首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Murata H  Babasaki K  Yamada A 《Mycorrhiza》2005,15(3):179-186
The ectomycorrhizal basidiomycete Tricholoma matsutake produces commercially valuable fruit bodies—matsutake—in Pinus sp. forest. Here we report that PCR with outward facing primers designed based on sequences comprising marY1, the long terminal repeat of the gypsy-type retroelement marY1, specifies strains of T. matsutake. PCR with a primer based on the 22-bp sequence conserved at the 5-end of marY1 conferred 73 reliable bands overall whose profiles depend upon strains of T. matsutake and T. magnivelare, the latter known as American matsutake. This PCR system gave no detectable band in any other species of Tricholoma tested, including T. bakamatsutake and T. fulvocastaneum, symbionts closely related to T. matsutake, as well as a host plant, Pinus densiflora. Similarly, PCR with a set of primers based on 26-bp and 28-bp sequences at bp 48–73 and bp 281–308 of marY1, internal regions that are mutated in a variant of marY1, conferred 90 reliable bands only in strains of T. matsutake. Theoretically, PCR with the 22-bp primer would allow generation of 273, or 9.4×1021, types of polymorphism, and PCR with a combination of 26- and 28-bp primers, 290, or 1.2×1027 types. The probability of falsely specifying two different isolates as the same strain is <1/1021. While polymorphisms conferred by the primer based on the 5 end of marY1 rather exhibit genetic conservation of a group of T. matsutake, those resulting from primers based on the internal sequences more clearly demonstrate intra-specific diversification. Both systems revealed that T. matsutake is divergent within the species. Ectomycorrhizas formed between P. densiflora and T. matsutake were identified by the PCR systems developed in the present study. This method, using marY1 as a genetic marker, is useful in analyzing the diversity of T. matsutake, monitoring the behavior of individual mycorrhizas, and specifying the ecological background of fruit bodies traded in markets.  相似文献   

2.
The main carotenoid of Flavobacterium strain R1560 has been identified as (3R,3R)-zeaxanthin. Also present were small amounts of 15-cis-phytoene, phytofluene, -carotene (7,8,7,8-tetrahydro-, -carotene plus 7,8,11,12-tetrahydro-, -carotene), neurosporene, lycopene, -zeacarotene, -carotene, -carotene, -cryptoxanthin, rubixanthin, 3-hydroxy--zeacarotene and several apo-carotenals. Zeaxanthin production was inhibited by nicotine (10 mM), and lycopene and rubixanthin accumulated. The biosynthesis of zeaxanthin is discussed in terms of pathways and also of half-molecule reaction sequences. The presence of zeaxanthin may be a characteristic of a group of Flavobacterium species, and may thus be useful in the taxonomic classification of these organisms.  相似文献   

3.
Dong A  Ye M  Guo H  Zheng J  Guo D 《Biotechnology letters》2003,25(4):339-344
Of 49 microbial strains screened for their capabilities to transform ginsenoside Rb1, Rhizopus stolonifer and Curvularia lunata produced four key metabolites: 3-O-[-d-glucopyranosyl-(1,2)--d-glucopyranosyl]- 20-O-[-d-glucopyranosyl]-3,12, 20(S)-trihydroxydammar-24-ene (1), 3-O-[-d-glucopyranosyl-(1,2)--d- glucopyranosyl]-20-O-[-d-glucopyranosyl]-3,12, 20(S)-trihydroxydammar-24-ol (2), 3-O-[-d-gluco- pyranosyl-(1,2)--d-glucopyranosyl]-3, 12, 20(S)-trihydroxydammar-24-ene (3), and 3-O--d-glucopyranosyl-3, 12, 20(S)-trihydroxydammar-24-ene (4), identified by TOF-MS, 1H- and 13C-NMR spectral data. Metabolites 1, 3 and 4 were from the incubation with R. stolonifer, and 1 and 2 from the incubation with C. lunata. Compound 2 was identified as a new compound.  相似文献   

