<Emphasis Type="Italic">Agrobacterium</Emphasis><Emphasis Type="Italic">tumefaciens</Emphasis>-mediated transformation of callus cells of <Emphasis Type="Italic">Crataegus</Emphasis><Emphasis Type="Italic">aronia</Emphasis>

A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l⁻¹ Indole-3-butyric acid (IBA) and 0.5 mg l⁻¹ 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l⁻¹ kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l⁻¹ hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.     

Identification of a novel <Emphasis Type="Italic">Plasmopara halstedii</Emphasis> elicitor protein combining <Emphasis Type="Italic">de novo</Emphasis> peptide sequencing algorithms and RACE-PCR

Background  

Often high-quality MS/MS spectra of tryptic peptides do not match to any database entry because of only partially sequenced genomes and therefore, protein identification requires de novo peptide sequencing. To achieve protein identification of the economically important but still unsequenced plant pathogenic oomycete Plasmopara halstedii, we first evaluated the performance of three different de novo peptide sequencing algorithms applied to a protein digests of standard proteins using a quadrupole TOF (QStar Pulsar i).     

Common genomic features of <Emphasis Type="Italic">Campylobacter jejuni</Emphasis> subsp. <Emphasis Type="Italic">doylei</Emphasis> strains distinguish them from <Emphasis Type="Italic">C. jejuni</Emphasis> subsp. <Emphasis Type="Italic">jejuni</Emphasis>

Background  

Campylobacter jejuni has been divided into two subspecies: C. jejuni subsp. jejuni (Cjj) and C. jejuni subsp. doylei (Cjd). Nearly all of the C. jejuni strains isolated are Cjj; nevertheless, although Cjd strains are isolated infrequently, they differ from Cjj in two key aspects: they are obtained primarily from human clinical samples and are associated often with bacteremia, in addition to gastroenteritis. In this study, we utilized multilocus sequence typing (MLST) and a DNA microarray-based comparative genomic indexing (CGI) approach to examine the genomic diversity and gene content of Cjd strains.     

Attenuation of fibrosis <Emphasis Type="Italic">in vitro</Emphasis> and <Emphasis Type="Italic">in vivo</Emphasis> with <Emphasis Type="Italic">SPARC</Emphasis> siRNA

Introduction  

SPARC is a matricellular protein, which, along with other extracellular matrix components including collagens, is commonly over-expressed in fibrotic diseases. The purpose of this study was to examine whether inhibition of SPARC can regulate collagen expression in vitro and in vivo, and subsequently attenuate fibrotic stimulation by bleomycin in mouse skin and lungs.     

Molecular analysis of type 3 fimbrial genes from <Emphasis Type="Italic">Escherichia coli</Emphasis>, <Emphasis Type="Italic">Klebsiella</Emphasis> and <Emphasis Type="Italic">Citrobacter</Emphasis> species

Background  

Catheter-associated urinary tract infection (CAUTI) is the most common nosocomial infection in the United States and is caused by a range of uropathogens. Biofilm formation by uropathogens that cause CAUTI is often mediated by cell surface structures such as fimbriae. In this study, we characterised the genes encoding type 3 fimbriae from CAUTI strains of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter koseri and Citrobacter freundii.     

<Emphasis Type="Italic">Erwinia carotovora</Emphasis> elicitors and <Emphasis Type="Italic">Botrytis cinerea</Emphasis> activate defense responses in <Emphasis Type="Italic">Physcomitrella patens</Emphasis>

Background  

Vascular plants respond to pathogens by activating a diverse array of defense mechanisms. Studies with these plants have provided a wealth of information on pathogen recognition, signal transduction and the activation of defense responses. However, very little is known about the infection and defense responses of the bryophyte, Physcomitrella patens, to well-studied phytopathogens. The purpose of this study was to determine: i) whether two representative broad host range pathogens, Erwinia carotovora ssp. carotovora (E.c. carotovora) and Botrytis cinerea (B. cinerea), could infect Physcomitrella, and ii) whether B. cinerea, elicitors of a harpin (HrpN) producing E.c. carotovora strain (SCC1) or a HrpN-negative strain (SCC3193), could cause disease symptoms and induce defense responses in Physcomitrella.     

