Electrochromic and electrofluorochromic properties of a new boron dipyrromethene–ferrocene conjugate

A new boron dipyrromethene–ferrocene (BODIPY–Fc) conjugate with pentafluorophenyl as the meso substituent and two Fc termini was synthesized and its spectroscopic and electrochemical features were analyzed. An intramolecular charge transfer from the donor Fc to the acceptor BODIPY has been predicted by theory and confirmed experimentally, leading to efficient fluorescence quenching when the dyad is in the neutral state. Fluorescence can be triggered by oxidizing both ferrocenyl units either chemically or electrochemically. Eventually, a fully reversible fluorescence switch is evidenced by coupling TIRF microscopy with electrolysis in an electrochemical cell

Expression of leaf nitrate reductase genes from tomato and tobacco in relation to light-dark regimes and nitrate supply

International audienc

Cloning of DNA fragments complementary to tobacco nitrate reductase mRNA and encoding epitopes common to the nitrate reductases from higher plants

International audienc

Molecular genetics of nitrate reduction in Nicotiana

International audienc

Effects of NO (+NO2) pollution on growth, nitrate reductase activities and associated protein contents in glasshouse lettuce grown hydroponically in winter CO2 enrichment.

Winter hydroponic growth of several lettuce cultivars under glass showed considerable inhibition (up to 47%) of growth after 6 wk exposure to concentrations of NO (+ NO2 450 nl −1 in total) typical of emissions from propane burners used for direct heating and CO2 enrichment. After a further 4 wk under similar conditions, however, these growth depressions were replaced by a swing into benefit so that, by harvest, pollutant-exposed lettuces were bigger and had faster assimilation rates than those growing in clean CO2-enriched air. This adaptation may partly be explained by enhanced use of NO2-derived N by lettuce leaves, a consequence of increased nitrate reductase (NaR) activities and amounts of associated NaR proteins, despite adequate nitrate also being available in the hydroponic fluid. Rates of NaR activity in the roots, by contrast, were depressed by NO (+ NO2) pollution. NaR activities were highest in early afternoon in clean or polluted air but these daily patterns did not coincide with the content of NaR-associated proteins determined by ELISA. Other mechanisms of modulating NaR activity must therefore be responsible