Characterization of the antigenic determinant on Fusarium oxysporum recognized by a genus-specific monoclonal antibody

The antigenic determinant of a monoclonal antibody (MAb) (API9-2) having specific reactivity with the fungi grouped into the genus Fusarium was analyzed. The culture supernatant of the fungi showed antigenicity against MAb API9-2, proving that the antigen exists as an exoantigen. The heat-resistant, proteinase K-resistant and periodate oxidation-labile features of the antigenic determinant indicated its carbohydrate nature. Also, lectin affinity tests and thin-layer chromatography analysis suggested that the monosaccharide making up the antigenic determinant was mainly mannose. Considering previous reports that the antigen exists on the surface of mycelia (by immunofluorescence assay) and is a - 55 kDa molecule (by Western blotting analysis), it was concluded that the antigenic determinant of MAb API9-2 on F. oxysporum is a mannan component existing on the surface of mycelia.     

Enhanced UV-B radiation has little effect on growth, δ13C values and pigments of pot-grown rice (Oryza sativa) in the field

Predicted increase in ultraviolet-B (UV-B: 280–320 mn) radiation may have adverse impacts on growth and yield of rice ( Oryza sativa L.), as has been found in studies hitherto. However, most of the studies were conducted in growth chambers or greenhouses where the plants are generally more sensitive to UV-B than in the field, presumably because of the distorted balance between UV-B and ultraviolet-A as well as PAR. This study was conducted to address the effects of enhanced UV-B on growth and yield of rice under a realistic spectral balance in the field. Three cultivars, "Koshihikari",'IR 45'and'IR 74'were pot-grown and irradiated with enhanced UV-B for most of the growing season in the field at Tsukuba, Japan (36°01'N, 140°07'E). The UV-B enhancement simulated ca 38% depletion of stratospheric ozone at Tsukuba. The results showed no UV-B effects on plant height, numbers of tillers and panicles, dry weight of the plant parts or the grain yield for any of the 3 cultivars. Natural abundance of ¹³C in the flag leaves was not altered by the UV-B enhancement either. While UV-absorbing compounds showed no response to the UV-B enhancement, chlorophyll contents decreased with enhanced UV-B. However, the decrease of chlorophyll was limited to an early growth stage with no effect later. We thus found no extraordinary impact of the nearly doubled UV-B radiation on rice in the field, and it would appear that a reliable prediction of the effects of UV-B will require experiments carried out over a number of years under various climatic and solar UV-B regimes.     

Purification of the Cytosolic CuZn-Superoxide Dismutase (CuZn-SOD) of Marachantia paleacea var. diptera and its Resemblance to CuZn-SOD from Chloroplasts

Suspension-cultured cells of Marchantia paleacea var. dipteracontain a single form of CuZn-superoxide dismutase (SOD; EC1.15.1.1 [EC] ) which is localized in the cytosol. SOD activity wasfound in cells cultured under heterotrophic, photoheterotrophicand photoautotrophic conditions. The CuZn-SOD was purified tohomogeneity from liverwort cells that had been cultued hetertrophically.Its molecular mass was 32.6 kDa, and it contained 17.5 kDa subunits,an indication that the enzyme is a homodimer. The enzyme hadpeaks of absorption at 252, 258 and 264 nm in the ultravioledregion, due to the presence of phenylalanine, and a peak at680 nm in the visible region, which is characteristic of CuZn-SODsfrom cholorplasts. The amino acid sequence of the amino-terminalregion of the enzyme exhibited a very high degree of homologyto those of cholorplast CuZn-SODs. An antiserum raised againstthe CuZn-SOD from liverwort cross-reacted more strongly withthe enzyme from spinach chloroplasts, than with the enzyme fromspinach cytosol. These results indicate that the CuZn-SOD ofliverwort resembles CuZn-SOD in chloroplasts even though theformer is located in the cytosol. (Received November 27, 1995; Accepted April 5, 1996)     

Transgenic fertile Scoparia dulcis L., a folk medicinal plant, conferred with a herbicide-resistant trait using an Ri binary vector

Summary Transgenic herbicide-resistant Scoparia dulcis plants were obtained by using an Ri binary vector system. The chimeric bar gene encoding phosphinothricin acetyltransferase flanked by the promoter for cauliflower mosaic virus 35S RNA and the terminal sequence for nopaline synthase was introduced in the plant genome by Agrobacterium-mediated transformation by means of scratching young plants. Hairy roots resistant to bialaphos were selected and plantlets (R0) were regenerated. Progenies (S1) were obtained by self-fertilization. The transgenic state was confirmed by DNA-blot hybridization and assaying of neomycin phosphotransferase II. Expression of the bar gene in the transgenic R0 and S1 progenies was indicated by the activity of phosphinothricin acetyltransferase. Transgenic plants accumulated scopadulcic acid B, a specific secondary metabolite of S. dulcis, in amounts of 15–60% compared with that in normal plants. The transgenic plants and progenies showed resistant trait towards bialaphos and phosphinothricin. These results suggest that an Ri binary system is one of the useful tools for the transformation of medicinal plants for which a regeneration protocol has not been established.Abbreviations CaMV cauliflower mosaic virus - NPT-II neomycin phosphotransferase - PAT phosphinothricin acetyltransferase - PPT phosphinothricin     

The cloning of size-heterogeneous,Y-specific repetitive DNAs and their clinical application

Four Y-specific DNAs of different sizes were isolated by screening a human Y-chromosome gene-library. After determining their structural characteristics, the possibility for their clinical application was examined. The results are as follows: 1. The 4 cloned DNAs had inserts of 3.3, 2.0, 1.9 and 1.4 kb; they were subcloned into plasmid pUC19, and designated pKY-2, pKY-3, pKY-4 and pKY-5, respectively. 2. All four clones hybridized specifically with the Y-specific 3.5 kb DNA but not with female DNA. However, they did not cross-hybridize with the 2.1 kb fragment known to be another Y-specific repetitive DNA of human genomes. 3. The newly cloned probes were applied to the detection of Y-specific DNA in abnormal Y-chromosomes [Turner Syndrome (45, X/46, X, -X, + marker), 46, XY-female, mosaicism (46, XY/47, XYY), 46, XX-male and super male (47, XYY)]. 4. Since the newly cloned DNAs did not hybridize with other eukaryotic genome DNAs such as monkey, rat, mouse, chicken, frog, or fish, their human gene specificities were confirmed.     

