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41.
The averaging method was applied for the analysis of the effect of intermittent light as well as for the analysis of the spontaneous spike activities of burster neurons in Helix pomatia and Aplysia depilans ganglia. Owing to such analyses by means of which the unwanted effects of permanently present noise (i.e., irregular frequency modulation of neuron impulse activity) were diminished, the dynamics of the neurons reaction to light and the longer time effects of intermittent illumination on neurons spontancous activity could be observed. The functional characteristics of burster neurons were determined by averaging and the least squares and equalization methods. The results were presented in the table and in two average curves which are asymmetrical with a horizontal asymptote. From these data it was concluded that the dynamics of the spontaneous activity of the two burster neurons in both specia is similar. The possibilities and limitations of the method in physiological analyses are discussed. 相似文献
42.
Barjaktarović Z Nordheim A Lamkemeyer T Fladerer C Madlung J Hampp R 《Journal of experimental botany》2007,58(15-16):4357-4363
In previous studies it has been shown that callus cell cultures of Arabidopsis thaliana respond to changes in gravitational field strengths by altered gene expression. In this study an investigation was carried out into how different g conditions affect the proteome of such cells. For this purpose, callus cells were exposed to 8 g (centrifugation) and simulated microgravity (2-D clinorotation: fast rotating clinostat, yielding 0.0016 g at maximum; and 3-D random positioning) for up to 16 h. Extracts containing total soluble protein were subjected to 2-D SDS-PAGE. Image analysis of Sypro Ruby-stained gels showed that approximately 28 spots reproducibly and significantly (P <0.05) changed in amount after 2 h of hypergravity (18 up- and 10 down-regulated). These spots were analysed by electrospray ionization tandem mass spectrometry (ESI-MS/MS). In the case of 2-D clinorotation, 19 proteins changed in a manner similar to hypergravity, while random positioning affected only eight spots. Identified proteins were mainly stress related, and are involved in detoxification of reactive oxygen species, signalling, and calcium binding. Surprisingly, centrifugation and clinorotation showed homologies which were not detected for random positioning. The data indicate that simulation of weightlessness is different between clinorotation and random positioning. 相似文献
43.
The effect of sucrose on fruiting, seed production, and seed germination of lesser centaury [Centaurium pulchellum (Sw.) Druce] was examined using explants of flowers and flower buds. Sucrose concentrations in the culture medium ranged
from 0.003 to 0.3 M. It has been shown that the number of auxiliary buds, capsules dimension, number of viable seeds per capsule
and seed dimensions increased with the increase of sucrose concentrations. The highest values were recorded at sucrose concentrations
higher than 0.03 M, except for seeds size, which were larger at sucrose concentration ranging from 0.003 to 0.1 M. The germination
of in vitro produced seeds was affected by previous culture history: a higher germination percentage was obtained in seeds that were
raised from explants originally grown on medium with sucrose concentrations higher than 0.003 M. 相似文献
44.
Cametti M Piantanida I Zinić M Dalla Cort A Mandolini L Marjanović M Kralj M 《Journal of inorganic biochemistry》2007,101(8):1129-1132
The Al(III)-salophen complex 1 exhibited strong spectroscopic changes specifically upon addition of polyG and GpG, while double stranded DNA and RNA, and single stranded polyA, polyU and polyC induced negligible spectral changes of 1. Titrations with mono-nucleotides yielded no spectroscopic changes, revealing that there must be at least two consecutive guanines in single stranded oligonucleotide structure for a measurable spectroscopic change of 1. Preliminary results show that 1 has moderate antiproliferative effect on a number of human tumour cell lines. 相似文献
45.
Ivana Momčilović Dragoljub Grubišić Milan Kojić Mirjana Nešković 《Plant Cell, Tissue and Organ Culture》1997,50(1):1-6
Shoots of micropropagated Gentiana acaulis, G. cruciata, G. lutea, and G. purpurea were inoculated with suspensions of Agrobacterium
rhizogenes cells, strains ATCC 15834 or A4M70GUS. Adventitious roots appeared at the sites of inoculation in all 4 species.
