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1.
Cells and cell-free solutions of the culture filtrate of the bacterial symbiont, Xenorhabdus nematophila taken from the entomopathogenic nematode Steinernema carpocapsae in aqueous broth suspensions were lethal to larvae of the diamondback moth Plutella xylostella. Their application on leaves of Chinese cabbage indicated that the cells can penetrate into the insects in the absence of the nematode vector. Cell-free solutions containing metabolites were also proved as effective as bacterial cells suspension. The application of aqueous suspensions of cells of X. nematophila or solutions containing its toxic metabolites to the leaves represents a possible new strategy for controlling insect pests on foliage.  相似文献   

2.
Cells and cell-free solutions of the culture filtrate of the bacterial symbiont, Xenorhabdus nematophila taken from the entomopathogenic nematode Steinernema carpocapsae in aqueous broth suspensions were lethal to larvae of the diamondback moth Plutella xylostella. Their application on leaves of Chinese cabbage indicated that the cells can penetrate into the insects in the absence of the nematode vector. Cell-free solutions containing metabolites were also proved as effective as bacterial cells suspension. The application of aqueous suspensions of cells of X. nematophila or solutions containing its toxic metabolites to the leaves represents a possible new strategy for controlling insect pests on foliage.  相似文献   

3.
Studies were conducted under pot conditions to determine the comparative efficacy of carbofuran at 1 mg a.i./kg soil, bavistin at 1 mg a.i./kg soil, neem (Azadirachta indica) seed powder at 50 mg/kg soil, green mould (Trichoderma harzianum) at 50.0 ml/kg soil, rhizobacteria (Pseudomonas fluorescens) at 50.0 ml/kg soil against root-knot nematode,Meloidogyne incognita-wilt fungus,Fusarium oxysporum disease complex on green gram,Vigna radiata cv ML-1108. All the treatments significantly improved the growth of the plants as compared to untreated inoculated plants. Analysis of data showed that carbofuran andA. indica seed powder increased plant growth and yield significantly more in comparison to bavistin andP. fluorescens. Carbofuran was highly effective against nematode, bavistin against fungus,A. indica seed powder against both the pathogens and both the bioagents were moderately effective against both the pathogens.  相似文献   

4.
Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained. Seven somatically hybridized plants and their parents were used for AFLP (amplified fragment length polymorphism) analysis using 8 primer pairs. Results confirmed that these plants were somatic hybrids containing the characteristic bands of both parents. The morphology of the regenerated rice showed characters of both O. sativa and O. meyeriana. Two somatic hybrids showed highest BB resistance and the other 8 plants showed moderate resistance. The new germplasms with highest resistance have been used in the rice breeding program for the improvement of bacterial blight resistance. Project (No. 98001) supported by Ningbo Agriculture Key Scientific Research Foundation, China  相似文献   

5.
A known species, Physarum melleum, was found fruiting on living leaves of Dendrobium candidum, which was collected in China in 2004. Its morphological characters were revealed by light microscopy (LM), environmental scanning electron microscopy (ESEM) and scanning electron microscopy (SEM). Character variations were distinguished by its olive-yellow peridium and its always thinner capillitium containing globulose granular material between the large calcareous nodes. The calcium carbonate granules, deposited on stalks, peridium and hypothallus as well as within stalks, were globose and smooth. Project (No. 2001BA744C) supported by the 10th Five-year National Key Technologies R & D Program, China  相似文献   

6.
Objective: Detecting the expression and mutation of human telomeric repeat binding factor (hTRF1) in 10 malignant hematopoietic cell line cells on the base of determining its genomic structure and its four pseudogenes to clarify if hTRF1 mutation is one of the factors of the activation of telomerase. Methods: hTRF1cDNA sequences were obtained from GenBank, its genome structure and pseudogenes were forecasted by BLAST and other biology information programs and then testified by sequencing. Real-time RT-PCR was used to detect the expression of hTRF1mRNA in 10 cell line cells, including myelogenous leukemia cell lines K562, HL-60, U-937, NB4, THP-1, HEL and Dami; lymphoblastic leukemia cell lines 6T-CEM, Jurkat and Raji. Telomerase activities of cells were detected by using telomeric repeat amplification (TRAP)-ELISA protocol. PCR and sequencing were used to detect mutation of each exon of hTRF1 in 10 cell line cells. Results: hTRF1 gene, mapped to 8q13, was divided into 10 exons and spans 38.6 kb. Four processed pseudogenes of hTRF1 located on chromosome 13, 18, 21 and X respectively, was named as ψhTRF1-13, ψhTRF1-18, ψhTRF1-21 and ψhTRF1-X respectively. All cell line cells showed positive telomerase activity. The expression of hTRF1 was significantly lower in malignant hematopoietic cell lines cells (0.0338, 0.0108:_0.0749) than in normal mononuclear cells (0.0493, 0.0369:_0.128) (P=0.004). But no significant mutation was found in all exons of hTRF1 in 10 cell line cells. Four variants were found in part of intron 1, 2 and 8 of hTRF1. Their infection on gene function is unknown and needs further studies. Conclusion: hTRF1 mutation is probably not one of the main factors for telomerase activation in malignant hematopoietic disease. Project supported by the National Basic Research Program (973) of China (No. 2002CB713700) and the National Natural Science Foundation of China (No. 39870339)  相似文献   

