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31.
NaCl stress effects on enzymes involved in nitrogen assimilation pathway in tomato "Lycopersicon esculentum" seedlings 总被引:4,自引:0,他引:4
Tomato plants (Lycopersicon esculentum Mill, cv. Chibli F1) grown for 10 days on control medium were exposed to differing concentrations of NaCl (0, 25, 50, and 100mM). Increasing salinity led to a decrease of dry weight (DW) production and protein contents in the leaves and roots. Conversely, the root to shoot (R/S) DW ratio was increased by salinity. Na(+) and Cl(-) accumulation were correlated with a decline of K(+) and NO(3)(-) in the leaves and roots. Under salinity, the activities of nitrate reductase (NR, EC 1.6.6.1) and glutamine synthetase (GS, EC 6.3.1.2) were repressed in the leaves, while they were enhanced in the roots. Nitrite reductase (NiR, EC 1.7.7.1) activity was decreased in both the leaves and roots. Deaminating activity of glutamate dehydrogenase (GDH, EC 1.4.1.2) was inhibited, whereas the aminating function was significantly stimulated by salinity in the leaves and roots. At a high salt concentration, the nicotinamide adenine dinucleotide reduced (NADH)-GDH activity was stimulated concomitantly with the increasing NH(4)(+) contents and proteolysis activity in the leaves and roots. With respect to salt stress, the distinct sensitivity of the enzymes involved in nitrogen assimilation is discussed. 相似文献
32.
Tarek Slatni Abdelmajid Krouma Houda Gouia Chedly Abdelly 《Symbiosis (Philadelphia, Pa.)》2009,47(1):35-42
Iron is an essential nutrient for plants, especially in symbiotic N2-fixing legumes. Although abundant in the soil, iron is generally not available to plants as it is predominantly in an insoluble
form (FeIII) . Mono- and dicotyledonous plants, except Grarnineae, have developed morphological and physiological responses, notably
an increase in rhizosphere acidification (H+-ATPase) and an enhanced plasma membrane ferric chelate reductase activity (Fe-CR) in the roots. However, studies on the physiological
responses of root nodules are lacking. The present study was initiated to investigate the acidification capacity and Fe-CR
activity of nodulated roots, and intact nodules, in two contrasting common bean varieties, Coco blanc sensitive to iron deficiency
and Flamingo tolerant to iron deficiency. The discovery of an induction of H+-ATPase and Fe-CR activities in root nodules of commonbean under iron deficiency, suggests that these organs participate in
improving iron availability for the contained bacteroids. 相似文献
33.
Kunihiko Hinohara Toshiaki Nakajima Michio Yasunami Shigeru Houda Taishi Sasaoka Ken Yamamoto Bok-Soo Lee Hiroki Shibata Yumiko Tanaka-Takahashi Megumi Takahashi Takuro Arimura Akinori Sato Taeko Naruse Jimin Ban Hidetoshi Inoko Yoshiji Yamada Motoji Sawabe Jeong-Euy Park Toru Izumi Akinori Kimura 《Human genetics》2009,126(4):539-547
Coronary artery disease (CAD) is based on the atherosclerosis of coronary artery and may manifest with myocardial infarction or angina pectoris. Although it is widely accepted that genetic factors are linked to CAD and several disease-related genes have been reported, only a few could be replicated suggesting that there might be some other CAD-related genes. To identify novel susceptibility loci for CAD, we used microsatellite markers in the screening and found six different candidate CAD loci. Subsequent single nucleotide polymorphism (SNP) association studies revealed an association between CAD and megakaryoblastic leukemia factor-1 gene (MKL1). The association with a promoter SNP of MKL1, ?184C > T, was found in a Japanese population and the association was replicated in another Japanese population and a Korean population. Functional analysis of the MKL1 promoter SNP suggested that the higher MKL1 expression was associated with CAD. These findings suggest that MKL1 is involved in the pathogenesis of CAD. 相似文献
34.
