Inhibitors Influencing Plant Enzymes of the Polyamine Biosynthetic Pathway

1989 ◽  
Vol 44 (1-2) ◽  
pp. 49-54 ◽  
Author(s):  
Marbeth Christ ◽  
Hansruedi Felix ◽  
Jost Harr
Keyword(s):  
Biosynthetic Pathway ◽  
Early Stage ◽  
Arginine Decarboxylase ◽  
Polyamine Biosynthesis ◽  
Polyamine Synthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Stage Of Development ◽  
Decarboxylase Inhibitors ◽  
Plant Enzymes ◽  
To Come

Absract Several enzymes involved in polyamine biosynthesis namely ornithine, arginine and S-adenosylmethionine decarboxylase as well as spermidine synthase, were analyzed in partially purified wheat extracts. For all enzymes effective inhibitors were found. Among them the most interesting was l-aminooxy-3-aminopropane, which inhibited all three decarboxylases. Classical polyamine biosynthesis inhibitors like difluoromethylornithine, difluoromethylarginine. methyl glyoxal bis- (guanylhydrazone) and cyclohexylamine were also inhibitory on plant enzymes. A remarkable difference in the amount of arginine and ornithine decarboxylase existed in wheat. Arginine decarboxylase seems to be more important at least during the early stage of development. Influence of polyamine synthesis inhibitors on polyamine levels is more likely to come from arginine decarboxylase inhibitors. As inhibitors of all essential enzymes involved in plant polyamine biosynthesis were found, the study of the importance of polyamines in plant physiology will be considerably facilitated.

scholarly journals Overexpression of arginine decarboxylase in transgenic plants

1997 ◽  
Vol 325 (2) ◽  
pp. 331-337 ◽  
Author(s):  
Daniel BURTIN ◽  
Anthony J. MICHAEL
Keyword(s):  
Transgenic Plants ◽  
Arginine Decarboxylase ◽  
Polyamine Metabolism ◽  
Morphological Development ◽  
Polyamine Biosynthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Two Generations ◽  
Key Enzyme ◽  
Polyamine Conjugate ◽  
And Control

The activity of arginine decarboxylase (ADC), a key enzyme in plant polyamine biosynthesis, was manipulated in two generations of transgenic tobacco plants. Second-generation transgenic plants overexpressing an oat ADC cDNA contained high levels of oat ADC transcript relative to tobacco ADC, possessed elevated ADC enzyme activity and accumulated 10–20-fold more agmatine, the direct product of ADC. In the presence of high levels of the precursor agmatine, no increase in the levels of the polyamines putrescine, spermidine and spermine was detected in the transgenic plants. Similarly, the activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase were unchanged. No diversion of polyamine metabolism into the hydroxycinnamic acid–polyamine conjugate pool or into the tobacco alkaloid nicotine was detected. Activity of the catabolic enzyme diamine oxidase was the same in transgenic and control plants. The elevated ADC activity and agmatine production were subjected to a metabolic/physical block preventing increased, i.e. deregulated, polyamine accumulation. Overaccumulation of agmatine in the transgenic plants did not affect morphological development.

scholarly journals In vivo trypanocidal activities of new S-adenosylmethionine decarboxylase inhibitors.

1996 ◽  
Vol 40 (6) ◽  
pp. 1448-1453 ◽  
Author(s):  
C J Bacchi ◽  
R Brun ◽  
S L Croft ◽  
K Alicea ◽  
Y Bühler
Keyword(s):  
Inhibitory Concentration ◽  
Central Nervous System Infection ◽  
Laboratory Model ◽  
African Origin ◽  
Polyamine Biosynthesis ◽  
Active Inhibitor ◽  
Adenosylmethionine Decarboxylase ◽  
Decarboxylase Inhibitors ◽  
Modest Activity

