Publications by authors named "Xiangyang Lu"

33 Publications

Diversity of Culturable Bacteria Isolated from Highland Barley Cultivation Soil in Qamdo, Tibet Autonomous Region.

Pol J Microbiol 2021 Mar 19;70(1):87-97. Epub 2021 Mar 19.

College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, China.

The soil bacterial communities have been widely investigated. However, there has been little study of the bacteria in Qinghai-Tibet Plateau, especially about the culturable bacteria in highland barley cultivation soil. Here, a total of 830 individual strains were obtained at 4°C and 25°C from a highland barley cultivation soil in Qamdo, Tibet Autonomous Region, using fifteen kinds of media. Seventy-seven species were obtained, which belonged to 42 genera and four phyla; the predominant phylum was Actinobacteria (68.82%), followed by Proteobacteria (15.59%), Firmicutes (14.29%), and Bacteroidetes (1.30%). The predominant genus was (22.08%, 17 species), followed by (6.49%, five species), (5.19%, four species), (5.19%, four species), and (3.90%, three species). The most diverse isolates belonged to a high G+C Gram-positive group; in particular, the genus is a dominant genus in the high G+C Gram-positive group. There were 62 species and 33 genera bacteria isolated at 25°C (80.52%), 23 species, and 18 genera bacteria isolated at 4°C (29.87%). Meanwhile, only eight species and six genera bacteria could be isolated at 25°C and 4°C. Of the 77 species, six isolates related to six genera might be novel taxa. The results showed abundant bacterial species diversity in the soil sample from the Qamdo, Tibet Autonomous Region.
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http://dx.doi.org/10.33073/pjm-2021-008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8008761PMC
March 2021

Dihydromyricetin Acts as a Potential Redox Balance Mediator in Cancer Chemoprevention.

Mediators Inflamm 2021 11;2021:6692579. Epub 2021 Mar 11.

College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China.

Dihydromyricetin (DHM) is a flavonoid extracted from the leaves and stems of the edible plant that has been used for Chinese Traditional Medicine. It has attracted considerable attention from consumers due to its beneficial properties including anticancer, antioxidative, and anti-inflammatory activities. Continuous oxidative stress caused by intracellular redox imbalance can lead to chronic inflammation, which is intimately associated with the initiation, promotion, and progression of cancer. DHM is considered a potential redox regulator for chronic disease prevention, and its biological activities are abundantly evaluated by using diverse cell and animal models. However, clinical investigations are still scanty. This review summarizes the current potential chemopreventive effects of DHM, including its properties such as anticancer, antioxidative, and anti-inflammatory activities, and further discusses the underlying molecular mechanisms of DHM in cancer chemoprevention by targeting redox balance and influencing the gut microbiota.
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http://dx.doi.org/10.1155/2021/6692579DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7979283PMC
March 2021

The ecdysone-induced protein 93 is a key factor regulating gonadotrophic cycles in the adult female mosquito .

Proc Natl Acad Sci U S A 2021 Feb;118(8)

State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, People's Republic of China;

Repeated blood feedings are required for adult female mosquitoes to maintain their gonadotrophic cycles, enabling them to be important pathogen carriers of human diseases. Elucidating the molecular mechanism underlying developmental switches between these mosquito gonadotrophic cycles will provide valuable insight into mosquito reproduction and could aid in the identification of targets to disrupt these cycles, thereby reducing disease transmission. We report here that the transcription factor ecdysone-induced protein 93 (E93), previously implicated in insect metamorphic transitions, plays a key role in determining the gonadotrophic cyclicity in adult females of the major arboviral vector Expression of the gene in mosquitoes is down-regulated by juvenile hormone (JH) and up-regulated by 20-hydroxyecdysone (20E). We find that E93 controls Hormone Receptor 3 (HR3), the transcription factor linked to the termination of reproductive cycles. Moreover, knockdown of expression via RNAi impaired fat body autophagy, suggesting that E93 governs autophagy-induced termination of vitellogenesis. RNAi silencing prior to the first gonadotrophic cycle affected normal progression of the second cycle. Finally, transcriptomic analysis showed a considerable E93-dependent decline in the expression of genes involved in translation and metabolism at the end of a reproductive cycle. In conclusion, our data demonstrate that E93 acts as a crucial factor in regulating reproductive cycle switches in adult female mosquitoes.
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http://dx.doi.org/10.1073/pnas.2021910118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7923369PMC
February 2021

Integrated Metabolome and Transcriptome Analysis Unveils Novel Pathway Involved in the Formation of Yellow Peel in Cucumber.

Int J Mol Sci 2021 Feb 2;22(3). Epub 2021 Feb 2.

College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China.

Yellow peel will adversely affect the appearance quality of cucumber fruit, but the metabolites and the molecular mechanism of pigment accumulation in cucumber peel remain unclear. Flavonoid metabolome and transcriptome analyses were carried out on the young peel and old peel of the color mutant L19 and the near-isogenic line L14. The results showed that there were 165 differential flavonoid metabolites in the old peel between L14 and L19. The total content of representative flavonoid metabolites in the old peel of L14 was 95 times that of L19, and 35 times that of young peel of L14, respectively. This might explain the difference of pigment accumulation in yellow peel. Furthermore, transcriptome analysis showed that there were 3396 and 1115 differentially expressed genes in the yellow color difference group (Young L14 vs. Old L14 and Old L14 vs. Old L19), respectively. These differentially expressed genes were significantly enriched in the MAPK signaling pathway-plant, plant-pathogen interaction, flavonoid biosynthesis and cutin, suberine and wax biosynthesis pathways. By analyzing the correlation between differential metabolites and differentially expressed genes, six candidate genes related to the synthesis of glycitein, kaempferol and homoeriodictyol are potentially important. In addition, four key transcription factors that belong to R2R3-MYB, bHLH51 and WRKY23 might be the major drivers of transcriptional changes in the peel between L14 and L19. Then, the expression patterns of these important genes were confirmed by qRT-PCR. These results suggested that the biosynthesis pathway of homoeriodictyol was a novel way to affect the yellowing of cucumber peel. Together, the results of this study provide a research basis for the biosynthesis and regulation of flavonoids in cucumber peel and form a significant step towards identifying the molecular mechanism of cucumber peel yellowing.
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http://dx.doi.org/10.3390/ijms22031494DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7867363PMC
February 2021

