Transcriptome profiling of rubber tree (Hevea brasiliensis) discovers candidate regulators of the cold stress respo

Xiao‑Xiao Gong,Bing‑Yu Yan,Jin Hu,Cui‑Ping Yang,Yi‑Jian Li,Jin‑Ping Liu,Wen‑Bin Liao 한국유전학회 2018 Genes & Genomics Vol.40 No.11

Tropical plant rubber tree (Hevea brasiliensis) is the sole source of commercial natural rubber and low-temperature stress is the most important limiting factor for its cultivation. To characterize the gene expression profiles of H. brasiliensis under the cold stress and discover the key cold stress-induced genes. Three cDNA libraries, CT (control), LT2 (cold treatment at 4 °C for 2 h) and LT24 (cold treatment at 4 °C for 24 h) were constructed for RNA sequencing (RNA-Seq) and gene expression profiling. Quantitative real time PCR (qRT-PCR) was conducted to validate the RNA-Seq and gene differentially expression results. A total of 1457 and 2328 differentially expressed genes (DEGs) in LT2 and LT24 compared with CT were respectively detected. Most significantly enriched KEGG pathways included flavonoid biosynthesis, phenylpropanoid biosynthesis, plant hormone signal transduction, cutin, suberine and wax biosynthesis, Pentose and glucuronate interconversions, phenylalanine metabolism and starch and sucrose metabolism. A total of 239 transcription factors (TFs) were differentially expressed following 2 h or/and 24 h of cold treatment. Cold-response transcription factor families included ARR-B, B3, BES1, bHLH, C2H, CO-like, Dof, ERF, FAR1, G2-like, GRAS, GRF, HD-ZIP, HSF, LBD, MIKC-MADS, M-type MADS, MYB, MYB-related, NAC, RAV, SRS, TALE, TCP, Trihelix, WOX, WRKY, YABBY and ZF-HD. The genome-wide transcriptional response of rubber tree to the cold treatments were determined and a large number of DEGs were characterized including 239 transcription factors, providing important clues for further elucidation of the mechanisms of cold stress responses in rubber tree.

Comparison of volatile organic compounds from uninfested and Monochamus alternatus Hope infested Pinus massoniana Lamb.

Xiao‐Juan Li,Guang-Ping DONG,Jian-Min FANG,Hong-Jian LIU,Wan-Lin GUO 한국곤충학회 2017 Entomological Research Vol.47 No.3

Monochamus alternatus is a destructive stem‐boring herbivore of Pinus massoniana, and the principal vector of pine wood nematode. To investigate the impacts of boring by M. alternatus larvae on the emission of volatile organic compounds (VOCs) from their host trees, the VOCs from uninfested and M. alternatus larvae infested P. massoniana trees were observed using a gas chromatograph–mass spectrometer. We detected 12, 9, 18 and 14 volatile organic compounds from infested xylem, infested phloem, uninfested xylem and uninfested phloem, respectively. In P. massoniana xylem, the boring of M. alternatus larvae induced cyclosativene, and inhibited 4‐carene, humulene, styrene, α‐phellandrene, β‐myrcene, β‐phellandrene and γ‐terpinene. The relative amounts of camphene, copacamphene, longicyclene, longifolene, tricyclene and α‐longipinene were significantly increased, and the relative amounts of α‐pinene and β‐pinene were significantly decreased by the boring behaviors of M. alternatus larvae. In P. massoniana phloem, the boring of M. alternatus larvae induced 2‐bornanone, copacamphene, longicyclene and α‐longipinene, and inhibited 2‐carene, 4‐carene, styrene, α‐phellandrene, β‐myrcene, β‐phellandrene, β‐pinene, γ‐terpinene and ο‐cymene. The relative amounts of camphene, caryophyllene and longifolene were significantly increased by the boring behaviors of M. alternatus larvae. The results indicate that the boring behaviors of M. alternatus larvae changed both the sorts and contents of the VOCs from P. massoniana trees.