A series of novel aromatic derivatives based on the structure of methylglyoxal bis(guanylhydrazone) (MGBG) was examined for trypanocidal activities in human and veterinary trypanosomes of African origin. One agent, CGP 40215A, a bicyclic analog of MGBG which also resembles the diamidines diminazene (Berenil) and pentamidine, was curative of infections by 19 isolates of Trypanosoma brucei subspecies as well as a Trypanosoma congolense isolate. Several of these isolates were resistant to standard trypanocides. Curative doses were < or = 25 mg/kg of body weight/day for 3 days in these acute laboratory model infections. In addition, CGP 40215A also cured a model central nervous system infection in combination with the ornithine decarboxylase inhibitor DL-alpha-difluoromethylornithine (DFMO; Ornidyl, eflornithine). Curative combinations were 14 days of oral 2% DFMO (approximately 5 g/kg/day) plus 5, 10, or 25 mg/kg/day for 3 or 7 days given by intraperitoneal injection or with a miniosmotic pump. Combinations were most effective if CGP 40215A was given in the second half or at the end of the DFMO regimen. MGBG has modest activity as an inhibitor of trypanosome S-adenosylmethionine decarboxylase (50% inhibitory concentration [IC50]. 130 microM), while CGP 40215A was a more active inhibitor (IC50, 20 microM). Preincubation of trypanosomes with CGP 40215A for 1 h caused a reduction in spermidine content (36%) and an increase in putrescine content (20%), indicating that one possible mechanism of its action may be inhibition of polyamine biosynthesis.

scholarly journals Polyamines Are Not Required for Aerobic Growth of Escherichia coli: Preparation of a Strain with Deletions in All of the Genes for Polyamine Biosynthesis

2009 ◽  
Vol 191 (17) ◽  
pp. 5549-5552 ◽  
Author(s):  
Manas K. Chattopadhyay ◽  
Celia White Tabor ◽  
Herbert Tabor
Keyword(s):  
Escherichia Coli ◽  
Ornithine Decarboxylase ◽  
Arginine Decarboxylase ◽  
Strictly Anaerobic ◽  
Lysine Decarboxylase ◽  
Free Medium ◽  
Aerobic Growth ◽  
Anaerobic Conditions ◽  
Polyamine Biosynthesis ◽  
Adenosylmethionine Decarboxylase

ABSTRACT A strain of Escherichia coli was constructed in which all of the genes involved in polyamine biosynthesis—speA (arginine decarboxylase), speB (agmatine ureohydrolase), speC (ornithine decarboxylase), spe D (adenosylmethionine decarboxylase), speE (spermidine synthase), speF (inducible ornithine decarboxylase), cadA (lysine decarboxylase), and ldcC (lysine decarboxylase)—had been deleted. Despite the complete absence of all of the polyamines, the strain grew indefinitely in air in amine-free medium, albeit at a slightly (ca. 40 to 50%) reduced growth rate. Even though this strain grew well in the absence of the amines in air, it was still sensitive to oxygen stress in the absence of added spermidine. In contrast to the ability to grow in air in the absence of polyamines, this strain, surprisingly, showed a requirement for polyamines for growth under strictly anaerobic conditions.

Regulation of ethylene and polyamine synthesis by elevated carbon dioxide in cherimoya fruit stored at ripening and chilling temperatures

1999 ◽  
Vol 26 (3) ◽  
pp. 201 ◽  
Author(s):  
M. T. Muñoz ◽  
P. Aguado ◽  
N. Ortega ◽  
M. I. Escribano ◽  
C. Merodio
Keyword(s):  
Ethylene Production ◽  
Oxidase Activity ◽  
Acc Oxidase ◽  
Arginine Decarboxylase ◽  
Chilling Temperature ◽  
Polyamine Biosynthesis ◽  
Polyamine Synthesis ◽  
High Co2 ◽  
Chilling Temperatures ◽  
Co2 Level

