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1.
A -amylase (EC 3.2.1.2) was identified in the outer pericarp (P) of developing seeds of wheat (Triticum aestivum L.) and compared with the well known -amylase which is synthesized during seed development in the starchy endosperm (E). The enzyme P already exists in the tissues before anthesis and vanishes at the time when E starts to accumulate. The isoelectric-focusing patterns of P and E are very similar. The relative molecular weight (Mr) of P is slightly higher than that of E (66 and 64.5 kDa, respectively). Both P and E exhibit common epitopes in addition to epitopes specific for each of them. The two enzymes were identified in small amounts in the green tissues of the developing seeds (inner pericarp and testa). No antigenic difference was detected between P and the -amylases of roots and leaves.Abbreviations P pericarp -amylase - E endosperm -amylase - IS1 anti--amylase immune serum - IS2 anti- and anti- amylase immune serum - IS3 anti- amylase immune serum - IEF isoelectric focusing - IgG immunoglobulin G The authors thank Dr. P. Ziegler (Universität Bayreuth, FRG) for stimulating discussion and for useful suggestions during the writing of the text. The authors thank Miss C. Mayer for her skillful technical assistance.  相似文献   

2.
Hybridizations ofElymus nutans andE. jacquemontii were carried out with one species ofPseudoroegneria (S genome), and 20Elymus species, each containing either of the SH, SY, SYH, or SYW genomes. Chromosome configurations were analysed at metaphase I of the two target taxa and their interspecific hybrids. It is concluded that (i)E. nutans is an allohexaploid containing the SYH genomes, andE. jacquemontii is an allotetraploid having the SY genomes; (ii) the genomic affinity is associated with the geographic distance between the species studied; (iii) minor genomic structural rearrangements have occurred within the hexaploid taxon ofE. nutans.  相似文献   

3.
TheN-linked carbohydrate chains of the-subunit of highly purified urinary human chorionic gonadotropin have been re-investigated. The oligosaccharides were released enzymatically by peptide-N 4-(N-acetyl--glucosaminyl)asparagine amidase-F, and fractionated by a combination of FPLC and HPLC. As a result of the application of improved fractionation methods, apart from the earlier reported carbohydrate chains, also small amounts of trisialo tri- and tri-antennary oligosaccharides were found. The primary structures of the latter carbohydrate chains have been determined by 500-MHz1H-NMR spectroscopy to beAbbreviations hCG human chorionic gonadotropin - hCG- -subunit - hCG- -subunit - PNGase-F peptide-N 4-(N-acetyl--glucosaminyl)asparagine amidase-F (E.C. 3.5.1.52) - endo-F endo--N-acetylglucosaminidase-F (E.C. 3.2.1.96) - SDS sodium dodecyl sulphate - PAGE polyacrylamide gel electrophoresis - CBB coomassie brilliant blue R 250 - GlcNAc N-acetylglucosamine - NeuAc N-acetylneuraminic acid - Man mannose - Gal galactose - Fuc fucose  相似文献   

4.
In vitro plant regeneration was achieved inCapsicum praetermissum, C. baccatum andC. annuum cvs. G4, Bhiwapuri Sweet pepper, Cayenne pepper and Hybrid pepper. Shoots were induced from hypocotyl, cotyledon and leaf explants on Murashige and Skoog medium supplemented with 5.7 M indoleacetic acid (IAA)+13.3 M benzyladenine (BA); 22 M BA; and 44 M BA. Analysis of variance revealed that the most significant effect on shoot regeneration was due to the explant and it accounted for 56.3% of total variation observed. The genotype x explant effect on regeneration was minor relative to all other 2- and 3-way interactions because leaf explants consistently regenerated more shoots than hypocotyls or cotyledons in all the genotypes and thereby reduced the variation among the genotypes. Explant x medium interaction revealed that 22 M BA was the best growth regulator supplement in regeneration medium for optimal shoot regeneration from leaf explants. Rooting of regenerated shoots was achieved on 5.7 M IAA-containing medium, and the rooting response was better from shoots induced on medium fortified with 5.7 M IAA plus 13.3 M BA. Complete plantlets with diploid chromosome number (2n=2x=24) were transferred to soil and 60–70% of these plantlets survived and grew well.  相似文献   

