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Jacek Kęsy Beata Maciejewska Magdalena Sowa Magdalena Szumilak Krzysztof Kawałowski Maja Borzuchowska Jan Kopcewicz 《Plant Growth Regulation》2008,55(1):43-50
It has been shown that both IAA and ethylene application inhibit flower induction in the short-day plant Pharbitis nil. However application of IAA has elevated ethylene production in this plant, as well. Strong enhancement of ethylene production
is also correlated with the night-break effect, which completely inhibits flowering. In order to determine what the role of
IAA and ethylene is in the photoperiodic flower induction in Pharbitis nil, we measured changes in their levels during inductive and non-inductive photoperiods, and the effects of ethylene biosynthesis
and action inhibitors on inhibition of flowering by IAA. Our results have shown that the inhibitory effect of IAA on Pharbitis nil flowering is not physiological but is connected with its effect on ethylene biosynthesis. 相似文献
3.
The influence of jasmonic acid (JA) on differentiation of meristems of the potato,Solanum tuberosum cv. Vesna, was investigated in vitro. Meristems were grown on Murashige and Skoog (MS) medium supplemented with indole-3-acetic acid (IAA) (10 μM), kinetin (10 μM), gibberellic acid (3 μM), as modified by Bang. Addition of JA in concentrations of 0.5–10 μM increased the number of meristems that developed into buds, particularly in meristems isolated from shoots grown from tubers in the dark. JA had no noticeable effect on meristems from germs grown in light. All added concentrations of JA retarded callus and root formation. The inhibitory effect on rhizogenesis disappeared immediately after transfer of the developed buds to medium without JA. 相似文献
4.
Experimental alloxan- or streptozotocin-produced diabetes in rats was accompanied by an increase in the levels of norepinephrine, dopamine, and serotonin, whereas the contents of metabolites, i.e., 5-hydroxyindoleacetic acid and homovanillic acid, in the whole brain gradually decreased with the duration of diabetes. Among the striatum, thalamus, and hypothalamus of alloxan diabetic rats, monoamine alterations were observed only in the hypothalamus; after 1 week an increase of norepinephrine content and after 13 weeks an increase of norepinephrine and dopamine contents were found. Tissues of 11 brain regions of 10 diabetic and 12 control patients post mortem were investigated for monoamine concentrations. Patients were all male, of similar age and interval between death and autopsy. Diabetic patients had an increase in the content of serotonin in the medial and lateral hypothalamus. The content of dopamine increased in the medial hypothalamus, putamen, and medial and lateral pallidus. In diabetic patients, the content of norepinephrine increased in the lateral pallidus and decreased in the nucleus accumbens and claustrum. Thus, it seems that diabetes mellitus in rats, as well as in humans is associated with regionally specific changes in brain monoamines. 相似文献
5.
Paul I. Ward Cameron P. Goater Maja Mikos 《Biological journal of the Linnean Society. Linnean Society of London》1997,61(1):139-149
Snails of the genus Lymnaea are morphologically variable and their taxonomy is unclear. In particular, the forms peregra and ovata , distinguished by shell shape, are often considered variants of the same species, L. peregra. We studied a rare situation in a Swiss mountain lake where both forms are sympatric. First, we found that the forms shows complete separation for a number of allozymes. Second, we examined the response of the two snail forms to infection by the trematode Diplostomum phoxini . For the ovata form, there was a transitory, 10% increase in the growth of infected snails compared to uninfected controls. The peregra form showed no gigantism and had higher parasite-induced mortality. Third, we assessed differences between the forms in reproduction under different environmental conditions. Density negatively influenced egg production to the same degree in both forms. However, decreasing water levels, characteristic of part of the lake studied, led to a 30% decrease in egg production for the ovata form, but only a 10% decrease for the peregra form. These differences are discussed in relation to the microdistributions of the snails in the lake and we conclude that the two forms are almost certainly separate species. 相似文献
6.
