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.

The effects of codon usage on the formation of secondary structures of nucleocapsid protein of peste des petits ruminants virus

Xiao‑xia Ma,Yi‑ning Wang,Xiao‑an Cao,Xue‑rui Li,Yong‑sheng Liu,Jian‑hua Zhou,Xue‑peng Cai 한국유전학회 2018 Genes & Genomics Vol.40 No.9

The nucleocapsid (N) protein of peste des petits ruminants virus (PPRV) with a conserved amino acid usage pattern plays an important role in viral replication. The primary objective of this study was to estimate roles of synonymous codon usages of PPRV N gene and tRNA abundances of host in the formation of secondary structure of N protein. The potential effects of synonymous codon usages of N gene and tRNA abundances of host on shaping different folding units (α-helix, β-strand and the coil) in N protein were estimated, based on the information about the modeling secondary structure of PPRV N protein. The synonymous codon usage bias was found in different folding units in PPRV N protein. To better understand the role of translation speed caused by variant tRNA abundances in shaping the specific folding unit in N protein, we modeled the changing trends of tRNA abundance at the transition boundaries from one folding unit to another folding unit (β-strand → coil, coil → β-strand, α-helix → coil, coil → α-helix). The obvious fluctuations of tRNA abundance were identified at the two transition boundaries (β-strand → coil and coil → β-strand) in PPRV N protein. Our findings suggested that viral synonymous codon usage bias and cellular tRNA abundance variation might have potential effects on the formation of secondary structure of PPRV N protein.

Meteorological driven factors of population growth in brown planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae), in rice paddies

Xiao‐Zhen Li,Yi ZOU,Hai-Yan YANG,Hai-Jun XIAO,Jian-Guo WANG 한국곤충학회 2017 Entomological Research Vol.47 No.5

Growth of brown planthopper (BPH) (Nilaparvata lugens Stål) in rice paddies is mainly driven by meteorological factors under similar management practices. By analyzing field investigation and meteorological data collected from 2008 to 2013 in Nanchang, China, we show that BPH population densities and monthly growth rates (BGR) changed greatly from May to October, and these changes were closely associated with meteorological factors. Stepwise regression and path analysis indicated average speed of winds (AW) in June and lowest temperature (LT) in July were the first factors entering analysis, which interpreted 46.20% and 31.90% of their influences on BGR. While highest temperature (HT) in August and average temperature (AT) in September were the most important factors affecting BGR, but their direct path coefficients were all smaller than their corresponding indirect path coefficients. In October, relative humidity (RH), AW and number of raining days (RD) had significant effects on BGR. According to the sum of each meteorological factor entering stepwise regression analysis sequences, we found AW had the utmost effect on BPH growth, followed by AT and RH, but LT and RD least. The work demonstrate dynamic meteorological factors driving BPH growth and outbreak in rice paddies, which would facilitate the development of durable approaches for forecasting and controlling this destructive rice pest.

WRKY Transcription Factor Functions as a Transcriptional Regulator of Xylanase Inhibitor RIXI, Involved in Rice Disease Resistance to Magnaporthe oryzae

Xiao‑yan Weng 한국식물학회 2020 Journal of Plant Biology Vol.63 No.3

Xylanase inhibitors are known to play important roles in response to fungal pathogens attack. WRKY transcription factors are also involved in plant defence against pathogens. However, whether WRKY transcription factors interacting with rice xylanase inhibitor RIXI remains unknown. 13 W-boxes, binding sites for WRKY transcription factors were found in RIXI promoter sequence of rice by analyzing RIXI promoter. ChIP-PCR analysis and dual luciferase reporter system assay were used to identify interaction between xylanase inhibitor RIXI and WRKY transcription factors. Results showed OsWRKY6 and OsWRKY46 directly bound to RIXI promoter and regulated RIXI expression diferently. Over-expressing OsWRKY6 and OsWRKY46 transgenic plants were achieved, and OsWRKY6 and OsWRKY46 overexpressed transgenic lines showed higher expression levels of RIXI and higher resistance to Magnaporthe oryzae G11 (M. oryzae G11) compared to wild type (WT). Increased RIXI expression in OsWRKY6 and OsWRKY46 overexpressed transgenic lines was accompanied by up-regulation of pathogenesis-related genes (PR genes). Moreover, higher levels of H2O2 and higher activities of antioxidant enzymes were found in transgenic lines compared to WT plants. Results indicated that over-expression of OsWRKY6 and OsWRKY46 in transgenic lines maybe enhanced rice disease resistance by regulating RIXI expression.

