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71.
B. F. Lownsbery E. H. Moody A. Moretto G. R. Noel T. M. Burlando 《Journal of nematology》1978,10(3):232-236
Preplanting treatment of soil naturally infested with Macroposthonia xenoplax with 1,2-dibromoethane (ethylene dibromide) significantly increased the growth rate of Juglans hindsii seedlings. When seedlings of J. hindsii, J. regia CV "Serf" and J. regia CV Eureka were inoculated with M. xenoplax, their growth was signilicantly less than that of nematode-free controls. This retarded growth rate was accompanied hy feeder root necrosis, longitudinal cracks in the older roots, and distinct lesions in the secondary phloem. 相似文献
72.
The inclusion of sub-lethal amounts ofthe herbicide atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] in the nutrient solution supplied to maize and barley increased the growth of the root and shoot and the uptake of nitrate. The activities of nitrate and nitrite reductases, glutamine synthetase and glutamate synthase were enhanced and the amino acid and nitrate contents of the xylem sap increased. All these effects of atrazine were found only in plants grown with nitrate as the nitrogen source. The uptake of 15NO3? and its incorporation into protein in the root and shoot of maize and barley seedlings was significantly greater in the atrazine treated plants. However, a stimulation in the incorporation of leucine-[14C] into TCA-precipitable protein of detached leaves from 7-day-old barley seedlings was obtained only in the absence of a supply of combined nitrogen either in the culture medium or in the in vitro incubation mixture containing the labelled amino acid. 相似文献
73.
32P was applied to a Laminaria digitata thallus and the pattern of 32P phosphorylated compounds was studied, as a function of time, in the different tissues involved in translocation, i.e. source, pathway and sinks. The results showed that, 3 hours after absorption by the uptake region (lamina), the bulk of the radioactivity was incorporated into organic compounds (70 to 80% of total 32P taken up), hexose monophosphates being the heaviest labelled. Further change in that region was marked by an accumulation of 32P in the inorganic pool (65 to 70% after 13 days). Conversely, the 32P pattern in the medulla of the stipe, which initially showed a similar pattern to the uptake region, did not vary during translocation. The pattern of 32P distribution into sinks (growing stipe peripheral tissue or hapteron) leads to accumulation of the radioactive element in inorganic and acid-insoluble fractions. These results are discussed in terms of comparative distribution of 32P in the different parts of the thallus and suggest that phosphate moves as Pi in that alga.Abbreviations TCA
trichloroacetic acid
- Po
organic phosphate
- Po sol
acid-soluble organic phosphate fraction
- Po insol
acidinsoluble organic phosphate fraction
- Pi
morganic phosphate fraction
- P lip
lipidic phosphate
- Np
protein nitrogen
- ATP
adenosine triphosphate
- ADP
adenosine diphosphate
- PEP
phosphoenolpyruvic acid
- PGA
phosphoglyceric acid
- G-1-P
glucose-1-phosphate
- G-6-P
glucose-6-phosphate
- UDPG
uridine diphosphoglucose 相似文献
74.
Yamazaki Y Hosono K Matsuda H Minami N Asai M Nakanishi H 《Biotechnology and bioengineering》1991,38(10):1218-1222
Twelve species of optically active metallocene derivatives having a 4-nitrophenyl group were prepared with horse liver alcohol dehydrogenase- or lipase-catalyzed optical resolution as the key step. The second harmonic generation (SHG) efficiently of these products was measured by the power method using the fundamental light from the Nd:YAG laser. (-)-1- (4-Nitrophenylthio)ethylferrocene (9), (+)-1-(4-nitrophenylthio)ethylruthenocene (16), (+)-1-(4-nitrophenylthio)ethylosmocene (19), (+) -1-(5-nitro-2-pyridylthio)ethylruthenocene (21), and (+) -1-[(4-nitrophenylhydrazono)methyl] -2-methylferrocene (12) showed SHG signals. The highest SHG efficiency was found with (+) -16, being 27 times more intense than the commonly used urea standard. 相似文献
75.
76.
Three strains of Bradyrhizobium, 280A, 2209A and 32H1, that nodulated peanuts (Arachis hypogaea L.), were tested for their ability to grow and survive at elevated temperatures of up to 42°C in laboratory culture. Strain 32H1 was unable to grow at 37°C and was more sensitive to elevated temperatures than the other two strains. All three produced heat-shock proteins of molecular weights 17 kDa and 18 kDa. Two greenhouse experiments were conducted to determine the effect of high root temperature on nodulation, growth and nitrogen fixation of peanut. Two peanut varieties (Virginia cv NC7 and Spanish cv Pronto) were inoculated and exposed to root temperatures of 30°, 37° and 40°C. Nodulation and nitrogen fixation were strongly affected by root temperature but there was no variety × temperature interaction. At a constant 40°C root temperature no nodules were formed. Nodules were formed when roots were exposed to this temperature with diurnal cycling but no nitrogen fixation occurred. Highest plant dry weight, shoot nitrogen content and total nitrogen were observed at a constant root temperature of 30°C. Increasing root temperature to 37°C reduced average nitrogen content by 37% and total nitrogen by 49% but did not reduce nodulation. The symbiotic performance of the strains corresponded to their abilities to grow and survive at high temperature in culture. 相似文献
77.
