Publications by authors named "Yulong Feng"

31 Publications

Pyrrole alkaloids from Solanum rostratum and their chemical defense function against Henosepilachna vigintioctomaculata.

Fitoterapia 2021 Sep 9;155:105031. Epub 2021 Sep 9.

College of Biological Science and Technology, Shenyang Agricultural University, Shenyang 110866, PR China. Electronic address:

Three pairs of novel enantiomeric pyrrole alkaloids (1a/1b, 2a/2b, 3a/3b) were isolated from the leaves of Solanum rostratum and their structures were determined via NMR analyses and ECD calculation. All the enantiomers displayed different levels of antifeedant and growth-inhibitory activities against Henosepilachna vigintioctomaculata (a noxious herbivore for Solanaceae), especially 1a and 2a. Interestingly, the results showed enantioselectivity, in which that the pyrrole alkaloids with R configuration at C-2' showed stronger chemical defense function than their enantiomers.
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http://dx.doi.org/10.1016/j.fitote.2021.105031DOI Listing
September 2021

Transport stress affects the fecal microbiota in healthy donkeys.

J Vet Intern Med 2021 Jul 31. Epub 2021 Jul 31.

National Engineering Research Center for Gelatin-based TCM, Dong-E E-Jiao Co., Ltd, Liaocheng, Shandong Province, China.

Background: With the development of large-scale donkey farming in China, long-distance transportation has become common practice, and the incidence of intestinal diseases after transportation has increased. The intestinal microbiota is important in health and disease, and whether or not transportation disturbs the intestinal microbiota in donkeys has not been investigated.

Objectives: To determine the effects of transportation on the fecal microbiota of healthy donkeys using 16S rRNA sequencing.

Animals: Fecal and blood samples were collected from 12 Dezhou donkeys before and after transportation.

Methods: Prospective controlled study. Cortisol, ACTH, and heat-shock protein 90 (HSP90) concentrations were measured. Sequencing of 16S rRNA was used to assess the microbial composition. Alpha diversity and beta diversity were assessed.

Results: Results showed significant (P < .05) increases in cortisol (58.1 ± 14.6 to 71.1 ± 9.60 ng/mL), ACTH (163.8 ± 31.9 to 315.8 ± 27.9 pg/mL), and HSP90 (10.8 ± 1.67 to 14.6 ± 1.75 ng/mL) on the day of arrival. A significantly lower (P = .04) level of bacterial richness was found in fecal samples after transportation, compared with that before transportation without distinct changes in diversity. Most notably, donkeys had significant decreases in Atopostipes, Eubacterium, Streptococcus, and Coriobacteriaceae.

Conclusions And Clinical Importance: Transportation can induce stress in healthy donkeys and have some effect on the composition of the in fecal microbiota. Additional studies are required to understand the potential effect of these microbiota changes, especially significantly decreased bacteria, on the development intestinal diseases in donkeys during recovery from transportation.
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http://dx.doi.org/10.1111/jvim.16235DOI Listing
July 2021

Severe pantothenic acid deficiency induces alterations in the intestinal mucosal proteome of starter Pekin ducks.

BMC Genomics 2021 Jun 30;22(1):491. Epub 2021 Jun 30.

State Key Laboratory of Animal Nutrition, Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.

Background: Pantothenic acid deficiency (PAD) results in growth depression and intestinal hypofunction of animals. However, the underlying molecular mechanisms remain to be elucidated. Mucosal proteome might reflect dietary influences on physiological processes.

Results: A total of 128 white Pekin ducks of one-day-old were randomly assigned to two groups, fed either a PAD or a pantothenic acid adequate (control, CON) diet. After a 16-day feeding period, two ducks from each replicate were sampled to measure plasma parameters, intestinal morphology, and mucosal proteome. Compared to the CON group, high mortality, growth retardation, fasting hypoglycemia, reduced plasma insulin, and oxidative stress were observed in the PAD group. Furthermore, PAD induced morphological alterations of the small intestine indicated by reduced villus height and villus surface area of duodenum, jejunum, and ileum. The duodenum mucosal proteome of ducks showed that 198 proteins were up-regulated and 223 proteins were down-regulated (> 1.5-fold change) in the PAD group compared to those in the CON group. Selected proteins were confirmed by Western blotting. Pathway analysis of these proteins exhibited the suppression of glycolysis and gluconeogenesis, fatty acid beta oxidation, tricarboxylic acid cycle, oxidative phosphorylation, oxidative stress, and intestinal absorption in the PAD group, indicating impaired energy generation and abnormal intestinal absorption. We also show that nine out of eleven proteins involved in regulation of actin cytoskeleton were up-regulated by PAD, probably indicates reduced intestinal integrity.

Conclusion: PAD leads to growth depression and intestinal hypofunction of ducks, which are associated with impaired energy generation, abnormal intestinal absorption, and regulation of actin cytoskeleton processes. These findings provide insights into the mechanisms of intestinal hypofunction induced by PAD.
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http://dx.doi.org/10.1186/s12864-021-07820-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8246668PMC
June 2021

A New Recognition Method for the Auditory Evoked Magnetic Fields.

Comput Intell Neurosci 2021 9;2021:6645270. Epub 2021 Feb 9.

State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics and Centre for Quantum Information Technology, Peking University, Beijing 100871, China.

