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 31 毫秒
1.
Synthesis of novel polyamines in Paracoccus, Rhodobacter and Micrococcus   总被引:1,自引:0,他引:1  
Abstract The Gram-negative facultative chemolithotroph, Paracoccus denitrificans contains putrescine, cadaverine, agmatine, spermidine, aminopropylcadaverine, spermine, thermospermine and aminopentylnorspermidine. This bacterium has the ability to produce norspermidine from supplemented diaminopropane. The halophile, Paracoccus halodenitrificans is devoid of any polyamines. Neither decarboxylation of ornithine, lysine or arginine, nor triamine synthetic activity from diamines was detected in this halophile. Two Gram-negative facultative photoautotrophs, Rhodobacter sphaeroides and Rhodobacter capsulatus contain putrescine, cadaverine, agmatine and spermidine and can produce norspermidine from supplemented diaminopropane. A Gram-negative eubacterium, Micrococcus cryophilus , contains histamine and homospermidine in addition to putrescine, cadaverine and spermidine. Hence, polyamine distribution patterns and polyamine biosynthetic activities were very different among the four groups of Gram-negative eubacteria examined.  相似文献   

2.
Accumulation and ethylene-dependent translocation of free polyamines was studied in various organs, the phloem and xylem exudates of common ice plants (Mesembryanthemum crystallinum L.). Under normal conditions (23–25°C), spermidine predominated among polyamines. Cadaverine was found in old leaves, stems, and, in large quantities, in roots. The heat shock treatment (HS; 47°C, 2 h) of intact plant shoots induced intense evolution of ethylene from leaves but reduced the leaf content of polyamines. Under these conditions, the concentration of polyamines in roots, particularly of cadaverine, increased many times. The HS treatment of roots (40°C, 2 h) induced translocation of cadaverine to stems and putrescine to leaves. An enhanced polyamine content after HS treatment was also found in the xylem and phloem exudates. The exposure of detached leaves to ethylene led to a reduction in their putrescine and spermidine and accumulation of cadaverine, which implies the ethylene-dependent formation of cadaverine and a possible relation between the HS-induced translocation of this diamine to roots and the transient ethylene evolution by leaves. To validate this hypothesis, we compared the ethylene evolution rate and interorgan partitioning of cadaverine and other polyamines for two lines of Arabidopsis thaliana: the wild type (Col-0) and ein4 mutant with impaired ethylene reception. In plants grown in light at 20–21°C, the rate of ethylene evolution by rosetted leaves was higher in the mutant than in the wild type. The content of putrescine and spermidine was reduced in mutant leaves, whereas cadaverine concentration increased almost threefold compared with the wild type. In roots, cadaverine was found only in the wild type and not in the mutant line. Our data indicate the ethylene-dependent formation of cadaverine in leaves and possible involvement of cadaverine and ethylene in the long-distance translocation of stress (HS) signal in plants.  相似文献   

3.
4.
Abstract Eighteen strains of Rhizobium including four species, R. leguminosarum, R. meliloti, R. loti and R. fredii , nine strains of Bradyrhizobium japonicum and three strains of Azorhizobium caulinodans contained putrescine and honospermidine as major polyamines. All these nodulating N2-fixing rhizobia lack spermidine. Spermidine and cadaverine were present only in a limited number of R. meliloti and B. japonicum . Polymanine-synthetic activity was not affected by the differences in ability to produce phytoxine (rhizobitoxine and dihydrorhizobitoxine) H2-uptake-hydrogenation in the organisms. Putrescine and homospermidine were major polyamined in a strain of Agrobacterium rhizogenes . All the eight strains of Agrobacterium tumefaciens as well as A. rubi, A. radiobacter and two other strains of A. rhizogenes contained putrescine and spermidine as major polyamines and homospermidine and spermine (and thermospermine) as minor polyamines.  相似文献   

5.
Abstract Polyamines were analyzed in 4 species of genus Agrobacterium . Not only putrescine, spermidine and spermine, but also homospermidine and thermospermine were found in A. tumefaciens, A. radiobacter, A. rubi and A. rhizogenes . Trace amounts of aminopropylhomospermidine were also observed. Norspermidine and norspermine were formed from diamonorpropane added to the medium. Aminopropylcadaverine and its aminopropyl derivative(s) (aminopentylnorspermidine and N,N '-bis(3-aminopropyl) cadaverine) were produced from the supplemented cadaverine. A strain of A. rhizogenes normally contains only putrescine and homospermidine; no other diamines, triamines and tetraamines were synthesized.  相似文献   