as an Oleaginous Platform for the Production of Value-Added Fatty Acid-Based Bioproducts.

Front Microbiol 2020 5;11:608662. Epub 2021 Jan 5.

College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, China.

The microbial fermentation process has been used as an alternative pathway to the production of value-added natural products. Of the microorganisms, , as an oleaginous platform, is able to produce fatty acid-derived biofuels and biochemicals. Nowadays, there are growing progresses on the production of value-added fatty acid-based bioproducts in . . However, there are fewer reviews performing the metabolic engineering strategies and summarizing the current production of fatty acid-based bioproducts in . To this end, we briefly provide the fatty acid metabolism, including fatty acid biosynthesis, transportation, and degradation. Then, we introduce the various metabolic engineering strategies for increasing bioproduct accumulation in . Further, the advanced progress in the production of fatty acid-based bioproducts by , including nutraceuticals, biofuels, and biochemicals, is summarized. This review will provide attractive thoughts for researchers working in the field of .
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http://dx.doi.org/10.3389/fmicb.2020.608662DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7813756PMC
January 2021

Comparative Analysis of the Gut Microbiota of Adult Mosquitoes From Eight Locations in Hainan, China.

Front Cell Infect Microbiol 2020 15;10:596750. Epub 2020 Dec 15.

Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine, Hainan Medical University, Haikou, China.

The midgut microbial community composition, structure, and function of field-collected mosquitoes may provide a way to exploit microbial function for mosquito-borne disease control. However, it is unclear how adult mosquitoes acquire their microbiome, how the microbiome affects life history traits and how the microbiome influences community structure. We analyzed the composition of 501 midgut bacterial communities from field-collected adult female mosquitoes, including , , , , and , across eight habitats using the HiSeq 4000 system and the V3-V4 hyper-variable region of 16S rRNA gene. After quality filtering and rarefaction, a total of 1421 operational taxonomic units, belonging to 29 phyla, 44 families, and 43 genera were identified. (75.67%) were the most common phylum, followed by (10.38%), (6.87%), (4.60%), and (1.58%). The genera (33.00%), (20.27%), (7.49%), (7.00%), (4.52%), and (4.31%) were dominant in the samples analyzed and accounted for 76.59% of the total genera. We characterized the midgut bacterial communities of six mosquito species in Hainan province, China. The gut bacterial communities were different in composition and abundance, among locations, for all mosquito species. There were significant differences in the gut microbial composition between some species and substantial variation in the gut microbiota between individuals of the same mosquito species. There was a marked variation in different mosquito gut microbiota within the same location. These results might be useful in the identification of microbial communities that could be exploited for disease control.
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http://dx.doi.org/10.3389/fcimb.2020.596750DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7769952PMC
December 2020

Purification and identification of angiotensin II type I receptor downregulating peptide from egg white hydrolysate.

J Food Biochem 2020 06 3;44(6):e13220. Epub 2020 Apr 3.

Department of Agricultural, Food and Nutritional Science (AFNS), University of Alberta, Edmonton, Canada.

The vasoconstricting effect of angiotensin II (Ang II) is mediated by Ang II type I receptor (AT1R); blocking or blunting AT1R is a key strategy for the development of antihypertensive drugs. Our previous study showed that the blood pressure lowering the activity of egg white hydrolysate (EWH) in spontaneously hypertensive rats was due to the downregulation of aortic AT1R expression, which promoted us to further identify the AT1R downregulating peptides in the present study. The protein expression of AT1R in a rat aortic vascular smooth muscle cell line A7r5 cells was used for the activity test. The hydrolysate was fractionated stepwise by C18 Sep-Pack cartridge and reverse-phase chromatography, and the peptide sequences were characterized by LC-MS/MS. Peptides including ITKPNDVYS, VVGSAEAGVDAAS, AVHAAHAEINEAGRE, AGREVVGSAEAGVD, and VVGSAEAGVD, were identified. ITKPNDVYS showed the most potent peptide for lowering the level of AT1R in A7r5 cells. These results suggested that ITKPNDVYS is the responsible peptide for lowering the AT1R level in EWH. PRACTICAL APPLICATIONS: A new peptide ITKPNDVYS was identified as a downregulator of AT1R from egg white hydrolysate, which provides a new approach for the development of food protein-derived antihypertensive peptides as nutraceuticals or functional food ingredients.
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http://dx.doi.org/10.1111/jfbc.13220DOI Listing
June 2020

Variations in phyllosphere microbial community along with the development of angular leaf-spot of cucumber.

AMB Express 2019 May 27;9(1):76. Epub 2019 May 27.

Key Laboratory of Pest Management of Horticultural Crops of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha, China.