Magnetoencephalography (MEG) is a persuasive tool to study the human brain in physiology and psychology. It can be employed to obtain the inference of change between the external environment and the internal psychology, which requires us to recognize different single trial event-related magnetic fields (ERFs) originated from different functional areas of the brain. Current recognition methods for the single trial data are mainly used for event-related potentials (ERPs) in the electroencephalography (EEG). Although the MEG shares the same signal sources with the EEG, much less interference from the other brain tissues may give the MEG an edge in recognition of the ERFs. In this work, we propose a new recognition method for the single trial auditory evoked magnetic fields (AEFs) through enhancing the signal. We find that the signal strength of the single trial AEFs is concentrated in the primary auditory cortex of the temporal lobe, which can be clearly displayed in the 2D images. These 2D images are then recognized by an artificial neural network (ANN) with 100% accuracy, which realizes the automatic recognition for the single trial AEFs. The method not only may be combined with the source estimation algorithm to improve its accuracy but also paves the way for the implementation of the brain-computer interface (BCI) with the MEG.
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http://dx.doi.org/10.1155/2021/6645270DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7892250PMC
July 2021

Genome-wide identification, evolution, expression, and alternative splicing profiles of peroxiredoxin genes in cotton.

PeerJ 2021 18;9:e10685. Epub 2021 Jan 18.

Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China.

Peroxiredoxin (PRX) is a ubiquitous thioredoxin-dependent peroxidase that can eliminate excessive free radicals produced by stress and protect cells from oxidative damage. s are also involved in reactive oxygen species (ROS)- and redox-dependent signaling by performing redox interactions with other proteins and modify their redox status. At present, family identification, evolution and regulation research has been conducted in some plants; however, systematic research about this family is lacking in cotton. In this study, a total of 44 s were identified in the cotton genome. Phylogenetic and conserved active site analyses showed that the s were divided into six subfamilies according to the conserved site (PxxxTxxC…S…W/F) and conserved cysteinyl residues positions. Segmental duplication and polyploid events were the main methods for family expansion, and the PRXs of diploid were the donors of s in the D subgenomes of allotetraploid and during the evolution of the family. qRT-PCR analysis confirmed that cis-acting elements play important roles in regulating the expression of s. Alternative splicing events occurred in GhPRX14-D that can increased the complexity of transcripts in . Subcellular localization showed that most members were located in chloroplasts, the cytoplasmic membrane and the nucleus. Our results provide systematic support for a better understanding of s in cotton and a starting point for further studies of the specific functions of s in cotton.
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http://dx.doi.org/10.7717/peerj.10685DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7819121PMC
January 2021

UDP-Glucose Dehydrogenases: Identification, Expression, and Function Analyses in Upland Cotton ().

Front Genet 2020 11;11:597890. Epub 2021 Jan 11.

State Key Laboratory of Cotton Biology, Key Laboratory of Biological and Genetic Breeding of Cotton, The Ministry of Agriculture, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China.

UDP-glucose dehydrogenase (UGD; EC1.1.1.22) is a NAD-dependent enzyme that catalyzes the two-fold oxidation of UDP-glucose (UDP-Glc) to produce UDP-glucuronic acid and plays an important role in plant cell wall synthesis. A total of 42 genes from four genomes including . , . , . , and . were identified and found that the gene family has conservative evolution patterns in gene structure and protein domain. The growth of fibers can be effectively promoted after adding the UDP-Glc to the medium, and the gene expression enhanced. In addition, the transgenic lines over-expressing had longer root lengths and higher gene expression level than the wild-type plants of . These results indicated that may play important roles in cotton fiber development and has a guiding significance for dissecting fiber development mechanism.
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http://dx.doi.org/10.3389/fgene.2020.597890DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7831515PMC
January 2021

A single nucleotide polymorphism variant located in the cis-regulatory region of the ABCG2 gene is associated with mallard egg colour.

Mol Ecol 2021 03 3;30(6):1477-1491. Epub 2021 Mar 3.

State Key Laboratory of Animal Nutrition, Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.

Avian egg coloration is shaped by natural selection, but its genetic basis remains unclear. Here, we used genome-wide association analysis and identity by descent to finely map green egg colour to a 179-kb region of Chr4 based on the resequencing of 352 ducks (Anas platyrhynchos) from a segregating population resulting from the mating of Pekin ducks (white-shelled eggs) and mallards (green-shelled eggs). We further narrowed the candidate region to a 30-kb interval by comparing genome divergence in seven indigenous duck populations. Among the genes located in the finely mapped region, only one transcript of the ABCG2 gene (XM_013093252.2) exhibited higher uterine expression in green-shelled individuals than in white-shelled individuals, as supported by transcriptome data from four populations. ABCG2 has been reported to encode a protein that functions as a membrane transporter for biliverdin. Sanger sequencing of the whole 30-kb candidate region (Chr4: 47.41-47.44 Mb) and a plasmid reporter assay helped to identify a single nucleotide polymorphism (Chr4: 47,418,074 G>A) located in a conserved predicted promoter region whose variation may alter ABCG2 transcription activity. We provide a useful molecular marker for duck breeding and contribute data to the research on ecological evolution based on egg colour patterns among birds.
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http://dx.doi.org/10.1111/mec.15785DOI Listing
March 2021

Effects of pantothenic acid on growth performance and antioxidant status of growing male white Pekin ducks.

Poult Sci 2020 Sep 20;99(9):4436-4441. Epub 2020 Jun 20.

