Effect of light fluctuations on photosynthesis and metabolic flux in Synechocystis sp. PCC 6803
Effect of light fluctuations on photosynthesis and metabolic flux in Synechocystis sp. PCC 6803
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光波动对集胞藻光合作用和代谢通量的影响。
DOI：
10.1002/btpr.3326
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发表时间：
2023
影响因子：
2.9
通讯作者：
Shimizu Hiroshi
中科院分区：
文献类型：
--
作者：
Imada Tatsumi;Yamamoto Chiaki;Toyoshima Masakazu;Toya Yoshihiro;Shimizu Hiroshi
在自然界中，光合生物暴露在波动的光下，它们的生理系统必须适应这种波动。为了维持体内平衡，这些生物具有光波动光保护机制，其在光系统和代谢中起作用。虽然已经研究了光系统中的光保护机制，但尚不清楚代谢如何在几秒钟内对光波动作出反应。在本研究中，我们研究了集胞藻的代谢反应。PCC 6803使用13 C代谢通量分析来进行光波动。调整光强度和占空比，使得光子总数或低光阶段期间的光强度相等。在实验条件下，光波动影响细胞生长和光合活性。然而，代谢通量分布和辅因子生产率不受光波动的影响。此外，估计的ATP和NADPH在光系统中的生产率表明，NADPH消耗电子耗散发生在波动的光条件下。虽然我们专注于水-水循环作为电子耗散路径，但在波动光下，在anflv 3-破坏应变中没有观察到生长效应，这表明在这些条件下，另一条路径有助于电子耗散。
In nature, photosynthetic organisms are exposed to fluctuating light, and their physiological systems must adapt to this fluctuation. To maintain homeostasis, these organisms have a light fluctuation photoprotective mechanism, which functions in both photosystems and metabolism. Although the photoprotective mechanisms functioning in the photosystem have been studied, it is unclear how metabolism responds to light fluctuations within a few seconds. In the present study, we investigated the metabolic response ofSynechocystissp. PCC 6803 to light fluctuations using13C‐metabolic flux analysis. The light intensity and duty ratio were adjusted such that the total number of photons or the light intensity during the low‐light phase was equal. Light fluctuations affected cell growth and photosynthetic activity under the experimental conditions. However, metabolic flux distributions and cofactor production rates were not affected by the light fluctuations. Furthermore, the estimated ATP and NADPH production rates in the photosystems suggest that NADPH‐consuming electron dissipation occurs under fluctuating light conditions. Although we focused on the water–water cycle as the electron dissipation path, no growth effect was observed in anflv3‐disrupted strain under fluctuating light, suggesting that another path contributes to electron dissipation under these conditions.