4.
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   

5.
-Amylase from a still culture filtrate of Tricholoma matsutake, an ectomycorrhizal fungus, was isolated and characterized. The enzyme was purified to a homogeneous preparation with Toyopearl-DEAE, gel filtration, and Mono Q column chromatography. The -amylase was highly purified (3580 fold) with a recovery of 10.5% and showed a single protein band by SDS-PAGE. The enzyme was most active at pH 5.0–6.0 toward soluble starch and stable within the broad pH range 4.0–10.0. This -amylase was a relatively thermostable enzyme (optimum temperature, 60°C; thermal stability, 50°C). The molecular mass was 34kDa by size-exclusion chromatography and 46kDa by SDS-PAGE. This enzyme was not inhibited by the Hg2+ ion. Measurement of viscosity and TLC and HPLC analysis of the hydrolysates obtained from amylose showed that the amylase from T. matsutake is an endo-type (-amylase). Substrate specificity was tested using amylose with different polysaccharides. This -amylase readily hydrolyzed the -1,4 glucoside bond in soluble starch and amylose A (MW, 2900), but did not hydrolyze the -1,6 bond and cyclic polysaccharides such as - and -cyclodextrin.  相似文献   

6.
Two new asterosaponins, (20R)-3-O--D-(2-O-methylxylopyranosyl)-24-propylcholest-4-ene-3,6,8,15,16,29-hexaol (sanguinoside A) and (20R,24S)-3-O--D-(2,3,4-tri-O-methylxylopyranosyl)-5-cholestane-3,4,6,8,15,24-hexaol (sanguinoside B), were isolated from two species of Pacific Far Eastern Starfish Henricia sanguinolenta and H. leviuscula leviuscula, collected in the Sea of Okhotsk. Both glycosides contain aglycones with pentahydroxysteroid nuclei of similar structures, which are substituted at the 3-hydroxy group with differently methylated -D-xylosyl residues. Sanguinoside A has an unusual structure of its aglycone side chain, whereas sanguinoside B has a unique permethylated carbohydrate chain. In addition, laevisculoside G, a known glycoside, was identified in the H. leviuscula starfish. The structures of the isolated glycosides were established by interpreting their spectral data and by comparing their spectral characteristics with those of known compounds.  相似文献   

7.
The somatic chromosomes ofTriticum timopheevi and those of two varieties ofT. aestivum, Chinese Spring and Bezostaya-1, have been identified by a Giemsa staining technique. The data suggest thatT. timopheevi and tetraploid wheats had a common ancestor from which their genomes differentiated due to chromosomal aberrations and the increase of heterochromatin in the chromosomes of theT. timopheevi G-genome. The differences between the chromosomes of the AB and AG genomes result in substitutions and large translocations between these chromosomes in interspecific hybrids.  相似文献   

8.
A novel syrup containing neofructo-oligosaccharides was produced from sucrose (Brix 70) by whole cells of Penicillium citrinum. The efficiency of fructo-oligosaccharides production was more than 55% and those of the main carbohydrate components, 1-kestose (Fruf 21Fruf 21 Glc), nystose (Fruf 21Fruf 21 Fruf 21 Glc) and neokestose (Fruf 26 Glc12 Fruf), were 22, 14 and 11%, respectively.  相似文献   

9.
The genes were cloned for the two apoprotein subunits, and ,of phycocyanin from the cyanobacterium Spirulina maxima = Arthrospiramaxima) strain F3. The - and -subunit gene-coding regionscontain 489 bp and 519 bp, respectively. The -subunit gene is upstreamfrom the -subunit gene, with a 111-bp segment separating them.Similarities between the -subunits of S. maxima and nine othercyanobacteria were between 58% and 99%, as were those between the -subunits. The maximum similarity between the - and -subunits from S. maxima was 27%.  相似文献   

