Identification of Insertion/Deletion Markers for Photoperiod Sensitivity in Rice (Oryza sativa L.).

The current study aims to identify candidate insertion/deletion (INDEL) markers associated with photoperiod sensitivity (PS) in rice landraces from the Vietnamese Mekong Delta. The whole-genome sequencing of 20 accessions was conducted to analyze INDEL variations between two photoperiod-sensitivity groups. A total of 2240 INDELs were identified between the two photoperiod-sensitivity groups. The selection criteria included INDELs with insertions or deletions of at least 20 base pairs within the improved rice group. Six INDELs were discovered on chromosomes 01 (5 INDELs) and 6 (1 INDEL), and two genes were identified: LOC_Os01g23780 and LOC_Os01g36500. The gene LOC_Os01g23780, which may be involved in rice flowering, was identified in a 20 bp deletion on chromosome 01 from the improved rice accession group. A marker was devised for this gene, indicating a polymorphism rate of 20%. Remarkably, 20% of the materials comprised improved rice accessions. This INDEL marker could explain 100% of the observed distinctions. Further analysis of the mapping population demonstrated that an INDEL marker associated with the MADS-box gene on chromosome 01 was linked to photoperiod sensitivity. The F1 population displayed two bands across all hybrid individuals. The marker demonstrates efficacy in distinguishing improved rice accessions within the indica accessions. This study underscores the potential applicability of the INDEL marker in breeding strategies.

Oxygen vacancy-rich high-pressure rocksalt phase of zinc oxide for enhanced photocatalytic hydrogen evolution.

The generation of hydrogen as a clean energy carrier by photocatalysis, as a zero-emission technology, is of significant scientific and industrial interest. However, the main drawback of photocatalytic hydrogen generation from water splitting is its low efficiency compared to traditional chemical or electrochemical methods. Zinc oxide (ZnO) with the wurtzite phase is one of the most investigated photocatalysts for hydrogen production, but its activity still needs to be improved. In this study, an oxygen-deficient high-pressure ZnO rocksalt phase is stabilized using a high-pressure torsion (HPT) method, and the product is used for photocatalysis under ambient pressure. The simultaneous introduction of oxygen vacancies and the rocksalt phase effectively improved photocatalytic hydrogen production to levels comparable to benchmark P25 TiO2, due to improving light absorbance and providing active sites for photocatalysis without any negative effect on electron-hole recombination. These results confirm the high potential of high-pressure phases for photocatalytic hydrogen generation.

An ecological economic comparison between integrated rice-fish farming and rice monocultures with low and high dikes in the Mekong Delta, Vietnam.

This study makes an ecological economic comparison between three different rice farming strategies in the Mekong Delta. Interviews were made with 30 farmers with two crops of rice and low dikes (2RLd), 30 farmers with three crops of rice and high dikes (3RHd) and 18 farmers with two crops of rice and one crop of fish (2RF). 2RF farmers had the highest annual net income and benefit cost ratio, because of low production costs and high yields of rice and fish. 2RLd farmers had the lowest annual net income. 3RHd had the highest annual rice yield, but also used the highest amount of rice seeds and agrochemicals, generating the lowest benefit cost ratio. Most farmers (70%) preferred two crops because of a higher production efficiency. High dikes and frequent use of pesticides and fertilizers were seen to decrease the water and rice quality, connectivity and biodiversity in farms with three crops. It is concluded that rice farming with two crops, and especially if integrated with fish and applying IPM, provides a sustainable alternative to rice farming with three crops and high dikes, because it makes use of the high connectivity within the rice-field ecosystem for an efficient production of healthy food through increased recycling of nutrients and  natural pest control mechanisms.

Stakeholders assessment of status and trends of ecosystem services in the Mekong Delta for improved management of multifunctional wetlands.

