摘要：
Oryza meyeriana, a wild species of rice from China, shows high resistance to Xanthomonas oryzae pv. oryzae (Xoo), the cause of rice bacterial blight, one of the most serious rice pathogens. To better understand the resistance mechanism, a proteomic study was conducted to identify changes in the proteins secreted in embryo cell suspension cultures in response to Xoo. After two-dimensional difference gel electrophoresis (2D-DIGE), 72 differentially expressed protein spots corresponding to 34 proteins were identified by Matrix-Assisted Laser Desorption/ Ionization Time of Flight Mass Spectrometry. Of the 34 proteins, 10 were up regulated and 24 down regulated. The secreted proteins identified were predicted to be involved in various biological processes, including signal transduction, defense, ROS and cell wall modification. 77% of the 34 proteins were predicted to have a signal peptide by Signal P. Quantitative Real-Time PCR showed that transcript levels of 14 secreted proteins were not well correlated with secreted protein levels. Peroxidase activity was up regulated in both O. meyriana and susceptible rice but was about three times higher in O. meyeriana. This suggests that peroxidases may play an important role in the early response to Xoo in O. meyeriana. These results not only provide a better understanding of the resistance mechanism of O. meyeriana, but have implications for studies of the interactions between other plants and their pathogens.
摘要：
Ascoviruses are insect-specific large DNA viruses that mainly infect noctuid larvae, and are transmitted by parasitoids in the fields. Heliothis virescens ascovirus 3h (HvAV-3h) has been recently isolated from Spodoptera exigua, without parasitoid vector identified previously. Here we report that Microplitis similis, a solitary endoparasitoid wasp, could transmit HvAV-3h between S. exigua larvae in the laboratory. When the female parasitoid wasp acquired the virus and served as a vector, the period of virion viability on the ovipositor was 4.1 ± 1.4 days. Infected host larvae were still acceptable for egg laying by parasitoids, and the parasitoids thereafter transmitted virus to healthy hosts. Virus acquisition occurred only from donor hosts between 3 and 9 days post infection. The peak of virus acquisition (80.9 ± 6.3%) was found when M. similis wasps oviposited in larvae that had been inoculated with the virus 7 days previously. When virus infection of the host took place during the life cycle of the parasitoid wasp, it caused 1- to 4-day-old immature parasitoids death in the host, whilst a small proportion of 5- to 6-day-old and the majority of 7-day-old parasitoids larvae survived from the virus-infected hosts. Viral contamination did not reduce the life span or fecundity of female M. similis.
摘要：
Informative gene selection can have important implications for the improvement of cancer diagnosis and the identification of new drug targets. Individual-gene-ranking methods ignore interactions between genes. Furthermore, popular pair-wise gene evaluation methods, e.g. TSP and TSG, are helpless for discovering pair-wise interactions. Several efforts to discover pair-wise synergy have been made based on the information approach, such as EMBP and FeatKNN. However, the methods which are employed to estimate mutual information, e.g. binarization, histogram-based and KNN estimators, depend on known data or domain characteristics. Recently, Reshef et al. proposed a novel maximal information coefficient (MIC) measure to capture a wide range of associations between two variables that has the property of generality. An extension from MIC(X; Y) to MIC(X1; X2; Y) is therefore desired. We developed an approximation algorithm for estimating MIC(X1; X2; Y) where Y is a discrete variable. MIC(X1; X2; Y) is employed to detect pair-wise synergy in simulation and cancer microarray data. The results indicate that MIC(X1; X2; Y) also has the property of generality. It can discover synergic genes that are undetectable by reference feature selection methods such as MIC(X; Y) and TSG. Synergic genes can distinguish different phenotypes. Finally, the biological relevance of these synergic genes is validated with GO annotation and OUgene database.
