排序方式: 共有95条查询结果,搜索用时 15 毫秒
41.
Sabah M’rah Helali Heifa Nebli Rym Kaddour Hela Mahmoudi Mokhtar Lachaâl Zeineb Ouerghi 《Plant and Soil》2010,329(1-2):65-74
We investigated the microbial community structure and population size of arboreal soils—including canopy and bromeliad epiphytic leaf-tank soils—and ground soils in a tropical lowland rainforest in Costa Rica using molecular and cultivation methods. PCR-DGGE analysis of 16S rRNA and 18S rRNA gene fragments and quantitative real-time PCR were applied to survey the bacteria, ammonia-oxidizing bacteria (AOB), and fungi. Bacteria from epiphytic tank soils were isolated and identified. Bacillaceae, Pseudomonadaceae and Micrococcaceae were the most abundant families. According to cluster analysis of DGGE fingerprints a significant difference among the three soil types was evident for bacterial communities. In addition, the microbial communities of canopy and tank soils clustered apart from ground soils. The fungal and AOB communities were diverse but non-specific for the soil types analyzed. 相似文献
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Marck C Kachouri-Lafond R Lafontaine I Westhof E Dujon B Grosjean H 《Nucleic acids research》2006,34(6):1816-1835
We present the first comprehensive analysis of RNA polymerase III (Pol III) transcribed genes in ten yeast genomes. This set includes all tRNA genes (tDNA) and genes coding for SNR6 (U6), SNR52, SCR1 and RPR1 RNA in the nine hemiascomycetes Saccharomyces cerevisiae, Saccharomyces castellii, Candida glabrata, Kluyveromyces waltii, Kluyveromyces lactis, Eremothecium gossypii, Debaryomyces hansenii, Candida albicans, Yarrowia lipolytica and the archiascomycete Schizosaccharomyces pombe. We systematically analysed sequence specificities of tRNA genes, polymorphism, variability of introns, gene redundancy and gene clustering. Analysis of decoding strategies showed that yeasts close to S.cerevisiae use bacterial decoding rules to read the Leu CUN and Arg CGN codons, in contrast to all other known Eukaryotes. In D.hansenii and C.albicans, we identified a novel tDNA-Leu (AAG), reading the Leu CUU/CUC/CUA codons with an unusual G at position 32. A systematic 'p-distance tree' using the 60 variable positions of the tRNA molecule revealed that most tDNAs cluster into amino acid-specific sub-trees, suggesting that, within hemiascomycetes, orthologous tDNAs are more closely related than paralogs. We finally determined the bipartite A- and B-box sequences recognized by TFIIIC. These minimal sequences are nearly conserved throughout hemiascomycetes and were satisfactorily retrieved at appropriate locations in other Pol III genes. 相似文献
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Ben Dhiab Rym Ghenim Nejeh Trabelsi Lamia Yahia Ali Challouf Rafika Ghozzi Khemissa Ammar Jihene Omrane Hela Ben Ouada Hatem 《Journal of applied phycology》2010,22(6):745-752
Combined effect of light intensity and glucose concentration on Arthrospira platensis growth and photosynthetic response was evaluated using a 32 factorial design. This design was carried out with light levels of 50, 100, and 150 μmol photons m−2 s−1 and glucose concentrations of 0.5, 1.5, and 2.5 g L−1. Results from the response surface methodology were that the highest level of light intensity and glucose concentration improved
biomass (1.33 g L−1), maximum specific growth rate (0.49 day−1), and net photosynthetic rate (139.89 μmol O2 mg Chl−1 h−1). Furthermore, the interaction of both factors showed that at low light, glucose had a low effect on maximum biomass and
maximal net photosynthetic rate. However, at the highest light levels, the effect of glucose was more sensitive and the increase
of glucose concentration increased the levels of all responses. The rates of the instantaneous relative growth, net photosynthesis,
and dark respiration of growth cultures showed two different phases in mixotrophic condition. The first was distinguished
by the preponderance of the photoautotrophic mode; the second was based mainly on photoheterotrophy. 相似文献
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Rym Fekih Hiroki Takagi Muluneh Tamiru Akira Abe Satoshi Natsume Hiroki Yaegashi Shailendra Sharma Shiveta Sharma Hiroyuki Kanzaki Hideo Matsumura Hiromasa Saitoh Chikako Mitsuoka Hiroe Utsushi Aiko Uemura Eiko Kanzaki Shunichi Kosugi Kentaro Yoshida Liliana Cano Sophien Kamoun Ryohei Terauchi 《PloS one》2013,8(7)
Advances in genome sequencing technologies have enabled researchers and breeders to rapidly associate phenotypic variation to genome sequence differences. We recently took advantage of next-generation sequencing technology to develop MutMap, a method that allows rapid identification of causal nucleotide changes of rice mutants by whole genome resequencing of pooled DNA of mutant F2 progeny derived from crosses made between candidate mutants and the parental line. Here we describe MutMap+, a versatile extension of MutMap, that identifies causal mutations by comparing SNP frequencies of bulked DNA of mutant and wild-type progeny of M3 generation derived from selfing of an M2 heterozygous individual. Notably, MutMap+ does not necessitate artificial crossing between mutants and the wild-type parental line. This method is therefore suitable for identifying mutations that cause early development lethality, sterility, or generally hamper crossing. Furthermore, MutMap+ is potentially useful for gene isolation in crops that are recalcitrant to artificial crosses. 相似文献
45.
