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11.
A coiling-inducing factor was isolated from tendrils of Bryonia dioica Jacq. and identified by infrared, 1H-, 13C-nuclear magnetic resonance and mass spectrometry as -linolenic acid. When applied to detached tendrils, exogenous -linolenic acid, but not linoleic acid or oleic acid, induced tendril coiling. Further investigations showed that metabolites of -linolenic acid, jasmonic acid and, even more so, methyljasmonate, are highly effective inducers of tendril coiling in B. dioica. Methyljasmonate was most active when administered by air and, in atmospheric concentrations as low as 40–80 nM, induced a full free-coiling response with kinetics similar to mechanical stimulation. Even atmospheric levels as low as 4–5 nM methyljasmonate were still found to be significantly active. Methyljasmonate could be one of the endogenous chemical signals produced in mechanically stimulated parts of a tendril and, being highly volatile, act as a diffusible gaseous mediator spreading through the intracellular spaces to trigger free coiling of tendrils.Abbreviations EI-MS
electron impact-mass spectrometry
- HPLC
high-performance liquid chromatography
- IAA
indole-3-acetic acid
- NMR
nuclear magnetic resonance
- TFA
trifluoroacetic acid
We are indebted to the Deutsche Forschungsgemeinschaft, Bonn and the Fonds der Chemischen Industrie, Frankfurt (literature provision) for their support and to Dr. C. Brückner, Halle, for jasmonic-acid determinations. 相似文献
12.
Elmar Hartmann 《Planta》1971,101(2):159-165
Summary The presence of a neurohormone in moss callus could be demonstrated by means of pharmacological experiments on the heart of the frog (Rana temporaria L.) and by chromatography.The hearts react in the same manner as they do to application of acetylcholine and the substance resembles acetylcholine in its Rf-value. Therefore it is suggested that this hormone is identical with acetylcholine. The concentration of the hormone in the callus cells is mediated by the phytochrome. Moss callus cultivated under red and far-red illumination contain less substance than moss callus grown in red light.
Herrn Dauscher, Institut für Physiologische Zoologie, danke ich für die Durchführung der pharmakologischen Tests am Froschherzen. 相似文献
Herrn Dauscher, Institut für Physiologische Zoologie, danke ich für die Durchführung der pharmakologischen Tests am Froschherzen. 相似文献
13.
The electron microscope has been used to determine the weight distribution of isolated subcellular particles from normal rat liver. The following results are reported: (1) There exist at least two well defined weight populations of subcellular particles; their respective median weights are 1.3 x 10-14 and 11 x 10-14 gm. The lighter fraction is considered to consist of lysosomes, the heavier of mitochondria. (2) The mitochondrial fraction shows a log-normal distribution of the particle weight. (3) By the introduction of morphologic criteria, the mitochondrial fraction is divided into two groups, one consisting of a spherical, the other of an oblong type of particle. The data found support the following concepts: (a) Mitochondria increase their weight from a certain size up by linear growth. (b) Mitochondria divide. The division is not necessarily symmetric; in all cases, however, one part of the division product is a spherical particle. It is felt that these results constitute a valuable demonstration of the general capabilities of quantitative electron microscopy and may stimulate many other useful applications of this technique in cytology, bacteriology, and virology. 相似文献
14.
Arabidopsis thaliana lines have been isolated that are insensitive to the fungal toxin fusicoccin (FC). Initial screening was done by selecting for plants that either grew well on high concentrations of FC or did not respond to FC by increases in H+-extrusion. All selected plants were tested, in several additional rounds of screening, for binding to microsomal proteins of a 3H-labeled radioligand of fusicoccin. A novel assay allowing for the direct selection of individual plants exhibiting reduced binding of FC was developed and used as screening procedure. Independent variant lines (43) with stably expressed, reduced binding of FC were isolated and subjected to a detailed characterization of their binding sites. The lines could be subdivided into several distinct classes with respect to these characteristics. In class-I lines, the data indicate a partial conversion of high-affinity binding sites to a low-affinity state. In class-II lines, the affinity of the binding site to FC is strongly reduced while the number of sites, as well as several other biochemical parameters, is completely unchanged, suggesting a specific alteration in the properties of the fusicoccin-binding protein. In class-III lines, the ligand-binding protein complex, while retaining its high affinity, is destabilized at supraoptimal concentrations of FC (such as those used for screening). In wild-type plants, only the high-affinity binding site was detected. Combined, these data prove that the high-affinity sites represent the plant's FC receptor.Abbreviations Ao
binding site concentration
- FC
fusicoccin
- FCBP
fusicoccin-binding protein
- FCol
9-nor-8-hydroxyfusicoccin
- KD
dissociation constant of the FCBP-radioligand complex
We are grateful to Iris Sandorf and Gudrun Henrichs for excellent technical assistance. This work was supported by the Deutsche Forschungsgemeinschaft, Bonn, Germany and by Fonds der Chemischen Industrie (literature provision). 相似文献
15.