A new biosensor for specific determination of sucrose was developed using an oxidoreductase of Zymomonas mobilis and invertase. Cells of Z. mobilis were permeabilized with toluene in order to utilize the enzymes of glucose-fructose oxidoreductase and gluconolactonase inside the intact cells. Permeabilized cells and invertase were coimmobilized in a gelatin membrane, and a whole cell enzyme electrode was constructed by fixing the membrane on a pH electrode. The production of hydrogen ion was detected using the biosensor-connected microcomputer, and the concentration of sucrose was determined by using both the initial rate and the steady-state methods. Optimum conditions for biosensor response were pH 6.2 and temperature 35 degrees C. The effect of interfering compounds on the electrode response was investigated, and the interference by various sugars was eliminated by determining sucrose concentration using the steady-state method. The biosensor developed is simple and reproducible, and the calibration curve for sucrose is linear up to 70 g/L. 相似文献
78.
Henrika G. M. Tiedink Laura H. J. De Haan Wim M. F. Jongen Jan H. Koeman 《Cell biology and toxicology》1991,7(4):371-386
4-chloro-methoxyindole is a naturally occurring compound in Vicia faba which can easily react with nitrite to form a N-nitroso compound. In this in vitro study, the potential genotoxic effects of nitrosated 4-chloro-6-methoxyindole and its structural analogue 4-chloroindole were evaluated for the first time by using both Salmonella and Chinese hamster V79 cells. Additionally, the inhibition of gap junctional intercellular communication in V79 cells by these compounds was determined; this is a validated parameter for tumor-promoting activity. Most assays were also performed with nitrosated indole-3-acetonitrile, a naturally occurring compound in brassicas. Both nitrosated chloroindoles were highly mutagenic to Salmonella typhimurium TA100 without the need of exogenous metabolic activation and were potent inducers of Sister Chromatid Exchanges. Nitrosated indole-3-acetonitrile generated the same effects, although at much higher concentrations. Equivocal results were obtained for the nitrosated chloroindoles in a forward mutation assay using the hypoxanthine guaninephosphoribosyltransferase locus. All nitrosated indole compounds significantly inhibited gap junctional intercellular communication. These results indicate that nitrosated chloroindoles and nitrosated indole-3-acetonitrile should be considered as mutagens and agents with potential tumor-promoting capacity.Abbreviations BrdU
5-bromo-2-deoxyuridine
- 4Cl
4-chloroindole
- 4C6MI
4-chloro-6-methoxy-indole
- DMSO
dimethyl sulfoxide
- EBSS
Earle's balanced salt solution
- EMS
ethyl methanesulfonate
- GJIC
gap junctional intercellular communication
- HBSS
Hanks balanced salt solution
- HGPRT
hypoxanthine guaninephosphoribosyl transferase
- I3A
indole-3-acetonitrile
- MNNG
1-methyl-1-nitroso-3-nitroguanidine
- NOC
N-nitroso compounds
- NQO
4-nitroquinolone-N-oxide
- SCE
sister chromatid exchange
- 6TG
6-thioguanine
- TPA
12-O-tetradecanoylphorbol-13-acetate 相似文献
79.
Oscar Lazcano Jorge Bilbao Robert S. Beissner Martha Vandiver Chin Yang Li 《Biotechnic & histochemistry》1992,67(1):14-20
Permanent preparations of air dried synovial fluids were prepared by staining calcium compounds with alizarin red S stain; each slide was coverslipped with Permount. Variables studied were: (a) concentration of the solution of alizarin red S, (b) pH of staining solution, (c) time of incubation in staining solution and aqueous and ethanolic content of staining solution. The staining effect of each solution was tested on calcium pyrophosphate dihydrate, calcium oxalate, apatite and monosodium urate (MSU). Of all the solutions, best results were obtained with 0.25% alizarin red S in 50% ethanol at pH 7.0 for 30 min. With this solution, the calcium-containing compounds were well stained. MSU did not stain and still preserved negative birefringence on polarizaton. Fixation of smears with ethanol served a double purpose: It fixed the slides without dissolving or removing MSU or the calcium compounds, yet it did dissolve five corticosteroids commonly used for intra-articular injection which may interfere with interpretation of compensated polarized light microscopy of synovial fluids. 相似文献
80.
菠萝黑心病是PPO催化氧化酚类物质形成褐色产物所致。低温或GA_3处理提高了PPO活性及其底物——儿茶酚、绿原酸和咖啡酸的含量,也导致了PAL活性增加;低温还使乙烯释放率增大。这些变化均有利于黑心病的发生和发展。 相似文献