6.
Effects of diamines, polyamines, and other basic amino acidson the growth of lettuce hypocotyls were investigated. Putrescine,cadaverine and agmatine enhanced the hypocotyl growth in thepresence of gibberellin, while spermidine and spermine werenon-effective. Arginine and ornithine, which may be precursorsof putrescine, had similar effect. While the growth inhibitiondue to arcaine (1,4-diguanidinobutane), which is a agmatineiminohydrolase inhibitor, was recovered by agmatine, cadaverine,putrescine, and spermidine, putrescine most effectively recoveredits growth-enhancing effect. (Received August 25, 1982; Accepted December 27, 1982)  相似文献   

7.
The distribution of the diamines cadaverine and putrescine and of the polyamines spermidine and spermine has been determined in pea seedlings at variou  相似文献   

8.
Qualitative and quantitative determinations of polyamines have been done in 4 photosynthetic eubacteria and 6 extreme-halophilic archaebacteria. For comparison, 5 moderate-halophilic eubacteria were also analyzed to determine their polyamine contents. Not only putrescine and spermidine but also homospermidine were found in the photosynthetic eubacteria, especially in the N2-fixing species, Rhodospirillum and Chromatium. Norspermidine, norspermine, and spermine were not detected in the phototrophic eubacteria. No appreciable amount of any polyamine was found in extreme-halophilic archaebacteria, Halobacterium and Halococcus, while moderate-halophilic eubacteria contained quite high concentrations of putrescine and spermidine and cadaverine. When arginine was incubated with cell lysates of these two archaebacteria, appreciable amounts of agmatine were produced; neither putrescine nor cadaverine was formed in the presence of ornithine or lysine. No detectable amount of spermidine was produced by the lysates on incubation with putrescine.  相似文献   

9.
Spermidine synthase genes are essential for survival of Arabidopsis   总被引:14,自引:0,他引:14       下载免费PDF全文
The cellular polyamines putrescine, spermidine, and spermine are ubiquitous in nature and have been implicated in a wide range of growth and developmental processes. There is little information, however, on mutant plants or animals defective in the synthesis of polyamines. The Arabidopsis genome has two genes encoding spermidine synthase, SPDS1 and SPDS2. In this paper, we describe T-DNA insertion mutants of both of these genes. While each mutant allele shows normal growth, spds1-1 spds2-1 double-mutant seeds are abnormally shrunken and they have embryos that are arrested morphologically at the heart-torpedo transition stage. These seeds contain significantly reduced levels of spermidine and high levels of its precursor, putrescine. The embryo lethal phenotype of spds1-1 spds2-1 is complemented by the wild-type SPDS1 gene. In addition, we observed a nearly identical seed phenotype among an F2 seed population from the cross between the spds2-1 allele and SPDS1 RNA interference transgenic lines. These data provide the first genetic evidence indicating a critical role of the spermidine synthase in plant embryo development.  相似文献   

10.
Sequence analysis of the chromosomal Tn5lacZ flanking regions of the Pseudomonas fluorescens WCS365 competitive root colonization mutant PCL1206 showed that the Tn5lacZ is inserted between genes homologous to bioA and potF. The latter gene is the first gene of the potF1F2GHI operon, which codes for a putrescine transport system in Escherichia coli. The position of the Tn5lacZ suggests an effect on the expression of the pot operon. A mutation in the potF1 gene as constructed in PCL1270, however, had no effect on competitive root colonization. The rate of uptake of [1,4-14C]putrescine by cells of mutant PCL1206 appeared to be increased, whereas cells of strain PCL1270 were strongly impaired in the uptake of putrescine. Dansylation of tomato root exudate and subsequent thin-layer chromatography showed the presence of a component with the same Rf value as dansyl-putrescine, which was identified as dansyl-putrescine by mass spectrometric analyses. Other polyamines such as spermine and spermidine were not detected in the root exudate. Growth of mutant strains, either alone or in competition with the wild type, was tested in media containing putrescine, spermine, or spermidine as the sole nitrogen source. The results show that mutant PCL1206 is strongly impaired in growth on putrescine and slightly impaired on spermine and spermidine. The presence of the polyamines had a similar effect on the growth rate of strain PCL1270 in the presence of putrescine but a less severe effect in the presence of spermine and spermidine. We conclude that an increased rate of putrescine uptake has a bacteriostatic effect on Pseudomonas spp. cells. We have shown that putrescine is an important tomato root exudate component and that root-colonizing pseudomonads must carefully regulate their rate of uptake because increased uptake causes a decreased growth rate and, therefore, a decreased competitive colonization ability.  相似文献   

