Botanisches Institut der Universität, D-5000 Köln 41, Federal Republic of Germany.
Plant Physiol. 1978 Jul;62(1):49-53. doi: 10.1104/pp.62.1.49.
Fucus serratus L., Fucus spiralis L., and Fucus vesiculosus L. (Fucales, Phaeophyceae) as well as Laminaria digitata (Huds.) Lamour., Laminaria hyperborea (Gunn.) Fosl., and Laminaria saccharina (L.) Lamour. (Laminariales, Phaeophyceae) have been investigated for the distribution of enzymic CO(2) fixation capacities via phosphoenolpyruvate carboxykinase (EC 4.1.1.32) (PEP-CK) and via ribulose-1,5-bisphosphate carboxylase (EC 4.1.1.39) (RubP-C) in different regions of the thalli. The maximum of PEP-CK activity is found to be confined to the growing regions of the algae, while the activity of RubP-C achieves its highest values in the entirely differentiated parts of the fronds. These findings are confirmed by the results of photosynthetic and light-independent (dark) carbon assimilation as determined by in vivo(14)CO(2) fixation. The physiological significance of these differential patterns of carboxylation patterns is discussed with respect to the ontogenetic stage and the chemical constitution of the different thallus parts.
裙带菜属（翅藻目，褐藻门）中的条斑紫菜、半叶马尾藻和泡叶藻，以及海带属（海带目，褐藻门）中的掌状海带、北昆布和长海带的不同藻体部位的磷酸烯醇式丙酮酸羧激酶（EC 4.1.1.32）（PEP-CK）和核酮糖-1,5-二磷酸羧化酶（EC 4.1.1.39）（RubP-C）的酶促 CO2 固定能力的分布情况进行了研究。PEP-CK 活性的最大值局限于藻类的生长区域，而 RubP-C 的活性在叶片完全分化的部位达到最高值。这些发现通过体内（14）CO2 固定测定的光合作用和非光依赖（黑暗）碳同化的结果得到了证实。根据不同藻体部位的个体发育阶段和化学组成，讨论了这些不同的羧化模式的生理意义。