Demonstration of IS<Emphasis Type="Italic">711</Emphasis> transposition in <Emphasis Type="Italic">Brucella ovis</Emphasis> and <Emphasis Type="Italic">Brucella pinnipedialis</Emphasis>

Background  

The Brucella genome contains an insertion sequence (IS) element called IS711 or IS6501, which is specific to the genus. The copy number of IS711 varies in the genome of the different Brucella species, ranging from 7 in B. abortus, B. melitensis and B. suis to more than 30 in B. ovis and in Brucella strains isolated from marine mammals. At present, there is no experimental evidence of transposition of IS711, but the occurrence of this element with a high copy number in some species, and the isolation of Brucella strains with "ectopic" copies of IS711 suggested that this IS could still transpose.     

Evolution of <Emphasis Type="Italic">mal</Emphasis> ABC transporter operons in the <Emphasis Type="Italic">Thermococcales</Emphasis> and <Emphasis Type="Italic">Thermotogales</Emphasis>

Background  

The mal genes that encode maltose transporters have undergone extensive lateral transfer among ancestors of the archaea Thermococcus litoralis and Pyrococcus furiosus. Bacterial hyperthermophiles of the order Thermotogales live among these archaea and so may have shared in these transfers. The genome sequence of Thermotoga maritima bears evidence of extensive acquisition of archaeal genes, so its ancestors clearly had the capacity to do so. We examined deep phylogenetic relationships among the mal genes of these hyperthermophiles and their close relatives to look for evidence of shared ancestry.     

Possible use of <Emphasis Type="Italic">ail</Emphasis> and <Emphasis Type="Italic">foxA</Emphasis> polymorphisms for detecting pathogenic <Emphasis Type="Italic">Yersinia enterocolitica</Emphasis>

Background  

Yersinia enterocolitica is an enteric pathogen that invades the intestinal mucosa and proliferates within the lymphoid follicles (Peyer's patches). The attachment invasion locus (ail) mediates invasion by Y. enterocolitica and confers an invasive phenotype upon non-invasive E. coli; ail is the primary virulence factor of Y. enterocolitica. The ferrioxamine receptor (foxA) located on the Y. enterocolitica chromosome, together with its transport protein, transports a siderophore specific for ferric ion. Currently, ail is the primary target gene for nucleic acid detection of pathogenic Y. enterocolitica.     

<Emphasis Type="Italic">In planta</Emphasis> gene expression analysis of <Emphasis Type="Italic">Xanthomonas oryzae</Emphasis> pathovar <Emphasis Type="Italic">oryzae</Emphasis>, African strain MAI1

Background  

Bacterial leaf blight causes significant yield losses in rice crops throughout Asia and Africa. Although both the Asian and African strains of the pathogen, Xanthomonas oryzae pv. oryzae (Xoo), induce similar symptoms, they are nevertheless genetically different, with the African strains being more closely related to the Asian X. oryzae pv. oryzicola (Xoc).     

Thidiazuron Promotes <Emphasis Type="Italic">In Vitro</Emphasis> Plant Regeneration of <Emphasis Type="Italic">Arachis correntina</Emphasis> (<Emphasis Type="Italic">Leguminosae</Emphasis>) via Organogenesis

Arachis correntina (Burkart) Krapov. & W.C. Gregory is a herbaceous perennial leguminous plant growing in the Northeast of the Province Corrientes, Argentina. It is important as forage. The development of new A. correntina cultivars with improved traits could be facilitated through the application of biotechnological strategies. The purpose of this study was to investigate the plant regeneration potential of mature leaves of A. correntina in tissue culture. Buds were induced from both petiole and laminae on 0.7% agar-solidified medium containing 3% sucrose, salts and vitamins from Murashige and Skoog (MS) supplemented with 0.5–25 M thidiazuron (TDZ). Shoot induction was achieved by transference of calli with buds to MS supplemented with 5 M TDZ. Fifty-four percent of the regenerated shoot rooted on MS + 5 M naphthaleneacetic acid. Histological studies revealed that shoots regenerated via organogenesis.     