摘要：
The genome sequence of pepper vein yellows virus (PeVYV) (PeVYV-HN, accession number KP326573), isolated from pepper plants (Capsicum annuum L.) grown at the Hunan Vegetables Institute (Changsha, Hunan, China), was determined by deep sequencing of small RNAs. The PeVYV-HN genome consists of 6244 nucleotides, contains six open reading frames (ORFs), and is similar to that of an isolate (AB594828) from Japan. Its genomic organization is similar to that of members of the genus Polerovirus. Sequence analysis revealed that PeVYV-HN shared 92 % sequence identity with the Japanese PeVYV genome at both the nucleotide and amino acid levels. Evolutionary analysis based on the coat protein (CP), movement protein (MP), and RNA-dependent RNA polymerase (RdRP) showed that PeVYV could be divided into two major lineages corresponding to their geographical origins. The Asian isolates have a higher population expansion frequency than the African isolates. Negative selection and genetic drift (founder effect) were found to be the potential drivers of the molecular evolution of PeVYV. Moreover, recombination was not the distinct cause of PeVYV evolution. This is the first report of a complete genomic sequence of PeVYV in China.
摘要：
The maximal information coefficient (MIC) captures dependences between paired variables, including both functional and non-functional relationships. In this paper, we develop a new method, ChiMIC, to calculate the MIC values. The ChiMIC algorithm uses the chi-square test to terminate grid optimization and then removes the restriction of maximal grid size limitation of original ApproxMaxMI algorithm. Computational experiments show that ChiMIC algorithm can maintain same MIC values for noiseless functional relationships, but gives much smaller MIC values for independent variables. For noise functional relationship, the ChiMIC algorithm can reach the optimal partition much faster. Furthermore, the MCN values based on MIC calculated by ChiMIC can capture the complexity of functional relationships in a better way, and the statistical powers of MIC calculated by ChiMIC are higher than those calculated by ApproxMaxMI. Moreover, the computational costs of ChiMIC are much less than those of ApproxMaxMI. We apply the MIC values tofeature selection and obtain better classification accuracy using features selected by the MIC values from ChiMIC.
摘要：
During their growth and development, plants are vulnerable to the effects of a variety of pathogens. Proteomics technology plays an important role in research studies of plant defense mechanisms by mining the expression changes of proteins in response to various biotic stresses. This review article provides a comprehensive overview of the latest developments in international proteomic research on plant biotic stress. It summarizes the methods commonly used in plant proteomic research to investigate biotic stress, analyze the protein responses of plants in adverse conditions, and reviews the applications of proteomics combined with transgenic technology in plant protection.
摘要：
In this study, we identified and compared nucleotide-binding site (NBS) domain-containing genes from three Citrus genomes (C. clementina, C. sinensis from USA and C. sinensis from China). Phylogenetic analysis of all Citrus NBS genes across these three genomes revealed that there are three approximately evenly numbered groups: one group contains the Toll-Interleukin receptor (TIR) domain and two different Non-TIR groups in which most of proteins contain the Coiled Coil (CC) domain. Motif analysis confirmed that the two groups of CC-containing NBS genes are from different evolutionary origins. We partitioned NBS genes into clades using NBS domain sequence distances and found most clades include NBS genes from all three Citrus genomes. This suggests that three Citrus genomes have similar numbers and types of NBS genes. We also mapped the re-sequenced reads of three pomelo and three mandarin genomes onto the C. sinensis genome. We found that most NBS genes of the hybrid C. sinensis genome have corresponding homologous genes in both pomelo and mandarin genomes. The homologous NBS genes in pomelo and mandarin suggest that the parental species of C. sinensis may contain similar types of NBS genes. This explains why the hybrid C. sinensis and original C. clementina have similar types of NBS genes in this study. Furthermore, we found that sequence variation amongst Citrus NBS genes were shaped by multiple independent and shared accelerated mutation accumulation events among different groups of NBS genes and in different Citrus genomes. Our comparative analyses yield valuable insight into the structure, organization and evolution of NBS genes in Citrus genomes. Furthermore, our comprehensive analysis showed that the non-TIR NBS genes can be divided into two groups that come from different evolutionary origins. This provides new insights into non-TIR genes, which have not received much attention.