10.
The effects of the average light irradiance (I) on growth and nitrate uptake kinetics of the cyanobacterium Oscillatoria agardhii, in nitrate-limited chemostat cultures, were studied. Light was nonsaturating for I <9.4 Wm–2, for all growth rates () studied. However, was throughout limited by the availability of nitrate. Under light-saturating conditions the kinetics of nitrate-limited growth could be adequately described by both the Monod and Droop equations. Under light-non-saturating conditions the internal nitrogen content (Q) was a function of both and I, for which new formulas were derived. The high uptake capacity (V max) of nitrate-limited cells was independent of , but was significantly increased for cells growing at I <9.4 Wm–2. The half-saturation constant for nitrate uptake (K s u ) increased with increasing , but was independent of the prevailing light conditions. The effects of light during nitrate-limited growth were associated with the regulation in the nitrogen-containing pigments.The results reported herein have important consequences for the use of Q, K s u and V max values as indicators of nutrient-deficiency of natural populations.  相似文献   

11.
Summary Isoelectric focusing of extracts from the endosperm of mature grains of hexaploid wheat and related species was used to study the genetic control of Iodine binding factor (IBF). Ten IBF bands were present in Chinese Spring (CS) and analysis of the nullisomictetrasomic and ditelosomic lines of CS showed nine of them to be controlled by genes on the long arms of the homoeologous group 5 chromosomes. Five alleles were detected at Ibf-A1 locus, four at Ibf-B1 and four at Ibf-D1 among a sample of 46 wheat genotypes. Homoeoloci were found on chromosome 5R of Secale cereale, 5E of Agropyron elongatum, 5U of Aegilops umbellulata, 5Agi of Agropyron intermedium, 5S1 and 4S1 of Aegilops sharonensis and 4H of Hordeum vulgare.  相似文献   

12.
Role of mitochondria in ethanol tolerance of Saccharomyces cerevisiae   总被引:7,自引:0,他引:7  
The presence of active mitochondria and oxidative metabolism is shown to be essential to maintain low inhibition levels by ethanol of the growth rate (), fermentation rate (v) or respiration rate () of Saccharomyces cerevisiae wild type strain S288C. Cells which have respiratory metabolism show K i (ethanol inhibition constant) values for , v and , higher (K i>1 M) than those of petite mutants or grande strains grown in anaerobiosis (K i=0.7 M). In addition, the relationship between or v and ethanol concentration is linear in cells with respiratory metabolism and exponential in cells lacking respiration. When functional mitochondria are transferred to petite mutants, the resulting strain shows K i values similar to those of the grande strain and the inhibition of and v by increasing ethanol concentrations becomes linear.  相似文献   

13.
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   

14.
Soybean (Glycine max (L.) Merr.) seeds contain the storage protein -conglycinin, encoded by a multigene family. -Conglycinin consists of three subunits; , , and . A genomic clone for a -subunit of -conglycinin has been characterized by restriction-enzyme mapping and hybrid selected in-vitro translation followed by immunoprecipitation. In order to determine the developmental regulation of this -subunit gene, its expression was studied in seeds of transgenic petunia (Petunia hybrida) and tobacco (Nicotiana tabacum L.) plants. The -subunit expressed in seeds of petunia and tobacco was recognized by anti--conglycinin serum at a relative molecular mass of 53 000, equivalent to that of the native protein. Separation of the petunia-seed proteins by isoelectric focusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis showed that multiple isoelectric forms of the -subunit were produced. There was approximately a twofold variation in the accumulation of the -subunit protein in the mature seeds of transgenic petunia plants, each containing a single -subunit gene. However, the level of protein accumulation in mature seeds and the amount of -subunit mRNA in developing seeds was not correlated. Accumulation of the -subunit protein in transgenic seeds was less than the -subunit protein that accumulated in transgenic petunia seeds containing a single -subunit gene and less than the amount of the -subunit in mature soybean seeds which contain 8–13 -subunit genes. In transgenic tobacco plants, the accumulation of the -subunit protein in seeds was generally well correlated with the number of genes that were incorporated in the different transformants.Abbreviations kb kilobase - kDa kilodalton - Mr relative molecular mass - SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis  相似文献   

