The effect of seed presowing treatment with polyamines (2.5 mM putrescine, 5.0 mM spermidine and 2.5 mM spermine) on growth and internal levels of different plant growth regulators in two spring wheat (Triticum aestivum L.) cultivars MH-97 and Inqlab-91 was studied. The primed seeds of each treatment and non-primed seeds were sown in a field in which NaCl salinity of 15 dS m was developed. Alth...

this study was carried out to investigate the effects of dietary putrescine (put) on broiler’s response fed low crude protein (cp) diets. a total of 192 male day old chicks were fed with four dietary treatments including two levels of put (0 and 0.03%) and two levels of cp (normal and low) with factorial combinations. weekly growth performance, nutrient digestibility and intestinal morphology (...

Polyamines, such as spermine, spermidine and putrescine, are ubiquitous polycationic compounds that are produced by almost all living organisms, including plants, animals, fungi and bacteria. Polyamines are multifunctional and interact with polyanionic biomolecules such as DNA or protein. However, despite their potential significance, the polyamine-dependent signal transduction system has not b...

Polyamines are ubiquitous organic cations of low molecular weight. The content of these amines is closely regulated by the cell according to the state of growth. The reactions responsible for the biosynthesis and interconversion of the polyamines and their precursor putrescine are described and the means by which polyamine content can be varied in response to exogenous stimuli are discussed. Th...

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...

Nucleoside analogs (NAs) are an important class of anti-retroviral compounds used against human immunodeficiency virus (HIV). We have analyzed the potential effect of polyamines on the incorporation of NAs during DNA synthesis by HIV type-1 (HIV-1) reverse transcriptase (RT). The polyamines exert the ability to decrease the incorporation of various dideoxynucleoside triphosphates (ddATP, ddTTP ...

Depletion of polyamines in 9L rat brain tumor cells by treatment with alpha-difluoromethylornithine dramatically altered DNA conformation as measured by viscoelastometry. The reduction of intracellular putrescine and spermidine concentrations to less than 5 percent of their concentrations in control cells decreased the sensitivity of 9L cell DNA to x-irradiation and increased the maximum viscoe...

1. Castration of adult rats resulted in marked decreases in the amounts of putrescine, spermidine and spermine in the ventral prostate gland. Spermidine concentrations decline rapidly over the first 11 days after androgen withdrawal, reaching a value of only 12% of normal controls. Spermine concentrations diminish more slowly, reaching 24% of normal within 11 days. The spermidine/spermine molar...

Possible changes in the intracellular concentrations of polyamines were investigated during the apoptosis of human promyelocytic leukemic HL-60 cells. Treatment of HL-60 cells with gallic acid and epigallocatechin gallate (EGCG) resulted in the rapid decline of the intracellular concentration of putrescine, whereas that of spermidine and spermine was not significantly changed during the first 3...

Adjustment of polyamine contents in Escherichia coli was studied with strains of Escherichia coli producing normal (DR112) and excessive amounts of ornithine decarboxylase [DR112(pODC)] or S-adenosylmethionine decarboxylase [DR112(pSAMDC)]. Although DR112(pODC) produced approximately 70 times more ornithine decarboxylase than DR112 did, the amounts of polyamines in the cells of both strains did...