Rym Kaddour Emna Draoui Olfa Baâtour Hela Mahmoudi Imen Tarchoun Nawel Nasri Margaret Gruber Mokhtar Lachaâl 《Acta Physiologiae Plantarum》2013,35(12):3427-3436
Nasturtium officinale R. Br. seedlings were treated with a range of NaCl concentrations (0, 50, 100 and 150 mM) for 21 days after seedling emergence. Physiological analysis based on growth and mineral nutrition, showed a substantial decrease in leaf dry matter with 150 mM NaCl treatment. The growth decrease was correlated with nutritional imbalance and a reduction in potassium accumulation and transport to the leaves. At the same time, we noted an increase in leaf sodium and chloride accumulation and transport. Salt tolerance of N. officinale under 100 mM NaCl was associated with osmotic adjustment via Na+ and Cl? and the maintenance of high K+/Na+ selectivity. Salt decreased carotenoid content more than chlorophylls and also disturbed membrane integrity by increasing malondialdehyde content and electrolyte leakage. At 150 mM NaCl, an increase in antioxidant enzyme-specific activities for superoxide dismutase, catalase and guaiacol peroxidase occurred in concert with a decrease in ascorbic acid, polyphenol, tannin and flavonoid content. These results indicate that N. officinale can maintain growth and natural antioxidant defense compounds such as, vitamin C, carotenoids, and polyphenols, when cultivated in 100 mM NaCl, but not at higher salt levels. 相似文献
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Hirche TO Benabid R Deslee G Gangloff S Achilefu S Guenounou M Lebargy F Hancock RE Belaaouaj A 《Journal of immunology (Baltimore, Md. : 1950)》2008,181(7):4945-4954
According to the widely accepted view, neutrophil elastase (NE), a neutrophil-specific serine protease, is a major contributor to Pseudomonas aeruginosa infection-associated host tissue inflammation and damage, which in severe cases can lead to death. Herein, we provide for the first time compelling evidence that the host rather employs NE to protect itself against P. aeruginosa infection. Using a clinically relevant model of pneumonia, targeted deficiency in NE increased the susceptibility of mice to P. aeruginosa. We found that NE was required for maximal intracellular killing of P. aeruginosa by neutrophils. In investigating the mechanism of NE-mediated killing of P. aeruginosa, we found that NE degraded the major outer membrane protein F, a protein with important functions, including porin activity, maintenance of structural integrity, and sensing of host immune system activation. Consistent with this, the use of an isogenic mutant deficient in outer membrane protein F negated the role of NE in host defense against P. aeruginosa infection. 相似文献
49.
Essential Oil Variability in Natural Populations of Artemisia campestris (L.) and Artemisia herba‐alba (Asso) and Incidence on Antiacetylcholinesterase and Antioxidant Activities 下载免费PDF全文
Faten Younsi Sameh Mehdi Oumayma Aissi Najoua Rahali Rym Jaouadi Mohamed Boussaid Chokri Messaoud 《化学与生物多样性》2017,14(7)
The intraspecific variability of Artemisia herba‐alba and A. campestris essential oils and the evaluation of their antioxidant and antiacetylcholinesterase activities were determined. Artemisia herba‐alba essential oil was found rich in camphor (19.61%), α‐thujone (19.40%), β‐thujone (9.44%), chrysanthenone (9.26%), and trans‐sabinyl acetate (8.43%). The major compounds of A. campestris essential oil were germacrene D (16.38%), β‐pinene (16.33%), and limonene (9.17%). Significant variation in the essential oil composition was observed among populations of each species. The divergence between populations was attributed to the variation of some climatic factors such as altitude, annual rainfall, winter cold stress, summer precipitation, summer drought stress, evapotranspiration, and humidity. Artemisia herba‐alba and A. campestris essential oils exhibited promising antioxidant and antiacetylcholinesterase activities. The level of activity varied significantly according to the species and the essential oil. The highest scavenging activity (IC50 = 0.14 mg/ml) and the uppermost capacity to prevent β‐carotene bleaching (IC50 = 0.10 mg/ml) characterized A. campestris from population 6. A. campestris population 3 possessed the uppermost ability to reduce ferric ions (450.7 μmol Fe2+/g EO). The population 2 of A. campestris showed the strongest antiacetylcholinesterase activity (IC50 = 0.02 mg/ml). The variation of these activities between the essential oils was explained by their composition differences. 相似文献
50.
Yosra Ben Halima Rym Kefi Marco Sazzini Cristina Giuliani Sara De Fanti Chokri Nouali Majdi Nagara Giacomo Mengozzi Sahar Elouej Abdelmajid Abid Henda Jamoussi Lotfi Chouchane Giovanni Romeo Sonia Abdelhak Donata Luiselli 《Genes & nutrition》2017,12(1):20