Beer S, Sand-Jensen K, Madsen T Vindbaek, Nielsen S L
Botanical Institute, University of Aarhus, 68 Nordlandsvej, DK-8240, Risskov, Denmark.
Oecologia. 1991 Sep;87(3):429-434. doi: 10.1007/BF00634602.
Activated carboxylase activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), as well as photosynthetic rates were measured for 42 species of freshwater and marine macrophytes. While the carboxylase activity varied greatly among the species investigated (0.2-12.5 μmol CO mg chlorophyll min), the submersed freshwater plants showed significantly lower activities than emergent, floating leaved or secondary submersed forms. The variability in photosynthetic rates correlated with the carboxylase activity only for the marine macroalgae, and their photosynthesis to carboxylase activity ratios were close to 1. These plants also had a consistently high inorganic carbon transport capability, and it is suggested that ribulose-1,5-bisphosphate carboxylase/oxygenase activity is an important internal factor regulating the photosynthetic capacity within this plant group where, apparently, the internal CO concentration is high and photorespiration is suppressed. Among the freshwater forms, it appears that their much lower inorganic carbon transport ability, rather than their carboxylase activity, limits the photosynthetic process.
对42种淡水和海洋大型植物测定了1,5-二磷酸核酮糖羧化酶/加氧酶（Rubisco）的活化羧化酶活性以及光合速率。在所研究的物种中，羧化酶活性差异很大（0.2 - 12.5 μmol CO₂/mg叶绿素·min），沉水淡水植物的活性明显低于挺水植物、浮叶植物或次生沉水植物。光合速率的变异性仅与海洋大型藻类的羧化酶活性相关，并且它们的光合速率与羧化酶活性之比接近1。这些植物还具有始终较高的无机碳转运能力，并且表明1,5-二磷酸核酮糖羧化酶/加氧酶活性是调节该植物类群光合能力的一个重要内在因素，显然，该类群内部CO₂浓度较高且光呼吸受到抑制。在淡水植物中，似乎是它们低得多的无机碳转运能力而非羧化酶活性限制了光合过程。