Root tips were excised and cultured on growth regulator-free media for 2-6 years. They exhibited very high branching and plagiotropism.
Spontaneous bud initiation occurred in roots of G. cruciata. Roots of G. lutea, G. acaulis and G. purpurea were cultured on
media with high kinetin concentration, which induced the formation of friable callus tissues. Only in G. purpurea were these
calluses organogenic. Regenerated shoots of G. cruciata and G. purpurea gave rise to plants, that displayed the typical phenotypes
of A. rhizogenes-transformed plants: short internodes and rolled leaves. In the roots of G. acaulis and G. cruciata, transformed
with A. rhizogenes A4M70GUS, a positive reaction with X-gluc indicated the activity of β-glucuronidase. The DNA extracted
from hairy roots and from the roots of transgenic plants hybridized with the appropriate genomic probes in Southern blotting.
This is taken as evidence of the stable genetic transformation in the 4 Gentiana species.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
46.
47.
Babić KH Schauss K Hai B Sikora S Redzepović S Radl V Schloter M 《Environmental microbiology》2008,10(11):2922-2930
Inoculation of leguminous seeds with selected rhizobial strains is practised in agriculture to ameliorate the plant yield by enhanced root nodulation and nitrogen uptake of the plant. However, effective symbiosis between legumes and rhizobia does not only depend on the capacity of nitrogen fixation but also on the entire nitrogen turnover in the rhizosphere. We investigated the influence of seed inoculation with two indigenous Sinorhizobium meliloti strains exhibiting different efficiency concerning plant growth promotion on nitrogen turnover processes in the rhizosphere during the growth of alfalfa. Quantification of six target genes (bacterial amoA, nirK, nirS, nosZ, nifH and archaeal amoA) within the nitrogen cycle was performed in rhizosphere samples before nodule formation, at bud development and at the late flowering stage. The results clearly demonstrated that effectiveness of rhizobial inocula is related to abundance of nifH genes in the late flowering phase of alfalfa. Moreover, other genes involved in nitrogen turnover had been affected by the inocula, e.g. higher numbers of amoA copies were observed during flowering when the more effective strain had been inoculated. However, the respective gene abundances differed overall to a greater extent between the three plant development stages than between the inoculation variants. 相似文献
48.
Davor Miličić 《Protoplasma》1957,48(1):170-171
Ohne ZusammenfassungDie vorliegenden Versuehe wurden während meines kurzen Aufenthalts im Pflanzenphysiologisehen Institut der Universität Wien ausgeführt. Herrn Prof. Dr. Karl Höfler und Herrn Dr. H. Kinzel danke ich sehönstens auch an dieser Stelle für die Untersfützung während der Arbeit. 相似文献
49.
50.
I. Koleška D. Hasanagić V. Todorović S. Murtić I. Maksimović 《The Annals of applied biology》2018,172(2):187-196
Two commercial tomato cultivars were used to determine whether grafting could prevent decrease of fruit weight and quality under salt stress conditions. The cultivars Buran F1 and Berberana F1 were grafted onto rootstock ‘Maxifort’ and grown under three levels of elevated soil salinity (EC 3.80 dS m?1, 6.95 dS m?1 and 9.12 dS m?1). Fruit weight reduction of grafted plants was lower (about 20–30%) in comparison with non‐grafted ones. Salt stress at the second salinity level (EC 6.95 dS m?1) induced the highest alteration of examined growth and quality parameters. The total increase of phenols, flavonoids, ascorbate and lycopene content in the fruits of both grafted and non‐grafted plants for both cultivars had a similar trend and intensity, though some inter‐cultivar variation was observed. The possibility of grafting tomato plants to improve salt tolerance without fruit quality loss is discussed. 相似文献