Oxidation of Elemental Sulfur to Sulfite by Thiobacillus thiooxidans Cells

Thiobacillus thiooxidans cells oxidized elemental sulfur to sulfite, with 1 mol of O₂ consumption per mol of sulfur oxidized to sulfite, when the oxidation of sulfite was inhibited with 2-n-heptyl-4-hydroxyquinoline N-oxide.     

Antenatal betamethasone dose effects in preterm rabbits studied at 27 days gestation

Pregnant rabbits received bethamethasone (0.05, 0.2, 0.4, or 0.5 mg.kg-1.day-1) or vehicle control for 2 days before delivery of fetuses at 27 days gestation to evaluate dose-related effects on surfactant pool sizes with and without ventilation, pressure-volume measurements, lung protein leaks, and precursor incorporation into lung saturated phosphatidylcholine (PC). Alveolar wash-saturated PC pool sizes in betamethasone-exposed fetuses were less than in controls (P less than 0.01). At higher doses, total lung saturated PC also decreased (P less than 0.01). Maximal lung volumes on pressure-volume loops were larger than controls only at the 0.4 mg.kg-1.day-1 dose (P less than 0.05). The larger maximal volumes, despite decreased saturated PC pools, indicated increased responsiveness of the steroid-treated lungs to the smaller saturated PC pool sizes. Vascular-to-alveolar iodinated albumin leak decreased with steroid treatment independently of dose (P less than 0.01). No consistent pattern of increased precursor incorporation into saturated PC by lung slices was seen. Our results indicate that, in preterm rabbits exposed to a range of maternal corticosteroid doses, the beneficial lung maturational effect of structural alterations with increased responses to endogenous saturated PC pools was maximal even at the lowest dose.     

Genetic transformation of foxglove (Digitalis purpurea) by chimeric foreign genes and production of cardioactive glycosides

The chimeric neo and gus genes on a mini Ti vector are efficiently transferred into the genome of fox glove (Digitalis purpurea L.) using a binary vector system based on a rootinducing Ri plasmid, pRi15834. The transgenic state of established transformed roots was confirmed by Southern blot analysis and by detection of agropine and mannopine. The expression of the chimeric genes controlled by the promoters from TR 1–2 genes, nos gene and cauliflower mosaic virus 35S RNA was demonstrated by enzymatic and histochemical assays of neomycin phosphotransferase II and ß-glucuronidase. Enzyme-linked immunosorbent assay (ELISA) was carried out using polyclonal antibody reactable against digitoxin to investigate the production of cardenolides. The results of ELISA indicated that the cardioactive glycosides were highly produced in the green transformed hairy roots.Abbreviations CaMV cauliflower mosaic virus - ELISA enzyme-linked immunosorbent assay - NPT-II neomycin phosphotransferase II - neo gene encoding NPT-II from Tn5 - GUS ß-glucuronidase - gus gene encoding GUS from Escherichia coli - Km kanamycin - nos gene encoding nopaline synthase - TR1–2 genes 1 and 2 of TR-DNA of pTiAch5 - Rif rifampicin - X-gluc 5-bromo-4-chloro-3-indolyl-ß-d-glucuronide     

Stable transfer and expression of chimeric genes in licorice (Glycyrrhiza uralensis) using an Ri plasmid binary vector

The pharmaceutically important plant, licorice (Glycyrrhiza uralenesis Fisher), was transformed with a binary vector system of an Ri plasmid, pRi15834, and a mini Ti vector, pGSGluc1, containing chimeric neo and gus genes. The transgenic state of transformed roots was confirmed by detection of agropine and mannopine and by Southern blot hybridization with T-DNA of pGSGluc1. One to three copies of T-DNA of pGSGluc1 was integrated into the genomic DNA of G. uralensis. The expression of chimeric neo and gus genes driven by TR 1 and 2 promoters, respectively, was demonstrated by enzymatic assays. Histochemical analysis showed that the chimeric TR2-gus gene was expressed specifically in phloem and pericycle tissues of the transformed licorice roots.Abbreviations NPT-II neomycin phosphotransferase II - neo NPT-II gene from Tn5 - GUS ß-glucuronidase - gus GUS gene from Escherichia coli - TR 1–2 genes 1 and 2 of TR-DNA of pTiAch5 - Rif rifampicin     

A miniature Clark-type oxygen electrode using a polyelectrolyte and its application as a glucose sensor

A miniature Clark-type oxygen electrode was fabricated by anisotropically etching silicon. A two-gold-electrode configuration was used and a double-layered gas-permeable membrane was formed directly on the electrolyte, poly(vinyl-4-ethylpyridinium bromide) in the sensitive area. These materials improved the electrode's stability in long-term storage and sterilization tolerance to a practical level. The 90% response time averaged 80 s and residual current 10%, with a good linear calibration curve. The oxygen electrode was also used to make an integrated sensor for the simultaneous determination of glucose and oxygen. The glucose sensor's response time was 50-110 s, with good linearity in glucose concentrations between 56 microM and 1.1 mM at 37 degrees C, pH 7.0.