The Acceptor Side of Photosystem II Is the Initial Target of Nitrite Stress in Synechocystis sp. Strain PCC 6803
The Acceptor Side of Photosystem II Is the Initial Target of Nitrite Stress in Synechocystis sp. Strain PCC 6803
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光系统 II 的受体侧是集胞藻中亚硝酸盐胁迫的初始目标。
DOI：
10.1128/aem.02952-16
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发表时间：
2016-11
影响因子：
4.4
通讯作者：
Wang, Qiang
中科院分区：
文献类型：
--
作者：
Zhan, Jiao;Chen, Hui;He, Chenliu;Wang, Qiang
摘要亚硝酸盐是无机氮的一种常见形式，可作为氮源通过氮素同化而被利用。然而，高水平的亚硝酸盐会抑制各种生物的光合作用。在这项研究中，我们调查了光合电子传递链的组件是针对亚硝酸盐胁迫集胞藻菌株PCC 6803细胞。全链和光系统II（PSII）介导的电子传递活动的测量结果表明，高水平的亚硝酸盐主要损害电子流PSII。在响应亚硝酸盐胁迫的PSII活性的变化发生在两个不同的阶段。在第一阶段，发生在第一个3小时的亚硝酸盐处理，电子转移从伯醌受体（QA）到仲醌受体（QB）被推迟，如叶绿素（Chl）荧光诱导，S-状态分布，和QA-再氧化测试。在亚硝酸盐暴露6小时后发生的第二阶段，反应中心被灭活，光系统II的供体侧被抑制，正如Chl荧光参数和热释光的变化以及免疫印迹分析所揭示的那样。我们的数据表明，亚硝酸盐胁迫是高度破坏PSII和破坏PSII活性的逐步机制，其中受体侧是初始目标。重要性在我们以前的研究中，提出了一种基于藻类的技术来固定从富含NOx的烟气中释放的大量亚硝酸盐，并被证明是一种有前途的烟气NOx生物修复的工业策略（W. Chen等人，Environ Sci Technol 50：1620-1627，2016，https://doi.org/10.1021/acs.est.5b04696; X. Zhang等人，Environ Sci Technol 48：10497-10504，2014，https://doi.org/10.1021/es5013824）。然而，高浓度的亚硝酸盐对藻类细胞的毒性效应仍然不清楚。在我们的研究中，对生长速率、光化学和蛋白质谱的分析提供了重要的证据，表明亚硝酸盐的抑制作用发生在两个阶段：在第一阶段，QA-和QB之间的电子转移被阻滞，而在第二阶段，PSII的供体侧受到影响。这是研究“早期”抑制作用（即，在第一个6小时内）在体内PSII电子传递链上。本文提供了新的见解亚硝酸盐抑制光合作用的机制在一个产氧光合蓝藻。
ABSTRACT Nitrite, a common form of inorganic nitrogen (N), can be used as a nitrogen source through N assimilation. However, high levels of nitrite depress photosynthesis in various organisms. In this study, we investigated which components of the photosynthetic electron transfer chain are targeted by nitrite stress in Synechocystis sp. strain PCC 6803 cells. Measurements of whole-chain and photosystem II (PSII)-mediated electron transport activities revealed that high levels of nitrite primarily impair electron flow in PSII. Changes in PSII activity in response to nitrite stress occurred in two distinct phases. During the first phase, which occurred in the first 3 h of nitrite treatment, electron transfer from the primary quinone acceptor (QA) to the secondary quinone acceptor (QB) was retarded, as indicated by chlorophyll (Chl) a fluorescence induction, S-state distribution, and QA− reoxidation tests. In the second phase, which occurred after 6 h of nitrite exposure, the reaction center was inactivated and the donor side of photosystem II was inhibited, as revealed by changes in Chl fluorescence parameters and thermoluminescence and by immunoblot analysis. Our data suggest that nitrite stress is highly damaging to PSII and disrupts PSII activity by a stepwise mechanism in which the acceptor side is the initial target. IMPORTANCE In our previous studies, an alga-based technology was proposed to fix the large amounts of nitrite that are released from NOX-rich flue gases and proved to be a promising industrial strategy for flue gas NOX bioremediation (W. Chen et al., Environ Sci Technol 50:1620–1627, 2016, https://doi.org/10.1021/acs.est.5b04696 ; X. Zhang et al., Environ Sci Technol 48:10497–10504, 2014, https://doi.org/10.1021/es5013824 ). However, the toxic effects of high concentrations of nitrite on algal cells remain obscure. The analysis of growth rates, photochemistry, and protein profiles in our study provides important evidence that the inhibition by nitrite occurs in two phases: in the first phase, electron transfer between QA− and QB is retarded, whereas in the second, the donor side of PSII is affected. This is an excellent example of investigating the “early” inhibitory effects (i.e., within the first 6 h) on the PSII electron transfer chain in vivo. This paper provides novel insights into the mechanisms of nitrite inhibition of photosynthesis in an oxygenic phototrophic cyanobacterium.
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影响因子：
4.3
作者：
P. N. Okafor;U. Ogbonna
通讯作者：
P. N. Okafor;U. Ogbonna
DOI：
--
发表时间：
2007
期刊：
--
影响因子：
--
作者：
Reto J Strassert;Alaka Srivastava 'and Govindjee
通讯作者：
Reto J Strassert;Alaka Srivastava 'and Govindjee
DOI：
10.1016/s1011-1344(99)00032-9
发表时间：
1999-02-01
影响因子：
5.4
作者：
Nedbal, L;Trtílek, M;Kaftan, D
通讯作者：
Kaftan, D
影响因子：
3.3
作者：
Chen, Weimin;Liu, Hao;Dai, Shugui
通讯作者：
Dai, Shugui
影响因子：
7.3
作者：
R. Tischner
通讯作者：
R. Tischner