Abstract
Ocean warming (OW) and acidification (OA) are expected to interactively impact key phytoplankton groups such as diatoms, but the underlying mechanisms, particularly under long-term acclimation, remain poorly understood. In this study, we investigated the responses of the toxic diatom Pseudo-nitzschia multiseries to combined changes in temperature (20 °C and 30 °C) and CO2 concentration (pCO2 400 μatm and 1000 μatm) using a multi-omics approach over an acclimation period of at least 251 generations. Physiological data suggest that elevated temperature, either alone or in combination with CO2, reduced the net photosynthesis and nitrate uptake rate, thus inhibiting P. multiseries growth. Conversely, elevated CO2 alone stimulated P. multiseries growth. Comparative genome analysis revealed the phenotypic plasticity in response to temperature and pCO2 variations, even after more than 251 generations acclimation period. Temperature was identified as the dominant environmental factor, showing stronger effects than CO2. Transcriptomic profiles indicated that genes involved in stress- and intracellular homeostasis such as Hsps, ubiquitination process and antioxidant defense were mostly down-regulated under long-term warming acclimation. This study demonstrates that P.multiseries responds similarly to both short-term and long-term experimental selection, suggesting that short-term experiments can be used to predict long-term responses.
| Original language | English |
|---|---|
| Article number | 106901 |
| Journal | Marine Environmental Research |
| Volume | 204 |
| DOIs | |
| State | Published - Feb 2025 |
| Externally published | Yes |
Funding
Further exploring the genetic evolutionary relationship among these groups, it was observed that a phylogenetic tree constructed with SNPs failed to separate the samples based on temperature or pCO2 (Fig. 2B). Principal component analysis (PCA) illustrated a similar pattern in that all of these tended to cluster together, with only HTAC having outliers, indicating a gradual progression in the three directions, though not yet apparent, which could emerge if the acclimation period was prolonged (Fig. S3). Linkage disequilibrium (LD) analyses again supported the above results, all treatment samples showed a sharp decline in the LD decay curve (Fig. S4).This work was supported by National key research and development program of China (2018YFD0900703), National Natural Science Foundation of China (41976110; 31772075); the Young Taishan Scholars Program to D.X. Taishan Scholars Funding and Talent Projects of Distinguished Scientific Scholars in Agriculture; Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology (NO. 2018SDKJ0406-3); Major Scientific and Technological Innovation Project of Shandong Provincial Key Research and Development Program (2019JZZY020706); Financial Fund of the Ministry of Agriculture and Rural Affairs, P. R. of China (NFZX2018); China Agriculture Research System (CARS-50); U.S. California Urban Ocean Sea Grant and National Science Foundation grants (OCE 1638804, OCE 1538525). This work was supported by National key research and development program of China (2018YFD0900703), National Natural Science Foundation of China (41976110; 31772075); the Young Taishan Scholars Program to D.X., Taishan Scholars Funding and Talent Projects of Distinguished Scientific Scholars in Agriculture; Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology (Qingdao) (NO. 2018SDKJ0406-3); Major Scientific and Technological Innovation Project of Shandong Provincial Key Research and Development Program (2019JZZY020706); Financial Fund of the Ministry of Agriculture and Rural Affairs, P. R. of China (NFZX2018); China Agriculture Research System (CARS-50); U.S. California Urban Ocean Sea Grant and National Science Foundation grants (OCE 1638804, OCE 1538525).