| Autor: |
Luo YW; State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, 361102, Xiamen, Fujian, China. ywluo@xmu.edu.cn., Shi D; State Key Laboratory of Marine Environmental Science and College of the Environment and Ecology, Xiamen University, 361102, Xiamen, Fujian, China. dshi@xmu.edu.cn., Kranz SA; Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL, 32306, USA., Hopkinson BM; Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA., Hong H; State Key Laboratory of Marine Environmental Science and College of the Environment and Ecology, Xiamen University, 361102, Xiamen, Fujian, China., Shen R; State Key Laboratory of Marine Environmental Science and College of the Environment and Ecology, Xiamen University, 361102, Xiamen, Fujian, China., Zhang F; State Key Laboratory of Marine Environmental Science and College of the Environment and Ecology, Xiamen University, 361102, Xiamen, Fujian, China. |
| Abstrakt: |
The response of the prominent marine dinitrogen (N 2 )-fixing cyanobacteria Trichodesmium to ocean acidification (OA) is critical to understanding future oceanic biogeochemical cycles. Recent studies have reported conflicting findings on the effect of OA on growth and N 2 fixation of Trichodesmium. Here, we quantitatively analyzed experimental data on how Trichodesmium reallocated intracellular iron and energy among key cellular processes in response to OA, and integrated the findings to construct an optimality-based cellular model. The model results indicate that Trichodesmium growth rate decreases under OA primarily due to reduced nitrogenase efficiency. The downregulation of the carbon dioxide (CO 2 )-concentrating mechanism under OA has little impact on Trichodesmium, and the energy demand of anti-stress responses to OA has a moderate negative effect. We predict that if anthropogenic CO 2 emissions continue to rise, OA could reduce global N 2 fixation potential of Trichodesmium by 27% in this century, with the largest decrease in iron-limiting regions. |
