Biology Department, Seoul Natinal University, Seoul 151, Korea.
Plant Physiol. 1981 Aug;68(2):464-8. doi: 10.1104/pp.68.2.464.
The enzymes necessary to assimilate ammonia either via glutamine synthetase and glutamate synthase or via the glutamate dehydrogenase pathways are present in both green and white leaf tissues of Kalanchoë fedtschenkoi. Nitrate reductase activity develops to a maximum in a Crassulacean acid metabolism (CAM) plant canopy before either ribulose 1,5-bisphosphate carboxylase, or phosphoenolpyruvate carboxylase, or CAM. Nitrate reductase also is activated each morning and is inactivated late in the day as in other plants. However, there does not appear to be any direct relationship between nitrate reductase activity and the level of acid, its daily pattern or the amplitude of CAM. Though nitrate reductase is activated maximally each day by light, in Kalanchoë leaves for six days the activity followed a precise daily pattern independent of continuous light or dark.
景天科的费氏伽蓝菜的绿色和白色叶片组织中均存在谷氨酰胺合成酶和谷氨酸合酶或谷氨酸脱氢酶途径来同化氨所需的酶。硝酸还原酶的活性在景天酸代谢 (CAM) 植物冠层中达到最大值,然后是核酮糖 1,5-二磷酸羧化酶、磷酸烯醇丙酮酸羧化酶或 CAM。硝酸还原酶也像其他植物一样,每天早晨被激活,傍晚失活。然而,硝酸还原酶活性与酸的水平、其日变化模式或 CAM 的幅度之间似乎没有直接关系。尽管硝酸还原酶每天都被光照最大程度地激活,但在费氏伽蓝菜叶片中,六天的时间里,其活性遵循一种精确的日变化模式,而不受连续光照或黑暗的影响。