In this study we focused on the effect of high CO2 level (20%) on ethylene and polyamine biosynthesis in cherimoya (Annona cherimola Mill.) fruits stored at ripening (20˚C) and chilling (6˚C) temperatures. At ripening temperature, CO2 inhibited ethylene production, but 1-aminocyclopropane-1- carboxylate (ACC) oxidase activity was similar to that in ripe control fruits. CO2 treatment led to a decline in putrescine (Put) and a major accumulation of spermidine (Spd) and spermine (Spm) without any effect on arginine decarboxylase (ADC) activity. These results confirm the preferential transformation of Put to Spd and Spm in CO2 -treated fruits. At chilling temperature, the increase in ACC oxidase activity was inhibited and the Vmax of ADC increased. A combination of chilling temperature storage and high CO2 level led to suppression of basal ethylene production while ACC oxidase activity remained unchanged. In addition, fruits held at these conditions had higher polyamine titres than the untreated control. We propose that, in CO2 -treated fruits, the absence of autocatalytic or basal ethylene production, depending on the temperature, may be due to deviation of the S-adenosylmethionine (SAM) pool towards polyamine synthesis, primarily Spd and Spm.

scholarly journals Altered polyamine metabolism in the PRO/Re strain of inbred mice

1976 ◽  
Vol 158 (3) ◽  
pp. 529-533 ◽  
Author(s):  
C A Manen ◽  
R L Blake ◽  
D H Russell
Keyword(s):  
Biosynthetic Pathway ◽  
Inbred Mice ◽  
Proline Accumulation ◽  
Polyamine Metabolism ◽  
Decarboxylase Activity ◽  
Polyamine Biosynthesis ◽  
Male And Female ◽  
Adenosylmethionine Decarboxylase ◽  
Significant Difference ◽  
High Concentrations

The PRO/Re strain of inbred mice are characterized by abnormally high concentrations of proline in both blood (hyperprolinaemia) and urine (prolinuria). They excrete increased amounts of polyamines in their urine. Male PRO/Re mice excreted putrescine at 175% and spermidine at 300% the amount of male C57BL/6J controls. Female PRO/Re mice excreted putrescine at 115% and spermidine at 150% of the amount in the urine of female controls. Examination of the enzymes involved in polyamine biosynthesis revealed that ornithine decarboxylase, the initial enzyme in the polyamine-biosynthetic pathway, was increased by 150% in the kidneys and by 100% in the liver of male PRO/Re mice. There was no significant difference between PRO/Re and C57BL/6J male mice for either putrescine- or spermidine-stimulated S-adenosylmethionine decarboxylase activity. Female PRO/Re mice showed no significant difference from female C57BL/6J mice for any of the enzymes examined. When the concentrations of the polyamines in the tissues of the PRO/Re mice were determined, spermidine and spermine concentrations in the kidneys of the male PRO/Re mice were twice those of the controls. Spermidine concentration in the livers of both male and female PRO/Re mice was approx. 130% that of the controls. Polyamine concentrations in the brains were similar in controls and mutants. The increased polyamine biosynthesis and excretion in the PRO/Re mutant mice may be a mechanism to decrease the extent of proline accumulation.

scholarly journals Urban Economy of Orlovskaya and Tambovskaya Guberniyas in the Late 18th-Early 19th Centuries (General Land Survey Data)

2020 ◽  
pp. 62-79
Author(s):  
Dmitrii Anatol'evich Chernenko
Keyword(s):  
Urban Economy ◽  
Early Stage ◽  
Gis Mapping ◽  
Small Enterprises ◽  
Total Size ◽  
Urban Network ◽  
Stage Of Development ◽  
Land Survey ◽  
To Come ◽  
General Land Survey