Increased agriculture and aquaculture production in the Mekong Delta during the last two decades has improved farmers' income, national export earnings and reduced poverty, but has also impacted on the environment and ecosystem services (ES) of importance to peoples' livelihoods and well-being. Through group discussions, interviews and questionnaires, this study assesses stakeholders' perceptions of the status and trends of ES in the Mekong Delta and how these have been influenced by agriculture development. 15 of 24 ES were assessed to be impacted negatively by agriculture intensification, and especially supporting and regulating ES (SRES). Only a few provisioning ES (PrES), related to farming, were assessed to be in a good and stable supply, because of human interventions to create favorable conditions for these ES. Among the ten highest ranked ES, eight belonged to PrES and two belonged to SRES. There was a positive correlation between rank and awareness of ES. The supply of most SRES was perceived to be in a low and declining status and assessed to be in a high need for improved management. Some ES, such as pest-control had been complemented with human-made substitutes, such as pesticides, which however sometimes weakened rather than strengthened the ES. Cultural ES (CES) were often ranked lower and of less management concern than the other groups of ES. It is concluded that future agriculture strategies need a more balanced management of ES for a long-term production of healthy food and increased resilience of the Mekong Delta to cope with future challenges, such as climate change and upstream dams.

Sesquiterpenoids from Tithonia diversifolia (Hemsl.) A. Gray induce apoptosis and inhibit the cell cycle progression of acute myeloid leukemia cells.

Three sesquiterpene lactones (1-3) were isolated from the aerial part of Tithonia diversifolia (Hemsl.) A. Gray grown in the Hoa Binh province in Viet Nam. The structures of these three sesquiterpene lactones were identified as tagitinin A (1), 1ß-hydroxytirotundin 3-O-methyl ether (2), and tagitinin C (3) by analyzing spectroscopic data. For the first time, compound 2 was isolated from T. diversifolia growing in Viet Nam. Furthermore, contrary to existing literature, we determined that compound 1 was the major isolate. Compounds 1 and 3 significantly decreased numbers of acute myeloid leukemia OCI-AML3 cells by promoting apoptosis and causing cell cycle arrest at G0/G1 phase at concentrations as low as 2.5 µg/mL (compound 1) and 0.25 µg/mL (compound 3). Additionally, all three compounds showed cytotoxic activity against five human cancer cell lines (A549, T24, Huh-7, 8505, and SNU-1), with IC50 values ranging from 1.32 ± 0.14 to 46.34 ± 2.74 µM. Overall, our findings suggest that compounds 1 and 3 may be potential anti-cancer therapeutics and thus warrant further study.

Chemical constituents of Impatiens parvisepala and their α-glucosidase inhibition activity.

The first chemical study of the whole Impatiens parvisepala S. X. Yu & Y. T. Hou led to the isolation of a new triterpene saponin, named Iparvisepala-1 (6) along with ten known compounds, which cover three flavonoid glycosides (1-3), one dihydrochalcone glucoside (4), one triterpenoid saponin (5), one triterpene (7) and four miscellaneous compounds (8-11). Their structures were elucidated by MS, NMR spectroscopic analyses as well as by comparisons of spectra data with those of the related published literatures. Additionally, flavonoid glucoside 2 showed impressive effect on α-glucosidase inhibition with the IC50 value of 12.53 ± 0.39 µM, much better than that of the positive control acabose (IC50 = 197.53 ± 2.68 µM).

New phenolics from Uraria crinita (L.) DC.

Reinvestigation of a methanol extract of Uraria crinita afforded a new 3- hydroxyisoflavanone, 3,5,7,2',4'-pentahydroxyisoflavanone (1), two new monoaryl glucosides, 3,4-dimethoxyphenyl 1-O-(6'-O-acetyl)-ß-D-glucopyranoside (2) and 3,4,5-trimethoxyphenyl 1-O-(6'-O-acetyl)-ß-D-glucopyranoside (3), in addition to three known compounds, 3'-O-methylorobol (4), robusflavone B (5), and apigenin (6). The structural elucidation of these compounds was achieved by analyses of their spectroscopic data (HR-ESI-MS, 1 D- and 2 D-NMR) and acidic hydrolysis. The U. crinita extracts and compounds 1-6 exhibited weak or no cytotoxic activity against KB, HepG2, Lu and MCF7 cell lines.

Chemical constituents of Impatiens chapaensis Tard. and their α-glucosidase inhibition activities.