5.
T. M. Butt  A. Beckett 《Protoplasma》1984,120(1-2):61-71
Summary A detailed account of the ultrastructure and behaviour of the spindle pole body (SPB) of the entomophthoraceous fungusErynia neoaphidis is presented for the first time.The SPB consists of extranuclear (ENC) and intranuclear (INC) components. The ENC is a saucepan-shaped structure which lies in a pocket of the nuclear envelope. It is composed of a forked, fibrillar handle and a shallow, cylindrical pan. The pan has a wall of two layers, both of which are thickened with a regular periodicity so that they appear to be beaded. It is postulated that the pan is formed from rough endoplasmic reticulum and that it synthesizes the amorphous, electron-dense material coating the ENC.The INC is a saucer-shaped, electron-dense plaque in which the ends of the spindle microtubules terminate. During metaphase, a clear zone separates the INC from the nuclear envelope and persists until telophase. The roles of the amorphous, electron-dense material and the clear zone as well as the method of SPB replication are discussed.  相似文献   

6.
Four glycosidases were analyzed in 10 mm apical segments prepared from growing roots (15 mm) of Zea mays L. The pH optima were found to be 5.8 for -glucosidase, 4.4 for -galactosidase, 6.4 for -glucosidase and 6.0 for -galactosidase. The -glucosidase showed 4-fold higher activity than the -galactosidase. The distribution of the -glucosidase activity was signifcantly different from that of the -galactosidase, -glucosidase and -galactosidase.Abbreviations -Glu -glucosidase - -Gal -galactosidase - -Glu -glucosidase - -Gal -galactosidase  相似文献   

7.
The seed storage globulins from sixHelianthus and four hybrids were studied using mono and bidimensional gel SDS electrophoresis (+ 2 mercaptoethanol). The polypeptide composition of each subunit was determined. Different pairs are specifically expressed according to the species studied. Three typical patterns were discriminated. All the studied species exhibit five subunits: two of them are expressed in all the species (11 and 22). The subunit corresponding to the 11 pair is present inH. petiolaris and in the three populations ofH. annuus studied. The 2b2 pair is common toH. annuus andH. argophyllus. H. petiolaris presents two specific 2a2 and 44 pairs andH. annuus a specific 33 pair. InH. argophyllus 11 33 or 44 are never observed but are replaced by 13 and 31 pairs. Some globulins, poorly represented, are of forms but present chains of higher molecular weights (in the range 54–56 kDa). Expressing variations in the banding patterns between these species by the use of a similarity index reveals complete identity between the three populations ofH. annuus. Identity between the twoH. petiolaris studied is also observed.H. annuus andH. argophyllus appear to be closer to each other thanH. petiolaris concerning the seed storage globulins.  相似文献   

8.
Summary The seven possible primary trisomics of Petunia (2 n= 14) located in the progenies of triploid, hypertriploid and hypotriploid plants were distinguished from one another and from diploid on the basis of cytological and morphological criteria. They were provisionally named as Oval, Semi, Slender, Pseudonormal, Arrow, Narrow and Giant. In three of the trisomics, the extra chromosome was identified for the first time at pachytene stage. Postpachytene studies revealed no precise relationship between the length of extra chromosome and the frequency of multiple association.  相似文献   

9.
Tissue-cultured plantlets of three sugarcane (Saccharum spp.) cultivars having a known field smut reaction were screened for susceptibility to Ustilago scitaminea H&P Sydow. Plantlets were inoculated with 0.5 l of a suspension of equally mixed quantities of plus and minus mating type sporidia of U. scitaminea at concentrations ranging from 1×101 to 1×106 cells. Fungal sori (whips) were produced in cultivar N12 (intermediate) 6weeks following inoculation with 1×105 mixed sporidia and thereafter in cultivar NCo310 (susceptible) but not in cultivar N19 (resistant). Sori bearing teliospores were produced up to 3months following inoculation and incubation at 26°C. No sori were produced at mixed sporidial concentrations lower than 1×105cells. The in vitro soral production in cultivars N19, N12 and NCo310 was 0, 27.5 and 47.5% respectively. Plantlets inoculated with 1×105sporidia of only one mating-type did not produce sori in any of the three cultivars tested. Blind scoring of an unknown sugarcane cultivar by this method corresponded exactly with its field smut rating.  相似文献   