15.
Feulgen and silver-stained karyotypes and meiosis of two triploid viviparous onion forms (Allium cepa var.viviparum), the Croatian Ljutika and the Indian Pran, were comparatively analyzed. The results of chromosome measurements show that Ljutika and Pran are karyologically not identical, although significant similarities were found in the morphology of their chromosomes. Five geographically distant clones of Ljutika showed good agreement in the number and gross morphology of the chromosomes and in the number and position of NORs and interphase nucleoli. Heterotrivalents were predominant in meiosis of Ljutika but a relatively high frequency of higher multivalents together with univalents and bivalents were also observed. The relationship between Ljutika and Pran and their possible origin are discussed.  相似文献   

16.
Somatic embryo formation was induced from cotyledon explants of Styrian pumpkin (Cucurbita pepo L. subsp. pepo var. styriaca Greb.) by using a solid MS medium supplemented with 16.11M NAA and 4.44M BA or 26.85M NAA and 13.32M BA. The callus proliferation was more efficient on medium supplemented with 26.85M NAA and 13.32M BA. In contrast, the embryogenic response was higher on medium with lower concentrations of growth regulators (16.11M NAA and 4.44M BA). The time needed for embryo induction did not depend on medium composition. Embryos in globular stage were transferred to three different maturation media, containing 2.89M GA3 in combination with 0.54M NAA, 11.42M IAA and growth regulator-free medium. The germination rate was the highest when embryos were cultured on medium with 11.42M IAA. Plantlets grown on this medium achieved maturity suitable for transplantation into soil within 9 to 10weeks. The regenerated plants were successfully transferred into field and developed fertile flowers and set fruits. Biochemical analysis showed significant lower total glutathione levels among in vitro grown plantlets compared to seedlings grown in soil. When the plantlets were transferred into soil, they reached a normal size within a month and the glutathione concentration was comparable to seed-derived plants at the same developmental stage. Transmission electron microscopy was used to investigate possible differences in the ultrastructure of cells from callus cultures, and leaf cells of regenerated and seed-derived plants. Differences in the ultrastructure were found within chloroplasts which contained only single thylakoids, large starch grains and small plastoglobuli in callus cells in comparison to leaf cells, which possessed a well developed thylakoid system, small starch grains and large plastoglobuli.  相似文献   

17.
Shoot regeneration from seed-derived callus cultures of Kentucky bluegrass (Poa pratensis L.) was tested on MS basal medium supplemented with four different growth regulators. Regeneration frequencies for medium supplemented with 10 M 2,4-dichlorophenoxyacetic acid (2,4-D), 60 M 4amino-3, 5,6-picolinic acid (picloram), or 30 M 3,6dichloro-o-anisic acid (dicamba) ranged from 0.4 to 4%. Medium supplemented with 30 M dicamba plus 10 M 6-benzylaminopurine (BA) resulted in regeneration of shoots from 20% of the calli tested. Higher rates of growth regulators (60 or 90 M dicamba, 20 M BA) resulted in regeneration of shoots from 45% of calli of the cultivar Baron. In a subsequent study, the response of 12 North American cultivars grown on these media was cultivar-specific, with mean frequencies of regeneration ranging from 4% to 40%.Abbreviations 2,4-D 2,4-dichlorophenoxyaceticacid - dicamba 3,6-dichloro-o-anisic acid - picloram 4-amino-3,5,6-picolinic acid - BA 6-benzylaminopurine  相似文献   

