Unraveling Epigenetic Changes in Calli: Impact of HDAC Inhibitors.

The ability for plant regeneration from dedifferentiated cells opens up the possibility for molecular bioengineering to produce crops with desirable traits. Developmental and environmental signals that control cell totipotency are regulated by gene expression via dynamic chromatin remodeling. Using a mass spectrometry-based approach, we investigated epigenetic changes to the histone proteins during callus formation from roots and shoots of seedlings.

Sulfate supplementation affects nutrient and photosynthetic status of Arabidopsis thaliana and Nicotiana tabacum differently under prolonged exposure to cadmium.

Hydroponic experiments were performed to examine the effect of prolonged sulfate limitation combined with cadmium (Cd) exposure in Arabidopsis thaliana and a potential Cd hyperaccumulator, Nicotiana tabacum. Low sulfate treatments (20 and 40 µM MgSO) and Cd stress (4 µM CdCl) showed adverse effects on morphology, photosynthetic and biochemical parameters and the nutritional status of both species. For example, Cd stress decreased NO root content under 20 µM MgSO to approximately 50% compared with respective controls.

[Catalytic activity of butyrylcholinesterase in biodegradation of organic ammonium salts in vitro].

Organic ammonium salts of N-(2-benzoyloxyethyl)-alkyldimethylammonium bromide (BCHn-1) type are formed by the homological series Ar-COO(CH2)2-N+(CH3)2CnH2a + 1.Br-, whose structure contains a biodegradably labile ester bond, on the basis of which they rank among disinfectants and antiseptics of soft character. They are preferentially biotransformed hydrolytically to produce benzoic acid and substituted choline.

[Inter-organ variability in enzymatic hydrolysis of ammonium salts in rats in vitro].

The study evaluated the rate and kinetics of enzymatic hydrolysis of N-(2-benzoyloxyethyl)-alkyl-dimethylammonium bromides, potential easily biodegradable disinfectants of soft character. The products of enzymatic hydrolysis of the substrates under study, catalysed by microsomal esterase, included substituted substrates choline and benzoic acid which, as a hydrolytic product, was essayed by HPLC. The effect of the length of the alkyl chain of the individual homologues on the rate of enzymatic hydrolysis and their affinity to microsomal esterase of the rat liver and lung in vitro was examined.

[Metabolic N- and S-oxygenation of dokloxytepin in vitro].

Dokloxytepin in the medium of the induced monooxygenase system of the microsomal fraction of the liver of the rat, rabbit and mice is metabolized into three metabolites: two identical, i.e., N-oxide and 5-sulfoxide, and a third different one.

[The effect of cofactors on microsomal S-oxygenation of oxyprothepine].

Oxyprothepine in the medium of the microsomal fraction of the rat liver is biotransformed to the corresponding metabolites originating by oxidation of both sulfur atoms. The formation of S-oxygenation products is bound to the presence of NADPH, with a marked synergism with NADH. Induction with phenobarbital increases the formation of the individual metabolites.

Characterization of a rat lung microsomal fraction obtained by sepharose 2B ultrafiltration.

A new procedure for obtaining rat lung microsomes essentially free of interfering hemoproteins has been developed. The method includes Sepharose 2B column chromatography of the 12,000 X g supernatant of lung homogenates, followed by ultracentrifugation of the material eluted in the void volume. Microsomes isolated in this manner contain specific levels of cytochromes b5 and P-450 and of NADPH-cytochrome c reductase that are among the highest ever reported for a rat lung microsomal fraction.