Metallothioneins are low-molecular-weight proteins capable of covalently binding heavy metal ions due to the presence of many cysteine residues in their sequences. We analyzed the predicted amino acid sequences of 19 metallothionein (7 from Arabidopsis thaliana and 12 from Oryza sativa) and their promoter sequences in silico in order to determine the potential regulatory cis-elements present in the promoters of metallothionein genes, from which it is possible to determine the putative functions of these genes. The PlantCARE and PLACE databases provided information about the putative regulatory elements in the metallothionein promoters. Metal response element sequences were found in the promoters of eleven O. sativa and two Arabidopsis metallothionein genes. Copper response elements were identified in both model plants, usually in many copies, particularly in O. sativa. Both the high cysteine content and the presence of metal response motifs in the promoters support the suggestion that metallothioneins play a key role in metal detoxification. The most common putative element in the analyzed promoters was CIRCADIAN, which was present in five A. thaliana and eight O. sativa sequences. The methyl jasmonate response sequence, root-specific expression element and drought response element were found only in O. sativa metallothioneins. Light and low temperature response elements, biotic and abiotic stress elements, an abscisic acid-responsive element and an ethylene-responsive element occur in selected metallothionein promoters of both species. A few promoters have putative organ-and cell-specific regulatory elements. The presence of many different motifs in the promoters of the Arabidopsis and O. sativa genes implies that metallothioneins are general stress response proteins with many important functions in plants, including regulation of their normal development and adaptation to changing environmental conditions. K Ke ey y w wo or rd ds s: : Plant metallothioneins, promoter, Oryza sativa, Arabidopsis thaliana.

The aim of the study was to obtain an efficient system for Carlina acaulis subsp. simplex propagation. The experimental materials were shoot tips, fragments of hipocotyls, cotyledons and roots isolated from 10-day-old seedlings. The explants were transferred to the proliferation medium supplemented with different types of cytokinin: BA (13.3 lM), kinetin (13.9 lM) and zeatin (13.7 lM) in combination with NAA (0.54 lM). The best morphogenetic response was observed when explants were cultured on the BA supplemented medium. The maximum shoot organogenesis frequency was observed for shoot tip (nearly 94%). On average 8.6 axillary shoots were induced per explant. Multiplication rate increased during the first three subcultures. The shoots revealed a wide range of morphogenetic responses. Differences were observed in the presence or absence of hair on the surface of lamina. These changes had epigenetic character and were the effect of changes in DNA methylation, which is shown by differences in methylation pattern between 18S rRNA and 25S rRNA genes in the analyzed regenerated plants. Nearly 94% of plantlets were rooted on auxin lacking medium. Addition of auxin (NAA or IAA) increased both the rooting percentage (100%) and the number of roots per shoot, but their growth was inhibited. Shortening of the auxin exposition time reduced the number of roots. Moreover, high efficiency (90%) was observed for ex vitro rooting. Plantlets with a large number of roots survived better than the ones with only a few roots. Plants were able to flower and gave viable seeds.

Streszczenie: Genetyczne, biochemiczne i cytologiczne studia na temat metylacji cytozyny w DNA u organizmów eukariotycznych sk³aniaj¹ do powi¹zania tego procesu z metylacj¹ histonów, interferencj¹ RNA (RNAi) i modelowaniem struktury chromatyny. Jest równie¿ oczywiste, ¿e nie ma pojedynczej drogi objaniaj¹cej powstawanie wszystkich znanych typów metylacji DNA u Eukaryota. W tym artykule zebrano wiedzê na temat kilku powszechnych mechanizmów odpowiedzialnych za kontrolê metylacji DNA.

Polycrystalline FeSe 0.88 was synthesized by solid-state reaction method in sealed quartz tube at different heat heating cycles. The identification and characterization of FeSe 0.88 samples were determined by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The electrical transport, magnetic and thermal transport properties of the obtained samples were also investigated. The results showed that the sensitivity of resistivity and magnetic susceptibility depends on heating cycles while the structural formation of samples does not. The upper critical field H c2 (0) has been determined with the magnetic field parallel to the sample surface and yielding a maximum value of 23.2 T. At the zero field coherence length, n, value was calculated to be 3.33 nm. Calculated l 0 H c2 (0)/k B T c rate indicated comparably higher value (3.17 T/K) than the Pauli limit (1.84 T/K) and obtained results were suggested unconventional nature of superconductivity in our samples.