Catabolism of Endogenous Dopamine in Peripheral Tissues: Is There an Independent Role for Dopamine in Peripheral Neurotransmission? 总被引:2,自引:1,他引:1
Abstract: Dopamine (DA) and its metabolites, homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC), have been measured in peripheral tissues of the rat and human by gas chromatography-mass spectrometry. The content of HVA and DOPAC in peripheral tissue is higher than in blood and is usually higher than the content of DA. In the rat, chemical denervation with 6-hydroxydopamine decreased the tissue content of DOPAC. inhibition of monoamine oxidase increased tissue DA. Apparently, in vivo , a large quantity of peripheral DA is catabolized rather than converted to norepinephrine (NE). These observations suggest that either NE synthesis is inefficient, with a large quantity of DA wasted and not converted to NE, or that DA is physiologically utilized as a neurotransmitter and/or cotransmitter in many peripheral nerves. A survey of the reported actions of DA on peripheral tissues suggests that the latter proposal is more likely. 相似文献
7.
8.
Chronic Helicobacter pylori Infection Does Not Significantly Alter the Microbiota of the Murine Stomach 总被引:1,自引:0,他引:1 下载免费PDF全文
Mai Ping Tan Maria Kaparakis Maja Galic John Pedersen Martin Pearse Odilia L. C. Wijburg Peter H. Janssen Richard A. Strugnell 《Applied microbiology》2007,73(3):1010-1013
We examined the impact of Helicobacter pylori infection on the murine gastric microbiota by culture and terminal-restriction fragment length polymorphism and found that neither acute nor chronic H. pylori infection substantially affected the gastric microbial composition. Interestingly, the total H. pylori burden detected by real-time PCR was significantly higher than that revealed by viable counts, suggesting that the antigenic load sustaining H. pylori-induced gastritis could be considerably higher than previously believed. 相似文献
9.
Christoph Heier Ulrike Taschler Maja Radulovic Philip Aschauer Thomas O. Eichmann Susanne Grond Heimo Wolinski Monika Oberer Rudolf Zechner Sepp D. Kohlwein Robert Zimmermann 《The Journal of biological chemistry》2016,291(22):11865-11875
Fatty acid ethyl esters (FAEEs) are non-oxidative metabolites of ethanol that accumulate in human tissues upon ethanol intake. Although FAEEs are considered as toxic metabolites causing cellular dysfunction and tissue damage, the enzymology of FAEE metabolism remains poorly understood. In this study, we used a biochemical screen in Saccharomyces cerevisiae to identify and characterize putative hydrolases involved in FAEE catabolism. We found that Yju3p, the functional orthologue of mammalian monoacylglycerol lipase (MGL), contributes >90% of cellular FAEE hydrolase activity, and its loss leads to the accumulation of FAEE. Heterologous expression of mammalian MGL in yju3Δ mutants restored cellular FAEE hydrolase activity and FAEE catabolism. Moreover, overexpression or pharmacological inhibition of MGL in mouse AML-12 hepatocytes decreased or increased FAEE levels, respectively. FAEEs were transiently incorporated into lipid droplets (LDs) and both Yju3p and MGL co-localized with these organelles. We conclude that the storage of FAEE in inert LDs and their mobilization by LD-resident FAEE hydrolases facilitate a controlled metabolism of these potentially toxic lipid metabolites. 相似文献
10.
Cipollini E Riccio M Di Giaimo R Dal Piaz F Pulice G Catania S Caldarelli I Dembic M Santi S Melli M 《Biochimica et biophysica acta》2008,1783(2):312-322
Progressive myoclonus epilepsy type 1 (EPM1) is a neurodegenerative disease correlating with mutations of the cystatin B gene. Cystatin B is described as a monomeric protein with antiprotease function. This work shows that, in vivo, cystatin B has a polymeric structure, highly resistant to SDS, urea, boiling and sensitive to reducing agents and alkaline pH. Hydrogen peroxide increases the polymeric structure of the protein. Mass spectrometry analysis shows that the only component of the polymers is cystatin B. EPM1 mutants of cystatin B transfected in cultured cells are also polymeric. The banding pattern generated by a cysteine-minus mutant is different from that of the wild-type protein as it contains only monomers, dimers and some very high MW bands while misses components of MW intermediate between 25 and 250 kDa. Overexpression of wild-type or EPM1 mutants of cystatin B in neuroblastoma cells generates cytoplasmic aggregates. The cysteine-minus mutant is less prone to the formation of inclusion bodies. We conclude that cystatin B in vivo has a polymeric structure sensitive to the redox environment and that overexpression of the protein generates aggregates. This work describes a protein with a physiological role characterized by highly stable polymers prone to aggregate formation in vivo. 相似文献