing and bioinformatic analyses of five typical rice landraces including three indica and two japonica with potential blast resistance. A total of 688.4 million 100 bp paired-end reads have yielded approximately 30-fold coverage to compare with the Nipponbare reference genome. Among them, a small number of reads were mapped to both chromosomes and organellar genomes. Over two million and eight hundred thousand single nucleotide polymorphisms (SNPs) and insertions and deletions (InDels) in indica and japonica lines have been determined, which potentially have significant impacts on multiple transcripts of genes. SNP deserts, contiguous SNP-low regions, were found on chromosomes 1, 4, and 5 of all genomes of rice examined. Based on the distribution of SNPs per 100 kilobase pairs, the phylogenetic relationships among the landraces have been constructed. This is the first step towards revealing several salient features of rice genomes in Vietnam and providing significant information resources to further marker-assisted selection (MAS) in rice breeding programs., Competing Interests: The authors declare that they have no competing interests.
- Published
- 2017
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33. Chemistry and pharmacology of Bidens pilosa : an overview.
- Author
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Xuan TD and Khanh TD
- Abstract
Bidens pilosa L. is an edible herb and has been traditionally used for a wide range of ailments in many countries. The aim of this review is to present comprehensive information of the chemical constituents, nutraceutical and ethnomedical uses as well as the biological and pharmacological effects and toxicity of this plant based on 218 literary sources reported over 40 years. Major chemical constituents (including 301 compounds) belonging to polyacetylenes, polyacetylene glycosides, flavonoids, flavone glycosides, aurones, chalcones, okanin glycosides, phenolic acids, terpenes, pheophytins, fatty acids and phytosterols have been identified or isolated from the different parts of this plant. Many of them have been considered as the bioactive compounds which are potentially responsible for the pharmacological actions. Various types of preparations, extracts and individual compounds derived from this plant have been found to possess biological and pharmacological activities such as anti-malarial, anti-allergy, anti-hypertensive and smooth muscle relaxant, anti-cancerogenic, anti-diabetic, anti-inflammatory, anti-microbial, antioxidant. The results of data analysis on the chemicals, pharmacological and toxicological characteristics of B. pilosa validate the view of its folk worldwide-medicinal uses. This herb has a great beneficial therapeutic property and is possibly used for complement or alternative to pharmaceutical drugs in some specific cases. However, this herb is known as hyperaccumulator and as-excluder; therefore, harvesting the herb for medicinal uses should be judiciously cautioned., (© The Korean Society of Pharmaceutical Sciences and Technology 2016.)
- Published
- 2016
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34. Molecular Breeding to Improve Salt Tolerance of Rice (Oryza sativa L.) in the Red River Delta of Vietnam.
- Author
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Linh le H, Linh TH, Xuan TD, Ham le H, Ismail AM, and Khanh TD
- Abstract
Rice is a stable food in Vietnam and plays a key role in the economy of the country. However, the production and the cultivating areas are adversely affected from the threats of devastation caused by the rise of sea level. Using marker-assisted backcrossing (MABC) to develop a new salt tolerance rice cultivar is one of the feasible methods to cope with these devastating changes. To improve rice salt tolerance in BT7 cultivar, FL478 was used as a donor parent to introgress the Saltol QTL conferring salt tolerance into BT7. Three backcrosses were conducted and successfully transferred positive alleles of Saltol from FL478 into BT7. The plants numbers IL-30 and IL-32 in BC(3)F(1) population expected recurrent genome recovery of up to 99.2% and 100%, respectively. These selected lines that carried the Saltol alleles were screened in field for their agronomic traits. All improved lines had Saltol allele similar to the donor parent FL478, whereas their agronomic performances were the same as the original BT7. We show here the success of improving rice salt tolerance by MABC and the high efficiency of selection in early generations. In the present study, MABC has accelerated the development of superior qualities in the genetic background of BT7.
- Published
- 2012
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35. Chemical interaction in the invasiveness of cogongrass (Imperata cylindrica (L.) Beauv.).