Nowadays, the solid-state chemistry of mixed-metal oxides containing both rare-earths and d-electron metals (4d, 5d or/and 6d) has attracted a great deal of interest. These inorganic materials adopt a diverse range of structures and show a wide range of electronic properties. Rare-earth compounds have been widely used in high-performance luminescent devices, magnets, photocatalysts, pigments [1-10] and other functional materials owing to the numerous well-defined transitions modes concerning the 4f shell of their ions. Thus, in recent years, more and more interest has been put in a synthesis and a photoluminescence of new rare-earths compounds.

Single and joint ectomycorrhizal (+ Hebeloma mesophaeum) and bacterial (+ Bacillus cereus) inoculations of willows (Salix viminalis) were investigated for their potential and mode of action in the promotion of cadmium (Cd) and zinc (Zn) phytoextraction. Dual fungal and bacterial inoculations promoted the biomass production of willows in contaminated soil. Single inoculations either had no effect on the plant growth or inhibited it. All inoculated willows showed increased concentrations of nutritional elements (N, P, K and Zn) and decreased concentrations of Cd in the shoots. The lowest biomass production and concentration of Cd in the willows (+ B. cereus) were combined with the strongest expression of metallothioneins. It seems that biotic stress from bacterial invasion increased the synthesis of these stress proteins, which responded in decreased Cd concentrations. Contents of Cd and Zn in the stems of willows were combination-specific, but were always increased in dual inoculated plants.

The sensitivity of spring and winter varieties of oilseed rape to heavy metals and rhizobacteria Słowa kluczowe: Brassica napus, bakterie ryzosferowe, metale ciężkie, wzrost roślin Streszczenie Sprawdzono wpływ metali ciężkich (cynk, kadm, miedź, ołów) oraz bakterii ryzosferowych na wzrost siewek Brassica napus L. Przeanalizowano trzy odmiany rzepaku: dwie jare -Belinda i Clipper oraz jedną ozimą -Kronos. Wykazano, że porównywane odmiany charakteryzowały się zróżnicowaną wrażliwością na obecność metali ciężkich w środowisku. Najbardziej wrażliwa na metale ciężkie była odmiana ozima Kronos, natomiast najmniej -odmiana Clipper. Wszystkie analizowane szczepy ryzobakterii: Bacillus sp., Bacteroidetes bacterium, Flavobacterium sp., Luteibactor rhizovicina, Pseudomonas fluorescens, Serratia entomophila i Variovorax sp. stymulowały wzrost siewek, zwłaszcza korzeni, odmian jarych rzepaku, zaś hamowały w przypadku odmiany ozimej. Szczepy Bacteroidetes bacterium i Bacillus sp. najsilniej stymulowały wzrost siewek odmiany Kronos, a Flavobacterium sp. siewek odmiany Belinda w obecności miedzi, cynku i kadmu. Większość badanych bakterii ułatwiała rozwój siewek odmiany Clipper w środowisku zanieczyszczonym jonami cynku i ołowiu.

I ntegralne białka błonowe (MIP) są zróżnicowaną klasą białek błonowych, które pośredniczą w przepływie wody (akwaporyny), małocząsteczkowych roztworów, takich jak glicerol oraz gazów poprzez błony komórkowe. W ostatnich latach badania dostarczyły istotnych informacji pozwalających na pełniejsze scharakteryzowanie u roślin tej dużej klasy białek, kanałów wodnych. Białka MIP zidentyfi kowano w wielu organizmach zarówno jedno-jak i wielokomórkowych. Akwaporyny pełnią istotna rolę w rozwoju roślin i ich adaptacji do zmieniającego się środowiska zewnętrznego. Wpływ na ekspresję genów kodujących akwaporyny, wywierają takich czynników jak: hormony, susza, wysokie stężenia soli i światło. Aktywność kanałów wodnych jest regulowana poprzez fosforylację i protony wewnątrzkomórkowe. Przypuszcza się, że istnieją też inne mechanizmy regulacji tych białek poprzez działanie gradientu ciśnienia osmotycznego i hydrostatycznego, kontrolę reaktywnych form tlenu czy tworzenie heterotetramerów.

The stringent response is a key regulatory reaction exhibited by bacteria in response to amino acid deprivation or carbon, nitrogen and phosphate limitation. In E. coli, the products of the relA and spoT genes regulate accumulation of the effector molecules of the stringent response--guanosine tetra- and pentaphosphates (ppGpp and pppGpp respectively). These unusual hyperphosphorylated nucleotides bind directly to the bacterial RNA polymerase and change transcriptional activity of some genes--transcription repression of genes associated with the translational apparatus and the simultaneous upregulation of genes encoding metabolic enzymes, especially those involved in amino acid biosynthesis, protein hydrolysis and coding for the sigma S factor. Sigma S factor binds to the core of the bacterial RNA polymerase and induce stationary-phase-specific and stress-response-specific genes expression.