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The inhibitory effects of cocaine and nicotine on placental amino acid transport, as a mechanism contributing to intrauterine growth restriction, were investigated in the in vitro placental perfusion model. Amino acids that represent substrates for known placental transporters were selected: alanine
A fusion of the strong cauliflower mosaic virus 35S promoter to the Activator (Ac) transposase (TPASE) gene does not trigger excision of Dissociation (Ds) continuously during tobacco cotyledon development, although once activated, the 35S promoter remains active throughout embryogeny. Epistasis
To explore the effects of altering the level of Activator (Ac) transposase (TPase) expression, a series of plasmids was constructed in which heterologous promoters were fused to the TPase gene. Promoters for the cauliflower mosaic virus (CaMV) 35S transcript and the octopine synthase (ocs) and
Neoplastic plant-tissue formation, termed crown gall disease, is induced on infection with Agrobacterium tumefaciens. The tumorous tissues develop an extensive vascular system, with a venation pattern distinct from that of native host plants. We report here that the plant-tumorigenic 6b gene of the
We studied the activation of cab gene expression by phytochrome-induced intercellular signalling and report insights into the mechanism of induction and outspread of a plant internal signal. By micro-beam irradiation techniques and use of a photon-imaging charge-coupled device (CCD) camera system we
Subunits II and III of the photosystem I reaction centre are encoded by the nuclear genes PsaD and PsaF, respectively. In spinach, the expression of both genes is highly synchronized with regard to time, space and in response to stimulators such as light. Nevertheless, promoter sequences as well as
The complete nicotine inhibition of lycopene cyclization during light-induced carotenogenesis in excised bean cotyledons was achieved. The inhibitory effect was easily reversible and removal of nicotine has allowed synthesis of the normal cyclic carotenoids.
Extensins are cell wall basic glycoproteins with a polypeptide backbone that is extremely rich in hydroxyproline. In this paper, the function of extensins in embryo development was studied in Nicotiana tabacum. By using Western blot and immunohistochemistry, the extensin JIM20 epitopes were found to
Maternal smoking during pregnancy causes reduction of fetal breathing movements, an effect attributed to nicotine in fetal blood. Nicotine is metabolized to cotinine which has a long plasma half-life and exhibits slow clearance across membrane barriers. It is also known to activate placental
Our objective was to study the characteristics of transfer and biotransformation of nicotine in the human term placenta. Nicotine transfer was studied by dually perfusing an isolated cotyledon of the human placenta in vitro. Nicotine metabolism to cotinine was investigated in intact tissue during
Chlorophyll degradation plays important roles in leaf senescence including regulation of degradation of chlorophyll-binding proteins. Although most genes encoding enzymes of the chlorophyll degradation pathway have been identified, the regulation of their activity has not been fully understood.