18.
Sodium salt of (20R)-3,4-dihydroxycholest-5-ene-21-yl sulfate and disodium salts of (20R)-4-hydroxycholest-5-ene-3,21-diyl disulfate, (20R)-24-methylcholest-5,24(28)-diene-3,21-diyl disulfate, (20R)-24-methyl-5-cholest-24(28)-ene-3,21-diyl disulfate, (20R)-cholest-5-ene-3,21-diyl disulfate, (20R)-5-cholestane-3,21-diyl disulfate, and (20R)-3-hydroxycholest-5-ene-2,21-diyl disulfate were isolated from the far eastern starfish Diplopteraster multipes and characterized. These compounds differ structurally from sulfated polyhydroxysteroids in other starfish species. At the same time, they are typical secondary metabolites of Ophiuroidea and have some structural features characteristic of the ophiuroid-isolated steroids, namely the 3-hydroxy (or 3-sulfoxy) and 21-sulfoxy groups. These data support the opinion of some taxonomists that starfishes and ophiuroids are phylogeneteically related classes and are closer to each other than to other classes of the Echinodermata phylum.  相似文献   

19.
Behavioral and physiological responses to hypoxia were examined in three sympatric species of sharks: bonnethead shark Sphyrna tiburo, blacknose shark, Carcharhinus acronotus, and Florida smoothhound shark, Mustelus norrisi, using closed system respirometry. Sharks were exposed to normoxic and three levels of hypoxic conditions. Under normoxic conditions (5.5–6.4mg l–1), shark routine swimming speed averaged 25.5 and 31.0cm s–1 for obligate ram-ventilating S. tiburo and C. acronotus respectively, and 25.0cm s–1 for buccal-ventilating M. norrisi. Routine oxygen consumption averaged about 234.6 mg O2kg–1h–1 for S. tiburo, 437.2mg O2kg–1h–1 for C. acronotus, and 161.4mg O2 kg–1 h–1 for M. norrisi. For ram-ventilating sharks, mouth gape averaged 1.0cm whereas M. norrisi gillbeats averaged 56.0 beats min–1. Swimming speeds, mouth gape, and oxygen consumption rate of S. tiburo and C. acronotus increased to a maximum of 37–39cm s–1, 2.5–3.0cm and 496 and 599mg O2 kg–1 h–1 under hypoxic conditions (2.5–3.4mg l–1), respectively. M. norrisi decreased swimming speeds to 16cm s–1 and oxygen consumption rate remained similar. Results support the hypothesis that obligate ram-ventilating sharks respond to hypoxia by increasing swimming speed and mouth gape while buccal-ventilating smoothhound sharks reduce activity.  相似文献   

20.
Fowl plague virus, strain Dutch, was metabolically labeled withd-[2-3H]mannose, or withd-[6-3H]glucosamine, and the small subunit (HA2; 0.8 mg in total) of the viral hemagglutinin was isolated by preparative sodium dodecylsulfate-polyacrylamide gel electrophoresis. After proteolytic digestion, the radioactive oligosaccharides were sequentially liberated from the glycopeptides by treatment with different endo--N-acetylglucosaminidases and with peptide:N-glycosidase or, finally, by hydrazinolysis. In this manner, four groups of glycans could be obtained by consecutive gel filtrations and were subfractionated by HPLC. The structures of the individual oligosaccharides were analyzed by micromethylation, by acetolysis or by digestion with exoglycosidases. The major species amongst the high mannose glycans at Ans-406 of the viral glycopolypeptide were found to be Man1-2Man1-3(Man1-2Man1-6)Man1-6(Man1-2Man1-2Man1-3)Man1-4GlcNac1-4GlcNAc and Man1-3(Man1-2Man1-6)Man1-6(Man1-2Man1-2Man1-3)Man1-4GlcNAc1-4GlcNAc, while the complex glycans at Asn-478 are predominantly GlcNAc1-2Man1-3(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc (lacking, in part, one of the outerN-acetylglucosamine residues) and GlcNAc1-2Man1-3(Gal1-4GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc.Abbreviation BSA bovine serum albumin - endo D (F,H) endo--N-acetyl-d-glucosaminidase D (F,H) - HA hemagglutinin (HA1, large subunit of HA - HA2 small subunit - FPV fowl plague virus - PNGase F peptide:N-glycosidase F - SDS sodium dodecylsulfate  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号