Abstract Atmospheric CO2 levels are rising rapidly due to anthropogenic activities. Although plants require CO2 to fuel photosynthesis, the relationship between CO2 and plant growth is complex. In phytotrons elevated CO2 was shown to stimulate growth of Arabidopsis thaliana. In nature, there is, however, a constant variation in temperature, the availability of sunlight, nutrients and water, in addition to biotic stresses. The aim of this study was to explore the impact of elevated CO2 on rosette growth and transcriptome profiles in Arabidopsis plants grown under natural radiation and air temperature. Because of its regulatory function in cell elongation, photosynthesis, stomatal closure and leaf senescence, the importance of ethylene for the response to elevated CO2 was investigated in wild-type plants (Col-0), and in plants with constitutive or reduced ethylene signaling (ctr1-1 and ein2-5, respectively). Rosette area measurements indicated that increased atmospheric CO2 did not increase vegetative growth in any of the genotypes. Moreover, both Col-0 and ein2-5 plants grown at elevated CO2 exhibited an increase in stress responsive gene expression compared to those grown at ambient CO2. A downregulation of photosynthesis and an upregulation of metabolism were, apart from the overrepresentation of stress genes, the most important responses to elevated CO2 in both wild-type and ethylene-insensitive plants. However, whereas in Col-0 starch biosynthesis and turnover were more strongly activated, lipid metabolism was enhanced in ein2-5. Through stomatal closure, sugar and lipid metabolism and leaf senescence, ethylene could be involved in the adaption of Arabidopsis rosettes to elevated CO2.

中文翻译：

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植物激素乙烯参与拟南芥玫瑰花结对增加的大气二氧化碳浓度的适应

摘要 由于人类活动，大气 CO2 水平正在迅速上升。尽管植物需要二氧化碳来促进光合作用，但二氧化碳与植物生长之间的关系是复杂的。在 phytotrons 中，升高的 CO2 被证明可以刺激拟南芥的生长。然而，在自然界中，除了生物胁迫之外，温度、阳光、养分和水的可用性也不断变化。本研究的目的是探讨 CO2 升高对在自然辐射和气温下生长的拟南芥植物的莲座丛生长和转录组谱的影响。由于其在细胞伸长、光合作用、气孔关闭和叶片衰老方面的调节功能，在野生型植物 (Col-0) 中研究了乙烯对 CO2 升高反应的重要性，在具有组成型或减少的乙烯信号（分别为 ctr1-1 和 ein2-5）的植物中。Rosette 面积测量表明，大气 CO2 的增加不会增加任何基因型的营养生长。此外，与在环境 CO2 下生长的那些植物相比，在高 CO2 下生长的 Col-0 和 ein2-5 植物表现出胁迫响应基因表达的增加。除了胁迫基因的过度表达外，光合作用的下调和代谢的上调是野生型和乙烯不敏感植物对二氧化碳升高的最重要反应。然而，虽然在 Col-0 中淀粉生物合成和转换被更强烈地激活，但在 ein2-5 中脂质代谢增强。通过气孔关闭、糖脂代谢和叶片衰老，