10.
The present study demonstrates a procedure for the rapid development of a high number of somatic embryos from embryogenic suspension culture. This method might be efficient for mass propagation of Phnix dactylifera L. Embryogenic callus placed in liquid medium with 10–5M ABA yielded an average 72 embryos per 100ml of culture medium within 2months, while those placed on solid medium yielded an average of 33, 20 and 16 embryos per 100ml of culture medium respectively for 10–7, 10–6 and 10–5 M ABA after 4months. The combination of 2,4-DIchlorophenoxyacetic acid (2,4-D) (4.5×10–7M), glutamine (6.7×10–4M), and ABA (10–5M) (L8 liquid medium) showed a beneficial effect on somatic embryos production compared to 2,4-D and glutamine alone, while this combination significantly (p<0.05) increased the accumulation of storage proteins (144 and 138mgg–1 DW respectively for Jihel and Bousthami noir cultivars) in somatic embryos. The somatic embryos which underwent maturation on medium containing only 4.5×10–7M 2,4-D and 10–5M ABA (L6 liquid medium) accumulated more sugars (292 and 265mgg–1 DW respectively for Jihel and Bousthami noir) than those matured on any other liquid medium. Histological studies revealed that somatic embryos (developed in L6 and L8 liquid media) accumulated less reserve compounds (proteins and sugars) than zygotic embryos. The addition of activated charcoal (0.25 and 0.5gl–1) and phytagel® (2.5gl–1) to the germination medium may be useful for enhancing the germination of Phnix dactyliferasomatic embryos.  相似文献   

11.
Forty-three strains ofFusarium moniliforme isolated from infected maize and sorghum plants in Italy were assayed for their ability to produce fertile crosses with A and F mating population tester strains, in relation to their ability to produce fumonisins on maize substrate. Most of the strains isolated from maize (ear and stalk rot and maize-based feed), producing fumonisin B1 (FB1) and B2 (FB2) (up to 4,100 and 855 mg/kg, respectively), belonged to the A mating population. All of the strains isolated from sorghum belonged to the F mating population and produced little or no FB1 and FB2. This is the first report of the occurrence of mating population F in Europe. Our data on strains from Italy are consistent with previous studies from the United States that found significant differences in sexual fertility and fumonisin production between strains from maize and sorghum.  相似文献   

12.
Cellulose acetate electrophoresis of mouse hemoglobins modified with the disulfide reagent cystamine permits rapid, unequivocal discrimination of all combinations of the codominant mouse hemoglobin single (Hbb s ) and diffuse (Hbb d and Hbb p ) alleles. The single, diffuse major, diffuse d-minor, and diffuse p-minor adult hemoglobins are all resolved by this method, which depends on the presence of a cysteine in the chains of diffuse mice which is not found in the chain of single mice.This work was supported by research grants ACS-VC58 and NIH CA-01074. The Jackson Laboratory is fully accredited by the American Association for Accreditation of Laboratory Animal Care.  相似文献   

13.
Summary In merodiploid cells containing a double dose of structural genes of RNA polymerase subunits-rpoBand rpoC-the rate of and subunits synthesis is 2 times higher than in haploidcells. Missence mutation rpoC1 (tsX) alters polypeptide and inducesthe and subunits synthesis at increased rate, particularly at a nonpermissive temperature. When rpoBCoperon carrying mutation rpoC1 is duplicated no dosage effect is observed. In the rpoC +/rpoC1 heterodiploid the rpoC1 mutation does not significantly accelerate RNA polymerase subunits synthesis i.e. is recessive with respect to rpoC + Rifampicin causes 6-fold stimulation of RNA polymerase subunits synthesis in a sensitive wild-type strain. The rpoC1 mutation itself accelerates the synthesis of these subunits 3-fold. In the presence of rifampicin the mutant strain produces 13–22-fold faster as compared to wild-type strain without the drug. Thus, the effects of rifampicin and the mutation are multiplied suggesting that these factors act independently. Similar data have also been obtained with rifampicin-treated cells of rpoB22 (ts22) amber-mutant.After UV-irradiation of cells and synthesis is depressed much stronger than the total protein synthesis. Infection with a transducing phage rif d-47 which carries rpoB gene provokes a higher rate of synthesis. When pre-irradiated cells (500 erg/mm2) are infected with this phage, the rate of synthesis grows 20-fold compared to irradiated, non-infected cells and 6.5-fold compared to intact cells.The data are discussed in terms of the possible regulatory mechanisms of RNA polymerase subunit synthesis.  相似文献   