Sixteen compounds (1-16) were isolated from Impatiens chapaensis. Chemical structures were determined by spectroscopic analyses and comparisons with previously published data. This report is the first to identify compounds 1, 5-7, 10, 12-14, and 16 from the genus Impatiens. Seven chosen isolates (5, 7, 10, 11, 12, 15, and 16) were submitted for α-glucosidase inhibition assays with acarbose as the positive control (IC50 = 227.14 ± 13.71 µM). Flavonoid 5 exhibited a significant inhibitory effect (IC50 = 101.00 ± 9.01 µM).

Pro-apoptoticeffect of diterpenoids from Fokienia hodginsii on acute myeloid leukemia cells.

Previously, we isolated four known diterpenoids, trans-communic acid (1), 13-oxo-15,16-dinor-labda-8(17), 11E-diene-19-oic acid (2), 3ß-hydroxytotarol (3), and totarolone (4) from Fokienia hodginsii leaves. Further study demonstrated the antiproliferative activity of all four compounds in acute myeloid leukemia (OCI-AML) cells due to impaired cell cycle progression. Interestingly, 3ß-hydroxytotarol (3) had very powerful bioactivity at low concentrations (5 µg/mL).

A new isoflavanone from Uraria crinita.

A new isoflavanone, (3S)-5,7-dihydroxy-2',3',4'-trimethoxy-6,5'-diprenylisoflavanone (1) and eight known compounds including five flavones (2-6), two triterpenes (7-8) and a steroid (9) were isolated from the whole plant of Uraria crinita (Leguminosae). The structure of 1 was elucidated by detailed spectroscopic means including IR, HR-ESI-MS, 1D and 2D NMR, and CD data. Compounds 1-9 were evaluated for their cytotoxicity against four human cancer cell lines KB (mouth epidermal carcinoma), HepG2 (hepatocellular carcinoma), Lu (lung carcinoma) and MCF7 (breast carcinoma). Compound 1 showed cytotoxic activity against the tested cell lines with IC50 values of 33.2, 29.4, 59.6 and 66.8 µM, respectively.

New phenolics from Dianella ensifolia.

Phytochemical investigation and chromatographic separation of extracts from the aerial parts of Dianella ensifolia (L.) DC. (synonym Dianella nemorosa Lam. Ex. Schiler f.) led to the isolation of 10 compounds, the structures of which were determined by HR-ESI-MS and 1 D- and 2 D-NMR spectroscopies, and by comparisons with published studies. Among the isolated compounds were three flavans, a biflavan, a biflavone, a tetralone, a naphthalen glycoside, an aromatic compound, and two steroids. Six of these were known chemicals, while three were identified as new compounds: 7-acetyl-4R,8-dihydroxy-6-methyl-1-tetralone, 2(S),2',4'-dihydroxy-7-methoxyflavan, and diaensi-biflavan. 2(S),7,4'-dimethoxy flavan was obtained for the first time as a natural product.

Cell Growth Inhibition of Saponin XII from Dipsacus japonicus Miq. on Acute Myeloid Leukemia Cells.

In previous studies, we isolated the known compound saponin XII from the roots of Dipsacus japonicus Miq. Here, we show that this compound reduced the number of acute myeloid leukemia OCI-AML3 cells as evaluated by a hemocytometer. Flow cytometry analyses demonstrated that the reported activity was associated with a significant increase of apoptosis and of cells in the G0/G1 phase of the cell cycle, with a decrease of cells in the S and G2/M phases. Thus, the inhibition of cell growth in OCI-AML3 cells was due to antiproliferative and pro-apoptotic effects. Interestingly, the bioactivity of saponin XII exerted its effect at a concentration as low as 1 µg/mL.

Artocarpus tonkinensis Protects Mice Against Collagen-Induced Arthritis and Decreases Th17 Cell Function.