The phyllosphere is colonized by a wide variety of microorganisms including epiphytes, plant-pathogenic fungus, bacteria, as well as human or animal pathogens. However, little is known about how microbial community composition changes with the development of angular leaf-spot of cucumber. Here, 18 mixed samples were collected based on the lesion coverage rate (LCR) of angular leaf-spot of cucumber from three disease severity groups (DM1: symptomatic-mild, DM2: symptomatic-moderate, DM3: symptomatic-severe). In our study, the microbial community structure and diversity were examined by Illumina MiSeq sequencing. A significant differences was observed in α diversity and community structure among three disease severity groups. The phyllosphere microbiota was observed to be dominated by bacterial populations from Proteobacteria, Actinobacteria, and Firmicutes, as well as fungal species from Ascomycota and Basidiomycota. In addition, some plant-specific microbe such as Sphingomonas, Methylobacterium, Pseudomonas, and Alternaria showed significant changes in their relative abundance of population. The LCR was correlated negatively with Sphingomonas, Methylobacterium, Quadrisphaera, and Lactobacillus, whereas correlated positively with Pseudomonas and Kineococcus (p < 0.05). The LCR was negatively correlated with Alternaria and Arthrinium of the fungal communities (p < 0.05). Molecular ecological networks of the microbial communities were constructed to show the interactions among the OTUs. Our current results indicated that the competitive relationships among species were broken with the development of angular leaf-spot of cucumber. The microbial community composition changed over the development of angular leaf-spot of cucumber. The result of molecular ecological networks indicated that the overall bacterial community tends toward mutualism from the competition. The development of angular leaf-spot of cucumber affected the ecosystem functioning by disrupting the stability of the microbial community network. This work will help us to understand the host plant-specific microbial community structures and shows how these communities change throughout the development of angular leaf-spot of cucumber.
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http://dx.doi.org/10.1186/s13568-019-0800-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6536563PMC
May 2019

Microarray Based Functional Analysis of Myricetin and Proteomic Study on Its Anti-Inflammatory Property.

Biomed Res Int 2019 7;2019:3746326. Epub 2019 Mar 7.

Core Research Program 1515, Key Laboratory for Food Science and Biotechnology of Hunan Province, College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China.

Myricetin has been reported as a promising chemopreventive compound with multiple biofunctions. To evaluate its influence on gene expressions in genome-wide set and further investigate its anti-inflammatory property, the present study performed Gene Ontology and Ingenuity Pathway Analysis (IPA) to describe the basic gene expression characteristics by myricetin treatment in HepG2 cells, confirmed its multi-biofunction by real-time fluorescent quantitative PCR (RT-qPCR), and further verified its anti-inflammatory property by Western blotting and bio-plex-based cytokines assay. The IPA data showed that 337 gene expressions (48% of the top molecules) are disturbed over 2-fold, and the most possible biofunctions of myricetin are the effect on "cardiovascular disease, metabolic disease, and lipid metabolism," via regulation of 28 molecules with statistic score of 46. RT-qPCR data confirmed the accuracy of microarray data, and cytokines assay results indicated that 6 of the total 27 inflammatory cytokine secretions were significantly inhibited by myricetin pretreatment, including TNF-, IFN-, IL-1, IL-1, IL-2, and IL-6. The present study is the first time to elucidate the multi-function of myricetin in genome-wide set by IPA analysis and verify its anti-inflammatory property by proteomics of cytokines assay. Therefore, these results enrich the comprehensive bioactivities of myricetin and reveal that myricetin has powerful anti-inflammatory property, which provides encouragement for studies to verify its possible health benefits.
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http://dx.doi.org/10.1155/2019/3746326DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6431437PMC
July 2019

Procyanidin B2 from lotus seedpod regulate NO/ADMA/DDAH pathway to treat insomnia in rats.

Fundam Clin Pharmacol 2019 Oct 16;33(5):549-557. Epub 2019 Apr 16.

Hunan Engineering Research Center of Veterinary Drug, Hunan Agricultural University, Changsha, 410128, China.

Recent studies show that nitric oxide/asymmetric dimethylarginine/dimethylarginine dimethylaminohydrolase (NO/ADMA/DDAH) pathway may contribute to the development of sleep disorder. The objective of this study was to explore the inhibitory effect of procyanidin B2 from lotus seedpod (LSPC), a naturally occurring catechin compound, on insomnia and the mechanisms involved. The experiments were performed in brain from Sprague-Dawley rat control and insomniac rats treated or not with LSPC (15, 30, and 45 mg/kg, intragastrically) for 7 days. LSPC treatment reduced walking time and forelimb lifting-up frequency, cerebral levels of noradrenaline, glutamic acid, ADMA, sleep latency, and 8-isoprostane; increased sleep duration, cerebral concentrations of 5-hydroxytryptamine, γ-aminobutyric acid, and NO concomitantly with upregulated cerebral expression of DDAH 1, DDAH2, and neuronal NO synthases in insomniac rats. The present results suggest that LSPC may regulate NO/ADMA/DDAH pathway by inhibiting oxidative stress to treat insomnia in rats when sleep evaluation was achieved on the basis of behavioral criteria.
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http://dx.doi.org/10.1111/fcp.12462DOI Listing
October 2019

Review on carbon dots in food safety applications.

Talanta 2019 Mar 6;194:809-821. Epub 2018 Nov 6.