- Author
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Xuan TD, Toyama T, Fukuta M, Khanh TD, and Tawata S
- Subjects
- Poaceae growth & development, Rhizome chemistry, Rhizome growth & development, Rhizome physiology, Plant Extracts analysis, Poaceae chemistry, Poaceae physiology
- Abstract
From gas chromatography-mass spectrometry (GC-MS), numerous plant growth inhibitors were found in the rhizome and root exudates of cogongrass, one of the most problematic weeds in the world. iso-Eugenol, iso-ferulic acid, linoleic acid, ferulic acid, and vanillin were the major chemicals in the rhizome (88.1-392.2 microg/g of fresh root), while 4-acetyl-2-methoxyphenol was the principle substance (872.6 microg/plant) in the root exudates. In fields, the use of cutting and plowing reduced weed biomass and weed density of cogongrass >70%. However, the alternative invasion of beggar tick might be a problem, because its density and biomass increased 33.3 and 62.5%, respectively. Chemicals from cogongrass showed selective effects against tested invasive species. Of them, 2,4-di-tert-butylphenol was the most potent (78.3-100% of inhibition), followed by iso-eugenol and 4-acetyl-2-methoxyphenol. These compounds may play important roles in the invasiveness of cogongrass and might be promising parent constituents of synthesis to develop novel herbicides for control of invasive plants.
- Published
- 2009
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36. Efficacy of extracting solvents to chemical components of kava (Piper methysticum) roots.
- Author
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Xuan TD, Fukuta M, Wei AC, Elzaawely AA, Khanh TD, and Tawata S
- Subjects
- Antioxidants isolation & purification, Biphenyl Compounds, Chalcones isolation & purification, Chromatography, High Pressure Liquid, Free Radical Scavengers isolation & purification, Gas Chromatography-Mass Spectrometry, Glutathione isolation & purification, Lactones isolation & purification, Phenols isolation & purification, Picrates chemistry, Plant Extracts chemistry, Plant Extracts isolation & purification, Pyrans isolation & purification, Pyrones isolation & purification, Solvents, Sonication, Antioxidants chemistry, Free Radical Scavengers chemistry, Kava chemistry, Plant Roots chemistry
- Abstract
The chemical composition of kava (Piper methysticum) lactones and various phytochemicals obtained following the sonication of ground kava roots extracted in the solvents hexane, chloroform, acetone, ethanol, methanol and water, respectively, was analyzed. Eighteen kava lactones, cinnamic acid bornyl ester and 5,7-dimethoxy-flavanone, known to be present in kava roots, were identified, and seven compounds, including 2,5,8-trimethyl-1-naphthol, 5-methyl-1-phenylhexen-3-yn-5-ol, 8,11-octadecadienoic acid-methyl ester, 5,7-(OH)(2)-4'-one-6,8-dimethylflavanone, pinostrobin chalcone and 7-dimethoxyflavanone-5-hydroxy-4', were identified for the first time. Glutathione (26.3 mg/g) was found in the water extract. Dihydro-5,6-dehydrokavain (DDK) was present at a higher level than methysticin and desmethoxyyagonin, indicating that DDK is also a major constituent of kava roots. Acetone was the most effective solvent in terms of maximum yield and types of kava lactones isolated, followed by water and chloroform, whereas hexane, methanol, and ethanol were less effective as solvents. Total phenolic and antioxidant activity varied among the extracting solvents, with acetone and chloroform producing the highest effects, followed by water, while methanol, ethanol and hexane were less effective.
- Published
- 2008
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37. Comparison of isoflavone concentrations in soybean (Glycine max (L.) Merrill) sprouts grown under two different light conditions.