7.
Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Collosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects; none of them died even at 3 d after treatment. The methanol extracts, however, had rapid lethal effects on both C. maculatus and S. zeamais. The mortality of C. maculatus by the lowest concentration of methanol extracts ranged from 95%∼100% whereas in S. zeamais, the mortality ranged from 87.5%∼100% and 70%∼100% in concentrations of 1 g extract+3 ml methanol and 1 g extract+5 ml methanol, respectively, from 24 to 48 h. The least concentration of 1 g extract+15 ml methanol had no significant lethal effect on Sitophilus zeamais.   相似文献   

8.
Scrubbing of NO x from the gas phase with Fe(II)EDTA has been shown to be highly effective. A new biological method can be used to convert NO to N2 and regenerate the chelating agent Fe(II)EDTA for continuous NO absorption. The core of this biological regeneration is how to effectively simultaneous reduce Fe(III)EDTA and Fe(II)EDTA-NO, two mainly products in the ferrous chelate absorption solution. The biological reduction rate of Fe(III)EDTA plays a main role for the NO x removal efficiency. In this paper, a bacterial strain identified asKlebsiella Trevisan sp. was used to demonstrate an inhibition of Fe(III)EDTA reduction in the presence of Fe(II)EDTA-NO. The competitive inhibition experiments indicted that Fe(II)EDTA-NO inhibited not only the growth rate of the iron-reduction bacterial strain but also the Fe(III)EDTA reduction rate. Cell growth rate and Fe(III)EDTA reduction rate decreased with increasing Fe(II)EDTA-NO concentration in the solution. Project (No. 20176052) supported by the National Natural Science Foundation of China and the Scientific Research Foundation for Returned Overseas Chinese Scholars, Ministry of Education  相似文献   

9.
The construction of multirate rearrangeable network has long been an interesting problem. Of many results published, all were achieved on 3-stage Clos network. The monotone routing algorithm proposed by Huet al. (2001) was also first applied to 3-stage Clos network. In this work, we adopt this algorithm and apply it to log d (N,m,p) networks. We first analyze the properties of log d (N,m,p) networks. Then we use monotone algorithm in log d (N,0,p) network. Furthermore we extend the result to construct multirate rearrangeable networks based on log d (N,m,p) network (1≤m≤n−1). Project (No. 10371028) supported by the National Natural Science Foundation of China  相似文献   

10.
Embryogenic calli were induced from the seeds of creeping bentgrass (Agrostis palustris Huds.) cv. Regent and colonial bentgrass (Agrostis Tenuis Sibth. Fl. Oxen.) cv. Tiger. The embryogenic calli were precultured on fresh medium for 4–7 days and then co-cultivated withAgrobacterium tumefaciens, LBA4404. which contains plasmid vector-pSBGM harboring bar coding region, synthetic green fluorescent protein (sGFP) coding region and matrix attachment region (MAR). After 3 days of co-cultivation, the calli were washed thoroughly and transferred to MS medium containing 2 mg/L of 2, 4-D, 12–15 mg/L phosphinothricin (PPT) and 250 mg/L of cefotaxime. After 2–3 months of selection, the actively growing calli of ‘Regent’ and ‘Tiger’ were transferred to MS medium with 12–15 mg/L PPT and 250 mg/L cefotazime for regeneration. The putative transformants were maintained on MS medium with 3 mg/L PPT for long period but control died within 1 month. After establishing in greenhouse, the transformants also showed strong resistance to 0.4% of herbicide Basta but control plants died within 2 weeks. Under confocal microscope, both young leaves and roots showed significant GFP expression. PCR analysis revealed the presence of a DNA fragment of GFP gene at the expected size (380 bp) in the transformants and its absence in a randomly selected control plant.  相似文献   

