Cellular and molecular mechanisms underlying single-cell C4 photosynthesis in Chenopodiaceae species

植物和藻类等光合作用生物执行最重要的生物过程，即光合作用，将大气中的二氧化碳转化为有机产品，对所有形式的生命的生长和发展至关重要。在陆地植物中，C3、C4和景天酸代谢(CAM)三种光合作用模式已被确定，其中C4和CAM植物在二氧化碳限制条件下效率最高。四十多年来，人们普遍认为，C4光合作用需要两种类型的细胞相互作用，即Kranz解剖学，每种细胞都有不同的叶绿体超微结构和生化。这种Kranz范式最近受到挑战，发现藜科的四个成员在单个细胞内执行C4光合作用途径。这些鸟脚类物种通过将主要细胞器和关键的光合酶划分为两个独立的胞内细胞质亚室，实现了在单个细胞中进行C4光合作用的新方法。因此，这些独特的物种提供了理想的模式系统，用来研究控制单个植物细胞中复杂结构和功能极性发展的调控因素。

Plants and photosynthetic organisms such as algae perform the most important biological process known as photosynthesis that converts atmospheric CO2 into organic products essential for growth and development of all forms of life. In terrestrial plants, three modes of photosynthesis, C3, C4 and Crassulacean acid metabolism (CAM), have been identified with C4 and CAM plants being the most efficient under CO2 limiting conditions. For more than forty years, it has been widely accepted that the C4 photosynthesis requires the interaction of two cell types known as Kranz anatomy, each has distinct chloroplast ultrastructure and biochemistry. This Kranz paradigm was recently challenged with findings that four members of family Chenopodiaceae perform C4 photosynthetic pathway within individual cells. These chenopod species achieve novel means for performing the C4 photosynthesis in a single cell by partitioning of major organelles and key photosynthetic enzymes into two separate intracellular cytoplasmic subcompartments. Thus, these unique species provide ideal model systems with which to examine the regulatory factors controlling the development of complex structural and functional polarity in a single plant cell.