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.

Effect of Different Cooling Rates in High Rheological Rate Forming Process on Mechanical Properties of Zr57Cu20Al10Ni8Ag5 Bulk Metallic Glass

Xiao‑Bo Mei,Bao‑Chuan Liu,Wei Jiang,Quan Xu,Qi‑Dong Zhang,Yu‑Bai Ma,Fang‑Qiu Zu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.9

The influence of cooling rates on the mechanical properties of a Zr-based bulk metallic glass prepared with high rheologicalrate forming (HRRF) was investigated and compared with traditional suction cast methods. Amorphous samples of Zr57Cu-20Ni8Al10Ag5 were prepared in copper molds with different sizes in order to obtain different cooling rates for both HRRFand traditional cast methods. These specimens were subjected to compression experiments, including microhardness testing,X-ray diffraction testing and differential scanning calorimetry analysis. The results indicate that the plasticity of the samplesformed by HRRF are higher than that of the as-cast ones at the same cooling rates, while the microhardness manifests theopposite principle. As the cooling rate increases further, the difference in plasticity further increases between two methods,indicating that the plasticity of metallic glasses is more sensitive to cooling rates during the HRRF process. At the core ofthis phenomenon is the fact that HRRF methods can introduce more free volume into glasses than traditional cast methodswith an elevated cooling rate are able to.

One-pot synthesis PdAu bimetallic composite nanoparticles and their catalytic activities for hydrogen peroxide generationl

( Xiao ),유태경 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.1

One-step Synthesis Pd@Pt Core-Shell Concave Cube by Facile Reduction Control toward formic acid oxidation reaction

( Xiao ),( Cun Liu ),( Pengfei Jiang ),유태경 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

The core-shell Pd@Pt nanocubes were successfully designed as concave structure by a galvanic replacement, one-step process. In this study, we chose the ascorbic acid and citric acid as the different strength reduction to facile control the Pd@Pt crystal growth. Firstly, the Pd nanocube formed using ascorbic acid as stronger reducing agent with accuracy control amount. In general, the different intensities reducing agent ascorbic acid and citric acid are the key-points to kinetic control the concave structure formed and the Br^- play the major role to enhance the galvanic replacement reaction between Pt(II)Cl₄^2-and Pd. In addition, the concave cubic Pd@Pt nanocrystal exhibited higher electrochemical performance compare to commercial Pt electrocatalyst toward formic acid oxidation reaction.

Effect of Prior Microstructures on Cementite Dissolution Behavior During Subcritical Annealing of High Carbon Steels

Xiao‑Yu Zhao,Xian‑Ming Zhao,Chun‑Yu Dong,Yang Yang,Huai‑Bin Han 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

The variation of the morphology and distribution of cementite particles in different prior structures with spheroidizingannealing process has been proceeded in this paper. It is found that the dissolution and coarsening progresses of variousinitial structures in spheroidizing annealing process are quite asynchronous due to the different interlamellar spacing. Thedissolution rate of degenerated pearlite (D-P) with finer interlamellar spacing is faster. The granular cementite in the spheroidizedmicrostructure is fine, uniform and dense. The mean diameter of spherical cementite is refined to 233 nm. However,the initial structure of degenerated pearlite (D-P) is highly sensitive to the austenitization temperature. The cementite iseasy to be coarsened under high austenitizing temperature. The coarsening is accompanied by the gradual increase of theCr content in the cementite, which increases the stability of the cementite. Therefore, the optimal austenitizing temperaturefor degenerated pearlite (D-P) is suggested to be 770 °C.

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.