Sabina Paglialunga Pierre Julien Youssef Tahiri Francois Cadelis Jean Bergeron Daniel Gaudet Katherine Cianflone 《Journal of lipid research》2009,50(6):1109-1119
Acylation stimulating protein (ASP, C3adesArg) is an adipose tissue derived hormone that stimulates triglyceride (TG) synthesis. ASP stimulates lipoprotein lipase (LPL) activity by relieving feedback inhibition caused by fatty acids (FA). The present study examines plasma ASP and lipids in male and female LPL-deficient subjects primarily with the P207L mutation, common in the population of Quebec, Canada. We evaluated the fasting and postprandial states of LPL heterozygotes and fasting levels in LPL homozygotes. Homozygotes displayed increased ASP (58–175% increase, P < 0.05–0.01), reduced HDL-cholesterol (64–75% decrease, P < 0.0001), and elevated levels of TG (19–38-fold, P < 0.0001) versus control (CTL) subjects. LPL heterozygotes with normal fasting TG (1.3–1.9 mmol/l) displayed increased ASP (101–137% increase, P < 0.05–0.01) and delayed TG clearance after a fatload; glucose levels remained similar to controls. Hypertriglyceridemics with no known LPL mutation also had increased ASP levels (63–192% increase, P < 0.001). High-TG LPL heterozygotes were administered a fatload before and after fibrate treatment. The treatment reduced fasting and postprandial plasma ASP, TG, and FA levels without changing insulin or glucose levels. ASP enhances adipose tissue fatty-acid trapping following a meal; however in LPL deficiency, high ASP levels are coupled with delayed lipid clearance. 相似文献
35.
Hadeer Lazim Houda Mankai Nedra Slama Insaf Barkallah Ferid Limam 《Journal of industrial microbiology & biotechnology》2009,36(4):531-537
The purpose of the present research is to study the production of thermophilic alkaline protease by a local isolate, Streptomyces sp. CN902, under solid state fermentation (SSF). Optimum SSF parameters for enzyme production have been determined. Various
locally available agro-industrial residues have been screened individually or as mixtures for alkaline protease production
in SSF. The combination of wheat bran (WB) with chopped date stones (CDS) (5:5) proved to be an efficient mixture for protease
production as it gave the highest enzyme activity (90.50 U g−1) when compared to individual WB (74.50 U g−1) or CDS (69.50 U g−1) substrates. This mixed solid substrate was used for the production of protease from Streptomyces sp. CN902 under SSF. Maximal protease production (220.50 U g−1) was obtained with an initial moisture content of 60%, an inoculum level of 1 × 108 (spore g−1 substrate) when incubated at 45°C for 5 days. Supplementation of WB and CDS mixtures with yeast extract as a nitrogen source
further increased protease production to 245.50 U g−1 under SSF. Our data demonstrated the usefulness of solid-state fermentation in the production of alkaline protease using
WB and CDS mixtures as substrate. Moreover, this approach offered significant benefits due to abundant agro-industrial substrate
availability and cheaper cost. 相似文献
36.
Hadeer Lazim Nedra Slama Houda Mankai Insaf Barkallah Ferid Limam 《World journal of microbiology & biotechnology》2010,26(7):1317-1322
Streptomyces rimosus CN08 isolated from Tunisian soil produced 8.6 mg l−1 of oxytetracycline (OTC) under submerged fermentation (SmF). Attempts were made for enhancing OTC production after irradiation-induced
mutagenesis of Streptomyces rimosus CN08 with Co60-γ rays. 125 OTC-producing colonies were obtained after screening on kanamycin containing medium. One mutant called Streptomyces rimosus γ-45 whose OTC production increased 19-fold (165 mg l−1) versus wild-type strain was selected. γ-45 mutant was used for OTC production under solid-state fermentation (SSF). Wheat
bran (WB) was used as solid substrate and process parameters influencing OTC production were optimized. Solid-state fermentation
increased the yield of antibiotic production (257 mg g−1) when compared with submerged fermentation. Ammonium sulphate as additional nitrogen source enhanced OTC level to 298 mg g−1. Interestingly, OTC production by γ-45 mutant was insensitive to phosphate which opens the way to high OTC production even
in medium containing phosphate necessary for optimal mycelia growth. 相似文献
37.