11.
In this study, freeze-dried water extract from the leaves of Myristica fragrans (Houtt.) was tested for mutagenic and antimutagenic potentials using the Allium cepa assay. Freeze-dried water extract alone and its combination with cyclophosphamide (CP) (50 mg/kg) were separately dissolved in tap water at 500, 1000, 2000, and 4000 mg/kg. Onions (A. cepa) were suspended in the solutions and controls for 48 h in the dark. Root tips were prepared for microscopic evaluation. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radicals’ scavenging power of the extract was tested using butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as standards. Water extract of Myristica fragrans scavenged free radicals better than BHA, but worse than BHT. The extract alone, as well as in combination with CP suppressed cell division, and induced chromosomal aberrations that were insignificantly different from the negative control (P≤0.05). However, cytotoxic and mutagenic actions of CP were considerably suppressed. The observed effects on cell division and chromosomes of A. cepa may be principally connected to the antioxidant properties of the extract. The obtained results suggest mitodepressive and antimutagenic potentials of water extract of the leaves of M. fragrans as desirable properties of a promising anticancer agent.  相似文献   

12.
Constant solutions to Yang-Baxter equation are investigated over Grassmann algebra for the case of 6-vertexR-matrix. The general classification of all possible solutions over Grassmann algebra and particular cases with 2,3,4 generators are studied. As distinct from the standard case, whenR-matrix over number field can have a maximum 5 nonvanishing elements, we obtain over Grassmann algebra a set of new full 6-vertex solutions. The solutions leading to regularR-matrices which appear in weak Hopf algebras are considered.  相似文献   

13.
Insertion mutagenesis has become one of the most popular methods for gene functions analysis. Here we report a two-elementAc/Ds transposon system containing enhancer trap and gene trap for gene tagging in rice. The excision ofDs element was examined by PCR amplification. The excision frequency ofDs element varied from 0% to 40% among 20 F2 populations derived from 11 differentDs parents. Southern blot analysis revealed that more than 70% of excisedDs elements reinserted into rice genome and above 70% of the reinsertedDs elements were located at different positions of the chromosome in rice. The result of histochemical GUS analysis indicated that 28% of enhancer trap and 22% of gene trap tagging plants displayed GUS activity in leaves, roots, flowers or seeds. The GUS positive lines will be useful for identifying gene function in rice. Project supported by the Hi-Tech Research and Development Program (863) of China (No. 2002AA2Z1003)  相似文献   

14.
Fusarium head blight (FHB) caused byFusarium graminearum is a devastating disease that results in extensive yield losses to wheat and barley. A green fluorescent protein (GFP) expressing plasmid pRP22-GFP was constructed for monitoring the colonization of two biocontrol agents,Brevibacillus brevis ZJY-116, on the spikes of barley and their effect on suppression of FHB. Survival and colonization of theBrevibacillus brevis ZJY-1 andBacillus subtilis ZJY-116 strains on spikes of barley were observed by tracking the bacterial transformants with GFP expression. Our field study revealed that plasmid pRP22-GFP was stably maintained in the bacterial strains without selective pressure. The retrieved GFP-tagged strains showed that the bacterial population fluctuation accorded with that of the rain events. Furthermore, both biocontrol strains gave significant protection against FHB on spikes of barley in fields. The greater suppression of barley FHB disease was resulted from the treatment of barley spikes with biocontrol agents before inoculation withF. graminearum. Project supported by the National Natural Science Foundation of China (No. 30230250) and Science and Technology Committee of Zhejiang Province (No. 2003C22029), China  相似文献   

15.
Water hyacinth (Eichhornia crassipes (Mart.) Solms) is a prolific free floating aquatic macrohpyte found in tropical and subtropical parts of the earth. The effects of pollutants from textile wastewater on the anatomy of the plant were studied. Water hyacinth exhibits hydrophytic adaptations which include reduced epidermis cells lacking cuticle in most cases, presence of large air spaces (7∼50 μm), reduced vascular tissue and absorbing structures. Textile waste significantly affected the size of root cells. The presence of raphide crystals was noted in parenchyma cells of various organs in treated plants. Project (No. 30070017) supported by the National Natural Science Foundation of China  相似文献   

