The growth of plants under high carbon dioxide (CO2) concentrations (≥ 1000 ppm) is explored for the climate change and the bioregenerative life support system (BLSS) environment of long-duration space missions. Wheat (Triticum aestivum L.) is a grass cultivated for cereal grain-a global staple food including astronauts. Light and CO2 are both indispensable conditions for wheat seedlings. This study provides insights on the physiology, antioxidant capacity and photosynthetic characteristics of wheat seedlings under a range of photosynthetic photon flux densities in a closed system simulating BLSS with high CO2 concentration. We found that the Fv/Fm, Fv/F0, chlorophyll content, intrinsic water use efficiencies (WUEi), membrane stability index (MSI), and malondialdehyde (MDA) of wheat seedlings grown under an intermediate light intensity of 600 μmol m-2 s-1 environment were all largest. Interestingly, the high light intensity of 1200 mol m-2 s-1 treatment group exhibits the highest net photosynthetic rate but the lowest MDA content. The stomatal conductance and F0 of high light intensity of 1000 μmol m-2 s-1 treatment group were both significantly higher than that of other groups. Our study provides basic knowledge on the wheat growth in different environments, especially in a closed ecosystem with artificial lights.

中文翻译：

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在封闭的人工生态系统中，高CO 2浓度下，不同的光照强度对小麦幼苗的生理，抗氧化能力和光合特性的影响。

探索了在高二氧化碳（CO2）浓度（≥1000 ppm）下植物的生长，以应对长期太空任务的气候变化和生物再生生命支持系统（BLSS）环境。小麦（Triticum aestivum L.）是一种种植谷物的草，谷物是包括宇航员在内的全球主要食品。光照和二氧化碳都是小麦幼苗必不可少的条件。这项研究提供了在密闭系统中模拟高CO2浓度的BLSS的一系列光合光子通量密度下，小麦幼苗的生理，抗氧化能力和光合特性的见解。我们发现Fv / Fm，Fv / F0，叶绿素含量，内在用水效率（WUEi），膜稳定性指数（MSI），在中等光照强度600μmolm-2 s-1环境下生长的小麦幼苗的丙二醛和丙二醛（MDA）均最大。有趣的是，1200 mol m-2 s-1处理组的高光强度表现出最高的净光合速率，但最低的MDA含量。1000μmolm-2 s-1处理组气孔导度和高光强度F0均显着高于其他组。我们的研究提供了有关小麦在不同环境中生长的基础知识，尤其是在带有人工照明的封闭生态系统中。1000μmolm-2 s-1处理组气孔导度和高光强度F0均显着高于其他组。我们的研究提供了有关小麦在不同环境中生长的基础知识，尤其是在带有人工照明的封闭生态系统中。1000μmolm-2 s-1处理组气孔导度和高光强度F0均显着高于其他组。我们的研究提供了有关小麦在不同环境中生长的基础知识，尤其是在带有人工照明的封闭生态系统中。