Peng Jin: School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
Jiaofeng Wan: School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
Yunyue Zhou: School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
Kunshan Gao: State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, 361005, Xiamen, China. ORCID
John Beardall: State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, 361005, Xiamen, China. ORCID
Jiamin Lin: School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
Jiali Huang: School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
Yucong Lu: School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
Shiman Liang: School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
Although high CO and warming could act interactively on marine phytoplankton, little is known about the molecular basis for this interaction on an evolutionary scale. Here we explored the adaptation to high CO in combination with warming in a model marine diatom Phaeodactylum tricornutum. Whole-genome re-sequencing identifies, in comparison to populations grown under control conditions, a larger genetic diversity loss and a higher genetic differentiation in the populations adapted for 2 years to warming than in those adapted to high CO. However, this diversity loss was less under high CO combined with warming, suggesting that the evolution driven by warming was constrained by high CO. By integrating genomics, transcriptomics, and physiological data, we found that the underlying molecular basis for this constraint is associated with the expression of genes involved in some key metabolic pathways or biological processes, such as the glyoxylate pathway, amino acid and fatty acid metabolism, and diel variability. Our results shed new light on the evolutionary responses of marine phytoplankton to multiple environmental changes in the context of global change and provide new insights into the molecular basis underpinning interactions among those multiple drivers.