16.
Qiu-min  Han  Hua-wu  Jiang  Xiao-peng  Qi  Jie  Yu  Ping  Wu 《浙江大学学报(A卷英文版)》2004,5(6):629-633
AtCRE1 is known to be a cytokinin receptor inArabidopsis. TheAtCRE1 protein contains CHASE domain at the N-terminal part, followed by a transmitter (histidine kinase) domain and two receiver domains. The N-terminal CHASE domain ofAtCRE1 contains putative recognition sites for cytokinin. Five CHASE domains containing proteins were found in rice,osCRL1a,OsCRL1b,OsCRL2,OsCRL3, andOsCRL4.OsCRL1a,OsCRL1b,OsCRL2 andOsCRL3 contain the four domains existing inCRE1, whereasOsCRL4 only contains the CHASE domain and a putative Ser/Thr protein kinase domain. The authors cloned the encoding geneOsCRL4 and found that it represents a new member of the cytokinin receptor protein in rice. Project supported by the National Natural Science Foundation of China  相似文献   

17.
This article reports first-principles band structure calculations forRMn6Sn6 (R=Tb, Dy). The calculation uses the linear muffin-tin orbitals (LMTO) method in the atomic-sphere-approximation (ASA), and yields results showing that both TbMn6Sn6 and DyMn6Sn6 are ferrimagnetic compounds with antiparallel aligned moments ofR and Mn atoms. In this research the 4f states ofR atoms are treated as localized states, i.e., the hybridization of 4f states with other valence electrons is neglected. The moments of Mn in both compounds were determined to be 2.43 μB and 2.38 μB, respectively. The considerably small additional moments for Mn from the spin-orbit coupling indicates that the spin-orbital coupling is not dominated for Mn atoms. The total moments of Tb and Dy atoms are 10.28 μB and 11.20 μB. All the calculation findings accorded well with experimental results. Project supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry of China.  相似文献   

18.
Study of the SISO mixedH 2/l1 problem for discrete time systems showed that there exists a unique optimal solution which can be approximated within any prescribed missing error bound inl 2 norm with solvable suboptimal solutions and solvable superoptimal solutions. Project supported by the National Natural Science Foundation of China (No. 60174026) and the Scientific Research Foundation for Returned Overseas Chinese Scholars of Zhejiang Province (No. J20020546)  相似文献   

19.
Although the biochemical dissection of parasitoid-host interactions is becoming well characterized, the molecular knowledge concerning them is minimal. In order to understand the molecular bases of the host immune response to parasitoid attack, we explored the response of Papilio xuthus parasitized by the endoparasitic wasp Pteromalus puparum using proteomic approach. By examining the differential expression of plasma proteins in the parasitized and unparasitized host pupae by two-dimensional (2D) electrophoresis, 16 proteins were found to vary in relation to parasitization compared with unparasitized control samples. All of them were submitted to identification by mass spectrometry coupled with a database search. The modulated proteins were found to fall into the following functional groups: humoral or cellular immunity, detoxification, energy metabolism, and others. This study contributes insights into the molecular mechanism of the relationships between parasitoids and their host insects. Project supported by the National Basic Research Program (973) of China (No. 2006CB102005), the National Natural Science Foundation of China (Nos. 30571251 and 30170626), the Program for New Century Excellent Talents in University of the Ministry of Education of China (No. NCET-05-0513), and the Innovation Research Team Program of the Ministry of Education of China (No. IRT0535)  相似文献   

20.
Objective: To evaluate the interaction between serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) andHelicobacter pylori (H. pylori) infection in patients with chronic gastritis and peptic ulcer. Methods: The serum levels of sICAM-1 in 205 patients with chronic gastric diseases were detected by ELISA method and the status ofH. pylori was determined by histologic examination, RUT,14C-UBT, and serology. The sera obtained from 18 healthy volunteers served as controls. Results: The serum levels of sICAM-1 were significantly higher in patients withH. pylori positive than those of H. pylori negative (889.43±32.52 ng/ml vs. 747.07±30.45 ng/ml,P<0.05). The serum levels of sICAM-1 in patients with mild, moderate and severe infection ofH. pylori were 841.68±72.36 ng/ml, 905.43±37.59 ng/ml and 1012.54±49.34 ng/ml, respectively (P<0.05). The serum levels of sICAM-1, proved to be significantly correlated with the density ofH. pylori colonization in gastric mucosa (r s=0.316,P<0.001). The serum levels of sICAM-1 in patients with chronic gastritis and peptic ulcer were significantly higher than those in healthy controls (P<0.05). Conclusions: These results indicated thatH. pylori infection up-regulates the expression of sICAM-1.  相似文献   

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