College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China. Electronic address:

As a new class of promising fluorescent carbon nanomaterials, carbon dots (CDs) have been well developed in recent years for their excellent fluorescent properties, simple synthetic approaches, good biocompatibility and various detection applications, which can be expected to replace the tradition semi-quantum dots. This review aims presents the current progress in the development of CDs with an emphasis on fluorescent properties, synthetic approaches and applications in food safety. First, the fluorescent properties of CDs are briefly introduced. To seek more reasonable synthetic approaches, the characteristics of the diverse methods of CD synthesis are summarized. And then, applications of CDs as fluorescent probes in food safety are discussed, with emphasis on the determination of metal ions/anions, pesticides, veterinary drugs, bacteria, functional components and banned additives. Finally, the challenges, such as how to explain the diversity of fluorescent properties, and how to form a uniform synthesis procedure to improve the quantum yield (QY), for CDs are presented. Although CDs have found many applications in food safety, it is still a challenge to detect a specific target in complex samples. Therefore, combination with other biochemistry technology to exploit novel ligands against the specific target with high binding affinity and selectivity is vitally important for developing sensitive and specific sensing probes in the future.
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http://dx.doi.org/10.1016/j.talanta.2018.11.005DOI Listing
March 2019

Lotus seed skin proanthocyanidin extract exhibits potent antioxidant property via activation of the Nrf2-ARE pathway.

Acta Biochim Biophys Sin (Shanghai) 2019 Jan;51(1):31-40

Core Research Program 1515, Key Laboratory for Food Science and Biotechnology of Hunan Province, College of Food Science and Technology, Hunan Agricultural University, Changsha, China.

Lotus seed is well known as traditional food and medicine, but its skin is usually discarded. Recent studies have shown that lotus seed skin contains a high concentration of proanthocyanidins that have multi-functions, such as antioxidation, anti-inflammation, and anti-cancer effects. In the present study, we aimed to isolate and purify the proanthocyanidins from lotus seed skin by acetone extraction and rotary evaporation, identify their chemical structures by HPLC-MS-MS and NMR, and further investigate the antioxidant properties of the extract purified by macroporous resin (PMR) from lotus seed skin both in vitro and in vivo. The results showed that PMR mainly contained oligomeric proanthocyanidins, especially dimeric procyanidin B1 (PB1), procyanidin B2 and procyanidin B4. Although it had limited ability to directly scavenge radicals in vitro, PMR could significantly enhance the expressions of antioxidant proteins via activation of nuclear factor-E2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway in HepG2 cells. Molecular data revealed that PB1, a major component in PMR, stabilized Nrf2 by inhibiting the ubiquitination of Nrf2, which led to subsequent activation of the Nrf2-ARE pathway, including the enhancements of Nrf2 nuclear translocation, Nrf2-ARE binding and ARE transcriptional activity. Moreover, the in vivo results in high fat diet-induced mice further verified the powerful antioxidant property of PMR. These results revealed that lotus seed skin is a promising resource for functional food development.
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http://dx.doi.org/10.1093/abbs/gmy148DOI Listing
January 2019

Excessive UDPG resulting from the mutation of UAP1 causes programmed cell death by triggering reactive oxygen species accumulation and caspase-like activity in rice.

New Phytol 2018 Jan 2;217(1):332-343. Epub 2017 Oct 2.

Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.

Lesion mimic mutants are valuable to unravel the mechanisms governing the programmed cell death (PCD) process. Uridine 5'-diphosphoglucose-glucose (UDPG) functions as a signaling molecule activating multiple pathways in animals, but little is known about its function in plants. Two novel allelic mutants of spl29 with typical PCD characters and reduced pollen viability were obtained by ethane methyl sulfonate mutagenesis in rice cv Kitaake. The enzymatic analyses showed that UDP-N-acetylglucosamine pyrophosphorylase 1 (UAP1) irreversibly catalyzed the decomposition of UDPG. Its activity was severely destroyed and caused excessive UDPG accumulation, with the lesion occurrence associated with the enhanced caspase-like activities in spl29-2. At the transcriptional level, several key genes involved in endoplasmic reticulum stress and the unfolded protein response were abnormally expressed. Moreover, exogenous UDPG could aggravate lesion initiation and development in spl29-2. Importantly, exogenous UDPG and its derivative UDP-N-acetylglucosamine could induce reactive oxygen species (ROS) accumulation and lesion mimics in Kitaake seedlings. These results suggest that the excessive accumulation of UDPG, caused by the mutation of UAP1, was a key biochemical event resulting in the lesion mimics in spl29-2. Thus, our findings revealed that UDPG might be an important component involved in ROS accumulation, PCD execution and lesion mimicking in rice, which also provided new clues for investigating the connection between sugar metabolism and PCD process.
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http://dx.doi.org/10.1111/nph.14818DOI Listing
January 2018

Photosynthetic bacterium Rhodopseudomonas palustris GJ-22 induces systemic resistance against viruses.

Microb Biotechnol 2017 05 14;10(3):612-624. Epub 2017 Mar 14.

College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, China.

Photosynthetic bacteria (PSB) have been extensively used in agriculture to promote plant growth and to improve crop quality. Their potential application in plant disease management, however, is largely overlooked. In this study, the PSB strain Rhodopseudomonas palustris GJ-22 was investigated for its ability to induce resistance against a plant virus while promoting plant growth. In the field, a foliar spray of GJ-22 suspension protected tobacco plants against tobacco mosaic virus (TMV). Under axenic conditions, GJ-22 colonized the plant phyllosphere and induced resistance against TMV. Additionally, GJ-22 produced two phytohormones, indole-3-acetic acid and 5-aminolevulinic acid, which promote growth and germination in tobacco. Furthermore, GJ-22-inoculated plants elevated their immune response under subsequent TMV infection. This research may give rise to a novel biological agent with a dual function in disease management while promoting plant growth.
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http://dx.doi.org/10.1111/1751-7915.12704DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5404195PMC
May 2017

Complete Genome Sequence of sp. Strain ODB01, a Bacterium That Degrades Crude Oil.

