Chantarotwong W, Huffaker R C, Miller B L, Granstedt R C
Plant Growth Laboratory and Department of Agronomy and Range Science, University of California Davis, California 95616.
Plant Physiol. 1976 Apr;57(4):519-22. doi: 10.1104/pp.57.4.519.
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 steady state rates in 3 to 4 hours, whereas extractable (in vitro) nitrate reductase activity was still increasing at 12 hours. In vivo reduction of nitrate was better correlated exponentially than linearly over time with in vitro activity of nitrate reductase. A similar relationship occurred over increasing concentration of nitrate in the ambient solution. The results suggest that the rate of in vivo reduction of nitrate in barley seedlings may be regulated by the rate of uptake at the ambient concentrations of nitrate employed in the study.
开展了一项研究，以探讨完整大麦幼苗（大麦属；Numar品种）体内硝酸盐还原与硝酸盐吸收、硝酸盐积累以及硝酸盐还原酶活性诱导之间的关系。硝酸盐吸收对时间和硝酸盐环境浓度的响应特性调节着还原和积累过程。吸收、积累和体内硝酸盐还原在3至4小时内达到稳态速率，而可提取的（体外）硝酸盐还原酶活性在12小时时仍在增加。随着时间推移，体内硝酸盐还原与硝酸盐还原酶体外活性呈指数关系，而非线性关系，相关性更好。在环境溶液中硝酸盐浓度增加时，也出现了类似关系。结果表明，在本研究采用的硝酸盐环境浓度下，大麦幼苗体内硝酸盐还原速率可能受吸收速率的调节。