14.
Uptake kinetics of nitrogen derived from sewage–seawater mixtures (2.5–20% v/v effluent) were determined in the laboratory for Ulva rigida (Chlorophyceae) native from Bahía Nueva (Golfo Nuevo, Patagonia, Argentine). In terms of nitrogen concentration, experimental enrichment levels varied between 53.7 and 362.3M of ammonium and between 0.77 and 6.21M of nitrate+nitrite. Uptake rates were fitted to the Michaelis–Menten equation, with the following kinetic parameters: ammonium: Vmax = 591.2molg–1h–1, K s=262.3M, nitrate+nitrite: V max=12.9molg–1h–1, K s=3.5M). Both nutrients were taken up simultaneously, but ammonium incorporation was faster in all cases. The results show a high capability of Ulva rigida to remove sewage-derived nitrogen from culture media. In the field, most of the nitrogen provided by the effluent would be tied up in algal biomass, supporting low nitrogen levels found at a short distance away from the source.  相似文献   

15.
Urease from Staphylococcus saprophyticus was purified more than 800-fold by liquid chromatography reaching homogeneity, as shown by isoelectric focussing, at a maximum specific activity of 1979 U/mg. The molecular weight of the native enzyme was 420000; it consisted of subunits with molecular weights of 72400 (), 20400 (), and 13900 () in an estimated ()4 stoichiometry. In native gradient polyacrylamide gel electrophoresis urease exhibited a multiple activity band pattern with molecular weights ranging from 420000 to 100000. In the native enzyme, 4.09 (±0.25) atoms of nickel per molecule were detected. The N-terminal amino acids of the urease subunits were identical to those from Staphylococcus xylosus, and amino acid analysis revealed high similarities in both enzymes; no cysteine was detected after acid hydrolysis of vinylpyridinylated urease. Electron micrographs of negatively stained urease specimens from both staphylococci showed identical size and structure.Abbreviation PAGE polyacrylamide gel electrophoresis  相似文献   

16.
In the legume Phaseolus vulgaris L., glutamine synthetase (GS) (EC.6.3.1.2.) occurs as three cytosolic polypeptides, , and , and a plastidic polypeptide, . This paper describes the subunit composition of active octameric GS isoenzymes from root nodules and plumules using ionexchange high-performance liquid chromatography followed by two-dimensional denaturing gel electrophoresis and Western immunodetection. Root nodules contained four separable GS activities, three of which were composed mainly of cytosolic , / and GS polypeptides, whereas the fourth activity, consisted of plastidic GS polypeptides. The increase in GS activity during nodulation was due largely to the appearance of -containing isoenzymes, and to a lesser extent on the isoenzyme, whereas the -isoenzyme activity remained approximately constant throughout. Plumule GS from imbibed seeds was found to be composed of separate and isoenzymes, but 2 d after germination, plumule GS consisted of a mixture of , / and isoenzymes. The results from both nodules and plumules indicate that different cytosolic GS polypeptides in P. vulgaris are able to assemble into both homo-octameric and heterooctameric isoenzymes. Moreover, the changes in the patterns of isoenzymes observed during nodule development and plumule growth are interpreted to be caused both by temporal changes in the denovo synthesis of the polypeptides and also by their spatial separation in different cell types.Abbreviations 1D, 2D one-, two-dimensional - GS glutamine synthetase - GSs GS semibiosynthetic activity - GSt GS transferase activity - IEX-HPLC ion-exchange high-performance liquid chromatography - kDa kilodaltons - SDS-PAGE sodium dodecyl sulphate-polyacrylamide gel electrophoresis  相似文献   