The article poses a problem of a multi-style character of the urban economy in Russia in the late 18th - early 19th centuries and its reflection in the General Land Survey taken in European Russia at that period. These are the Economic Comments to the General Land Survey which recorded the main parameters of the urban economy within the framework of the unified description program that provide for comparing its agrarian, commercial and industrial components. The study uses the materials of the Economic Comments on 26 cities of two Black Earth Region Guberniyas of Russia &ndash; Orlovskaya and Tambovskaya ones. The specificity of the region is determined by its relatively late development and the formation of the urban network within the framework of large defensive projects of the Moscow state. Statistical analysis and GIS-mapping of the Comments data allowed one to come to the following conclusions. This region is commonly characterized by the formation of large agricultural complexes with large (more than 5 thousand desyatins) areas of arable and hay fields surrounding the cities during the General Land Survey. This circumstance significantly increased the area of the city within the framework of the "general urban boundary", but to a much lesser extent influenced the total size of its population. The industry of the cities of the region consisted almost exclusively of small "plants" while big manufacturing production was at its early stage of development and was not dependent on the processes of concentration of small enterprises in individual cities. The function of the cities of the region as centers of trade was much more pronounced. Fairs and/ or weekly auctions were held in most of them. The results of the Economic Comments statistics correlation analysis allow one to assume that further development of the Black Earth Region cities was mainly related to commercial and industrial branches of their economy.

scholarly journals Gibberellin and spermidine synergistically regulate polyamine metabolism during Rhododendron flower development

2021 ◽  
Author(s):  
Qian Xu ◽  
Huaxiong Li ◽  
Shiliang Liu ◽  
Wenpei Huang ◽  
Xiaolin Xian ◽  
...  
Keyword(s):  
Structural Equation ◽  
Early Stage ◽  
Arginine Decarboxylase ◽  
Equation Model ◽  
Flower Senescence ◽  
Polyamine Metabolism ◽  
Flower Bud ◽  
Adenosylmethionine Decarboxylase ◽  
Flower Bud Formation ◽  
Positive Effect

Abstract Polyamines (PAs) are involved in various plants developmental processes, especially in flowering. Their significant influence has been established, but the exact mechanisms by which PAs modulate flowering are not yet understood. To understand the PA metabolism during flowering/senescence in Rhododendron simsii ‘Zichendian’ plants, exogenous gibberellin (GA3, 0-2400 mg L− 1) and spermidine (Spd, 0–1 mM) were applied separately or in combination during the early stage of flower bud formation. The application of GA3 alone advanced the initial flowering by promoting the free Put (F) fraction and decreasing the Spd/Put ratio at the squaring stage, whereas Spd alone delayed the initial flowering by increasing the soluble conjugated (C) form, insoluble bound Put (B) fraction and Spd/Put ratio. When GA3 plus Spd was applied, the initial flowering advanced by 2 days. Furthermore, endogenous PA levels as well as the C and B fractions of PAs and key enzymes (diamine oxidase, PA oxidase, arginine decarboxylase, ornithine decarboxylase and S-adenosylmethionine decarboxylase) of PA metabolism increased, while the Spd/Spm ratio decreased by GA3 and Spd applications during flowering, resulting in delayed flower senescence. In addition, the structural equation model (SEM) showed that Spd directly participated in PA metabolism, while GA3 regulated flowering by modulating PA metabolism via Spd (c.f. 0.27). Taken together, our study provides comprehensive evidence regarding the clear relationships between GA3, Spd and flowering time, supporting the positive effect of PA metabolism on delaying flower senescence, and helps to provide a thorough understanding of the PA interconversions, biosynthesis and catabolism during flowering and senescence.

The Application of UX Research in New Energy Vehicle Innovation

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Menghan TAO ◽  
Ning XIAO ◽  
Xingfu ZHAO ◽  
Wenbin LIU
Keyword(s):  
Early Stage ◽  
Rapid Expansion ◽  
The Other ◽  
Innovative Product ◽  
Stage Of Development ◽  
New Energy ◽  
New Energy Vehicle ◽  
The One ◽  
New Energy Vehicles ◽  
Degree Of Innovation

New energy vehicles(NEV) as a new thing for sustainable development, in China, on the one hand has faced the rapid expansion of the market; the other hand, for the new NEV users, the current NEVs cannot keep up with the degree of innovation. This paper demonstrates the reasons for the existence of this systematic challenge, and puts forward the method of UX research which is different from the traditional petrol vehicles research in the early stage of development, which studies from the user's essence level, to form the innovative product programs which meet the needs of users and being real attractive.

Sign in / Sign up

Export Citation Format

Share Document