作者机构：
[张毅军; 丁肖庆; 魏竹清; 胡梅] Institute of Applied Chemistry, Henan Institute of Science and Technology, Xinxiang, 453003, China;[周小毛] Pesticide Research Institute, Hunan Agricultural University, Changsha, 410128, China;[杨靖华] Institute of Applied Chemistry, Henan Institute of Science and Technology, Xinxiang, 453003, China, Pesticide Research Institute, Hunan Agricultural University, Changsha, 410128, China
通讯机构：
[Zhang, Y.] I;Institute of Applied Chemistry, Henan Institute of Science and Technology, Xinxiang, China
摘要：
The rapid preparation of molecularly imprinted polymer (MIP) fibers was reported using bisphenol A (BPA) as the template molecular, acetonitrile (ACN) as the porogenic solvent, α-methacrylic acid (MAA) as the functional monomer, ethylene dimethacrylate ( EDMA ) as the crosslinker, and azodiisobutyronitrile (AIBN) as the thermal initiator. It was carried out within a capillary of 530 μm inner diameter (I. D.) by microwave irradiation in 7 min. The resulted BPA-MIP fibers were pushed out from the capillary, eluted in a vial and inserted in the capillary again followed by the application of the solid phase microextraction (SPME) procedure. The extraction performance was investigated in detail by varying the molar ratios between the template and the monomer (BPA / MAA), the concentration of NaCl, the extraction and desorption time, the pH value and the desorption solvents. The selectivity of the prepared MIP and non-molecularly imprinted polymer (NIP) fibers was comparatively evaluated by selecting two structurally-related compounds, phenol (P) and 4-phenyl- phenol (PP), and non-analogue dicyandiamide (DCD). The established method was successfully applied for the pretreatment and determination of BPA from beverage samples coupled to high performance liquid chromatography (HPLC). Under the optimal conditions, the linear range of BPA was 10-400 μg / L; the detection limit (LOD) was 0.45 μg / L and the recoveries spiked in the mineral water were 88.4% -102.8%. The results demonstrated that the developed method can determine BPA in real samples with some advantages of simple pretreatment, rapid analysis, low limit of detection and low consumption of materials.
关键词：
Rhizoctonia solani;Mycovirus;Unclassified family
摘要：
Here we present the genome sequence of a novel dsRNA virus we designed as Rhizoctonia solani RNA virus HN008 (RsRV-HN008) from a filamentous fungus R. solani. Its genome (7596 nucleotides) contains two non-overlapping open reading frames (ORF1 and ORF2). ORF1 encoded a 128 kDa protein that showed no significant identity to any other virus sequence in the NCBI database. ORF2 encoded a protein with a molecular weight of 140 kDa and shared a low percentage of sequence identity to the RdRps of unclassified dsRNA viruses. Sequence analysis revealed that RsRV-HN008 may be a member of a novel unclassified family of mycoviruses.
摘要：
Acremonium implicatum is an endophytic fungus with biocontrol potential against Meloidogyne incognita based on its opportunistic egg-parasitic, hatching inhibition, and toxic properties. To understand its mode of plant endophytism and opportunistic egg parasitism, GFP-tagged A. implicatum was constructed by PEG-mediated protoplast transformation. By laser scanning confocal microscopy (LSCM), we evaluated the endophytism and opportunistic egg parasitism of a stable gfp transformant (Acr-1). Acr-1 could colonize epidermal tissue, cortical tissue, and xylem of roots and form a mutualistic symbiosis with tomato host plants. LSCM of Acr-1 infecting M. incognita eggs revealed that hyphae penetrated the shell and grew inside eggs to form trophic hyphae. A large number of hyphae enveloped parasitized eggs. In addition, the egg shell integrity was destroyed by fungal penetration. The percentage of egg parasitism was 33.8 %. There were no marked differences between the wild type and mutant in nematode second-stage juvenile mortality and egg hatching and in fungal control efficiency in a pot experiment. In conclusion, gfp-transformation did not change the nematicidal activity of A. implicatum and is a tool to examine the mode of plant endophytism and opportunistic egg parasitism of A. implicatum.