Genome Announc 2017 Mar 9;5(10). Epub 2017 Mar 9.

Hunan Province University Key Laboratory for Agricultural Biochemistry and Biotransformation, Hunan Agricultural University, Changsha, China

sp. strain ODB01, which was isolated from the Changqing oil field, can degrade crude oil efficiently and use crude oil as its sole source of carbon and energy. We report the complete genome sequence of ODB01. The results promote its application in the remediation of petroleum contaminants.
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http://dx.doi.org/10.1128/genomeA.01763-16DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5347254PMC
March 2017

Biochars with excellent Pb(II) adsorption property produced from fresh and dehydrated banana peels via hydrothermal carbonization.

Bioresour Technol 2017 May 12;232:204-210. Epub 2017 Feb 12.

College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China; Hunan Province University Key Laboratory for Agricultural Biochemistry and Biotransformation, Hunan Agricultural University, Changsha 410128, China.

Fresh and dehydrated banana peels were used as biomass feedstock to produce highly effective sorbent biochars through a facile one-step hydrothermal carbonization approach with 20%vol phosphoric acid as the reaction medium. The elemental ratio of oxygen content of the two as-prepared biochars were about 20%, and the FT-IR analysis confirmed the existence of abundant surface functional groups such as hydroxyl and carboxyl which greatly enhanced the adsorption performance. The sorbents showed excellent lead clarification capability of 359mg·g and 193mg·g for dehydrated and fresh banana peels based biochars, respectively. The change of the CO/OCO and the appearance of PbO/PbOC on the surface after adsorption confirmed that the ion exchange might be the dominant mechanism. The dehydration and pulverization pre-treatment and the addition of phosphoric acid can benefit the formation of those functional groups and hydrothermal carbonization can be a promising method to transfer biomass like fruit peels into biochars with excellent adsorption performance.
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http://dx.doi.org/10.1016/j.biortech.2017.01.074DOI Listing
May 2017

Extraction of Opuntia dillenii Haw. Polysaccharides and Their Antioxidant Activities.

Molecules 2016 Nov 24;21(12). Epub 2016 Nov 24.

College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China.

Use of natural polysaccharides in medicine and food has wide interest in research. In this study, we extracted and purified some polysaccharides from cactus Haw. (ODP). Some preliminary functions of these products were characterized. Under the optimal purification conditions, the yield of ODP extracted from the 2-4 month-old Haw. (T-ODP) was 30.60% ± 0.40%, higher than that of ODP from the 5-10 month-old materials (O-ODP) (18.97% ± 0.58%). The extracted ODP was purified by DEAE sepharose fast flow anion exchange and Sephacryl S-400 chromatography with four fractions obtained (ODP-Ia, ODP-Ib, ODP-IIa and ODP-IIb). Analysis with UV-vis chromatography indicated that ODP-Ia and ODP-IIa were relatively homogeneous molecules with a molecular weight of 339 kD and 943 kD, respectively. Results of infrared spectroscopy indicated that ODP, ODP-Ia, and ODP-IIa were acidic polysaccharides. Further, the antioxidant activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radical, hydroxyl radicals, and superoxide radical in vitro demonstrated that the T-ODP exhibited higher antioxidant activity than the O-ODP, and the purified fraction (ODP-Ia) was superior to the ODP. These results will offer a theoretical basis for further research on the structure-function relationship of ODP and the rational utilization of Haw.
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http://dx.doi.org/10.3390/molecules21121612DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6273547PMC
November 2016

Complete genome sequence of the Streptomyces sp. strain CdTB01, a bacterium tolerant to cadmium.

J Biotechnol 2016 Jul 7;229:42-3. Epub 2016 May 7.

Hunan Province University Key Laboratory for Agricultural Biochemistry and Biotransformation, Hunan Agricultural University, Changsha 410128, China; College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China; Hunan Co-Innovation Center for Ultilization of Botanical Functional Ingredients, Changsha 410128, China; Hunan Agricultural Product Processing Institute, Changsha 410125, China. Electronic address:

Streptomyces sp. Strain CdTB01, which is tolerant to high concentrations of heavy metals, particularly cadmium, was isolated from soil contaminated with heavy metals. Two contigs with total genome size of 10.19Mb were identified in the whole genome sequencing and assembly, and numerous homologous genes known to be involved in heavy metal resistance were found in the genome.
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http://dx.doi.org/10.1016/j.jbiotec.2016.04.040DOI Listing
July 2016

OsERF2 controls rice root growth and hormone responses through tuning expression of key genes involved in hormone signaling and sucrose metabolism.

Plant Mol Biol 2016 Feb 10;90(3):293-302. Epub 2015 Dec 10.

Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.

Root determines plant distribution, development progresses, stress response, as well as crop qualities and yields, which is under the tight control of genetic programs and environmental stimuli. Ethylene responsive factor proteins (ERFs) play important roles in plant growth and development. Here, the regulatory function of OsERF2 involved in root growth was investigated using the gain-function mutant of OsERF2 (nsf2857) and the artificial microRNA-mediated silenced lines of OsERF2 (Ami-OsERF2). nsf2857 showed short primary roots compared with the wild type (WT), while the primary roots of Ami-OsERF2 lines were longer than those of WT. Consistent with this phenotype, several auxin/cytokinin responsive genes involved in root growth were downregulated in nsf2857, but upregulated in Ami-OsERF2. Then, we found that nsf2857 seedlings exhibited decreased ABA accumulation and sensitivity to ABA and reduced ethylene-mediated root inhibition, while those were the opposite in Ami-ERF2 plants. Moreover, several key genes involved in ABA synthesis were downregulated in nsf2857, but unregulated in Ami-ERF2 lines. In addition, OsERF2 affected the accumulation of sucrose and UDPG by mediating expression of key genes involved in sucrose metabolism. These results indicate that OsERF2 is required for the control of root architecture and ABA- and ethylene-response by tuning expression of series genes involved in sugar metabolism and hormone signaling pathways.
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http://dx.doi.org/10.1007/s11103-015-0416-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4717165PMC
February 2016

Isolation of Rhp-PSP, a member of YER057c/YjgF/UK114 protein family with antiviral properties, from the photosynthetic bacterium Rhodopseudomonas palustris strain JSC-3b.

