Department of Botany, University of British Columbia, Vancouver, B.C., Canada V6T 2B1.
Plant Physiol. 1990 Aug;93(4):1426-32. doi: 10.1104/pp.93.4.1426.
(13)NO(3) (-) was used to investigate patterns of NO(3) (-) influx into roots of barley plants (Hordeum vulgare L. cv Klondike) previously grown with (;induced') or without (;uninduced') a source of external NO(3) (-) (NO(3) (-)). In both induced and uninduced plants, (13)NO(3) (-) influx was biphasic in the range from 0.005 to 50 moles per cubic meter NO(3) (-). In the low concentration range (<1 mole per cubic meter for induced plants and <0.3 mole per cubic meter for uninduced plants), influx was saturable and V(max) and K(m) values for influx either increased or decreased according to NO(3) (-) pretreatment. By contrast, (13)NO(3) (-) influx in the high concentration range revealed a strictly linear concentration dependence. These fluxes appeared to be mediated by a constitutive, rather than an inducible, transport system.
（13）NO3（-）被用来研究先前在有（诱导）或没有（未诱导）外部 NO3（-）源[NO3（-）]（0）生长的大麦植物（Hordeum vulgare L. cv Klondike）根部中 NO3（-）流入的模式。在诱导和未诱导的植物中，（13）NO3（-）的流入在 0.005 至 50 毫摩尔/立方米[NO3（-）]（0）的范围内呈双相。在低浓度范围内（诱导植物 <1 毫摩尔/立方米，未诱导植物 <0.3 毫摩尔/立方米），流入是可饱和的，流入的 V（max）和 K（m）值根据 NO3（-）预处理而增加或减少。相比之下，（13）NO3（-）在高浓度范围内的流入显示出严格的线性浓度依赖性。这些通量似乎是由组成型而不是诱导型运输系统介导的。
