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1.
Soumaya Zouari Ellouzi Dorra Driss Sameh Maktouf Monia Blibech Manel Affes Hounaida Kamoun Semia Ellouze Chaabouni Raoudha Ellouze Ghorbel 《Journal of Cereal Science》2014
Gluten extracted from fresh pasta by-products (PG) was enzymatically hydrolyzed by two different commercial proteases (Alcalase 2.4 L and Pancreatin) to different degrees of hydrolysis (DH 2.0, 4.0 and 8.0%). Commercial gluten (CG) was used as reference. The evaluation of functional properties of hydrolyzates from pasta gluten (PGH) and commercial gluten (CGH) showed that Pancreatin hydrolyzates had the highest emulsifying capacities. Regarding the foaming activity, all hydrolyzates performed better than unhydrolyzed gluten. PGH and CGH were added to wheat flour (1%) and their effects on dough rheology were studied. Most hydrolyzates with DH 8% increased dough thermal stability and elasticity during mixing, accelerated the denaturation rate of the protein network, and delayed the gelatinization speed of starch as the temperature increased. Texture profiles and specific volumes of breads from low quality wheat flour with added Pancreatin hydrolyzates (DH 8%) were comparable to those of breads from high quality flour. This showed the potential suitability of PGH and CGH as bread improvers. 相似文献
2.
Kamoun PG Campbell DB Ostro SJ Pettengill GH Shapiro II 《Science (New York, N.Y.)》1982,216(4543):293-295
The nucleus of the periodic comet Encke was detected in November 1980 with the Arecibo Observatory's radar system (wavelength, 12.6 centimeters). The echoes in the one sense of circular polarization received imply a radar cross section of 1.1 +/- 0.7 square kilometers. The estimated bandwidth of these echoes combined with an estimate of the rotation vector of Encke yields a radius for the nucleus of l.5(+2.3)(-1.0) kilometers. The uncertainties given are dependent primarily on the range of models considered for the comet and for the manner in which its nucleus backscatters radio waves. Should this range prove inadequate, the true value of the radius of the nucleus might lie outside the limits given. 相似文献
3.
Raffaele S Farrer RA Cano LM Studholme DJ MacLean D Thines M Jiang RH Zody MC Kunjeti SG Donofrio NM Meyers BC Nusbaum C Kamoun S 《Science (New York, N.Y.)》2010,330(6010):1540-1543
Many plant pathogens, including those in the lineage of the Irish potato famine organism Phytophthora infestans, evolve by host jumps followed by specialization. However, how host jumps affect genome evolution remains largely unknown. To determine the patterns of sequence variation in the P. infestans lineage, we resequenced six genomes of four sister species. This revealed uneven evolutionary rates across genomes with genes in repeat-rich regions showing higher rates of structural polymorphisms and positive selection. These loci are enriched in genes induced in planta, implicating host adaptation in genome evolution. Unexpectedly, genes involved in epigenetic processes formed another class of rapidly evolving residents of the gene-sparse regions. These results demonstrate that dynamic repeat-rich genome compartments underpin accelerated gene evolution following host jumps in this pathogen lineage. 相似文献
4.
Signatures of adaptation to obligate biotrophy in the Hyaloperonospora arabidopsidis genome 总被引：2，自引：0，他引：2
Baxter L Tripathy S Ishaque N Boot N Cabral A Kemen E Thines M Ah-Fong A Anderson R Badejoko W Bittner-Eddy P Boore JL Chibucos MC Coates M Dehal P Delehaunty K Dong S Downton P Dumas B Fabro G Fronick C Fuerstenberg SI Fulton L Gaulin E Govers F Hughes L Humphray S Jiang RH Judelson H Kamoun S Kyung K Meijer H Minx P Morris P Nelson J Phuntumart V Qutob D Rehmany A Rougon-Cardoso A Ryden P Torto-Alalibo T Studholme D Wang Y Win J Wood J Clifton SW Rogers J Van den Ackerveken G Jones JD 《Science (New York, N.Y.)》2010,330(6010):1549-1551
Many oomycete and fungal plant pathogens are obligate biotrophs, which extract nutrients only from living plant tissue and cannot grow apart from their hosts. Although these pathogens cause substantial crop losses, little is known about the molecular basis or evolution of obligate biotrophy. Here, we report the genome sequence of the oomycete Hyaloperonospora arabidopsidis (Hpa), an obligate biotroph and natural pathogen of Arabidopsis thaliana. In comparison with genomes of related, hemibiotrophic Phytophthora species, the Hpa genome exhibits dramatic reductions in genes encoding (i) RXLR effectors and other secreted pathogenicity proteins, (ii) enzymes for assimilation of inorganic nitrogen and sulfur, and (iii) proteins associated with zoospore formation and motility. These attributes comprise a genomic signature of evolution toward obligate biotrophy. 相似文献
5.
