Appearance and role of CuZnSOD proteins during early land plant evolution

铜锌超氧化物歧化酶(CuZnSOD)蛋白在大约24亿年前的大氧化事件期间出现。在高等植物中存在三种隔室特异蛋白，即胞质蛋白、胞质蛋白和过氧化物体蛋白，其中胞质蛋白似乎是最先进化的，因为它已经存在于淡水轮藻中。我们发现，在拟南芥中，胞质形式对于胚胎发育是必不可少的，CSD1蛋白具有两个功能：一方面作为抗氧化酶，另一方面作为核转录调节因子。淡水藻类中CuZnSOD的出现表明，它可能代表了一种早期的分子适应，使其能够过渡到陆地。本研究旨在揭示CuZnSOD在胚胎发育过程中的作用，以及通过调控苯丙烷类代谢来调节早期陆地植物的非生物胁迫耐受性。我们以多形地钱和小球藻为研究对象，揭示了胞质CuZnSOD在植物区域化过程中的双重作用。

Copper Zinc Superoxide Dismutase (CuZnSOD) proteins appeared around the time of the Great Oxidation Event around 2.4 billion years ago. In higher plants three compartment specific proteins are present, namely a cytosolic, plastidic and peroxisomal protein, of which the cytosolic form appears to have evolved first since it is already present in the freshwater algea Chara braunii. We found that the cytosolic form in Arabidopsis is essential for embryogenesis and that the CSD1 protein has two functions: on the one hand as an antioxidant enzyme and on the other as a nuclear transcriptional regulator. The appearance of CuZnSOD in freshwater algae indicate that it might represent an early molecular adaptation to enable the transition to land. Here we aim at revealing the role of CuZnSOD during embryogenesis and the regulation of abiotic stress tolerance in early land plants by modulating phenylpropanoid metabolism. We focus on Marchantia polymorpha and Physcomitrella patens to unravel the dual role of the cytosolic CuZnSOD during plant terrestrialization.