Yufei Zhang1, Zipeng Gu1, Yudong Ren1, Lu Wang1, Jian Zhang1, Chengwei Liang2, Shanying Tong3, Yitao Wang4,5, Dong Xu4,5, Xiaowen Zhang4,5, Naihao Ye6,7. 1. College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, 266042, China. 2. College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, 53 Zhengzhou Road, Qingdao, 266042, China. liangchw117@126.com. 3. School of Life Sciences, Ludong University, 186 Hongqi Middle Road, Yantai, 264025, China. 4. Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 106 Nanjing Road, Qingdao, 266071, China. 5. National Oceanographic Center, Qingdao, 266071, China. 6. Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 106 Nanjing Road, Qingdao, 266071, China. yenh@ysfri.ac.cn. 7. National Oceanographic Center, Qingdao, 266071, China. yenh@ysfri.ac.cn.
Abstract
With atmospheric CO2 increasing, a large amount of CO2 is absorbed by oceans and lakes, which changes the carbonate system and affects the survival of aquatic plants, especially microalgae. The main aim of our study was to explore the responses of Chlamydomonas reinhardtii (Chlorophyceae) to elevated CO2 by combined transcriptome and metabolome analysis under three different scenarios: control (CK, 400 ppm), short-term elevated CO2 (ST, 1000 ppm), and long-term elevated CO2 (LT, 1000 ppm). The transcriptomic data showed moderate changes between ST and CK. However, metabolic analysis indicated that fatty acids (FAs) and partial amino acids (AAs) were increased under ST. There was a global downregulation of genes involved in photosynthesis, glycolysis, lipid metabolism, and nitrogen metabolism but increase in the TCA cycle and β-oxidation under LT. Integrated transcriptome and metabolome analyses demonstrated that the nutritional constituents (FAs, AAs) under LT were poor compared with CK, and most genes and metabolites involved in C and N metabolism were significantly downregulated. However, the growth and photosynthesis of cells under LT increased significantly. Thus, C. reinhardtii could form a specific adaptive evolution to elevated CO2, affecting future biogeochemical cycles.
With atmospheric CO2 increasing, a large amount of n class="Chemical">CO2 is absorbed by oceans and lakes, which changes the carbonate system and affects the survival of aquatic plants, especially microalgae. The main aim of our study was to explore the responses of Chlamydomonas reinhardtii (Chlorophyceae) to elevated CO2 by combined transcriptome and metabolome analysis under three different scenarios: control (CK, 400 ppm), short-term elevated CO2 (ST, 1000 ppm), and long-term elevated CO2 (LT, 1000 ppm). The transcriptomic data showed moderate changes between ST and CK. However, metabolic analysis indicated that fatty acids (FAs) and partial amino acids (AAs) were increased under ST. There was a global downregulation of genes involved in photosynthesis, glycolysis, lipid metabolism, and nitrogen metabolism but increase in the TCA cycle and β-oxidation under LT. Integrated transcriptome and metabolome analyses demonstrated that the nutritional constituents (FAs, AAs) under LT were poor compared with CK, and most genes and metabolites involved in C and N metabolism were significantly downregulated. However, the growth and photosynthesis of cells under LT increased significantly. Thus, C. reinhardtii could form a specific adaptive evolution to elevated CO2, affecting future biogeochemical cycles.