Karmous-Benailly H Martinovic J Gubler MC Sirot Y Clech L Ozilou C Auge J Brahimi N Etchevers H Detrait E Esculpavit C Audollent S Goudefroye G Gonzales M Tantau J Loget P Joubert M Gaillard D Jeanne-Pasquier C Delezoide AL Peter MO Plessis G Simon-Bouy B Dollfus H Le Merrer M Munnich A Encha-Razavi F Vekemans M Attié-Bitach T 《American journal of human genetics》2005,76(3):493-504
Bardet-Biedl syndrome (BBS) is a multisystemic disorder characterized by postaxial polydactyly, progressive retinal dystrophy, obesity, hypogonadism, renal dysfunction, and learning difficulty. Other manifestations include diabetes mellitus, heart disease, hepatic fibrosis, and neurological features. The condition is genetically heterogeneous, and eight genes (BBS1-BBS8) have been identified to date. A mutation of the BBS1 gene on chromosome 11q13 is observed in 30%-40% of BBS cases. In addition, a complex triallelic inheritance has been established in this disorder--that is, in some families, three mutations at two BBS loci are necessary for the disease to be expressed. The clinical features of BBS that can be observed at birth are polydactyly, kidney anomaly, hepatic fibrosis, and genital and heart malformations. Interestingly, polydactyly, cystic kidneys, and liver anomalies (hepatic fibrosis with bile-duct proliferation) are also observed in Meckel syndrome, along with occipital encephalocele. Therefore, we decided to sequence the eight BBS genes in a series of 13 antenatal cases presenting with cystic kidneys and polydactyly and/or hepatic fibrosis but no encephalocele. These fetuses were mostly diagnosed as having Meckel or "Meckel-like" syndrome. In six cases, we identified a recessive mutation in a BBS gene (three in BBS2, two in BBS4, and one in BBS6). We found a heterozygous BBS6 mutation in three additional cases. No BBS1, BBS3, BBS5, BBS7, or BBS8 mutations were identified in our series. These results suggest that the antenatal presentation of BBS may mimic Meckel syndrome. 相似文献
38.
Laura García-Gutiérrez Houda Zeriouh Diego Romero Jaime Cubero Antonio Vicente Alejandro Pérez-García 《Microbial biotechnology》2013,6(3):264-274
Biological control of plant diseases has gained acceptance in recent years. Bacillus subtilis UMAF6639 is an antagonistic strain specifically selected for the efficient control of the cucurbit powdery mildew fungus Podosphaera fusca, which is a major threat to cucurbits worldwide. The antagonistic activity relies on the production of the antifungal compounds iturin and fengycin. In a previous study, we found that UMAF6639 was able to induce systemic resistance (ISR) in melon and provide additional protection against powdery mildew. In the present work, we further investigated in detail this second mechanism of biocontrol by UMAF6639. First, we examined the signalling pathways elicited by UMAF6639 in melon plants, as well as the defence mechanisms activated in response to P. fusca. Second, we analysed the role of the lipopeptides produced by UMAF6639 as potential determinants for ISR activation. Our results demonstrated that UMAF6639 confers protection against cucurbit powdery mildew by activation of jasmonate- and salicylic acid-dependent defence responses, which include the production of reactive oxygen species and cell wall reinforcement. We also showed that surfactin lipopeptide is a major determinant for stimulation of the immune response. These results reinforce the biotechnological potential of UMAF6639 as a biological control agent. 相似文献
39.
Chun Yang Wei Xiong Qian Qiu Houda Tahiri Carmen Gagnon Guoxiang Liu Pierre Hardy 《Journal of visualized experiments : JoVE》2015,(96)
Interest in the biological roles of cell membrane–derived vesicles in cell–cell communication has increased in recent years. Microparticles (MPs) are one such type of vesicles, ranging in diameter from 0.1 μm to 1 μm, and typically shed from the plasma membrane of eukaryotic cells undergoing activation or apoptosis. Here we describe the generation of T lymphocyte–derived microparticles (LMPs) from apoptotic CEM T cells stimulated with actinomycin D. LMPs are isolated through a multistep differential centrifugation process and characterized using flow cytometry. This protocol also presents an in situ cell death detection method for demonstrating the proapoptotic effect of LMPs on bronchial epithelial cells derived from mouse primary respiratory bronchial tissue explants. Methods described herein provide a reproducible procedure for isolating abundant quantities of LMPs from apoptotic lymphocytes in vitro. LMPs derived in this manner can be used to evaluate the characteristics of various disease models, and for pharmacology and toxicology testing. Given that the airway epithelium offers a protective physical and functional barrier between the external environment and underlying tissue, use of bronchial tissue explants rather than immortalized epithelial cell lines provides an effective model for investigations requiring airway tract tissue. 相似文献
40.
Guesmi Houda Kalghoum Anwar Ghazel Cherif Saidane Leila Azouz 《Cluster computing》2021,24(3):1945-1954
Cluster Computing - Trust management systems give way to trustworthy interactions in cloud computing. However, malicious cloud users can intentionally provide unfair ratings to benefit or reduce a... 相似文献