Detection of Gold Nanoparticles in Rat Organs by Transmission Electron Microscopy.

The effects of water-dispersed gold nanoparticles (8.0±0.9 nm in diameter) on the rat small intestinal mucosa and Peyer plaques, liver, and spleen were studied by electron microscopy. Water-dispersed gold nanoparticles injected into isolated intestinal loop not only accumulated in the small intestinal mucosa and Peyer plaques, but also penetrated into other organs, e.g. liver and spleen. Ultrastructural changes in the cells (hyperplasia of endoplasmic reticulum) were detected in the studied organs.

Identification of silver nanoparticles in the small intestinal mucosa, liver, and spleen of rats by transmission electron microscopy.

The effects of water-dispersed Ag nanoparticles on the small intestinal mucosa, liver, and spleen of rats were studied by transmission electron microscopy. Acute experiments demonstrated penetration of Ag nanoparticles injected into the isolated intestinal loop into the intestinal mucosa, liver, and splenic tissues. Ultrastructural changes (lobed nucleus, megamitochondria) were found in the studied organs. These data indicated that injection of water-dispersed Ag nanoparticles into the gastrointestinal tract was followed by their penetration through the epithelium of the small intestinal mucosa into other organs, e.g. into the liver and spleen. This fact is essential for evaluation of potential risks of the nanoparticle effects on human health and environment.

[Effect of melafen on mitochondrial apparatus of apical meristem in growth regulation in potato tubers].

Growth stimulation in potato Solanum tuberosum L. tubers by melafen preparation caused an increase in area ofmitochondrial apparatus (increase in mitochondrial size) in apical meristem cells. Melafen stimulated mitochondrial differentiation (increase in number of condensed mitochondria enriched in cristas). Obtained data revealed an increase in activity of mitochondrial apparatus which is connected with an increase in energetic demands of cells in potato tuber apexes at melafen growth activation.

[Changes in the plastid apparatus of apical meristem cells of potato tubers upon growth regulation with jasmonic acid].

A comparative ultramorphometric study of the effect of jasmonic acid (JA) on the plastid apparatus in apical cells of potato tubers varying in physiological state was performed. When tubers were treated with JA at forced rest, the plastid apparatus of apical cells decreased in area and plastid proliferation was suppressed. When treatment was performed during growth, the area of the plastid apparatus remained unchanged, division was suppressed, and plastid budding was stimulated in apical cells. There was also a common response to JA that was independent of the physiological state of tubers. JA stimulated the development of the internal membrane system in plastids, reduced the amount of protein inclusions, and increased the portion of plastids having cisterns of the granular endoplasmic reticulum (GER) around their envelopes. The ultrastructural changes in plastids made it possible to assume that JA increases the biosynthetic activity of the plastid apparatus in apical meristem cells of potato tubers.

[Effect of melafen on the function of endoplasmic reticulum and plasmalemmal H+ -ATPase in the regulation of growth processes in potato tubers].

The mechanism of the stimulatory effect of melafen on potato tuber sprouting was studied. The treatment with 10(-8) M melafen intensified division and stretching and activated granular endoplasmic reticulum of apical meristem cells. An increase in the activity of membrane-bound H+-ATPase in the plasmalemma of parenchymal cells of melafen-treated potato tubers and enhancement of passive proton permeability of the plasmalemma was observed. In vitro studies showed that melafen at concentrations of 10(-5-10-12) M stimulated the activity of plasmalemmal H+-ATPase in a concentration-dependent manner.

[The effect of melamine salt of bis(oxymethyl)phosphinic acid (melafen) on the growth processes and cytoplasmic membrane function in potato tuber cells].

The effects of a new synthetic growth regulator, preparation melafen, on the growth processes in potato plant tubers and the H+ -ATPase activity in cell plasmalemma were studied. It was demonstrated that melafen could both stimulate and inhibit the growth of potato tubers depending on its concentration and the physiological state of the tubers. It is likely that one of the manifestations of melafen action is its influence on the division and extension of apical meristem cells. The growth stimulation caused by melafen is connected with modifications of the plasmalemma of potato tuber cells, namely, the activation of H+ -ATPase and increase in the membrane proton permeability.

[Ultramorphometric study of the plastids in apical tuber cells of original and transgenic potato plants treated with ambiol].

Ultramorphometric characteristics of plastids in cells of apical tuber meristems of original and defensin gene-transfected potato (Solanum tuberosum L.) plants, either maintained under normal conditions or subjected to treatment with the antioxidant ambiol, were compared. Under normal conditions, the tuber cells of the original and transgenic potato plants differed in neither the number nor size of the plastids. Only certain quantitative distinctions in the development of individual ultrastructural characteristics of plastids were detected. Treatment with ambiol enhanced the differentiation of the internal membrane system of plastids in the cells of original and transgenic plants, especially the tubular membrane systems. Certain differences in the responses to ambiol of cell plastids of original and transgenic plants were related to plastid sizes and development of individual intraplastid structures. The results comply with earlier data on varying responses of mitochondria of original and transgenic plants to ambiol treatment.