11.
Veillonella alcalescens strain ATCC 17745 was shown to require putrescine or cadaverine for growth. None of the other compounds tried, including magnesium and spermidine, were able to substitute for the diamines. Studies with labeled diamines showed that spermidine was made from putrescine in this organism. A polyamine analogous to spermidine, but made from cadaverine, was not found. A combination of growth experiments and chemical assays suggested that protein synthesis was limited in diamine-starved cells. Protein synthesis occurred prior to nucleic acid synthesis when putrescine was added to starved cells.  相似文献   

12.
The properties of the protein encoded by YKL174c (TPO5) were studied. It was found that TPO5 excretes putrescine effectively and spermidine less effectively. Gamma-aminobutyric acid slightly inhibited the excretion of putrescine, but basic amino acids did not affect excretion, suggesting that TPO5 preferentially recognizes polyamines. Accordingly, yeast cells transformed with the plasmid encoding YKL174c (TPO5) were resistant to toxicity caused by 120 mm putrescine or by 3 mm spermidine, and a mutant with a disrupted YKL174c (TPO5) gene was sensitive to toxicity by 90 mm putrescine. The growth of this mutant was faster than that of the wild-type strain. In parallel, there was an increase in putrescine and spermidine content of the YKL174c (TPO5) mutant compared with wild-type. It is noted that TPO5 functions as a suppressor of cell growth by excreting polyamines. The level of YKL174c (TPO5) mRNA was increased by the addition of polyamines to the medium. The degree of induction of the mRNA was spermine > spermidine > putrescine. The subcellular localization of TPO5 was determined by immunostaining of hemagglutinin-tagged TPO5, and it was found on Golgi or post-Golgi secretory vesicles. Excretion of putrescine and spermidine by TPO5 was reduced in cells that have mutations in the secretory or endocytic pathways, indicating that both processes are involved in the excretion of polyamines.  相似文献   

13.
The diamines putrescine and cadaverine and the polyamines spermine and spermidine inhibited the senescence of nonphotosynthetic cultures of Paul's Scarlet rose. Response was observed when the media of stationary phase cultures was adjusted to either 1 mM of cadaverine or putrescine; or 0.1 μM of either spermine or spermidine along with 2% sucrose in all cases. Senescence of the cultures was followed by microscopic examination of cell aliquots removed at 10 day intervals and treated with the vital stain, fluorescein diacetate.  相似文献   

14.
15.
1. The specificity of rat prostatic spermidine synthase and spermine synthase with respect to the amine acceptor of the propylamine group was studied. 2. Spermidine synthase could use cadaverine (1,5-diaminopentane) instead of putrescine, but the Km for cadaverine was much greater and the rate with 1mM-cadaverine was only 10% of that with putrescine. 1,3-Diaminopropane was even less active (2% of the rate with putrescine) and no other compound tested (including longer alpha,omega-diamines, spermidine and its homologues and monoacetyl derivatives) was active. 3. Spermine synthase was equally specific. The only compounds tested that showed any activity were 1,8-diamino-octane, sym-homospermidine, sym-norspermidine and N-(3-aminopropyl)-cadaverine, which at 1mM gave rates 2, 17, 3 and 4% of the rate with spermidine respectively. 4. The formation of polyamine derivatives of cadaverine and to a very small extent of 1,3-diaminopropane was confirmed by exposing transformed mouse fibroblasts to these diamines when synthesis of putrescine was prevented by alpha-difluoromethylornithine. Under these conditions the cells accumulated significant amounts of N-(3-aminopropyl)cadaverine and NN'-bis(3-aminopropyl)cadaverine when exposed to cadaverine and small amounts of sym-norspermidine and sym-norspermine when exposed to 1,3-diaminopropane.  相似文献   

16.
Polyamine contents of various species of plants and fungi including Bryophyta, Pteridophyta, Gymnospermae, Ascomycota, Basidiomycota, and Lichenobionta were determined by the combination of six chromatographic techniques. Polyamines examined included putrescine, spermidine, spermine, 1,3-diaminopropane (diaminopropane), sym-norspermidine (norspermidine), sym-norspermine (norspermine), thermospermine, caldopentamine, homocaldopentamine, cadaverine, aminopropylcadaverine, sym-homospermidine (homospermidine), agmatine, and canavalmine. In addition to the widely occurring polyamines (putrescine, spermidine, and spermine), the "unusual" polyamines norspermidine and norspermine were found to be widely distributed in Bryophyta and Lichenobionta. These two polyamines were not detected in any species of Pteridophyta, Gymnospermae, and fungi even though their possible precursor, diaminopropane, was found in some species. Homospermidine was one of the major polyamines in Bryophyta and Lichenobionta, and was detected in most species of Pteridophyta and sporadically in higher plants. Agmatine was detected in most species of Bryophyta and in certain species of Gymnospermae. These data suggest that norspermidine, norspermine, and homospermidine can serve as chemical phylogenic and taxonomic markers in Plantae and Fungi.  相似文献   