摘要：
Pathogen-mediated interactions between insect vectors and their host plants can affect herbivore fitness and the epidemiology of plant diseases. While the role of plant quality and defense in mediating these tripartite interactions has been recognized, there are many ecologically and economically important cases where the nature of the interaction has yet to be characterized. The Bemisia tabaci (Gennadius) cryptic species Mediterranean (MED) is an important vector of tomato yellow leaf curl virus (TYLCV), and performs better on virus-infected tomato than on uninfected controls. We assessed the impact of TYLCV infection on plant quality and defense, and the direct impact of TYLCV infection on MED feeding. We found that although TYLCV infection has a minimal direct impact on MED, the virus alters the nutritional content of leaf tissue and phloem sap in a manner beneficial to MED. TYLCV infection also suppresses herbivore-induced production of plant defensive enzymes and callose deposition. The strongly positive net effect on TYLCV on MED is consistent with previously reported patterns of whitefly behavior and performance, and provides a foundation for further exploration of the molecular mechanisms responsible for these effects and the evolutionary processes that shape them.
摘要：
The nematophagous fungus Pochonia chlamydosporia, which belongs to the family Clavicipitaceae (Ascomycota: Pezizomycotina: Sordariomycetes: Hypocreales), is a promising biological control agent for root-knot and cyst nematodes. Its biocontrol effect has been confirmed by pot and field trials. The genome sequence of the fungus was completed recently; therefore, genome-wide functional analyses will identify its infection-associated genes. Gene knockout techniques are useful molecular tools to study gene functions. However, cultures of P. chlamydosporia are resistant to high levels of a range of fungal inhibitors, which makes the gene knockout technique difficult in this fungus. Fortunately, we found that the wild P. chlamydosporia strain PC-170 could not grow on medium containing 150 mu g ml(-1) G418 sulfate, representing a new selectable marker for P. chlamydosporia. The neomycin-resistance gene (neo), which was amplified from the plasmid pKOV21, conferred G418-resistance on the fungus; therefore, it was chosen as the marker gene. We subsequently developed a gene knockout system for P. chlamydosporia using split-marker homologous recombination cassettes with resistance selection and protoplast transformation. The split-marker cassettes were developed using fusion PCR, and involved only two rounds of PCR. The final products comprised two linear constructs. Each construct contained a flanking region of the target gene and two thirds of the neo gene. Alkaline serine protease and chitinase were confirmed to be produced by P. chlamydosporia during infection of nematode eggs and could participate in lysis of the eggshell of nematode eggs. Here, we knocked out one chitinase gene, VFPPC_01099, and two protease genes (VFPPC_10088, VFPPC_06535). We obtained approximately 100 suspected mutants after each transformation. After screening by PCR, the average rate of gene knockout was 13%: 11% (VFPPC_01099), 13% (VFPPC_10088) and 15% (VFPPC_06535). This efficient and convenient technique will accelerate functional genomic studies in P. chlamydosporia. (C) 2014 Elsevier GmbH. All rights reserved.
作者：
Zhang, Ru Jia;Zhong, Jie;Shang, Hong Hong;Pan, Xian Ting;Zhu, Hong Jian*;...
期刊：
Archives of Virology,2015年160(7):1805-1809 ISSN：0304-8608
通讯作者：
Zhu, Hong Jian
作者机构：
[Gao, Bi Da; Zhong, Jie; Shang, Hong Hong; Zhang, Ru Jia; Zhu, Hong Jian; Pan, Xian Ting] Hunan Agr Univ, Hunan Prov Key Lab Biol & Control Plant Dis & Ins, Changsha 410128, Hunan, Peoples R China.;[Zhu, Hong Jian] Hunan Agr Univ, Hunan Prov Key Lab Biol & Control Plant Dis & Ins, Nongda Rd 1, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Zhu, Hong Jian] H;Hunan Agr Univ, Hunan Prov Key Lab Biol & Control Plant Dis & Ins, Nongda Rd 1, Changsha 410128, Hunan, Peoples R China.