State Key Laboratory of Animal Nutrition, Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China. Electronic address:

An experiment was conducted to investigate the effects of dietary pantothenic acid levels on growth performance, carcass traits, pantothenic acid status, and antioxidant status of male white Pekin ducks from 15 to 42 D of age and to evaluate the requirement of this vitamin for growing ducks. Different levels pantothenic acid (0, 2, 4, 6, 8, and 10 mg/kg) were supplemented to a corn-soy isolate protein basal diet to produce 6 dietary treatments with different analyzed total pantothenic acid levels (4.52, 6.44, 8.37, 9.88, 12.32, and 14.61 mg/kg). A total of 240 15-day-old male white Pekin ducks were allotted to 6 dietary treatments with 8 replicate pens of 5 birds per pen. At 42 D of age, growth performance, carcass traits, tissue pantothenic acid concentrations, and antioxidant status of white Pekin ducks were examined. Significant effects of dietary pantothenic acid on BW, average daily weight gain (ADG), plasma, and liver pantothenic acid concentrations were observed (P < 0.05) but not carcass traits. The growing ducks fed the basal diet without pantothenic acid supplementation had the lowest BW, ADG, plasma, and liver pantothenic acid content among all ducks (P < 0.05). In addition, the ducks fed the basal diet without pantothenic acid supplementation showed the lowest antioxidant capacity indicated by greatest plasma malondialdehyde content and lowest liver total antioxidant capacity (P < 0.05). And, these criteria responded linearly as dietary pantothenic acid levels increased (P < 0.05). These results indicated that dietary pantothenic acid supplementation improved growth performance and antioxidant status of the growing ducks. In accordance with the broken-line model, the pantothenic acid requirements (based on dietary total pantothenic acid) of male white Pekin ducks from 15 to 42 D of age for BW, ADG, and plasma and liver pantothenic acid contents were 10.18, 10.27, 12.06, and 10.79 mg/kg, respectively.
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http://dx.doi.org/10.1016/j.psj.2020.05.021DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7597976PMC
September 2020

The Addition of a Synthetic LPS-Targeting Domain Improves Serum Stability While Maintaining Antimicrobial, Antibiofilm, and Cell Stimulating Properties of an Antimicrobial Peptide.

Biomolecules 2020 07 8;10(7). Epub 2020 Jul 8.

Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada.

Multi-drug resistant (MDR) bacteria and their biofilms are a concern in veterinary and human medicine. Protegrin-1 (PG-1), a potent antimicrobial peptide (AMP) with antimicrobial and immunomodulatory properties, is considered a potential alternative for conventional antibiotics. AMPs are less stable and lose activity in the presence of physiological fluids, such as serum. To improve stability of PG-1, a hybrid peptide, SynPG-1, was designed. The antimicrobial and antibiofilm properties of PG-1 and the PG-1 hybrid against MDR pathogens was analyzed, and activity after incubation with physiological fluids was compared. The effects of these peptides on the IPEC-J2 cell line was also investigated. While PG-1 maintained some activity in 25% serum for 2 h, SynPG-1 was able to retain activity in the same condition for up to 24 h, representing a 12-fold increase in stability. Both peptides had some antibiofilm activity against and . While both peptides prevented biofilm formation of methicillin-resistant (MRSA), neither could destroy MRSA's pre-formed biofilms. Both peptides maintained activity after incubation with trypsin and porcine gastric fluid, but not intestinal fluid, and stimulated IPEC-J2 cell migration. These findings suggest that SynPG-1 has much better serum stability while maintaining the same antimicrobial potency as PG-1.
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http://dx.doi.org/10.3390/biom10071014DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7407491PMC
July 2020

Recording brain activities in unshielded Earth's field with optically pumped atomic magnetometers.

Sci Adv 2020 Jun 12;6(24):eaba8792. Epub 2020 Jun 12.

State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics, and Center for Quantum Information Technology, Peking University, Beijing 100871, China.

Understanding the relationship between brain activity and specific mental function is important for medical diagnosis of brain symptoms, such as epilepsy. Magnetoencephalography (MEG), which uses an array of high-sensitivity magnetometers to record magnetic field signals generated from neural currents occurring naturally in the brain, is a noninvasive method for locating the brain activities. The MEG is normally performed in a magnetically shielded room. Here, we introduce an unshielded MEG system based on optically pumped atomic magnetometers. We build an atomic magnetic gradiometer, together with feedback methods, to reduce the environment magnetic field noise. We successfully observe the alpha rhythm signals related to closed eyes and clear auditory evoked field signals in unshielded Earth's field. Combined with improvements in the miniaturization of the atomic magnetometer, our method is promising to realize a practical wearable and movable unshielded MEG system and bring new insights into medical diagnosis of brain symptoms.
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http://dx.doi.org/10.1126/sciadv.aba8792DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7292643PMC
June 2020

Study on Electron-Induced Surface Plasmon Coupling with Quantum Well Using a Perturbation Method.

Nanomaterials (Basel) 2020 May 9;10(5). Epub 2020 May 9.

State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.

Ag nanoparticles (NPs) are filled in a photonic crystal (PhC) hole array on green light emitting diodes (LEDs). The localized surface plasmon (LSP)-quantum well (QW) coupling effect is studied by measuring the cathodoluminescence (CL) spectra impinging at the specific spots on the Ag NPs. Twenty-six percent and fifty-two percent enhancements of the CL intensities are obtained at the center and edge of the Ag NP, respectively, compared to the result that the electron-beam (e-beam) excites the QW directly. To illustrate the coupling process of the three-body system of e-beam-LSP-QW, a perturbation theory combining a three-dimensional (3D) finite difference time domain (FDTD) simulation is put forward. The effects of the polarization orientation of the dipole and the field symmetry of the LSP on the LSP-QW coupling are also discussed.
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http://dx.doi.org/10.3390/nano10050913DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7279149PMC
May 2020

Postintroduction evolution contributes to the successful invasion of .