Sci Rep 2015 Nov 4;5:16121. Epub 2015 Nov 4.

Key Laboratory for the Integrated Management of Pest and Disease on Horticultural Crops in Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China.

Rhodopseudomonas palustris strain JSC-3b isolated from a water canal adjacent to a vegetable field produces a protein that was purified by bioactivity-guided fractionation based on ammonium sulfate precipitation, ion-exchange absorption and size exclusion. The protein was further identified as an endoribonuclease L-PSP (Liver-Perchloric acid-soluble protein) by shotgun mass spectrometry analysis and gene identification, and it is member of YER057c/YjgF/UK114 protein family. Herein, this protein is designated Rhp-PSP. Rhp-PSP exhibited significant inhibitory activities against tobacco mosaic virus (TMV) in vivo and in vitro. To our knowledge, this represents the first report on the antiviral activity of a protein of the YER057c/YjgF/UK114 family and also the first antiviral protein isolated from R. palustris. Our research provides insight into the potential of photosynthetic bacterial resources in biological control of plant virus diseases and sustainable agriculture.
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http://dx.doi.org/10.1038/srep16121DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4632080PMC
November 2015

Microbial community structures in an integrated two-phase anaerobic bioreactor fed by fruit vegetable wastes and wheat straw.

J Environ Sci (China) 2014 Dec 4;26(12):2484-92. Epub 2014 Nov 4.

College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China; Bioprocess control (Sweden) Co., Ltd., Beijing Representative Office, Beijing 100027, China.

The microbial community structures in an integrated two-phase anaerobic reactor (ITPAR) were investigated by 16S rDNA clone library technology. The 75L reactor was designed with a 25L rotating acidogenic unit at the top and a 50L conventional upflow methanogenic unit at the bottom, with a recirculation connected to the two units. The reactor had been operated for 21 stages to co-digest fruit/vegetable wastes and wheat straw, which showed a very good biogas production and decomposition of cellulosic materials. The results showed that many kinds of cellulose and glycan decomposition bacteria related with Bacteroidales, Clostridiales and Syntrophobacterales were dominated in the reactor, with more bacteria community diversities in the acidogenic unit. The methanogens were mostly related with Methanosaeta, Methanosarcina, Methanoculleus, Methanospirillum and Methanobacterium; the predominating genus Methanosaeta, accounting for 40.5%, 54.2%, 73.6% and 78.7% in four samples from top to bottom, indicated a major methanogenesis pathway by acetoclastic methanogenesis in the methanogenic unit. The beta diversity indexes illustrated a more similar distribution of bacterial communities than that of methanogens between acidogenic unit and methanogenic unit. The differentiation of methanogenic community composition in two phases, as well as pH values and volatile fatty acid (VFA) concentrations confirmed the phase separation of the ITPAR. Overall, the results of this study demonstrated that the special designing of ITPAR maintained a sufficient number of methanogens, more diverse communities and stronger syntrophic associations among microorganisms, which made two phase anaerobic digestion of cellulosic materials more efficient.
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http://dx.doi.org/10.1016/j.jes.2014.06.035DOI Listing
December 2014

Cloning and characterization of a new β-glucosidase from a metagenomic library of rumen of cattle feeding with Miscanthus sinensis.

BMC Biotechnol 2014 Oct 2;14:85. Epub 2014 Oct 2.

College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China.

Background: The study on the second generation bio-fuel is a hot area of current research of renewable energy. Among series of key points in this area, the role of β-glucosidase in the degradation of intermediate gluco-oligosaccharides limits the rate of the complete saccharification of lignocellulose.

Results: In this study, a new β-glucosidase gene, unglu135B12, which was isolated from a metagenomic library of rumen of cattle feeding with Miscanthus sinensis by the function-based screening, encodes a 779 amino acid polypeptide that contains a catalytic domain belonging to glycoside hydrolase family 3 (GH3). It was recombinantly expressed, purified and biochemically characterized. The recombinant β-glucosidase, unglu135B12, displayed optimum enzymatic activity at pH 5.0 at 38°C, and showed the highest specific activity of 2.5 × 10(3) U/mg under this optimal condition to p-nitrophenyl-β-D-glucopyranoside (pNPG), and its Km and Vmax values were 0.309 mmol/L and 7.292 μmol/min, respectively. In addition, the presence of Ca2+, K+, Na+ slightly improved β-glucosidase activity of unglu135B12 by about 5%, while about 10~85% loss of β-glucosidase activity was induced by addition of Mn2+, Fe3+, Zn2+, Cu2+. Interestingly, unglu135B12 was activated by glucose at the concentration lower than 40 mM.

Conclusions: Our findings indicate that unglu135B12 is a new β-glucosidase derived from rumen of cattle, and it might be a potent candidate for saccharification of lignocellulose in industrial application.
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http://dx.doi.org/10.1186/1472-6750-14-85DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4287584PMC
October 2014

Study on the steady operating state of a micro-pulse electron gun.

