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Journal of Experimental Botany Sep 2022The ornithine-urea cycle (urea cycle) makes a significant contribution to the metabolic responses of lower photosynthetic eukaryotes to episodes of high nitrogen...
The ornithine-urea cycle (urea cycle) makes a significant contribution to the metabolic responses of lower photosynthetic eukaryotes to episodes of high nitrogen availability. In this study, we compared the role of the plant urea cycle and its relationships to polyamine metabolism in ammonium-fed and nitrate-fed Medicago truncatula plants. High ammonium resulted in the accumulation of ammonium and pathway intermediates, particularly glutamine, arginine, ornithine, and putrescine. Arginine decarboxylase activity was decreased in roots, suggesting that the ornithine decarboxylase-dependent production of putrescine was important in situations of ammonium stress. The activity of copper amine oxidase, which releases ammonium from putrescine, was significantly decreased in both shoots and roots. In addition, physiological concentrations of ammonium inhibited copper amine oxidase activity in in vitro assays, supporting the conclusion that high ammonium accumulation favors putrescine synthesis. Moreover, early supplementation of plants with putrescine avoided ammonium toxicity. The levels of transcripts encoding urea-cycle-related proteins were increased and transcripts involved in polyamine catabolism were decreased under high ammonium concentrations. We conclude that the urea cycle and associated polyamine metabolism function as important protective mechanisms limiting ammonium toxicity in M. truncatula. These findings demonstrate the relevance of the urea cycle to polyamine metabolism in higher plants.
Topics: Amine Oxidase (Copper-Containing); Ammonium Compounds; Medicago truncatula; Ornithine; Polyamines; Putrescine; Spermidine; Urea
PubMed: 35608836
DOI: 10.1093/jxb/erac235 -
Scientific Reports Mar 2023Bacterial phytopathogens living on the surface or within plant tissues may experience oxidative stress because of the triggered plant defense responses. Although it has...
Bacterial phytopathogens living on the surface or within plant tissues may experience oxidative stress because of the triggered plant defense responses. Although it has been suggested that polyamines can defend bacteria from this stress, the mechanism behind this action is not entirely understood. In this study, we investigated the effects of oxidative stress on the polyamine homeostasis of the plant pathogen Pseudomonas syringae and the functions of these compounds in bacterial stress tolerance. We demonstrated that bacteria respond to HO by increasing the external levels of the polyamine putrescine while maintaining the inner concentrations of this compound as well as the analogue amine spermidine. In line with this, adding exogenous putrescine to media increased bacterial tolerance to HO. Deletion of arginine decarboxylase (speA) and ornithine decarboxylate (speC), prevented the synthesis of putrescine and augmented susceptibility to HO, whereas targeting spermidine synthesis alone through deletion of spermidine synthase (speE) increased the level of extracellular putrescine and enhanced HO tolerance. Further research demonstrated that the increased tolerance of the ΔspeE mutant correlated with higher expression of HO-degrading catalases and enhanced outer cell membrane stability. Thus, this work demonstrates previously unrecognized connections between bacterial defense mechanisms against oxidative stress and the polyamine metabolism.
Topics: Polyamines; Spermidine; Putrescine; Pseudomonas syringae; Hydrogen Peroxide; Oxidative Stress; Ornithine Decarboxylase
PubMed: 36922543
DOI: 10.1038/s41598-023-31239-x -
Behavioural Processes Dec 2021As in many other species of nonhuman primates, chimpanzee mothers with a dead infant may continue to care for and transport the infant for days, weeks, or even longer....
As in many other species of nonhuman primates, chimpanzee mothers with a dead infant may continue to care for and transport the infant for days, weeks, or even longer. The bereaved females do this despite what humans perceive as the foul odour from the putrefying corpse. Putrescine is a major contributor to the "smell of death," and it elicits behaviours aimed at getting rid of the source of the smell, or escape responses in mammals including humans. However, it has never been shown that the odour of putrescine is aversive to chimpanzees. To address this question, we visually presented six adult chimpanzees with the corpse of a small bird, or a stuffed glove, in association with putrescine, ammonia, or water, and recorded the chimpanzees' reactions. The apes spent significantly less time near the object when it was paired with putrescine than the other substances, although they showed no signs of increased arousal or anxiety. We interpret the findings as evidence of an aversion to the smell of death in chimpanzees, discuss the implications for understanding the continued maternal-like behaviour of bereaved female chimpanzees, and suggest future research directions for the field of comparative evolutionary thanatology.
