Symbiodinium sp. cells produce light-induced intra- and extracellular singlet oxygen, which mediates photodamage of the photosynthetic apparatus and has the potential to interact with the animal host in coral symbiosis.
Symbiodinium sp. cells produce light-induced intra- and extracellular singlet oxygen, which mediates photodamage of the photosynthetic apparatus and has the potential to interact with the animal host in coral symbiosis.
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DOI：
10.1111/nph.14056
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发表时间：
2016-10
期刊：
影响因子：
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通讯作者：
A. Rehman;M. Szabó;Z. Deák;L. Sass;A. Larkum;P. Ralph;I. Vass
中科院分区：
文献类型：
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作者：
A. Rehman;M. Szabó;Z. Deák;L. Sass;A. Larkum;P. Ralph;I. Vass
珊瑚白化是一种重要的环境现象，其发生机制尚不清楚。活性氧物种(ROS)的参与已经被牵连，但关于参与其中的哪些物种、它们的位置和产生机制的直接证据仍然未知。用组氨酸介导的化学捕捉法和单线态氧传感器绿(SOSG)法检测共生线虫培养物细胞内外单线态氧((1)O2)。热应激或强光抑制Calvin-Benson循环可促进细胞内O2的形成。组氨酸的加入减少了细胞内O2的含量，对光系统II的光失活和叶绿素(Chl)漂白提供了部分保护。(1)在共生藻培养的无细胞培养液中也可以产生O2，这种效应在热光胁迫下会增强，并可归因于从细胞中排出对O2敏感的代谢物。使用SOSG的共聚焦显微镜成像显示，大部分细胞外O2围绕细胞表面，但它也在远离细胞的介质中产生。我们第一次证明了共生线虫在细胞内和细胞外产生氧气。细胞内(1)O2与光系统II的光损伤和色素漂白有关，而细胞外(1)O2有可能在珊瑚漂白过程中介导虫黄藻与其动物宿主之间共生相互作用的破坏。
Coral bleaching is an important environmental phenomenon, whose mechanism has not yet been clarified. The involvement of reactive oxygen species (ROS) has been implicated, but direct evidence of what species are involved, their location and their mechanisms of production remains unknown. Histidine-mediated chemical trapping and singlet oxygen sensor green (SOSG) were used to detect intra- and extracellular singlet oxygen ((1) O2 ) in Symbiodinium cultures. Inhibition of the Calvin-Benson cycle by thermal stress or high light promotes intracellular (1) O2 formation. Histidine addition, which decreases the amount of intracellular (1) O2 , provides partial protection against photosystem II photoinactivation and chlorophyll (Chl) bleaching. (1) O2 production also occurs in cell-free medium of Symbiodinium cultures, an effect that is enhanced under heat and light stress and can be attributed to the excretion of (1) O2 -sensitizing metabolites from the cells. Confocal microscopy imaging using SOSG showed most extracellular (1) O2 around the cell surface, but it is also produced across the medium distant from the cells. We demonstrate, for the first time, both intra- and extracellular (1) O2 production in Symbiodinium cultures. Intracellular (1) O2 is associated with photosystem II photodamage and pigment bleaching, whereas extracellular (1) O2 has the potential to mediate the breakdown of symbiotic interaction between zooxanthellae and their animal host during coral bleaching.