Rev Sci Instrum 2014 Sep;85(9):093304

State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China.

Micro-pulse electron gun (MPG) employs the basic concept of multipacting to produce high-current and short-pulse electron beams from a radio-frequency (RF) cavity. The concept of MPG has been proposed for more than two decades. However, the unstable operating state of MPG vastly obstructs its practical applications. This paper presents a study on the steady operating state of a micro-pulse electron gun with theory and experiments. The requirements for the steady operating state are proposed through the analysis of the interaction between the RF cavity and the beam load. Accordingly, a MPG cavity with the frequency of 2856 MHz has been designed, constructed, and tested. Some primary experiments have been finished. Both the unstable and stable operating states of the MPG have been observed. The stable output beam current has been detected at about 3.8 mA. Further experimental study is under way now.
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http://dx.doi.org/10.1063/1.4895604DOI Listing
September 2014

[AFLP analysis of genetic diversity of Evodia rutaecarpa].

Zhongguo Zhong Yao Za Zhi 2012 Feb;37(3):278-82

College of Bioscience and Technology, Hunan Agricultural University, Changsha 410128, China.

Objective: To study the genetic background of Evodia rutaecarpa by AFLP, and analyze the genetic diversity of E. rutaecarpa from different areas.

Method: E. rutaecarpa genomic DNA was extracted. The AFLP reaction system was established and AFLP primer pairs were chosen for the analysis. Forty-six individuals of E. rutaecarpa which from five provinces were analyzed by AFLP. The NTSYS-pc 2.1 software was used for cluster analysis.

Result: Six out of the original 72 pairs of primers were optimized for the study; AFLP analysis revealed the similarity coefficient of 0.53, the samples of E. rutaecarpa var. officinalis from Zhejiang province was separated from other accessions; E. rutaecarpa var. officinalis also showed more pronounced genetic variation than the E. rutaecarpa, and strong geo-related relevance.

Conclusion: Variance of genetic background of E. rutaecarpa are large, AFLP analysis method can obviously identify different varieties of E. rutaecarpa, and can detect the genetic characteristics of inter-regional differences.
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February 2012

Overexpression of ethylene response factor TERF2 confers cold tolerance in rice seedlings.

Transgenic Res 2011 Aug 7;20(4):857-66. Epub 2010 Dec 7.

Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.

Rice (Oryza sativa L.) is a warm-season plant exposed to various stresses. Low temperature is an important factor limiting extension of rice cultivation areas and productivity. Previously, we have demonstrated that tomato ERF protein TERF2 enhances freezing tolerance of transgenic tobacco and tomato plants. Herein, we report that overexpression of TERF2 enhances transgenic rice tolerance to cold without affecting growth or agronomic traits. Physiological assays revealed that TERF2 could not only increase accumulation of osmotic substances and chlorophyll, but also reduce reactive oxygen species (ROS) and malondialdehyde (MDA) content and decrease electrolyte leakage in rice under cold stress. Further analysis of gene expression showed that TERF2 could activate expression of cold-related genes, including OsMyb, OsICE1, OsCDPK7, OsSODB, OsFer1, OsTrx23, and OsLti6, in transgenic rice plants under natural condition or cold stress. Thus, our findings demonstrated that TERF2 modulated expression of stress-related genes and a series of physiological adjustments under cold stress, indicating that TERF2 might have important regulatory roles in response to abiotic stress in rice and possess potential utility in improving crop cold tolerance.
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http://dx.doi.org/10.1007/s11248-010-9463-9DOI Listing
August 2011

Low-frequency vibrational modes of DL-homocysteic acid and related compounds.

Spectrochim Acta A Mol Biomol Spectrosc 2009 Sep 24;73(5):884-91. Epub 2009 Apr 24.

State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, China.

In this paper several polycrystalline molecules with sulfonate groups and some of their metal complexes, including DL-homocysteic acid (DLH) and its Sr- and Cu-complexes, pyridine-3-sulphonic acid and its Co- and Ni-complexes, sulfanilic acid and L-cysteic acid were investigated using THz time-domain methods at room temperature. The results of THz absorption spectra show that the molecules have characteristic bands in the region of 0.2-2.7 THz (6-90 cm(-1)). THz technique can be used to distinguish different molecules with sulfonate groups and to determine the bonding of metal ions and the changes of hydrogen bond networks. In the THz region DLH has three bands: 1.61, 1.93 and 2.02 THz; and 0.85, 1.23 and 1.73 THz for Sr-DLH complex, 1.94 THz for Cu-DLH complex, respectively. The absorption bands of pyridine-3-sulphonic acid are located at 0.81, 1.66 and 2.34 THz; the bands at 0.96, 1.70 and 2.38 THz for its Co-complex, 0.76, 1.26 and 1.87 THz for its Ni-complex. Sulphanilic acid has three bands: 0.97, 1.46 and 2.05 THz; and the absorption bands of l-cysteic acid are at 0.82, 1.62, 1.87 and 2.07 THz, respectively. The THz absorption spectra after complexation are different from the ligands, which indicate the bonding of metal ions and the changes of hydrogen bond networks. M-O and other vibrations appear in the FIR region for those metal-ligand complexes. The bands in the THz region were assigned to the rocking, torsion, rotation, wagging and other modes of different groups in the molecules. Preliminary assignments of the bands were carried out using Gaussian program calculation.
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http://dx.doi.org/10.1016/j.saa.2009.04.011DOI Listing
September 2009

Expression, purification, and characterization of hepatitis B virus surface antigens (HBsAg) in yeast Pichia Pastoris.