关键词：
Capsid Protein;dsRNA Segment;Amplify cDNA Product;Full Nucleotide Sequence;Putative Capsid Protein
摘要：
In this study, a novel virus designated Phomopsis vexans RNA virus 1 (PvRV1) was identified in a strain of Phomopsis vexans. The complete genomic nucleotide sequence was determined and analyzed. Sequence analysis indicated that PvRV1 is closely related to viruses in the genus Victorivirus of the family Totiviridae. Two open reading frames (ORF1 and 2) were found in the PvRV1 sequence, and these showed significant similarity to the capsid protein (CP) and RNA-dependent RNA polymerase (RdRp), respectively, of members of the family Totiviridae. The two ORFs were spaced 98 nt apart, which is unique to PvRV1 and different from the overlapping arrangement in most victoriviruses. The expression strategies of the CP and RdRp are discussed based on in silico RNA secondary structure analysis.
摘要：
To develop new agents against strawberry grey mould and to aid in the development of biological pesticides, we investigated the inhibitory effect of a natural compound, phenazine-1-carboxamide (PCN), against Botrytis cinerea using a growth rate assay. Additionally, indoor toxicity and the in vitro control effect of PCN were further studied to determine its potential mechanisms of action on B. cinerea. PCN was inhibitory against B. cinerea with a 50% effective concentration (EC50) of 108.12 mu g/mL; the toxicity of PCN was equivalent to that of carbendazim (CBM). The best in vitro control effect of PCN against grey mould in strawberry (fruit) reached 75.32%, which was slightly higher than that of CBM. The field control effect of PCN against grey mould reached a maximum of 72.31% at a PCN concentration of 700 mu g/mL, which was 1.02 times higher than that of CBM. Fungistatic activity was observed at low concentrations of PCN, while high concentrations of PCN resulted in fungicidal activity against B. cinerea. This natural compound strongly inhibited both spore and sclerotium germination of B. cinerea, with the best relative inhibition rates of 77.03% and 82.11%, respectively. The inhibitory effect of PCN on mycelial growth of B. cinerea was significant and reached levels of 87.32%. Scanning electron microscopy observations revealed that after 48 h of PCN treatment, the mycelia appeared loose, locally twisted, and folded, with exudation of contents; the mycelia was withered and twisted, with edge burrs, deformations, ruptures and a sheet-like structure. Transmission electron microscopy observations revealed that after 48 h of PCN treatment, the structure of the cell nucleus was unclear and the vacuoles had ruptured; additionally, various organelles exhibited disordered structures, there were substantial non-membrane transparent inclusions, the cells were plasmolysed, the cell walls were collapsed in some cases, and the hyphal tissue was essentially necrotic. A PCN dosage of 35-140 mu g/mL had no effect on the cell membrane permeability of the mycelia, while a PCN dosage of 700 mu g/mL resulted in significant permeability. PCN inhibited B. cinerea toxin; the mycotoxin level was approximately 0.41 of the value recorded for the control at a PCN dosage of 700 mu g/mL. PCN affected the activity of pectin methylgalacturonase (PMG), polygalacturonase (PG), cellulase (Cx) and beta-glucosidase (BG); the lowest activities of PMG, PG, BG and Cx reached 0.3 U/mg, 0.62 U/mg, 0.64 U/mg, and 0.79 U/mg, respectively, after treatment with 700 mu g/mL PCN.
摘要：
A new pseudoguaianolide 1 and two new guaiane-type sesquiterpene glucosides 2 and 3, were isolated from the aerial parts of Ambrosia artemisiifolia L together with two known sesquiterpene dilactones 4 and 5. The new compounds were determined on the basis of spectroscopic and chemical methods to be 3β-acetoxy-4β-hydroxy-1α,7α, 10β,11αH-pseudoguaia-12,8β-olide (1), 1β,7β,9β,10β,13αH-guaia-4(5)-en-12,6β-olide 9-O-β-d-glucoside (2) and 4β-hydroxy-1α,5α,7α,9αH-guaia-10(14),11(13)-dien-12-acid 9-O-β-d-glucoside (3). The isolated compounds were evaluated for cytotoxicity against human promyelocytic leukemia HL-60 cell lines in vitro, but were all inactive.