16.
Michael Neubeck Elmar Prenner Predrag Horvat Rudolfo Bona Albin Hermetter Anton Moser 《Archives of microbiology》1993,160(2):101-107
The bacterial secretion of glutamate was studied through plasma membrane fluidity, measured by anisotropy using the fluorophore TMA-DPH incorporated in the lipid part of the cell membrane. Cells of Brevibacterium sp. ATCC 13869 (wild type) were switched from the biotin-limited, producing state to the biotin-supplemented, non-producing state, and back. The following conclusions could be drawn: 1. It was not possible to detect any change in anisotropy by switching the cells from biotin-limited biotin-supplemented, as well as from biotin-supplemented, to biotin-limited, media. 2. The anisotropy value in the glutamic acid fermentation remains constant during the lag, exponential, growth, production and stationary phases. 3. The treatment of cells with a neutral synthetic polyester of ethylene-and propyleneoxide with soya oil-fatty acids increased the anisotropy values, indicating incorporation of the surfactant. 4. Glutamate secretion is not coupled with membrane fluidity, so a leak providing a general fluidization of the membrane could not be detected. 相似文献
17.
Plant hormone immunoassay 总被引:1,自引:0,他引:1
Elmar W. Weiler 《Physiologia plantarum》1982,54(2):230-234
18.
Summary A heme-nonapeptide (H-9-P)1, applicable to electron microscopic cytochemistry via peroxidase-like activity, was prepared by passing horse heart cytochrome c through a column with Sepharose and covalently attached trypsin. After purification by column chromatography (Sephadex G50 Superfine, Biogel P-2) a maximal yield of 50% and purity of >99% was achieved. A concise schedule allows for inexpensive preparation of H-9-P with standard laboratory equipment. H-9-P has the following properties: Its structure is (14) Cys-Ala-Gln-Cys-His-Thr-Val-Glu-Lys (22) with heme attached to Cys (14) and (17). MW=1630, pI=4.95,
E(max)
pH 7
= 397.5 nm,
22 °C, pH 7
397.5 nm
= 1.11 × 105 [Liter/Mole x cm]. With the use of a diaminobenzidine-H2O2-medium — as applied for cytochemistry — we determined spectrophotometrically a pHopt=12.5 and an apparent K5 = 3.14 × 10– 3 [M]. Glutardialdehyde leads to considerable de-activation and, according to SDS-polyacrylamide-gel-electrophoresis, to diffuse crosslinking accompanied by a shift of the active pH-region towards neutral pH values. An attempt was made to optimize the cytochemical assay. The peroxidase-like activity of H-9-P is well comparable to that of other heme-tracers; only horseradish peroxidase has a higher turnover number. When injected to mice or added to cell suspensions, even high concentrations of H-9-P did not entail any signs of toxicity.Abbreviations AAA
amino acid analysis
- AHC
ammoniumhydrogencarbonate
- BSA
bovine serum albumin
- Cyt c
cytochrome c
- DAB
5,3-diaminobenzidine
- GA
glutardialdehyde
- H-8-P
heme-octapeptide
- H-9-P
heme-nonapeptide
- H-11-P
heme-undecapeptide
- HR-POX
horseradish peroxidase
- MW
molecular weight
- PAGE
polyacrylamid-gel-electrophoresis
- pI
isoelectric point
- SDS
sodiumdodecylsulphate
- SG-TLC
silicagel-thin-layer-chromatography
This work was supported by the Österreichische Forschungsfonds 相似文献
19.
20.
Levels of abscisis acid (ABA) were determined in isolated guard cell (GCP) and mesophyll cell (MCP) protoplasts of Vicia faba L. in relation to water stress. Incubation of GCP and MCP in 0.4 M or 0.8 M mannitol resulted in an average increase in the level of free abscisic acid (ABA) in the cells of 34% (GCP) and 38% (MCP) within 15–60 min. It is concluded that guard cell protoplasts form ABA in response to osmotic stress.Abbreviations ABA
abscisic acid
- BHT
butylated hydroxytoluene
- GCP
guard cell protoplasts
- MCP
mesophyll cell protoplasts
- MES
[2-(N-morpholino)-ethanesulfonic acid]
- TLC
thin layer chromatography
Part 20 in the series, Use of Immunoassay in Plant Science 相似文献