Appl Biochem Biotechnol 2009 Aug 29;158(2):432-44. Epub 2009 Jan 29.

College of Life Sciences, Hunan Normal University, Changsha 410081, China.

Prevention of the prevalence of HB depends upon the development of efficient diagnostic reagent and preventive vaccine. Pichia pastoris offers many advantages over the other expression systems in the production of recombinant HBsAg. In this study, we reported that the recombinant P. pastoris strains were cultured in shake flasks and then scaled up in a 5.0-l bioreactor: approximately 27 mg/l of the protein and the maximal cell OD at 600 nm of 310 were achieved in the bioreactor. The recombinant HBsAg was purified by three steps of purification procedures. SDS-PAGE showed that the purified recombinant HBsAg constituted only one homogeneous band of approximately 24 kDa. CsCl density gradient ultracentrifugation assay indicated that the density of the HBsAg was 1.2 mg/ml, which was in agreement with the natural HBsAg, the HBsAg expressed in Saccharomyces cerevisiae and in mammalian cells. Electron microscope observation revealed that the purified recombinant HBsAg was homogeneous 22-nm particles, suggesting the HBsAg expressed in P. pastoris was self-assembled to virus-like structures. Competitive ELISA indicated that P. pastoris-derived HBsAg possessed the excellent immunoreaction with anti-HBsAg. Animal immunization showed that the immunogenicity of P. pastoris-derived HBsAg was superior to that of S. cerevisiae-derived HBsAg. Together, our results demonstrated that the recombinant HBsAg expressed in P. pastoris could provide promising, inexpensive, and large-scale materials for the diagnostic reagent and vaccine to prevent HBV infection.
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http://dx.doi.org/10.1007/s12010-009-8527-xDOI Listing
August 2009

Co-metabolic degradation of dimethoate by Raoultella sp. X1.

Biodegradation 2009 Jun 7;20(3):363-73. Epub 2008 Nov 7.

School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, People's Republic of China.

A bacterium Raoultella sp. X1, based on its 16S rRNA gene sequence, was isolated. Characteristics regarding the bacterial morphology, physiology, and genetics were investigated with an electron microscopy and conventional microbiological techniques. Although the isolate grew and degraded dimethoate poorly when the chemical was used as a sole carbon and energy source, it was able to remove up to 75% of dimethoate via co-metabolism. With a response surface methodology, we optimized carbon, nitrogen and phosphorus concentrations of the media for dimethoate degradation. Raoultella sp. X1 has a potential to be a useful organism for dimethoate degradation and a model strain for studying this biological process at the molecular level.
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http://dx.doi.org/10.1007/s10532-008-9227-xDOI Listing
June 2009

Expression of TERF1 in rice regulates expression of stress-responsive genes and enhances tolerance to drought and high-salinity.

Plant Cell Rep 2008 Nov 6;27(11):1787-95. Epub 2008 Sep 6.

Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.

Drought and high-salinity are the important constraints that severely affect plant development and crop yield worldwide. It has been established that ethylene response factor (ERF) proteins play important regulatory roles in plant response to abiotic and biotic stresses. Our previous researches have revealed that transgenic tobacco over-expressing TERF1 (encoding a tomato ERF protein) showed enhanced tolerance to abiotic stress. Here, we further investigate the function of TERF1 in transgenic rice. Compared with the wild-type plants, overexpression of TERF1 resulted in an increased tolerance to drought and high-salt in transgenic rice. And the enhanced tolerance may be associated with the accumulation of proline and the decrease of water loss. Furthermore, TERF1 can effectively regulate the expression of stress-related functional genes Lip5, Wcor413-l, OsPrx and OsABA2, as well as regulatory genes OsCDPK7, OsCDPK13 and OsCDPK19 under normal growth conditions. Our analyses of cis-acting elements show that there exist DRE/CRT and/or GCC-box existing in TERF1 targeted gene promoters. Our results revealed that ectopic expression of TERF1 in rice caused a series of molecular and physiological alterations and resulted in the transgenic rice with enhanced tolerance to abiotic stress, indicating that TERF1 might have similar regulatory roles in response to abiotic stress in tobacco and rice.
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http://dx.doi.org/10.1007/s00299-008-0602-1DOI Listing
November 2008

Genetic association of ETHYLENE-INSENSITIVE3-like sequence with the sex-determining M locus in cucumber (Cucumis sativus L.).

Theor Appl Genet 2008 Oct 16;117(6):927-33. Epub 2008 Jul 16.

Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China.

Cucumber (Cucumis sativus L.) has served as the model system for sex expression in flowering plants and its sex type is predominantly controlled by two genetic loci, F and M. Ethylene is the major plant hormone that regulates sex expression in cucumber. The current model predicts that ethylene serves as both a promoter of femaleness via the F locus and an inhibitor of the male sex via the M locus. In support of this model, genetic, genomic, and transcript analyses indicate that the F gene encodes a key enzyme in ethylene biosynthesis. In this study, we discovered that the M locus co-segregates with an ETHYLENE-INSENSITIVE3 (EIN3)-like genomic sequence in an F2 population of 96 individuals. This genetic association agrees with the prediction that the M locus is involved in ethylene signaling, thus providing another line of evidence in favor of the model. In addition, we generated an amplified fragment length polymorphism (AFLP) map of the M locus, which was delimited into a genetic interval of 2.5 cM. The genetic association and the local map will assist the molecular isolation of the M gene using the combination of positional cloning and candidate gene approach.
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http://dx.doi.org/10.1007/s00122-008-0832-1DOI Listing
October 2008