Topics: Animals; Cues; Death; Female; Pan troglodytes; Putrescine; Social Behavior
PubMed: 34742895
DOI: 10.1016/j.beproc.2021.104538 -
Plant Physiology Mar 2022Growth promotion induced by the endosymbiont Piriformospora indica has been observed in various plants; however, except growth phytohormones, specific functional...
Growth promotion induced by the endosymbiont Piriformospora indica has been observed in various plants; however, except growth phytohormones, specific functional metabolites involved in P. indica-mediated growth promotion are unknown. Here, we used a gas chromatography-mass spectrometry-based untargeted metabolite analysis to identify tomato (Solanum lycopersicum) metabolites whose levels were altered during P. indica-mediated growth promotion. Metabolomic multivariate analysis revealed several primary metabolites with altered levels, with putrescine (Put) induced most significantly in roots during the interaction. Further, our results indicated that P. indica modulates the arginine decarboxylase (ADC)-mediated Put biosynthesis pathway via induction of SlADC1 in tomato. Piriformospora indica did not promote growth in Sladc1-(virus-induced gene silencing of SlADC1) lines of tomato and showed less colonization. Furthermore, using LC-MS/MS we showed that Put promoted growth by elevation of auxin (indole-3-acetic acid) and gibberellin (GA4 and GA7) levels in tomato. In Arabidopsis (Arabidopsis thaliana) adc knockout mutants, P. indica colonization also decreased and showed no plant growth promotion, and this response was rescued upon exogenous application of Put. Put is also important for hyphal growth of P. indica, indicating that it is co-adapted by both host and microbe. Taken together, we conclude that Put is an essential metabolite and its biosynthesis in plants is crucial for P. indica-mediated plant growth promotion and fungal growth.
Topics: Basidiomycota; Chromatography, Liquid; Gene Expression Regulation, Plant; Plant Roots; Putrescine; Tandem Mass Spectrometry
PubMed: 34791442
DOI: 10.1093/plphys/kiab536 -
Comparison of Mobile Phone and CCD Cameras for Electrochemiluminescent Detection of Biogenic Amines.Sensors (Basel, Switzerland) Sep 2022Biogenic amines are an important and widely studied class of molecules due to their link to the physiological processes of food-related illnesses and histamine...
Biogenic amines are an important and widely studied class of molecules due to their link to the physiological processes of food-related illnesses and histamine poisoning. Electrochemiluminescent (ECL) detection offers an inexpensive and portable analytical method of detection for biogenic amines when coupled with recent advancements in low-cost carbon-based electrodes and a smartphone camera. In this work, a mobile phone camera was evaluated against a piece of conventional instrumentation, the charge-coupled device, for the detection of ECL from the reaction of biogenic amines with the luminescent compound tris(2,2'-bipyridyl)ruthenium(II). Assisted by a 3D-printed light-tight housing, the mobile phone achieved limits of detection of 127, 425 and 421 μM for spermidine, putrescine, and histamine, respectively. The mobile phone's analytical figures of merit were lesser than the CCD camera but were still within the range to detect contamination. In an exploration of real-world samples, the mobile phone was able to determine the contents of amines in skim milk on par with that of a CCD camera.
Topics: Biogenic Amines; Carbon; Cell Phone; Histamine; Luminescent Measurements; Organometallic Compounds; Putrescine; Spermidine
PubMed: 36146357
DOI: 10.3390/s22187008 -
Journal of Neurology, Neurosurgery, and... Feb 1986The contents of free and conjugated polyamines in cyst fluids of brain tumours were analysed. The putrescine and N1-acetylspermidine levels in cyst fluids of malignant...