Ecol Evol 2020 Feb 14;10(3):1252-1263. Epub 2020 Jan 14.

Liaoning Key Laboratory for Biological Invasions and Global Changes Shenyang Agricultural University Shenyang China.

The evolution of increased competitive ability (EICA) hypothesis states that, when introduced in a novel habitat, invasive species may reallocate resources from costly quantitative defense mechanisms against enemies to dispersal and reproduction; meanwhile, the refinement of EICA suggests that concentrations of toxins used for qualitative defense against generalist herbivores may increase. Previous studies considered that only few genotypes were introduced to the new range, whereas most studies to test the EICA (or the refinement of EICA) hypotheses did not consider founder effects.In this study, genetic and phenotypic data of populations sampled across native and introduced ranges were combined to investigate the role of postintroduction evolution in the successful invasion of .Compared with native populations, the introduced populations exhibited lower levels of genetic diversity. Moreover, different founder effects events were interpreted as the main cause of the genetic structure observed in introduced ranges. Three Florida, two Trinidad, and two Puerto Rico populations may have been the sources of the invasive in Asia.When in free of competition conditions, plants from introduced ranges perform better than those from native ranges at high nutrient supply but not at low nutrient level. The differences in performance due to competition were significantly greater for plants from the native range than those from the introduced range at both nutrient levels. Moreover, the differences in performance by competition were significantly greater for putative source populations than for invasive populations.Quantities of three types of secondary compounds in leaves of invasive populations were significantly higher than those in putative source populations. These results provide more accurate evidence that the competitive ability of the introduced is increased with postintroduction evolution.
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http://dx.doi.org/10.1002/ece3.5979DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7029091PMC
February 2020

Secondary Metabolites from and Their Antifeedant Defense Mechanisms against .

J Agric Food Chem 2020 Jan 24;68(1):88-96. Epub 2019 Dec 24.

is a worldwide malignant invasive weed, causing serious harm to the ecological environment and biodiversity. Strong chemical defense against herbivorous insects is supposed to be one of the successful invasive mechanisms of this exotic plant. However, the real defense components and their action mechanisms and distributions are still unknown. To address these problems, we bioassay-guided isolated compounds from the aerial part of and determined their structures using high-resolution electrospray ionization mass spectrometry, nuclear magnetic resonance, and electronic circular dichroism calculation. One new and seven known compounds were identified, and all of the isolates exhibited different levels of antifeedant activities, especially compounds and . Consistently, compounds and displayed potent inhibitory effects on antifeedant-related enzymes (AchE and CarE). The action mechanisms of active compounds and were revealed by molecular docking and molecular dynamic simulation studies. Furthermore, the distributions of the active compounds in leaves, stems, and flowers were also analyzed by liquid chromatography-mass spectrometry.
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http://dx.doi.org/10.1021/acs.jafc.9b06768DOI Listing
January 2020

Drying features of microwave and far-infrared combination drying on white ginseng slices.

Food Sci Biotechnol 2019 Aug 19;28(4):1065-1072. Epub 2019 Apr 19.

Department of Agricultural Mechanization Engineering, Shenyang Agricultural University, 120 Dongling-road, Shen-yang, 110-866 Liaoning China.

In this study microwave and far-infrared combination drying were conducted to investigate the effect of microwave and far-infrared heating mode switching point water content (SW), ginseng slice thickness, and far-infrared drying temperature on drying indicators (surface colour difference, ginsenosides content, and surface shrinkage rate) and drying efficiency (drying time) during the process of drying white ginseng slices. Regarding microwave drying, the microwave drying time cannot exceed 150 s, and the ginseng slice water content cannot be less 50%. For the combination drying, SW, far-infrared drying temperature and slice thickness increased, the colour difference and surface shrinkage rate first decreased and then increased, and the content of ginsenosides first increased and then decreased. In addition, the combination drying showed faster drying rate, higher ginsenosides contents value, colour difference (ΔE) value and lower surface shrinkage rate than single far-infrared drying.
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http://dx.doi.org/10.1007/s10068-018-00541-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6595014PMC
August 2019

Nonlinearity of root trait relationships and the root economics spectrum.

Nat Commun 2019 05 17;10(1):2203. Epub 2019 May 17.

Liaoning Key Laboratory for Biological Invasions and Global Change, Shenyang Agricultural University, 110866, Shenyang, Liaoning Province, China.

The root economics spectrum (RES), a common hypothesis postulating a tradeoff between resource acquisition and conservation traits, is being challenged by conflicting relationships between root diameter, tissue density (RTD) and root nitrogen concentration (RN). Here, we analyze a global trait dataset of absorptive roots for over 800 plant species. For woody species (but not for non-woody species), we find nonlinear relationships between root diameter and RTD and RN, which stem from the allometric relationship between stele and cortical tissues. These nonlinear relationships explain how sampling bias from different ends of the nonlinear curves can result in conflicting trait relationships. Further, the shape of the relationships varies depending on evolutionary context and mycorrhizal affiliation. Importantly, the observed nonlinear trait relationships do not support the RES predictions. Allometry-based nonlinearity of root trait relationships improves our understanding of the ecology, physiology and evolution of absorptive roots.
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http://dx.doi.org/10.1038/s41467-019-10245-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6525182PMC
May 2019

Co-Expression Network Analysis and Hub Gene Selection for High-Quality Fiber in Upland Cotton (Gossypium hirsutum) Using RNA Sequencing Analysis.

