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31.
Engineered Polyamine Catabolism Preinduces Tolerance of Tobacco to Bacteria and Oomycetes 总被引:1,自引:0,他引:1 下载免费PDF全文
Panagiotis N. Moschou Panagiotis F. Sarris Nicholas Skandalis Athina H. Andriopoulou Konstantinos A. Paschalidis Nickolas J. Panopoulos Kalliopi A. Roubelakis-Angelakis 《Plant physiology》2009,149(4):1970-1981
Polyamine oxidase (PAO) catalyzes the oxidative catabolism of spermidine and spermine, generating hydrogen peroxide. In wild-type tobacco (Nicotiana tabacum ‘Xanthi’) plants, infection by the compatible pathogen Pseudomonas syringae pv tabaci resulted in increased PAO gene and corresponding PAO enzyme activities; polyamine homeostasis was maintained by induction of the arginine decarboxylase pathway and spermine was excreted into the apoplast, where it was oxidized by the enhanced apoplastic PAO, resulting in higher hydrogen peroxide accumulation. Moreover, plants overexpressing PAO showed preinduced disease tolerance against the biotrophic bacterium P. syringae pv tabaci and the hemibiotrophic oomycete Phytophthora parasitica var nicotianae but not against the Cucumber mosaic virus. Furthermore, in transgenic PAO-overexpressing plants, systemic acquired resistance marker genes as well as a pronounced increase in the cell wall-based defense were found before inoculation. These results reveal that PAO is a nodal point in a specific apoplast-localized plant-pathogen interaction, which also signals parallel defense responses, thus preventing pathogen colonization. This strategy presents a novel approach for producing transgenic plants resistant to a broad spectrum of plant pathogens. 相似文献
32.
Testa G Schaft J van der Hoeven F Glaser S Anastassiadis K Zhang Y Hermann T Stremmel W Stewart AF 《Genesis (New York, N.Y. : 2000)》2004,38(3):151-158
Alteration of the mouse genome through homologous recombination in embryonic stem (ES) cells is the most accurate and versatile way to dissect gene function in a vertebrate model. Most often, a selectable marker is used to create a knockout allele by replacing an essential part of the gene. However, knockout strategies are limited because the mutation is present constitutively. Conditional approaches based on the Cre-loxP site-specific recombination (SSR) system address this limitation; however, it requires that all parts of the targeted gene remain in ES cells. Here we report success with a "knockout-first" strategy that ablates gene function by insertion of RNA processing signals without deletion of any of the target gene. Incorporation of site-specific recombination target sites creates a multipurpose allele for both knockout and conditional applications. 相似文献
33.
Copeland A Sikorski J Lapidus A Nolan M Glavina T Del Rio Lucas S Chen F Tice H Pitluck S Cheng JF Pukall R Chertkov O Brettin T Han C Kuske C Bruce D Goodwin L Ivanova N Mavromatis K Mikhailova N Chen A Palaniappan K Chain P Rohde M Göker M Bristow J Eisen JA Markowitz V Hugenholtz P Kyrpides NC Klenk HP Detter JC 《Standards in genomic sciences》2010,2(3):361-362
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Yasawong M Teshima H Lapidus A Nolan M Lucas S Glavina Del Rio T Tice H Cheng JF Bruce D Detter C Tapia R Han C Goodwin L Pitluck S Liolios K Ivanova N Mavromatis K Mikhailova N Pati A Chen A Palaniappan K Land M Hauser L Chang YJ Jeffries CD Rohde M Sikorski J Pukall R Göker M Woyke T Bristow J Eisen JA Markowitz V Hugenholtz P Kyrpides NC Klenk HP 《Standards in genomic sciences》2010,3(2):126-135
Arcanobacterium haemolyticum (ex MacLean et al. 1946) Collins et al. 1983 is the type species of the genus Arcanobacterium, which belongs to the family Actinomycetaceae. The strain is of interest because it is an obligate parasite of the pharynx of humans and farm animal; occasionally, it causes pharyngeal or skin lesions. It is a Gram-positive, nonmotile and non-sporulating bacterium. The strain described in this study was isolated from infections amongst American soldiers of certain islands of the North and West Pacific. This is the first completed sequence of a member of the genus Arcanobacterium and the ninth type strain genome from the family Actinomycetaceae. The 1,986,154 bp long genome with its 1,821 protein-coding and 64 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project. 相似文献
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Asprouli Eleni Kalafati Ioanna Panagiota Sakellari Aikaterini Karavoltsos Sotirios Vlachogiannakos John Revenas Konstantinos Kokkinos Alexander Dassenakis Manos Dedoussis George V. Kalogeropoulos Nick 《Biological trace element research》2019,188(2):326-333
Biological Trace Element Research - Nonalcoholic fatty liver disease (NAFLD) is considered as the hepatic manifestation of metabolic syndrome. Its global prevalence is estimated between 25 and 45%,... 相似文献
37.