17.
Zusammenfassung An Hand von 229 Brutbeginn-Daten von freilebenden Gänsen, die während der Jahre 1956–1966 in Seewiesen (Obb.) (48°N, 11°11E) brüteten, wurden die mittleren Brutbeginn-Daten von 5 Gänsearten und von Artbastarden bestimmt. Es zeigte sich, daß die untersuchten Arten unter diesen Bedingungen in derselben Reihenfolge brüteten, wie ihre Artgenossen in freier Wildbahn. Die mittleren Brutbeginn-Termine wurden allerdings um so mehr vorverlegt, je später die Art normalerweise brütet (Abb. 1). , die mit artfremden verpaart waren, brüteten zur selben Zeit wie ihre Artgenossen, die mit artgleichen verpaart waren (Abb. 1). GraugansxSchneegans-Bastard-, die mit Schneegantern verpaart waren, begannen meist nach den Graugänsen, aber stets vor den Schneegänsen zu brüten (Abb. 1, 2). Das intermediäre Brüten dieser wird als starkes Argument für die Richtigkeit der Hypothese gewertet, nach welcher die artspezifisch verschiedenen Brutzeiten wenigstens zum Teil genetisch bedingt sind. In der Diskussion wird die Frage kritisch erörtert, wie weit schon allein die Tatsache, daß die verschiedenen Arten über Generationen hinweg in derselben Reihenfolge wie ihre wildlebenden Artgenossen zu brüten beginnen, als Beweis für derartige genetische Unterschiede angesehen werden kann.
Summary In 229 cases onset of breeding was recorded from free-living geese of 5 species and of some hybrids of these species, kept in Seewiesen/Obb. (48° N, 11° 11E) from 1956 to 1966. It was found that the species under these conditions bred in the same seasonal sequence as did wild birds. The mean breeding times, however, were found to be advanced in relation to the onset of breeding in the wild (Fig. 1). This was especially evident in the case of late-breeding species. paired with of another species came into breeding condition at the same time as paired with of the same species (Fig. 1). GraylegxSnowgoose hybrid paired with Snowgoose in most cases started to breed later than Greyleg geese but always earlier than the mean breeding time for Snowgeese (Fig. 1, 2). This intermediate breeding time is taken as a strong argument for the hypothesis that the species specific differences in breeding times are, at least in part, genetic in origin. The question as to the extent to which the differences in breeding times alone, persisting for generations in the same sequence as those of wild birds, can be attributed to genetic differences between the species, is critically discussed.
  相似文献   

18.
Summary The potential of-lactams as intermediates for the access to- and-amino acid-derived peptides is shortly reviewed, with major focus on the technologies developed in our group. The two general strategies lie, on one side, in the oxidative ring expansion of 3-hydroxy-lactams toN-carboxy-amino acid anhydrides or Leuch's anhydrides and subsequent coupling with-amino acid esters and, on the other side, in the nucleophilic ring opening ofN-Boc--lactams. Both approaches have been successfully applied to the synthesis of,-diamino acid,-amino--hydroxy acid, polyhydroxylated-amino acid,,-disubstituted-amino acid,-amino acid,-amino--hydroxy acid and,-disubstituted-amino acid derived peptides. Because of the mild reaction conditions needed for the above transformations and the highly stereoselective procedures employed for the construction of the starting-lactam ring, the whole process allows the production of optically pure final products.  相似文献   

19.
Plantlets of Bidens pilosus L., considered to be basically symmetrical, can be lateralized (A/B) by being administered a symmetry-breaking signal such as puncturing one of the plant cotyledons. The induced asymmetry remains latent as long as the plants have not been made permissive, i.e. as long as the plant apex is left functioning. When the apex has been removed (plant decapitation), the latent asymmetry is expressed by one of the cotyledonary buds (a/b) statistically beginning to elongate before the other. The interval of time between delivering the symmetry-breaking signal and making the plant permissive is the memorization-time, t. Memorization can be quantified by using a precedence index, q, the values of which range from 0 (no detectable asymmetry with regard to bud growth) to ±1 (bud growth perfectly asymmetric in favour of either bud b or a). Even for memorization times, t, up to 14 d, q-values up to 0.4 (or even larger) are observed. Various experimental characteristics (e.g. light, temperature, presence or absence of the root system) but not the plant age can affect the q-values, at the moment when the treatments are performed, at least in the range of 6 to 25 d. Combining several puncturing treatments either increases or decreases the q-values, depending on the nature of these treatments and the time-intervals, t, between them. Symmetrically removing both cotyledons in the minutes following the puncturing of one of them does not significantly alter the results, which means that the symmetry-breaking message is rapidly transported and memorized within the plant. Non-traumatic asymmetrical treatments (droplets of saline solutions, light-gradients) can also act as symmetry-breaking signals and be memorized. Plants other than Bidens are likely to possess similar memorization ability, although the q-values observed up to now have not been very large.  相似文献   

20.
The interaction of 3,5-bis-O-(,,,-tetrafluoropyrid--yl)thymidine with various nucleophilic reagents was studied to evaluate the possibility of molecular design of new types of nucleic acid analogues using S NAr reactions. The reactions with morpholine and sodium azide led to the introduction of one and two nucleophilic residues into each of the polyfluorinated pyridine rings. The nucleophilic polycondensation with bifunctional reagents ethylenediamine and hexamethylenediamine depended on the nature of nucleophile and reaction conditions and resulted in the formation of supramolecules containing about five or more than 20 pyrimidine bases.  相似文献   

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