Genes (Basel) 2019 02 6;10(2). Epub 2019 Feb 6.

State Key Laboratory of Cotton Biology, Key Laboratory of Biological and Genetic Breeding of Cotton, The Ministry of Agriculture, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, Henan, China.

Upland cotton () is grown for its elite fiber. Understanding differential gene expression patterns during fiber development will help to identify genes associated with fiber quality. In this study, we used two recombinant inbred lines (RILs) differing in fiber quality derived from an intra- population to explore expression profiling differences and identify genes associated with high-quality fiber or specific fiber-development stages using RNA sequencing. Overall, 72/27, 1137/1584, 437/393, 1019/184, and 2555/1479 differentially expressed genes were up-/down-regulated in an elite fiber line (L1) relative to a poor-quality fiber line (L2) at 10, 15, 20, 25, and 30 days post-anthesis, respectively. Three-hundred sixty-three differentially expressed genes (DEGs) between two lines were colocalized in fiber strength (FS) quantitative trait loci (QTL). Short Time-series Expression Miner (STEM) analysis discriminated seven expression profiles; gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation were performed to identify difference in function between genes unique to L1 and L2. Co-expression network analysis detected five modules highly associated with specific fiber-development stages, especially for high-quality fiber tissues. The hub genes in each module were identified by weighted gene co-expression network analysis. Hub genes encoding actin 1, Rho GTPase-activating protein with PAK-box, TPX2 protein, bHLH transcription factor, and leucine-rich repeat receptor-like protein kinase were identified. Correlation networks revealed considerable interaction among the hub genes, transcription factors, and other genes.
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http://dx.doi.org/10.3390/genes10020119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6410125PMC
February 2019

Study on the Coupling Mechanism of the Orthogonal Dipoles with Surface Plasmon in Green LED by Cathodoluminescence.

Nanomaterials (Basel) 2018 Apr 16;8(4). Epub 2018 Apr 16.

State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.

We analyzed the coupling behavior between the localized surface plasmon (LSP) and quantum wells (QWs) using cathodoluminescence (CL) in a green light-emitting diodes (LED) with Ag nanoparticles (NPs) filled in photonic crystal (PhC) holes. Photoluminescence (PL) suppression and CL enhancement were obtained for the same green LED sample with the Ag NP array. Time-resolved PL (TRPL) results indicate strong coupling between the LSP and the QWs. Three-dimensional (3D) finite difference time domain (FDTD) simulation was performed using a three-body model consisting of two orthogonal dipoles and a single Ag NP. The LSP–QWs coupling effect was separated from the electron-beam (e-beam)–LSP–QW system by linear approximation. The energy dissipation was significantly reduced by the z-dipole introduction under the e-beam excitation. In this paper, the coupling mechanism is discussed and a novel emission structure is proposed.
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http://dx.doi.org/10.3390/nano8040244DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5923574PMC
April 2018

Investigation on strain relaxation distribution in GaN-based μLEDs by Kelvin probe force microscopy and micro-photoluminescence.

Opt Express 2018 Mar;26(5):5265-5274

GaN/InGaN multi-quantum-wells (MQWs) micron light emitting diodes (µLEDs) with the size ranging from 10 to 300 µm are fabricated. Effects of strain relaxation on the performance of µLEDs have been investigated both experimentally and numerically. Kelvin probe force microscopy (KPFM) and micro-photoluminescence (µPL) are used to characterize the strained area on micron pillars. Strain relaxation and reducing polarization field in MQWs almost affects the whole mesa for 10 µm LEDs and about 4% area around the lateral for 300 µm LEDs. It makes a great contribution to high performance for smaller size µLEDs. Moreover, an indirect nanoscale strain measurement for µLEDs are provided.
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http://dx.doi.org/10.1364/OE.26.005265DOI Listing
March 2018

The effects of nanocavity and photonic crystal in InGaN/GaN nanorod LED arrays.

Nanoscale Res Lett 2016 Dec 20;11(1):340. Epub 2016 Jul 20.

State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Haidian, Beijing, China.

InGaN/GaN nanorod light-emitting diode (LED) arrays were fabricated using nanoimprint and reactive ion etching. The diameters of the nanorods range from 120 to 300 nm. The integral photoluminescence (PL) intensity for 120 nm nanorod LED array is enhanced as 13 times compared to that of the planar one. In angular-resolved PL (ARPL) measurements, there are some strong lobes as resonant regime appeared in the far-field radiation patterns of small size nanorod array, in which the PL spectra are sharp and intense. The PL lifetime for resonant regime is 0.088 ns, which is 40 % lower than that of non-resonant regime for 120 nm nanorod LED array. At last, three dimension finite difference time domain (FDTD) simulation is performed. The effects of guided modes coupling in nanocavity and extraction by photonic crystals are explored.
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http://dx.doi.org/10.1186/s11671-016-1548-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4954795PMC
December 2016

Study on Light Extraction from GaN-based Green Light-Emitting Diodes Using Anodic Aluminum Oxide Pattern and Nanoimprint Lithography.

Sci Rep 2016 Feb 23;6:21573. Epub 2016 Feb 23.

State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.

