nitrate concentration of the soil, at the start of growing season, is high due to minerali-zation of soil organic n during the fall and the addition of n fertilizers. it may be useful to exploit this n form as much as possible. therefore, the nitrate uptake, assimilation and dry matter production of several wheat cultivars were examined in a series of experiments using a hydroponic culture syst...

nitrate and ammonium forms of nitrogen are being applied to improve plant growth and uptake of other nutrients. given that the effect of application of different nitrate to ammonium ratios accompanied by other fertilizers (i.e. fe, mn and zn) has not been studied on wheat growth as well as uptake of fe, mn and zn, three glasshouse pot studies were conducted with factorial arrangement of treatme...

it is extremely challenging to measure first-order rate coefficients for soil nitrate transformation processes directly, either in the laboratory or in the field. in this study, an improved inverse method was proposed to optimize the first-order rate coefficients by considering the intermediate changing processes of the integrated functions. a numerical experiment was designed to test the accur...

to investigate the impact of overexpression of atnrt2.1 transgene from arabidopsis on nitrate uptake rate and to understand the regulation of endogenous hats by nitrate and glutamine amino acid (gln) in tobacco plants, wild-type and transgenic (f line) plants grown on soil for 4 weeks were transferred to hydroponic culture in a controlled-environment with a 16/8h l:d photoperiod at 24? c/20...

To investigate the impact of overexpression of AtNRT2.1 transgene from Arabidopsis on nitrate uptake rate and to understand the regulation of endogenous HATS by nitrate and glutamine amino acid (Gln) in tobacco plants, wild-type and transgenic (F line) plants grown on soil for 4 weeks were transferred to hydroponic culture in a controlled-environment with a 16/8h L:D photoperiod at 24? C/20...

The characteristics of nitrate uptake and induction of nitrate reductase were studied in excised roots of corn (Zea mays L.). Upon initial exposure to nitrate, the low initial rate of nitrate uptake gradually increased until a steady uptake rate was achieved in 1 to 2 hours depending on the NO(3) (-) concentration. The pattern was observed over a wide range (0.2-5 mm) of nitrate concentrations ...

A nitrate uptake system is induced (along with nitrate reductase) when NH(4) (+)-grown Penicillium chrysogenum is incubated with inorganic nitrate in synthetic medium in the absence of NH(4) (+). Nitrate uptake and nitrate reduction are probably in steady state in fully induced mycelium, but the ratios of the two activities are not constant during the induction period. Substrate concentrations ...

A study was done to relate the in vivo reduction of nitrate to nitrate uptake, nitrate accumulation, and induction of nitrate reductase activity in intact barley seedlings (Hordeum vulgare L. var. ;Numar'). The characteristics of nitrate uptake in response to both time and ambient concentration of nitrate regulated reduction and accumulation. Uptake, accumulation, and in vivo reduction achieved...

Two maize hybrids were grown under growth chamber conditions on solution or vermiculite medium that contained 2.5, 7.5, or 15 millimolar nitrate. The objectives were to determine: (a) the effect of nitrate supply on N metabolism and growth and (b) the interrelationship between nitrate uptake, flux, and reduction on the accumulation of reduced N and nitrate by the various plant parts and for the...

In plants, the nitrate transporters, NRT1.1 and NRT2.1, are mainly responsible for nitrate uptake. Intriguingly, both nitrate transporters are located in a complementary manner in different cells layers of the mature root suggesting that their coordination should occur during nitrate uptake and plant growth. This hypothesis was examined on 5-d-old rape seedlings grown on agar medium supplemente...