Data_Sheet_1_Photobleaching and Recovery of Symbiodiniaceae Effrenium voratum SCS01 Reveals Life Form Transformation Under Thermal Stress.CSV

Dinoflagellates in the family Symbiodiniaceae contain a number of species and play an important role in the establishment of coral reef ecosystems in oligotrophic marine waters. Effrenium voratum is likely an exclusively free-living and heterotrophic species of Symbiodiniaceae. How this species responds and acclimates to warming is largely unknown. The present study experimentally established the phenotypic landscapes related to the photobleaching and recovery processes of Effrenium voratum SCS01 following thermal stress. We found that thermal stress bleached the plastids of E. voratum SCS01 and caused the cells to become lighter in color. Thereafter, the bleached cells recovered rapidly when they returned to the optimal temperature. The dominant life form of E. voratum SCS01 shifted from mastigote cells to coccoid cells then returned to mastigote cells. Transcriptome analysis revealed that the photobleaching of E. voratum SCS01 was due to increased degradation and decreased biosynthesis of photosynthetic pigments. The thermally induced life form changes were related to the downregulation of genes for cell motility. Our results revealed the mechanism of photobleaching in E. voratum SCS01 and indicated life form transformation as a newly identified survival strategy of Effrenium voratum SCS01 under thermal stress.

在寡营养海洋水域中，裸甲藻科（Symbiodiniaceae）中的双鞭藻类包含多种物种，并在珊瑚礁生态系统的建立中扮演着至关重要的角色。Effrenium voratum很可能是一种仅以自由生活和非自主营养为特征的裸甲藻科物种。该物种对温度升高的响应和适应机制尚不明确。本研究通过实验方法建立了Effrenium voratum SCS01在热应激后，与光合失活和恢复过程相关的表型景观。研究发现，热应激导致E. voratum SCS01的叶绿体发生失活，使得细胞颜色变浅。随后，当细胞回到最适宜的温度时，失活的细胞迅速恢复。E. voratum SCS01的占主导地位的生命形态从鞭毛细胞转变为球形细胞，然后又回归到鞭毛细胞。转录组分析揭示了E. voratum SCS01的光合失活是由于光合色素降解增加和生物合成减少。由热应激诱导的生命形态变化与细胞运动基因的下调有关。我们的研究结果揭示了E. voratum SCS01光合失活的机制，并表明生命形态的转化是Effrenium voratum SCS01在热应激下的一种新的生存策略。