Establishment of Asian citrus psyllid (<Emphasis Type="Italic">Diaphorina citri</Emphasis>) primary cultures

The Asian citrus psyllid (AsCP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a highly competent vector of the phloem-inhabiting bacterium Candidatus Liberibacter asiaticus associated with the citrus disease huanglongbing (HLB). Commonly referred to as citrus greening disease in the USA, HLB causes reduced fruit yields, quality, and ultimately tree death and is considered the most serious citrus disease. HLB has become a major limiting factor to the production of citrus worldwide. Studies of HLB have been impeded by the fact that C. Liberibacter has not yet been cultured on artificial nutrient media. After being acquired by a psyllid, C. Liberibacter asiaticus is reported to replicate within the psyllid and is retained by the psyllid throughout its life span. We therefore hypothesized that C. Liberibacter asiaticus could be cultured in vitro using psyllid cell cultures as the medium and investigated the establishment of a pure culture for AsCP cells. Several commercially available insect cell culture media along with some media we developed were screened for viability to culture cells from AsCP embryos. Cells from psyllid tissues adhered to the plate and migration was observed within 24 h. Cells were maintained at 20°C. We successfully established primary psyllid cell cultures, referred to as DcHH-1, for D. citri Hert-Hunter-1, with a new media, Hert-Hunter-70.     

Proteomic analysis of the fish pathogen <Emphasis Type="Italic">Flavobacterium columnare</Emphasis>

Background  

Flavobacterium columnare causes columnaris disease in cultured and wild fish populations worldwide. Columnaris is the second most prevalent bacterial disease of commercial channel catfish industry in the United States. Despite its economic importance, little is known about the expressed proteins and virulence mechanisms of F. columnare. Here, we report the first high throughput proteomic analysis of F. columnare using 2-D LC ESI MS/MS and 2-DE MALDI TOF/TOF MS.     

Remobilization of <Emphasis Type="Italic">Tol2</Emphasis> transposons in <Emphasis Type="Italic">Xenopus tropicalis</Emphasis>

Background  

The Class II DNA transposons are mobile genetic elements that move DNA sequence from one position in the genome to another. We have previously demonstrated that the naturally occurring Tol2 element from Oryzias latipes efficiently integrates its corresponding non-autonomous transposable element into the genome of the diploid frog, Xenopus tropicalis. Tol2 transposons are stable in the frog genome and are transmitted to the offspring at the expected Mendelian frequency.     

Viable nonsense mutants for the essential gene <Emphasis Type="Italic">SUP45</Emphasis> of <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis>

Background  

Termination of protein synthesis in eukaryotes involves at least two polypeptide release factors (eRFs) – eRF1 and eRF3. The highly conserved translation termination factor eRF1 in Saccharomyces cerevisiae is encoded by the essential gene SUP45.     

The iron-sulfur cluster assembly genes <Emphasis Type="Italic">iscS</Emphasis> and <Emphasis Type="Italic">iscU</Emphasis> of <Emphasis Type="Italic">Entamoeba histolytica</Emphasis> were acquired by horizontal gene transfer

Background  

Iron-sulfur (FeS) proteins are present in all living organisms and play important roles in electron transport and metalloenzyme catalysis. The maturation of FeS proteins in eukaryotes is an essential function of mitochondria, but little is known about this process in amitochondriate eukaryotes. Here we report on the identification and analysis of two genes encoding critical FeS cluster (Isc) biosynthetic proteins from the amitochondriate human pathogen Entamoeba histolytica.