An anodic aluminum oxide (AAO) patterned sapphire substrate, with the lattice constant of 520 ± 40 nm, pore dimension of 375 ± 50 nm, and height of 450 ± 25 nm was firstly used as a nanoimprint lithography (NIL) stamp and imprinted onto the surface of the green light-emitting diode (LED). A significant light extraction efficiency (LEE) was improved by 116% in comparison to that of the planar LED. A uniform broad protrusion in the central area and some sharp lobes were also obtained in the angular resolution photoluminescence (ARPL) for the AAO patterned LED. The mechanism of the enhancement was correlated to the fluctuations of the lattice constant and domain orientation of the AAO-pattern, which enabled the extraction of more guided modes from the LED device.
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http://dx.doi.org/10.1038/srep21573DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4763243PMC
February 2016

Are invasive plants more competitive than native conspecifics? Patterns vary with competitors.

Sci Rep 2015 Oct 22;5:15622. Epub 2015 Oct 22.

Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan Province 666303, China.

Invasive plants are sometimes considered to be more competitive than their native conspecifics, according to the prediction that the invader reallocates resources from defense to growth due to liberation of natural enemies ['Evolution of Increased Competitive Ability' (EICA) hypothesis]. However, the differences in competitive ability may depend on the identity of competitors. In order to test the effects of competitors, Ageratina adenophora plants from both native and invasive ranges competed directly, and competed with native residents from both invasive (China) and native (Mexico) ranges respectively. Invasive A. adenophora plants were more competitive than their conspecifics from native populations when competing with natives from China (interspecific competition), but not when competing with natives from Mexico. Invasive A. adenophora plants also showed higher competitive ability when grown in high-density monoculture communities of plants from the same population (intrapopulation competition). In contrast, invasive A. adenophora plants showed lower competitive ability when competing with plants from native populations (intraspecific competition). Our results indicated that in the invasive range A. adenophora has evolved to effectively cope with co-occurring natives and high density environments, contributing to invasion success. Here, we showed the significant effects of competitors, which should be considered carefully when testing the EICA hypothesis.
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http://dx.doi.org/10.1038/srep15622DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4650833PMC
October 2015

[Screening, identification, and promoting effect of phosphate-solubilizing bacteria in rhizosphere of Taxus chinensis var. mairei].

Wei Sheng Wu Xue Bao 2012 Mar;52(3):295-303

Department of Biological Science and Technology, Changzhi College, Changzhi 046011, China.

Objective: Phosphate-solubilizing bacteria (PSB) were isolated, screened and identified from the rhizosphere of Taxus chinensis var. mairei, and growth-promoting effects on T. chinensis var. mairei by high effective PSB were determined.

Methods: By using selective culture media, PSB were isolated from rhizospheric soil, the high effective PSB was further screened using NBRI-BPB medium, and the molybdenum-antimony anti-spectrophotometric method was applied to determine the phosphate-dissolving ability of the high effective PSB after four days fermentation in NBRIP medium. Bacteria were identified by the Biolog system combined with 16S rDNA gene sequence analysis and morphological, physiological and biochemical characteristics. The inoculation test in potted seedlings was carried out under the greenhouse.

Conclusion: Four strains of high effective PSB were screened and identified as Pseudomonas fluorescens, Bacillus cereus, Sinorhizobium meliloti and Bacillus licheniformis, respectively. These strains had significant effects on improving the growth of the seedlings of T. chinensis var. mairei.
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March 2012

Novel weapons and invasion: biogeographic differences in the competitive effects of Centaurea maculosa and its root exudate (+/-)-catechin.

Oecologia 2009 Apr 14;159(4):803-15. Epub 2009 Feb 14.

State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences (CAS), Beijing 100093, China.

Recent studies suggest that the invasive success of Centaurea maculosa may be related to its stronger allelopathic effects on native North American species than on related European species, one component of the "novel weapons" hypothesis. Other research indicates that C. maculosa plants from the invasive range in North America have evolved to be larger and better competitors than conspecifics from the native range in Europe, a component of the "evolution of increased competitive ability" hypothesis. These hypotheses are not mutually exclusive, but this evidence sets the stage for comparing the relative importance of evolved competitive ability to inherent competitive traits. In a competition experiment with a large number of C. maculosa populations, we found no difference in the competitive effects of C. maculosa plants from North America and Europe on other species. However, both North American and European C. maculosa were much better competitors against plants native to North America than congeners native to Romania, collected in areas where C. maculosa is also native. These results are consistent with the novel weapons hypothesis. But, in a second experiment using just one population from North America and Europe, and where North American and European species were collected from a broader range of sites, competitive interactions were weaker overall, and the competitive effects of C. maculosa were slightly stronger against European species than against North American species. Also consistent with the novel weapons hypothesis, (+/-)-catechin had stronger effects on native North American species than on native European species in two experiments. Our results suggest that the regional composition of the plant communities being invaded by C. maculosa may be more important for invasive success than the evolution of increased size and competitive ability.
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http://dx.doi.org/10.1007/s00442-008-1234-4DOI Listing
April 2009

[Fog water absorption by the leaves of epiphytes and non - epiphytes in Xishuangbanna].

Ying Yong Sheng Tai Xue Bao 2006 Jun;17(6):977-81

College of Life Sciences, Hebei University, Baoding 071002, China.

