Department of Biology I, Botany, LMU Munich, Grosshaderner Str. 2-4, 82152, Planegg-Martinsried, Germany.
Protoplasma. 2012 Oct;249(4):957-66. doi: 10.1007/s00709-011-0373-3. Epub 2012 Jan 8.
More than 70 years of studies have indicated that chloroplasts contain a significant amount of calcium, are a potential storage compartment for this ion, and might themselves be prone to calcium regulation. Many of these studies have been performed on the photosynthetic light reaction as well as CO(2) fixation via the Calvin-Benson-Bassham cycle, and they showed that calcium is required in several steps of these processes. Further studies have indicated that calcium is involved in other chloroplast functions that are not directly related to photosynthesis and that there is a calcium-dependent regulation similar to cytoplasmic calcium signal transduction. Nevertheless, the precise role that calcium has as a functional and regulatory component of chloroplast processes remains enigmatic. Calcium concentrations in different chloroplast subcompartments have been measured, but the extent and direction of intra-plastidal calcium fluxes or calcium transport into and from the cytosol are not yet very well understood. In this review we want to give an overview over the current knowledge on the relationship between chloroplasts and calcium and discuss questions that need to be addressed in future research.
70 多年的研究表明，叶绿体中含有大量的钙，是这种离子的潜在储存室，并且可能本身容易受到钙的调节。这些研究中的许多都是在光合作用的光反应以及卡尔文-本森-巴斯汉姆循环中的 CO2 固定中进行的，它们表明钙在这些过程的几个步骤中是必需的。进一步的研究表明，钙参与了与光合作用没有直接关系的其他叶绿体功能，并且存在类似于细胞质钙信号转导的钙依赖性调节。然而，钙作为叶绿体过程的功能和调节成分的确切作用仍然是一个谜。已经测量了不同叶绿体亚区室中的钙浓度，但对质体内钙流的程度和方向或钙从质体向内质网的运输仍了解得不是很清楚。在这篇综述中，我们想概述叶绿体与钙之间的关系，并讨论未来研究中需要解决的问题。