The contents of free and conjugated polyamines in cyst fluids of brain tumours were analysed. The putrescine and N1-acetylspermidine levels in cyst fluids of malignant brain tumours were significantly higher than those of benign tumours. The free spermidine levels in malignant and benign tumours were about the same, while the total spermidine levels were higher in malignant than those in benign tumours. These results suggest that polyamine levels in cyst fluids reflect the altered polyamine metabolism in brain tumours.
Topics: Brain; Brain Neoplasms; Cysts; Humans; Putrescine; Spermidine; Spermine
PubMed: 3950641
DOI: 10.1136/jnnp.49.2.209 -
Journal of Plant Physiology Jul 2019Treatment of Arabidopsis thaliana seedlings with the PSII-inhibiting herbicide atrazine results in xenobiotic and oxidative stress, developmental arrest, induction of...
Treatment of Arabidopsis thaliana seedlings with the PSII-inhibiting herbicide atrazine results in xenobiotic and oxidative stress, developmental arrest, induction of senescence and cell death processes. In contrast, exogenous sucrose supply confers a high level of atrazine stress tolerance, in relation with genome-wide modifications of transcript levels and regulation of genes involved in detoxification, defense and repair. However, the regulation mechanisms related to exogenous sucrose, involved in this sucrose-induced tolerance, are largely unknown. Characterization of these mechanisms was carried out through a combination of transcriptomic, metabolic, functional and mutant analysis under different conditions of atrazine exposure. Exogenous sucrose was found to differentially regulate genes involved in polyamine synthesis. ARGININE DECARBOXYLASE ADC1 and ADC2 paralogues, which encode the rate-limiting enzyme (EC 4.1.1.19) of the first step of polyamine biosynthesis, were strongly upregulated by sucrose treatment in the presence of atrazine. Such regulation occurred concomitantly with significant changes of major polyamines (putrescine, spermidine, spermine). Physiological characterization of a mutant affected in ADC activity and exogenous treatments with sucrose, putrescine, spermidine and spermine further showed that modification of polyamine synthesis and of polyamine levels could play adaptive roles in response to atrazine stress, and that putrescine and spermine had antagonistic effects, especially in the presence of sucrose. This interplay between sucrose, putrescine and spermine is discussed in relation with survival and anti-death mechanisms in the context of chemical stress exposure.
Topics: Arabidopsis; Atrazine; Cell Death; Herbicide Resistance; Herbicides; Oxidative Stress; Photosynthesis; Photosystem II Protein Complex; Putrescine; Real-Time Polymerase Chain Reaction; Seedlings; Spermidine; Spermine; Sucrose; Transcriptome
PubMed: 31121522
DOI: 10.1016/j.jplph.2019.04.012 -
International Journal of Molecular... Oct 2021Although the relationship between polyamines and photosynthesis has been investigated at several levels, the main aim of this experiment was to test...
Although the relationship between polyamines and photosynthesis has been investigated at several levels, the main aim of this experiment was to test light-intensity-dependent influence of polyamine metabolism with or without exogenous polyamines. First, the effect of the duration of the daily illumination, then the effects of different light intensities (50, 250, and 500 μmol m s) on the polyamine metabolism at metabolite and gene expression levels were investigated. In the second experiment, polyamine treatments, namely putrescine, spermidine and spermine, were also applied. The different light quantities induced different changes in the polyamine metabolism. In the leaves, light distinctly induced the putrescine level and reduced the 1,3-diaminopropane content. Leaves and roots responded differently to the polyamine treatments. Polyamines improved photosynthesis under lower light conditions. Exogenous polyamine treatments influenced the polyamine metabolism differently under individual light regimes. The fine-tuning of the synthesis, back-conversion and terminal catabolism could be responsible for the observed different polyamine metabolism-modulating strategies, leading to successful adaptation to different light conditions.
Topics: Light; Photosynthesis; Plant Leaves; Polyamines; Putrescine; Spermidine; Spermine; Triticum
PubMed: 34769148
DOI: 10.3390/ijms222111717 -
Journal of Bacteriology Oct 2016In bacteria, the functions of polyamines, small linear polycations, are poorly defined, but these metabolites can influence biofilm formation in several systems....
