原绿球藻对环境胁迫的生理和分子响应机制

Physiological and molecular mechanisms of Prochlorococcus in response to environmental stresses

摘要:

原绿球藻（Prochlorococcus）作为海洋丰度最高的浮游植物，对海洋生态系统的物质循环和能量流动起着重要的驱动作用。原绿球藻生长和光合作用活性容易受到环境胁迫的影响，进而影响整个海洋生态系统的稳定性。因此，研究原绿球藻应对环境胁迫的响应机制具有重要的生态意义。原绿球藻主要通过分化出不同的生态型来适应不同光照和营养盐的海洋环境，但仍然会很难快速适应各种突如其来的海洋环境变化。本文从原绿球藻应对环境胁迫的角度，探讨了其生理和分子响应机制的最新研究进展，包括光系统I循环电子传递在光照变化时发挥的重要作用，通过RNA快速响应而调控基因表达应对环境胁迫，以及在辅助异养细菌的保护下应对活性氧的胁迫等。本文也展望了原绿球藻对环境胁迫响应的生理和分子机制的未来研究方向，旨在为原绿球藻抗逆机制的深入研究提供参考。

Abstract:

As the most abundant phytoplankton in the marine environment, Prochlorococcus plays a vital role in driving element cycle and energy flow of marine ecosystem. Numerous studies indicate that the growth and photosynthetic activity of Prochlorococcus are vulnerable to environmental stresses, thus resulting in the damage to marine ecosystem stability. Therefore, it is crucial to study the responses of Prochlorococcus to environmental stresses for maintaining the marine ecological stability. Generally, Prochlorococcus could adapt to different light and nutrient conditions in the ocean by differentiating into different ecotypes. However, they cannot cope with sudden changes in the marine environment. Here, we review the progress on the responses of Prochlorococcus at physiological and molecular level to environmental stresses, which includes the important role of cyclic electron transport around photosystem I in light changes, RNA-regulated gene expression, and the protection Prochlorococcus against oxidative stress by heterotrophic bacteria. Moreover, we discuss the future directions for studies on Prochlorococcus responding to environmental stresses, aiming to provide fundamental bases to further explore anti-stress mechanisms of Prochlorococcus.