Serra J L, Llama M J, Cadenas E
Departamento de Bioquímica, Facultad de Ciencias, Universidad de Bilbao, Bilbao, Spain.
Plant Physiol. 1978 Dec;62(6):991-4. doi: 10.1104/pp.62.6.991.
Nitrate utilization has been characterized in nitrogen-deficient cells of the marine diatom Skeletonema costatum. In order to separate nitrate uptake from nitrate reduction, nitrate reductase activity was suppressed with tungstate. Neither nitrite nor the presence of amino acids in the external medium or darkness affects nitrate uptake kinetics. Ammonium strongly inhibits carrier-mediated nitrate uptake, without affecting diffusion transfer. A model is proposed for the uptake and assimilation of nitrate in S. costatum and their regulation by ammonium ions.
已对海洋硅藻中肋骨条藻缺氮细胞的硝酸盐利用情况进行了表征。为了将硝酸盐吸收与硝酸盐还原区分开来,用钨酸盐抑制了硝酸还原酶活性。外部培养基中的亚硝酸盐、氨基酸的存在或黑暗均不影响硝酸盐吸收动力学。铵强烈抑制载体介导的硝酸盐吸收,但不影响扩散转运。提出了一个关于中肋骨条藻中硝酸盐吸收与同化及其受铵离子调控的模型。