Xishuangbanna is located at the northern margin of tropics. Its climate is different from that of typical tropics, but the rainforest there is not very different from that of the typical tropics in Southeast Asia. The main problems in Xishuangbanna are seasonal drought and low temperature. Fog may contribute to the development of rainforest here, but related studies are few. This study is aimed to know whether the leaves of epiphytes and non - epiphytes in Xishuangbanna can directly absorb fog water and contribute to their water status recovery, and whether epiphytes are more competent than non - epiphytes in their leaf fog water absorption. The study was conducted in dry season, and four species of epiphytes and six species of non - epiphytes were investigated. The effect of fog was imitated by spraying leaves with distilled water. For epiphytes and non - epiphytes, their leaf water potential (phi), relative water content (RWC), and amount of absorbed water increased gradually with the time of spraying, but the phi of epiphytes increased more quickly than that of non - epiphytes. The leaves of epiphytes Bolbitis scandens and Rhaphidophora decursiva could absorb fog water more quickly, and increase their RWC more greatly than those of non - epiphytes, indicating that these epiphytes were more competent than non - epiphytes in their leaf fog water absorption. The fog water absorption capacity of the leaves in epiphytic orchid Coelogyne occultata and Staurochilus dawsonianus was lower than that in Amischotolype hispida and Mananthus patentflora, but higher than that in other four non - epiphytes. The phi of epiphytes at early evening when no fog was formed was significantly lower than that at early morning, suggesting that fog water was absorbed by epiphytes at night to improve their leaf water status. Non - epiphytes did not need to absorb fog water directly through leaves, and they could recover their leaf water status through absorbing soil water by root system. Epiphytes except C. occultata had a much more leaf biomass than non - epiphytes, which was also beneficial to their leaf fog water absorption. Because there was abundant fog in dry season in Xishuangbanna, the phi of test ten species was higher than -0.8 MPa, indicating that water stress was not serious in dry season.
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June 2006

[Effects of soil phosphorus level on morphological and photosynthetic characteristics of Ageratina adenophora and chromolaena odorata].

Ying Yong Sheng Tai Xue Bao 2006 Apr;17(4):602-6

Kunming Division, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunrzing 650223, China.

In this paper, a comparative study was made on the growth, morphology, biomass allocation, and photosynthesis of two invasive plant species Ageratina adenophora and Chromolaena odorata under five soil phosphorus levels, aimed to know how the test plant species acclimate to the changes of soil phosphorus level, evaluate which plant traits were associated with the invasiveness of the two species, and know whether the increased level of soil phosphorus could facilitate their invasion. The results showed that the two species had considerable phenotypic plasticity and ? phosphorus acclimation ability. At low phosphorus levels, their root mass ratio increased, which could enhance the nutrient capture ability, while at high phosphorus levels, their specific leaf area, maximum net photosynthetic rate, light saturation point, and chlorophyll and carotenoid contents per unit area were high, and the assimilative capacity and area increased, which could facilitate their carbon gain. A. adenophora had higher phosphorus acclimation ability than C. odorata. With the increase of phosphorous level, the relative growth rate, total biomass, branch number, leaf area index, and maximum net photosynthetic rate of the two species increased significantly, and most of the parameters were not decreased significantly under over-optimal phosphorus level. The two species could grow better under high phosphorus levels which were usually excessive and/or harmful for most native species, and enhanced soil phosphorus level might promote their invasion. At high phosphorus levels, the two invasive plant species might shade out native species through increasing their plant height, branch number, and leaf area index. The two species could maintain relatively high growth rate under high phosphorus levels in dry season when native plant species almost stopped growing. The ability that the invasive plant species could temporally use natural resources which native plant species could not use was also associated with their invasiveness.
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April 2006

[Effects of 6-BA and AsA on photosynthesis photoinhibition of attached poplar leaves under osmotic stress of root].

Ying Yong Sheng Tai Xue Bao 2004 Dec;15(12):2233-6

Kunming Division, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China.

In order to know more about the relationships between photosynthesis photoinhibition and reactive oxygen species metabolism, the effects of 6-benzyladenine (6-BA) and ascorbate (AsA) on net photosynthetic rate (Pn), apparent quantum yield (AQY), superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities, O2-* generation rate, and H2O2 and malondialdehyde (MDA) contents were studied with attached leaves of poplar clone seedlings under osmotic stress of root. Under osmotic stress, the photosynthesis photoinhibition of attached poplar leaves, judged by the significant decrease of Pn and AQY, was aggravated, and the balance of reactive oxygen species metabolism was destroyed. The superoxide dismutase (SOD) activity increased, but ascorbate peroxidase (APX) activity decreased. In the meantime, the O2-* generation rate and the contents of H2O2 and malondialdehyde (MDA) increased. When osmotic stressed poplar seedlings were pretreated with 6-BA and AsA, the activities of SOD and APX increased, O2-* generation rate and H2O2 and MDA contents decreased, and photosynthesis photoinhibition was alleviated. The contents of reactive oxygen species and MDA in poplar leaves were negatively correlated with net photosynthetic rate and apparent quantum yield. It's indicated that the photosynthesis photoinhibition of attached leaves of poplar clone seedlings had intrinsic relations with the accumulation of reactive oxygen species under osmotic stress of root, and the alleviation effects of 6-BA and AsA on photosynthesis photoinhibition were related to their promotion effects to the scavenging system of reactive oxygen species.
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December 2004

[Adaptation of Eupatorium adenophorum photosynthetic characteristics to light intensity].

Ying Yong Sheng Tai Xue Bao 2004 Aug;15(8):1373-7

Kunming Division, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences.