Petritis K Koukaki G Koussissi E Elfakir C Dreux M Dourtoglou V 《Phytochemical analysis : PCA》2003,14(6):347-351
Varying concentrations of cyclopropane-1,1-dicarboxylic acid (CDA), an inhibitor of 1-aminocyclopropane-1-carboxylic acid oxidase, added to the solid culture medium of tomato nodal shoot segments resulted in a reduction in the level of endogenous ethylene according to the concentration of inhibitor applied. Following treatment with inhibitor, plants were homogenised and the concentrations of CDA and of 1-aminocyclopropane-1-carboxylic acid (ACC) were measured simultaneously in the resulting juice using an HPLC-ESI/MS-MS method. The levels of CDA and ACC measured in the plant tissues were associated with the concentration of inhibitor added to the solid medium. The HPLC-ESI/MS-MS method described produced limits of detection of 0.8 pmol for ACC and of 4 pmol for CDA. 相似文献
38.
Predictive Modeling of the Shelf Life of Fish under Nonisothermal Conditions 总被引:2,自引:0,他引:2 下载免费PDF全文
Konstantinos Koutsoumanis 《Applied microbiology》2001,67(4):1821-1829
The behavior of the natural microflora of Mediterannean gilt-head seabream (Sparus aurata) was monitored during aerobic storage at different isothermal conditions from 0 to 15°C. The growth data of pseudomonads, established as the specific spoilage organisms of aerobically stored gilt-head seabream, combined with data from previously published experiments, were used to model the effect of temperature on pseudomonad growth using a Belehradek type model. The nominal minimum temperature parameters of the Belehradek model (Tmin) for the maximum specific growth rate (μmax) and the lag phase (tLag) were determined to be −11.8 and −12.8°C, respectively. The applicability of the model in predicting pseudomonad growth on fish at fluctuating temperatures was evaluated by comparing predictions with observed growth in experiments under dynamic conditions. Temperature scenarios designed in the laboratory and simulation of real temperature profiles observed in the fish chill chain were used. Bias and accuracy factors were used as comparison indices and ranged from 0.91 to 1.17 and from 1.11 to 1.17, respectively. The average percent difference between shelf life predicted based on pseudomonad growth and shelf life experimentally determined by sensory analysis for all temperature profiles tested was 5.8%, indicating that the model is able to predict accurately fish quality in real-world conditions. 相似文献
39.
A software algorithm has been developed to investigate the folding process in B-DNA structures in vacuum under a simple and accurate force field. This algorithm models linear double stranded B-DNA sequences based on a local, sequential minimization procedure. The original B-DNA structures were modeled using initial nucleotide structures taken from the Brookhaven database. The models contain information at the atomic level allowing one to investigate as accurately as possible the structure and characteristics of the resulting DNA structures. A variety of DNA sequences and sizes were investigated containing coding and non-coding, random and real, homogeneous or heterogeneous sequences in the range of 2 to 40 base pairs. The force field contains terms such as angle bend, Lennard-Jones, electrostatic interactions and hydrogen bonding which are set up using the Dreiding II force field and defined to account for the helical parameters such as twist, tilt and rise. A close comparison was made between this local minimization algorithm and a global one (previously published) in order to find out advantages and disadvantages of the different methods. From the comparison, this algorithm gives better and faster results than the previous method, allowing one to minimize larger DNA segments. DNA segments with a length of 40 bases need approximately 4 h, while 2.5 weeks are needed with the previous method. After each minimization the angles between phosphate–oxygen-carbon A1, the oxygen–phosphate–oxygen A2 and the average helical twists were calculated. From the generated fragments it was found that the bond angles are A1=150°±2°and A2=130°±10°, while the helical twist is 36.6°±2° in the A strand and A1=150°±6° and A2=130±6° with helical twist 39.6°±2° in the B strand for the DNA segment with the same sequence as the Dickerson dodecamer.Figure The final minimized DNA segment of the Dickerson dodecamer sequence represented by ball drawings and viewed (left) perpendicular and (right) down the helical axis 相似文献
40.