Identification of differentially expressed immunity‐related genes in Monochamus alternatus Hope (Coleoptera: Cerambycidae) larvae parasitized by Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae)

Xiao‐Juan Li,Guang-Ping DONG,Jian-Min FANG,Hong-Jian LIU,Wan-Lin GUO 한국곤충학회 2018 Entomological Research Vol.48 No.4

The pine sawyer Monochamus alternatus Hope (Coleoptera: Cerambycidae) is a serious pest of several Pinus species, and the ectoparasitoid larvae of Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) is an important natural enemy of this pest. The transcriptome of M. alternatus larvae was sequenced using the Illumina platform and immunity‐related genes were specifically analyzed. De novo assembly resulted in the identification of 24 241 unigenes, with a mean length of 1122 bp, in unparasitized M. alternatus larvae and 23 807 unigenes, with a mean length of 1140 bp, for parasitized larvae. Removal of redundant unigenes resulted in 26 095 all‐unigenes, of which 16 959 (64.99%) showed clear homology with some of the known genes in the National Center for Biotechnology Information nr database. Parasitization had notable effects on the transcriptome profile of M. alternatus larvae. In all, 2702 genes were differentially expressed in M. alternatus larvae after parasitization, with 1491 (55.18%) upregulated and 1211 (44.82%) downregulated. Moreover, expression levels of immunity‐related genes in M. alternatus larvae were markedly altered in response to parasitization by D. helophoroides. In conclusion, the transcriptome profiling data, especially the discovered of immunity‐related genes, help illustrate the molecular mechanisms of parasitism between D. helophoroides and M. alternatus and provide new insights into developing immunity regulation‐mediated control methods of M. alternatus.

Comparison between Matrix Method, Equation Method and Full Air-Buoyancy Correction Method for Dissemination of Microgram Weights

Xiao-Ping Ren,Jian Wang,Chang-Qing Cai,Shuang Su 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.9

Over the past 9 years since 2007, there has been growing interest in the field of small weight measurement, like determination of sensitivity property of microbalance. This drives the requirement for more accurate small weight measurement down to microgram level. NMIs researched on the microgram from manufacture, material and shape, storage and holding method, measurement equipment and weighing scheme. Subdivision comparison is commonly adopted and matrix method (MM) is used to solve the measurement Eq.. In this paper, the density of test and standard weight rather than the volume were adopted in MM. Details on how to use this method based on Matlab software were presented. Then the comparison between MM, Eqution method (EM) and full air-buoyancy correction method (FACM) were made. Differences between these three methods were analyzed and evaluation results were given out. Experiment showed that EM and FACM were of the same relative uncertainty, but MM had lower measurement uncertainty than EM and FACM.

Research on magnetorheological damper suspension with permanent magnet and magnetic valve based on developed FOA-optimal control algorithm

Ping Xiao,Hong Gao,Limin Niu 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.7

Due to the fail safe problem, it was difficult for the existing Magnetorheological damper (MD) to be widely applied in automotive suspensions. Therefore, permanent magnets and magnetic valves were introduced to existing MDs so that fail safe problem could be solved by the magnets and damping force could be adjusted easily by the magnetic valve. Thus, a new Magnetorheological damper with permanent magnet and magnetic valve (MDPMMV) was developed and MDPMMV suspension was studied. First of all, mechanical structure of existing magnetorheological damper applied in automobile suspensions was redesigned, comprising a permanent magnet and a magnetic valve. In addition, prediction model of damping force was built based on electromagnetics theory and Bingham model. Experimental research was conducted on the newly designed damper and goodness of fit between experiment results and simulated ones by models was high. On this basis, a quarter suspension model was built. Then, fruit Fly optimization algorithm (FOA)-optimal control algorithm suitable for automobile suspension was designed based on developing normal FOA. Finally, simulation experiments and bench tests with input surface of pulse road and B road were carried out and the results indicated that working performance of MDPMMV suspension based on FOA-optimal control algorithm was good.

Investigations on Gilbert damping, Curie temperatures and thermoelectric properties in CoFeCrZ quaternary Heusler alloys

Xiao-Ping Wei,Peifeng Gao,Ya-Ling Zhang 한국물리학회 2020 Current Applied Physics Vol.20 No.4