As an invasive species, Eupatorium adenophorum threatens the biodiversity security in Southwest China. To explore its light adaptation characteristics and related eco-physiological mechanism, this paper studied the physiological and morphological properties, e. g., gas exchange, fluorescence kinetics, chlorophyll content and specific leaf weight (SLW), of E. adenophorum grown in Xishuangbanna, China, during the dry season under four light regimes (100%, 36%, 12.5% and 4.5% full sunshine). Under full sunshine, the Fv/Fm and phiPS II decreased with increasing diurnal light intensity, but quickly re-increased when light intensity decreased, indicating that photoinhibition was occurred but not serious. E. adenophorum under full sunshine could increase excessive light energy dissipation through the enhancement of diurnal thermal dissipation and anti-oxidation and the reversible inactivation of PS II reaction center, increase light energy utilization, and decrease light absorption by increasing SLW and decreasing chlorophyll concentration. All these processes enabled E. adenophorum to avoid the photodamage of photosynthetic apparatus. Under low light intensities (36%, 12.5% and 4.5% of full sunshine), E. adenophorum had a higher light absorption and utilization efficiency through decreasing SLW and diurnal thermal dissipation, increasing chlorophyll concentration, and keeping high photosynthetic capacity. The effective dissipation of excessive light energy under high light and the sufficient absorption of light energy under low light allowed E. adenophorum to utilize light energy effectively and grow healthily in a wide range of light intensity, which might be one of the reasons that made E. adenophorum a vigorous invader.
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August 2004

[A comparative study on Amomum villosum cultivation under tropical wet seasonal rainforest and secondary forest at Xishuangbanna].

Ying Yong Sheng Tai Xue Bao 2004 Aug;15(8):1318-22

Kunming Division, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences.

In order to protect rainforests, change the present Amomum villosum cultivation model, and explore the possibility of cultivating A. villosum under secondary forest, a comparative study was made on the growth and fruit yield of A. villosum cultivated under tropical wet seasonal rainforest and secondary forest at Xishuangbanna. The results showed that A. villosum cultivation had a significant effect on rainforest biomass and net productivity, but no effect on secondary forest. Under both rainforest and secondary forest, the order of plant density and biomass, from big to small, was vigorous plant, senescent plant, seedling, and shoot. The sum of shoot and seedlings was 3.95 and 1.66 times of senescent plant under rainforest and secondary forest, respectively, which meant that A. villosum could maintain population stability. Under rainforest, many of A. villosum seedlings were poorly growing old ones, and most of them could not grow and develop normally. The density and biomass of vigorous plant were not significantly different under rainforest and secondary forest, but those of shoot, seedling and senescent plant were significantly higher under secondary forest than under rainforest, suggesting that A. villosum rejuvenescence was faster under secondary forest. A. villosum fruit yield was 78.068 kg x hm(-2) in secondary forest, slightly higher than that in rainforest. It was worthwhile to notice that A. villosum yield was very low, its stem biomass ratio was very high (above 0.6), and the fruit biomass ratio was extremely low (about 0.01), which showed that the yield-increasing potency of A. villosum was great through improving biomass partition between fruit and stem. The biomass and canopy coverage of secondary forest was lower than those of rainforest, but the soil water content of secondary forest was similar to that of rainforest, which was favorable to the growth and development of A. villosum. The results presented above indicated that A. villosum could be cultivated in secondary forest.
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August 2004

[Relationship between photo-inhibition of photosynthesis and reactive oxygen species in leaves of poplars suffering root osmotic stress].

Ying Yong Sheng Tai Xue Bao 2003 Aug;14(8):1213-7

Kunming Section, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China.

To know more about the photo-inhibition of photosynthesis under field conditions, its relationship with reactive oxygen species (ROS) in leaves of poplar clone seedlings was studied under osmotic stress conditions. With the increasing duration of osmotic stress and the enhancement of stress intensity, the ROS level, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity increased, while the activities of catalase (CAT) and ascorbate peroxidase (APX) decreased, resulted in the unbalanced ROS metabolism and intensified photo-inhibition. The inhibition of SOD activity by copper diethyldithiocarbamate or the accelerated generation of O2-. with methyl viologen (MV) could also induce the photo-inhibition. The decrease of the ability of poplar clone seedlings in scavenging H2O2 under osmotic conditions limited the dissipation of excess light energy and the role of photosynthetic apparatus in protecting against photo-inhibition through Mehler reaction. Photo-inhibition might be related to the accumulation of ROS.
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August 2003

[Acclimation of foliar photosynthetic apparatus of three tropical woody species to growth irradiance].

Ying Yong Sheng Tai Xue Bao 2003 Apr;14(4):493-6

Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China.

The photosynthetic characteristics and protective role of leaf antioxidant systems were studied for seedlings of three woody species, Anthocephalus chinensis, Barringtonia pendala, Garcinia hanburyi, acclimated to 8%, 25%, 50% of natural sunlight for four months. As growth irradiance increased, the saturation points, the light compensation points of photosynthesis, the maximum net photosynthetic rate, and the non-photochemical quenching efficiency of three species were increased, while the apparent quantum yield (AQY), the effective quantum efficiency (Fv'/Fm'), and the photochemical quenching efficiency (qP) were decreased. In protective enzymes systems, SOD and APX activities increased with increasing growth irradiance, but CAT activity was not consistent with PFD. AsA exhibited the most dramatic increase in response to growth irradiance. It could be concluded that besides the increase in xanthophyll cycle-dependent energy dissipation, the enhancement of leaf antioxidants was also a protective pathway against high light intensity.
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April 2003
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