Artocarpus tonkinensis (Moraceae) is a tree that grows in north Vietnam whose leaf decoction is used as a traditional remedy by the Hmong ethnic group to treat arthritis and backache. Our study evaluated the decoction's efficacy and mechanism of action in DBA/1J mice with collagen-induced arthritis (CIA). Mice treated with the decoction (At) either from the first collagen immunization or after CIA development experienced significantly less joint edema and inflammatory infiltration, whereas CIA-induced cartilage damage could only be prevented by early At treatment. Autoimmune gene expression profiles showed that Th17 cell-associated chemokine CCL20 and cytokines IL-6, IL-17, and IL-22 were strongly downregulated by At. Reduced expression of IL-2, IL-17, IL-22, and FasL in lymph node cells from At-treated mice was further confirmed by real-time PCR. The decoction also inhibited polarization of Th17 cells from CD4+ splenic T cells according to levels of IL-17 and RORC, a Th17 cell-specific transcription factor. Chromatographic analysis identified At's major component as maesopsin-ß-D-glucoside, which could inhibit in vitro differentiation of Th17 cells. The decoction significantly alleviated the signs and symptoms of CIA and inhibited the development and function of Th17 cells, highlighting its potent anti-inflammatory activity.

Chemical constituents of Oldenlandia pinifolia and their antiproliferative activities.

This study describes the chemical constituents of Oldenlandia pinifolia (Wall. Ex G. Don) Kuntze (synonym Hedyotis pinifolia Wall. Ex G. Don) and discusses their anti-proliferative activities. Thirteen compounds were isolated from the n-hexane, ethyl acetate and n-butanol extracts of whole plants O. pinifolia by chromatography method. Their structures were elucidated using MS and NMR analysis and compared with reported data. They are three anthraquinones, a carotenoid, two triterpenes, four iridoid glycosides and three flavonoid glycosides. Among them, 2-methyl-1,4,6-trihydroxy-anthraquinone is a new one, and three compounds were found for the first time in this genus. MTT assay resulted that the n-butanol extract and four isolated compounds inhibited the proliferation of chronic myelogenous leukaemia cells. The results from Hoechst 33343 staining and caspase 3-inducing exhibited that those four tested compounds induced apoptosis and activated caspase 3 (p < 0.05). One of them, isorhamnetin-3-O-ß-rutinoside showed the most activity with IC50 value of 394.68 ± 25.12 µM.

Anti-proliferative diterpenes from Dacrycarpus imbricatus.

A new diterpene, cassipouryl hexadecanoate (2), in addition to the cassipourol (1) and four terpenes (3-6) were isolated from the twigs and leaves of Dacrycarpus imbricatus (Blume) de Laub. The structures of the two monocyclic diterpenes (1, 2), were elucidated on the basic of 1D and 2D NMR spectroscopic data and compared with the literature. These two monocyclic diterpenes (1, 2) were tested for their anti-proliferative activity on acute myeloid leukemia (OCI-AML) cells. The results showed that 1 had significantly anti-proliferative activity whereas 2 was weakly active.

Profiling SNP and Nucleotide Diversity to Characterize Mekong Delta Rice Landraces in Southeast Asian Populations.

CORE IDEAS: Single nucleotide polymorphism (SNP) analyses are a powerful tool to examine structure of local rice population. 3000 dataset of IRRI facilitates SNP profiling of Southeast Asian rice populations. Mekong Delta population is featured by comparisons with the other populations. The low π-value SNPs well-profile unique genetic regions in their genomes. Recent analyses using single nucleotide polymorphism (SNP) are a feasible mean for local collections which potentially possess useful, but not large, genetic variations. Genomic sequences of more than 3000 accessions released by the International Rice Research Institute (IRRI) can be used to characterize various local rice (Oryza sativa) populations. The aim of this study was to develop a method to facilitate genomic characterization of local rice populations. We mainly used 99 indica rice accessions (81 landraces and 18 improved varieties) from the Mekong Delta Development Research Institute (MDI). We obtained 2301 SNPs after a genomic sequencing analysis of the 99 rice accessions and subsequent filtering. Within the IRRI's dataset, the landraces fell into a cluster consisting of accessions from Southeast Asian countries (Ind3 cluster), and the MDI improved varieties were grouped in a cluster containing IRRI improved varieties (Ind1B cluster). A principal component analysis suggested that geographical location strongly affects phylogenetic relationships, and the MDI landraces were placed into a Vietnam+Cambodia group. To detect the nucleotide diversity within a population, π-value is commonly used. We think that whole genome distribution of π-values representing the nucleotide diversity of each population can be used to characterize local populations. Our simple profiling using low π-value genomic regions was able to reveal regional characteristics of rice genomes and should be useful for identifying local rice populations.