17.
The ubiquitous polyamines spermidine and spermine are known as modulators of glutamate receptors and inwardly rectifying potassium channels. They are synthesized by a set of specific enzymes in which spermidine synthase is the rate-limiting step catalysing the formation of the spermine precursor spermidine from putrescine. Spermidine and spermine were previously localized to astrocytes, probably reflecting storage rather than synthesis in these cells. In order to identify the cellular origin of spermidine and spermine synthesis in the brain, antibodies were raised against recombinant mouse spermidine synthase. As expected, strong spermidine synthase-like immunoreactivity was obtained in regions known to express high levels of spermidine and spermine, such as the hypothalamic paraventricular and supraoptic nuclei. In the striatum, spermidine synthase was found in neurones and the neuropil of the patch compartment (striosome) as defined by expression of the micro opiate receptor. The distinct expression pattern of spermidine synthase, however, only partially overlapped with the distribution of the products spermidine and spermine in the striatum. In addition, spermidine synthase-like immunoreactivity was seen in patch compartment-apposed putative interneurones. These spermidine synthase-positive neurones did not express any marker characteristic of the major striatal interneurone classes. The neuropil labelling in the patch compartment and in adjacent putative interneurones may indicate a role for polyamines in intercompartmental signalling in the striatum.  相似文献   

18.
Homospermidine synthase is the first specific enzyme in the biosynthesis of pyrrolizidine alkaloids. Whereas the substrates putrescine and spermidine are part of the highly dynamic polyamine pool of plants, the product homospermidine is incorporated exclusively into the necine base moiety of pyrrolizidine alkaloids. Recently, the gene encoding homospermidine synthase has been shown to have been recruited several times independently during angiosperm evolution by the duplication of the gene encoding deoxyhypusine synthase. To test whether high levels of homospermidine suffice for conversion, at least in traces, to precursors of pyrrolizidine alkaloids, transgenic tobacco plants were generated expressing homospermidine synthase. Analyses of the polyamine content revealed that, in the transgenic plants, about 80% of spermidine was replaced by homospermidine without any conspicuous modifications of the phenotype. Tracer-feeding experiments and gas chromatographic analyses suggested that these high levels of homospermidine were not sufficient to explain the formation of alkaloid precursors. These results are discussed with respect to current models of pathway evolution.  相似文献   

19.
Hamana K  Nakagawa Y 《Microbios》2001,106(413):7-17
Cellular polyamines of eighteen genera belonging to the Flavobacterium-Flexibacter-Cytophaga complex were analysed by ion exchange liquid chromatography. Homospermidine was the major polyamine in the genera Bergeyella, Riemerella, Ornithobacterium, Weeksella, Capnocytophaga, Polaribacter and Psychroflexus belonging to the family Flavobacteriaceae. In the family Spirosomaceae, Runella, Spirosoma and Flectobacillus species contained spermidine whereas Cyclobacterium species contained homospermidine. Within a divergent cluster, Haliscomenobacter and Lewinella species contained spermidine whereas Saprospira grandis contained agmatine alone. The major polyamine of Chitinophaga and Sporocytophaga species was homospermidine. Flexithrix dorotheae contained spermidine. Microscilla marina, the type species of the genus Microscilla, contained spermidine and cadaverine. However, 'Microscilla sericea' contained homospermidine, 'Microscilla furvescens' contained spermidine, and 'Microscilla arenaria' lacked all polyamines. Polyamine profiles serve as a phenotypic chemotaxonomic marker for the reclassification of the genera belonging to the complex.  相似文献   

20.
The effect of polyamines and related metabolites on several parameters of leaf senescence was followed in detached radish ( Raphanus sativus L. var. radicular cv. "Giant Butter") leaves floated on test solutions in darkness. Leaf senescence was accompanied by a marked loss of chlorophyll, which started at 24–48 h of incubation. The polyamines, spermine and spermidine, and the diamines, putrescine and cadaverine, were highly effective in arresting chlorophyll loss over a period of at least 96 h. l -arginine, and especially l -ornithine, were less active. Polyaminens prevented the marked chlorophyll loss in dark-incubated leaves, but did not compensate for the moderate chlorophyll loss when the leaves were aged in light. Polyamines were also highly effective in retarding earlier events of leaf senescence, prior to chlorophyll loss: both protein degradation and ribonuclease activity were inhibited by spermidine. Chlorophyll and protein loss in dark-or light-incubated suspensions of either "intact" or disrupted chloroplasts was not affected by polyamines. – It is concluded that polyamines are highly effective in preventing chlorophyll loss from detached leaves, possibly by controlling early senescence-linked events which occur in darkness rather than by direct inhibition of chlorophyll degradation.  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