UNLABELLED
In bacteria, the functions of polyamines, small linear polycations, are poorly defined, but these metabolites can influence biofilm formation in several systems. Transposon insertions in an ornithine decarboxylase (odc) gene in Agrobacterium tumefaciens, predicted to direct synthesis of the polyamine putrescine from ornithine, resulted in elevated cellulose. Null mutants for odc grew somewhat slowly in a polyamine-free medium but exhibited increased biofilm formation that was dependent on cellulose production. Spermidine is an essential metabolite in A. tumefaciens and is synthesized from putrescine in A. tumefaciens via the stepwise actions of carboxyspermidine dehydrogenase (CASDH) and carboxyspermidine decarboxylase (CASDC). Exogenous addition of either putrescine or spermidine to the odc mutant returned biofilm formation to wild-type levels. Low levels of exogenous spermidine restored growth to CASDH and CASDC mutants, facilitating weak biofilm formation, but this was dampened with increasing concentrations. Norspermidine rescued growth for the odc, CASDH, and CASDC mutants but did not significantly affect their biofilm phenotypes, whereas in the wild type, it stimulated biofilm formation and depressed spermidine levels. The odc mutant produced elevated levels of cyclic diguanylate monophosphate (c-di-GMP), exogenous polyamines modulated these levels, and expression of a c-di-GMP phosphodiesterase reversed the enhanced biofilm formation. Prior work revealed accumulation of the precursors putrescine and carboxyspermidine in the CASDH and CASDC mutants, respectively, but unexpectedly, both mutants accumulated homospermidine; here, we show that this requires a homospermidine synthase (hss) homologue.
IMPORTANCE
Polyamines are small, positively charged metabolites that are nearly ubiquitous in cellular life. They are often essential in eukaryotes and more variably in bacteria. Polyamines have been reported to influence the surface-attached biofilm formation of several bacteria. In Agrobacterium tumefaciens, mutants with diminished levels of the polyamine spermidine are stimulated for biofilm formation, and exogenous provision of spermidine decreases biofilm formation. Spermidine is also essential for A. tumefaciens growth, but the related polyamine norspermidine exogenously rescues growth and does not diminish biofilm formation, revealing that the growth requirement and biofilm control are separable. Polyamine control of biofilm formation appears to function via effects on the cellular second messenger cyclic diguanylate monophosphate, regulating the transition from a free-living to a surface-attached lifestyle.
Topics: Agrobacterium tumefaciens; Bacterial Proteins; Biofilms; Cellulose; Gene Expression Regulation, Bacterial; Mutation; Polyamines; Putrescine; Spermidine
PubMed: 27402627
DOI: 10.1128/JB.00265-16 -
Medical Sciences (Basel, Switzerland) Aug 2022Polyamines are small organic cations that are essential for many biological processes such as cell proliferation and cell cycle progression. While the metabolism of...
Polyamines are small organic cations that are essential for many biological processes such as cell proliferation and cell cycle progression. While the metabolism of polyamines has been well studied, the mechanisms by which polyamines are transported into and out of cells are poorly understood. Here, we describe a novel role of Chmp1, a vesicular trafficking protein, in the transport of polyamines using a well-defined leg imaginal disc assay in larvae. We show that overexpression had no effect on leg development in , but does attenuate the negative impact on leg development of Ant44, a cytotoxic drug known to enter cells through the polyamine transport system (PTS), suggesting that the overexpression of downregulated the PTS. Moreover, we showed that the addition of spermine did not rescue the leg development in -overexpressing leg discs treated with difluoromethylornithine (DFMO), an inhibitor of polyamine metabolism, while putrescine and spermidine did, suggesting that there may be unique mechanisms of import for individual polyamines. Thus, our data provide novel insight into the underlying mechanisms that are involved in polyamine transport and highlight the utility of the imaginal disc assay as a fast and easy way to study potential players involved in the PTS.
Topics: Animals; Drosophila melanogaster; Eflornithine; Polyamines; Putrescine; Spermidine; Spermine
PubMed: 36135830
DOI: 10.3390/medsci10030045