Aissa I Bouaziz M Ghamgui H Kamoun A Miled N Sayadi S Gargouri Y 《Journal of agricultural and food chemistry》2007,55(25):10298-10305
The ability of a noncommercial immobilized lipase from Staphylococcus xylosus (SXLi) to catalyze the transesterification of tyrosol and ethyl acetate was investigated. Response surface methodology was used to evaluate the effects of the temperature (40-60 degrees C), the enzyme amount (50-500 UI), and the ethyl acetate/hexane volume ratio (0.2-1) on the tyrosol acetylation conversion yield. Two independent replicates were carried out under the optimal conditions predicted by the model (reaction temperature 54 degrees C, enzyme amount 500 UI, and volume ratio ethyl acetate/hexane 0.2). The maximum conversion yield reached 95.36 +/- 3.6%, which agreed with the expected value (96.8 +/- 3.7%). The ester obtained was characterized by spectroscopic methods. Chemical acetylation of tyrosol was performed, and the products were separated using HPLC. Among the eluted products from HPLC, mono- and diacetylated derivatives were identified by positive mass spectrometry. Tyrosol and its monoacetylated derivative exert similar antiradicalar activity on 2,2-diphenyl-1-picrylhydrazyle. 相似文献
6.
Sébastien?Saint-JeanEmail author Antonino?Testa Sophien?Kamoun Laurence.?V.?Madden 《European journal of plant pathology / European Foundation for Plant Pathology》2005,112(4):391-394
The purpose of this study was to develop a new technique to evaluate the number of spores incorporated in splash droplets by the use of an engineered fluorescent pathogen strain and image analysis hardware and software. The inoculum source consisted of a tomato leaflet infected with a Phytophthora infestans strain transformed with the gene encoding the green fluorescent protein (GFP). Splash droplets formed after impact of incident drops on sporulating lesions were collected on microscope slides located at different distances from the source. Each slide was examined using a fluorescent microscope to visualize the GFP expressing sporangia. Photographs were taken and assessed using image processing to count the sporangia incorporated in each droplet. Data analysis confirmed characteristics of splash dispersal shown using other methods. The use of fluorescent sporangia also facilitates the selective detection and counting of viable (living) sporangia, and is a tool that can be use in the study of splash dispersed diseases*Authors S. Saint-Jean and A. Testa contributed equally to this work and should both be considered first author. 相似文献
7.
Mahdhi A Esteban MÁ Hmila Z Bekir K Kamoun F Bakhrouf A Krifi B 《Research in veterinary science》2012,93(3):1151-1159
The probiotic properties of Bacillus strains isolated from Artemia culture and the effect of marine stress on viability and survival were investigated, as well as the changes occurring in their properties. Analyses showed that these bacteria corresponded to the genus Bacillus sp. Antagonism and adherence assays revealed that Bacillus strains have an inhibitory effect against tested pathogenic bacteria and are fairly adherent. Normal and starved cells showed different enzymatic profiles. Challenge tests performed with Artemia larvae provided evidence that the tested Bacillus strains were neither pathogenic nor toxic to the host and conferred protection for Artemia culture against pathogens. The tested strains maintained their viability and their probiotic properties during the period of study. The results suggest that the tested strains have suffered changes allowing them to survive in seawater in the absence of nutrients and outside their natural host, identifying them as potential probiotic candidates for Artemia culture. 相似文献
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9.
Loss of Production of the Elicitor Protein INF1 in the Clonal Lineage US-1 of Phytophthora infestans
Kamoun S van der Lee T van den Berg-Velthuis G de Groot KE Govers F 《Phytopathology》1998,88(12):1315-1323
ABSTRACT The extracellular protein INF1 of Phytophthora infestans is a member of the elicitin family of protein elicitors known to induce a hypersensitive response on some solanaceous and cruciferous plants. The presence of INF1 elicitin in culture filtrates of 102 P. infestans isolates from 15 countries was examined. All tested isolates produced INF1 except five isolates collected in 1976 and 1977 from infected potatoes in East Germany (the former German Democratic Republic). Based on hybridization to the multi-locus DNA fingerprint probe RG57, all the INF1-nonproducing isolates were shown to belong to the clonal lineage US-1 that dominated world populations until the 1980s. Phylogenetic analysis of a set of European US-1 isolates using amplified fragment length polymorphism fingerprint data indicated that loss of INF1 production evolved independently in separate lineages within US-1. DNA and RNA blot hybridizations showed that INF1-nonproducing isolates still retain a copy of the inf1 gene, whereas little inf1 mRNA could be detected. Hypothetical interpretations of the evolution in a restricted geographic area of P. infestans lineages deficient in the production of a specific elicitor protein are discussed. 相似文献
10.
Alfano G Ivey ML Cakir C Bos JI Miller SA Madden LV Kamoun S Hoitink HA 《Phytopathology》2007,97(4):429-437
ABSTRACT A light sphagnum peat mix inoculated with Trichoderma hamatum 382 consistently provided a significant (P = 0.05) degree of protection against bacterial spot of tomato and its pathogen Xanthomonas euvesicatoria 110c compared with the control peat mix, even though this biocontrol agent did not colonize aboveground plant parts. To gain insight into the mechanism by which T. hamatum 382 induced resistance in tomato, high-density oligonucleotide microarrays were used to determine its effect on the expression pattern of 15,925 genes in leaves just before they were inoculated with the pathogen. T. hamatum 382 consistently modulated the expression of genes in tomato leaves. We identified 45 genes to be differentially expressed across the replicated treatments, and 41 of these genes could be assigned to at least one of seven functional categories. T. hamatum 382-induced genes have functions associated with biotic or abiotic stress, as well as RNA, DNA, and protein metabolism. Four extensin and extensin-like proteins were induced. However, besides pathogenesis-related protein 5, the main markers of systemic acquired resistance were not significantly induced. This work showed that T. hamatum 382 actively induces systemic changes in plant physiology and disease resistance through systemic modulation of the expression of stress and metabolism genes. 相似文献