Exchange interactions and Curie temperatures of CoFeCrZ (Z=P, As, Sb, Ge) quaternary Heusler alloys are studied by using the spin-polarized relativistic Korringa-Kohn-Rostoker method. Electronic calculations show that the CoFeCrZ alloys apart from CoFeCrP are ferromagnetic half-metals, and their integer magnetic moments obey the Slater-Pauling rule. It is confirmed that the calculated Curie temperatures are evidently higher than room temperature. Further, we discuss the dependency of magnetic moments and Curie temperatures with respect to lattice constants. A smaller Gilbert damping parameters imply that these alloys have lower energy loss in spintronics applications. In addition, the thermoelectric properties of CoFeCrZ in both spin channels are calculated based on the BoltzTrap code. Results indicate that the Seebeck coefficients of CoFeCrZ (Z=As, Sb, Ge) are remarkably higher than 1000 μV/K. Overall, we think that the CoFeCrAs, CoFeCrSb and CoFeCrGe alloys are promising candidates in future spintronic and thermoelectric applications.

Preparation of Homogeneous Microstructure Pure Lead Metaniobate by Two-Step Sintering

Xiao-gang Zhao,Peng Liu,Bo Chao,Su Juan Liu,Ming Pang,Xiao-Ming Chen,Jian-Ping Zhou 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.1

The purpose of the present work is to obtain the Lead metaniobate ceramics with the orthorhombic phase via a two-step sintering method. The samples were first sintered at 1320°C for 10 min, and then sintered separately at 1260°C, 1220°C, and 1180°C for 4 h. All the ceramics show orthorhombic phase and homogeneous microstructure. It was found that the abnormal grain growth was restrained obviously.

Seismic Bearing Capacity of Shallow Foundations Resting on Rock Masses Subjected to Seismic Loads

Xiao-Ping Zhou,Xin-Bao Gu,Mao-Hong Yu,Qi-Hu Qian 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.1

This paper analyzes the bearing capacity of shallow foundations resting on rock masses subjected to seismic loads based on limit analysis theory. The non-linear twin shear strength criterion is used to consider the effects of intermediate principal stress on the bearing capacity of shallow foundations. The pseudo-dynamic approach is applied to account for the effects of seismic loads on the bearing capacity of shallow foundations. Both the horizontal and vertical seismic acceleration coefficients and the effects of an amplification factor on the upper bound evaluations of the foundation’s bearing capacity are investigated. The Π-functions are then applied to derive the upper bound solution of the load-bearing capacity. A numerical computation is performed and indicates that the seismic acceleration coefficients, amplification factor and the intermediate principal stress parameter significantly affect the bearing capacity of shallow foundations.

Aromatic Compounds from the Halotolerant Fungal Strain of Wallemia sebi PXP-89 in a Hypersaline Medium

Xiao-Ping Peng,Wei-Ming Zhu,Yi Wang,Pei-Pei Liu,Kui Hong,Hao Chen,Xia Yin 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.6

A new cyclopentanopyridine alkaloid, 3-hydroxy-5-methyl-5,6-dihydro-7H-cyclopenta[b]pyridin-7-one (1), together with 11 known aromatic compounds were isolated from the secondary metabolites of the halotolerant fungal strain Wallemia sebi PXP-89 in 10% NaCl. Their structures including the absolute configurations of (2S,3S)-1-(4-hydroxyphenyl)butane-2,3-diol (2), (2R,3S)-1-(4-hydroxyphenyl)butane-2,3-diol (3), and (S)-3-hydroxy-4-(4-hydroxyphenyl)-2-one (4) were elucidated by spectroscopic analysis and a modified Mosher’s method. Compound 1 exhibited antimicrobial activity against Enterobacter aerogenes with a MIC of 76.7 μM. The absolute configurations of compounds 2-4 were determined for the first time.

Improvement of CF/ABS Composite Properties by Anodic Oxidation of Pitch based C-type Carbon Fiber

Xiao Ping Yang,Cheng Zhong Wang,Yun Hua Yu,Seung-Kon Ryu 한국탄소학회 2002 Carbon Letters Vol.3 No.2

The surface treatment of C-type isotropic pitch-based carbon fiber was carried out by anodic oxidation in 5 wt% NH4NO3 electrolyte. The changes of fiber surface and carbon fiber/ABS resin composites were characterized by SEM, XPS and mechanical properties test. The oxygen functional groups on the surface, such as hydroxyl (-C-OH), carboxyl (-COOH) groups etc., increased after oxidation. Tensile strength, flexural strength and modulus of carbon fiber/ABS composites were also enhanced. However, the impact strength decreased with the improvement of the surface adhesion between CF and matrix.