- Author
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Lee SJ, Ahn JK, Khanh TD, Chun SC, Kim SL, Ro HM, Song HK, and Chung IM
- Subjects
- Cotyledon chemistry, Plant Roots chemistry, Seeds chemistry, Isoflavones analysis, Light, Glycine max chemistry, Glycine max growth & development
- Abstract
We determined and compared the composition and content of isoflavones in the cotyledon, hypocotyl, and root of 17 soybean sprout varieties grown under dark and light conditions. The total average isoflavone concentrations in 17 soybean sprout varieties were 2167 microg g(-1) (green sprout) and 2538 microg g(-1) (yellow sprout) in cotyledons, 1169 microg g(-1) (green sprout) and 1132 microg g(-1) (yellow sprout) in hypocotyls, and 2399 microg g(-1) (green sprout) and 2852 microg g(-1) (yellow sprout) in roots. There were no significant differences in total isoflavone concentrations between the green and yellow sprouts. However, significant differences in total isoflavone amounts were observed among the three organs, with roots exhibiting the highest total isoflavone concentrations followed by cotyledons and hypocotyls. Total daidzin concentrations of green (775 microg g(-1)) and yellow (897 microg g(-1)) sprouts increased to more than 4 times that in seeds (187 microg g(-1)). Yellow sprouts contained the highest (1122 microg g(-1)) total genistin concentrations, and green (155 microg g(-1)) and yellow (155 microg g(-1)) sprouts had more total glycitin concentrations than seeds. In cotyledons of green and yellow sprouts, genistin, daidzen, and glycitin constituted more than 67%, more than 28%, and less than 4% of the total isoflavone contents, respectively. In hypocotyls, total daidzin represented more than 45% of the total isoflavones, and total glycitin was higher than in cotyledons and roots. Malonylglycoside concentrations were highest in cotyledons, whereas glycoside concentrations were highest in hypocotyls and roots. The high accumulation of isoflavones in roots is consistent with isoflavones serving as signal molecules in the induction of microbial genes involved in soybean (Glycine max) nodulation.
- Published
- 2007
- Full Text
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38. Identification of phytotoxic substances from early growth of barnyard grass (Echinochloa crusgalli) root exudates.
- Author
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Xuan TD, Chung IM, Khanh TD, and Tawata S
- Subjects
- Echinochloa drug effects, Echinochloa growth & development, Lactuca drug effects, Lactuca growth & development, Medicago sativa drug effects, Medicago sativa growth & development, Oryza growth & development, Pheromones isolation & purification, Plant Roots drug effects, Plant Roots growth & development, Plant Shoots drug effects, Plant Shoots growth & development, Sesamum drug effects, Sesamum growth & development, Echinochloa metabolism, Oryza drug effects, Pheromones pharmacology, Plant Roots metabolism
- Abstract
Barnyard grass is a problematic weed worldwide. It competes with crops and causes reduction in crop yields. In this study, barnyard grass suppressed rice emergence, and the degree of rice inhibition was proportional to the density of barnyard grass. Root exudates of barnyard grass reduced germination and growth of lettuce, rice, and monochoria. Fifteen compounds potentially involved in the phytotoxic activities of barnyard grass were isolated and identified, including phenolics, long-chain fatty acids, lactones, diethyl phthalate, acenaphthene, and derivatives of phthalic acids, benzoic acid, and decane. Quantities of diethyl phthalate, decanoic acid, myristic acid, stearic acid, 7,8-dihydro-5,6-dehydrokavain, and 7,8-dihydrokavain were 2.7, 11.1, 19.6, 35.5, 10.3, and 15.5 microg/ml of barnyard grass root exudates, respectively. The two lactones exhibited the greatest inhibition, followed by the phenolics and the derivatives of phthalic acids. Fatty acids had stronger suppression than diethyl phthalate and ethyl ester-4-ethoxy-benzoic acid. The acenaphthene and decane derivatives were the least phytotoxic. The phytotoxins released by barnyard grass roots showed strong inhibition on growth of broadleaf indicator plants and paddy weeds, but were less effective on barnyard grass itself and rice. Our study revealed that in addition to competition, barnyard grass also interferes with rice and other plants in its surroundings by chemical means.
- Published
- 2006
- Full Text
- View/download PDF
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