THE TRANSPORT OF CALCIUM and OTHER CATIONS IN SUBMERGED AQUATIC PLANTS

作者：Benjamin Lowenhaupt · 发表于：Biological reviews/Biological reviews of the Cambridge Philosophical Society · 年份：1956 · DOI：10.1111/j.1469-185x.1956.tb01555.x · 被引用次数：47 · 研究领域：Hemoglobin structure and function、Photosynthetic Processes and Mechanisms、Electrochemical sensors and biosensors

SUMMARY Photosynthetic bicarbonate assimilation and cation transport by aquatic plants are reviewed. It is suggested that these two processes stand in a causal relation to one another. A number of observations of cation transport not directly associated with photosynthesis are also reviewed, and are related to current concepts of active transport in the plant kingdom. These characteristics of cation transport have been observed in many submerged aquatic plants: Cations are transported through the leaves in the light but not in the dark. Cations are accumulated at the abaxial leaf surface from the contiguous external medium and are excreted from the adaxial surface into the medium. Therefore accumulation and excretion can be studied separately. A new theory of cation transport in bicarbonate‐assimilating aquatic plants is presented. The theory entails the following propositions: Two active membranes pump cations through the leaf in the light. The membrane on the abaxial leaf surface pumps cations into the leaf; that on the adaxial surface pumps cations out of the leaf. The cell plasma membranes on the abaxial and adaxial leaf surfaces form these two active membranes. In the light–i.e. when the transport mechanism is functioning–the biochemical reactions of transport reach steady‐state levels. These levels are determined by the rates of reaction between the constituents. One can therefore alter the steady‐state levels by suitably altering the conditions of one or more of these ...