[Effect of ambiol on the ultrastructure of mitochondria in the apical cells of tubers of original and transgenic potato plants]. / Vliianie ambiola na ul'trastrukturu mitokhondrii v kletkakh apeksov klubnei iskhodnykh i transgennykh rastenii kartofelia.

The ultrastructure of the mitochondrial apparatus of apical tuber cells of original and transgenic (defensin gene-transfected) potato have been compared in normal and ambiol-treated plants, using morphometric approaches. No qualitative or quantitative differences were found between the mitochondria of original and transgenic plants under normal conditions (control). Treatment with ambiol produced only quantitative differences (in the number of mitochondria and their volume) between the cells of original and transgenic plants. This observation has been attributed to (1) changes in the physiology and biochemistry of transgenic plants, induced by the expression of the gene of defensin (hormonal balance, functional activity of the plasmalemmata, etc.), and (2) direct effects of ambiol.

[Morphogenetic changes in ambiol-treated regenerates of parent and transgenic potato plants]. / Morfogeneticheskie izmeneniia u regenerantov iskhodnykh i transgennykh rastenii kartofelia pod vliianiem ambiola.

The effects of ambiol, a new growth regulator, on the formation of leaves and roots in parent and defensin gene-transformed regenerants of potato Solanum tuberosum L. (cultivar Desire). Various concentrations of ambiol induced differences in morphogenetic parameters between parent and transgenic plants. In some cases, ambiol caused the formation of shoots without leaves or with rudimentary leaves. The data suggest that features of root and leaves formation in parent and transgenic regenerants induced by ambiol are due to changes in hormone balance in transgenic plants caused by expression of the defensin gene and the effect of ambiol on the plant hormonal balance.

[Effect of ambiol on stem growth in regenerants of source and transgenic potato plants]. / Vliianie ambiola na rost steblei u regenerantov iskhodnykh i transgennykh rastenii kartofelia.

The effects of ambiol, a new growth regulator, on stem growth and morphological features of stem development have been compared in regenerants of potato (Solanum tuberosum L., var. Desire) plants transgenic for a defensin gene and in original potato plants. The original and transgenic plants exhibited differences in shoot development, which were observed both in control settings (no ambiol) and in the presence of various ambiol concentrations. In addition to normal plants of both forms, plant regenerants with morphological deviations were present in ambiol-treated groups. It is suggested that the abnormal shoot development observed in original and transgenic potato plants treated with ambiol is associated with (a) hormonal changes caused by expression of the defensin gene in the transgenic plants and (b) effects of ambiol on the hormonal balance of the plants.

[Isolation of genetically modified potato plant containing the gene of defensive peptide from Amaranthus]. / Poluchenie geneticheski modifitsirovannykh rastenii kartofelia, nesushchikh gen zashchitnogo peptida amaranta.

The plants of potato (Solanum tuberosum L., var. Desire) have been transformed with a pH22Kneo vector carrying the gene ac2, encoding the fungicidal peptide (defensin) from the seed of amaranth (Amaranthus caudatus L.). The transformation involved co-cultivation of potato stem explants (excised from aseptically grown plants) and Agrobacterium tumefaciens on solid MS medium. Factors affecting in vitro regeneration of the explants and the transformation efficiency were optimized. Regenerated potato plants harboring the amaranth defensin gene were selected by two traits, growth and ability to form roots on kanamycin-supplemented MS medium. The transgenic state was confirmed PCR analysis of ac2 in tissues of the kanamycin-resistant plants. The transgenic organisms thus obtained differed from the original ambiol-treated plants in growth patterns and proton translocation across the plasma membrane of the tuber cells.

[Effect of gibberellin and auxin on the synthesis of abscisic acid and ethylyne in buds of dormant and sprouting potato tuber]. / Deistvie gibberellina i auksina na obrazovanie abstsizovoi kisloty i étilena v tochkakh rosta klubnei kartofelia v pokoe i pri prorastanii.

Gibberellic and beta-indolylacetic acids at concentrations of 10(-7)-10(-5) M were shown to change the hormonal status and duration of dormancy in potato tubers. Gibberellic acid shortened the dormancy and decreased the contents of abscisic acid and ethylene in apical meristems. beta-Indolylacetic acid elongated the dormancy, decreased abscisic acid production, but caused a more than tenfold increase in the production of ethylene by apical tissues. The data suggest that beta-indolylacetic acid and ethylene, as well as gibberellic and abscisic acids, are involved in the regulation of dormancy in potato tubers.