A new oleanane triterpene from the leaves of Ficus hirta.

Repeated column chromatography of the n-hexane extract of Ficus hirta leaves (Moraceae) led to isolation of a new oleanane triterpene, 3ß-hydroxy-11-oxo-olean-12-enyl-3-stearate (1) in addition to three known compounds, taraxerol (2), 3ß-acetoxy-11α-methoxy-12-ursene (3) and 3ß-acetoxy-11α-hydroxy-12-ursene (4). Their structures were elucidated by spectroscopic methods and by comparison with data reported in the literatures.

The combined effect of Bassa 50EC and Vitashield 40EC on the brain acetylcholinesterase activity in climbing perch (Anabas testudineus).

The combined effect of Vitashield 40EC (chlorpyrifos ethyl-CPF) and Bassa 50EC (fenobucarb-F) was compared with the effects from exposure to the two pesticides separately, by measuring the brain acetylcholinesterase (AChE) activity in climbing perch fingerlings (Anabas testudineus). The experiment was conducted under controlled laboratory conditions and included three treatments containing 0.173 mg/L of CPF, 1.137 mg/L of F, 0.173 mg/L of CPF + 1.137 mg/L of F (M), and a control. The inhibition of the brain AChE activity in fish exposed to F was weaker and shorter than in fish exposed to CPF. The inhibition by the mixture of CPF and F was significantly lower and less prolonged than the inhibition by only CPF but significantly higher than the inhibition by only F.

Chemical constituents from the leaves of Pinus dalatensis Ferré.

A phytochemical study of n-hexane and ethyl acetate extracts of Pinus dalatensis Ferré leaves led to the isolation of 11 compounds, including one caryolane sesquiterpenoid (1), five labdane diterpenoids (2, 3, 4, 5, 6), one serratane triterpenoid (7), one diacylated flavonoid glucoside (8), one stilbenoid (9) and two sterols (10, 11). The structural characterisation of the isolated compounds was elucidated by spectroscopic data and comparison with the literature report on the chemical constituents from Pinus dalatensis Ferré. Futhermore, three compounds 1, 4 and 6 were obtained for the first time from the genus Pinus. Besides, compounds (2, 3, 5, 8, 9) were also subjected to cytotoxicity effect on SK-LU-1, MCF-7 and Hep-G2 cell lines, but only compound 9 expressed activities with IC50 values of 141.22, 127.81 and 166.84 µM, respectively.

Decreased use of pesticides for increased yields of rice and fish-options for sustainable food production in the Mekong Delta.

This study assesses the use of pesticides and the attitude to pest management strategies among rice and rice-fish farmers in the Can Tho and Tien Giang provinces in Vietnam. Interviews were made with 80 farmers. The farmers were divided in to farmers cultivating only rice with a high use (RHP) and low use (RLP) of pesticides, and farmers cultivating rice and fish with a high use (RFHP) and low use (RFLP) of pesticides. 80% of the HP farmers relied mainly on pesticides to control pests, while >80% of the LP farmers also applied IPM strategies. Insecticides were the most commonly used pesticides. 85% of all farmers experienced health effects from using pesticides. 80% of the farmers felt that the yield of fish had decreased over the last three years, and that this mainly was caused by pesticides. The RFHP farmers had lower fish survival and fish yields as compared to the RFLP farmers. The RFHP farmers also had significant lower rice yields than the RFLP farmers, and there were significant correlations between both decreased fish yields and rice yields with increased use of pesticides among rice-fish farmers. Increased rice yields were positively correlated with increased fish survival, indicating the synergistic effects between rice and fish production. Overall, the RFLP farmers had the highest income of the four farmers´ groups, while RFHP farmers had the lowest income. This shows that rice-fish farming provides a competitive and sustainable alternative to intensive rice-farming, but only if the farmer restricts the use of pesticides. This would not only help to reduce the production costs, but also to decrease environmental and health effects, and it is proposed that rice-fish farming with a low use of pesticides provides an attractive alternative to rice-monocropping for a sustainable and diversified food production in the Mekong Delta.