Excess manganese differentially inhibits photosystem I versus II in Arabidopsis thaliana.
Excess manganese differentially inhibits photosystem I versus II in Arabidopsis thaliana.
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DOI：
10.1093/jxb/ers339
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发表时间：
2013-01
影响因子：
6.9
通讯作者：
Hüner NP
中科院分区：
文献类型：
--
作者：
Millaleo R;Reyes-Díaz M;Alberdi M;Ivanov AG;Krol M;Hüner NP
比较了实验开始时逐渐增加的锰浓度（50 ~ 1500µM）对拟南芥光系统II （PSII）和光系统I （PSI）功能性能及光合机构组成的影响。与早期的研究一致，过量的Mn对PSII光化学效率（以Fv/Fm测量）的影响很小，尽管在Mn浓度最高时，S2/3QB -电荷重组的特征峰温度转移到较低的温度。SDS-PAGE和免疫印迹分析也没有显示PSII相关多肽的相对丰度有任何显著变化：PSII反应中心蛋白D1、Lhcb1 （LHCII复合体的主要光收集蛋白）和PsbO （OEC33，一种33kDa的氧进化复合体蛋白）。此外，Rubisco的丰度也没有随Mn处理而改变。然而，过量Mn条件下生长的植株对PSII光抑制的敏感性增加。相比之下，PSI反应中心（P700）的体内氧化还原瞬态测量显示，与对照组相比，Mn浓度增加时P700光氧化（P700+）的程度逐渐下降。这伴随着P700+再还原速率较慢，表明psi依赖的循环电子流下调。最高Mn浓度下植株PSI反应中心多肽（PsaA和PsaB）丰度也显著低于对照。研究结果首次表明，PSI是拟南芥光合机构中Mn毒性的主要靶点。讨论了锰毒性特异性靶向PSI的可能参与机制。
The effects of exposure to increasing manganese concentrations (50–1500 µM) from the start of the experiment on the functional performance of photosystem II (PSII) and photosystem I (PSI) and photosynthetic apparatus composition of Arabidopsis thaliana were compared. In agreement with earlier studies, excess Mn caused minimal changes in the PSII photochemical efficiency measured as Fv/Fm, although the characteristic peak temperature of the S2/3QB – charge recombinations was shifted to lower temperatures at the highest Mn concentration. SDS-PAGE and immunoblot analyses also did not exhibit any significant change in the relative abundance of PSII-associated polypeptides: PSII reaction centre protein D1, Lhcb1 (major light-harvesting protein of LHCII complex), and PsbO (OEC33, a 33kDa protein of the oxygen-evolving complex). In addition, the abundance of Rubisco also did not change with Mn treatments. However, plants grown under excess Mn exhibited increased susceptibility to PSII photoinhibition. In contrast, in vivo measurements of the redox transients of PSI reaction centre (P700) showed a considerable gradual decrease in the extent of P700 photooxidation (P700+) under increased Mn concentrations compared to control. This was accompanied by a slower rate of P700+ re-reduction indicating a downregulation of the PSI-dependent cyclic electron flow. The abundance of PSI reaction centre polypeptides (PsaA and PsaB) in plants under the highest Mn concentration was also significantly lower compared to the control. The results demonstrate for the first time that PSI is the major target of Mn toxicity within the photosynthetic apparatus of Arabidopsis plants. The possible involvement mechanisms of Mn toxicity targeting specifically PSI are discussed.
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影响因子：
5.7
作者：
Demirevska-Kepova, K;Simova-Stoilova, L;Feller, U
通讯作者：
Feller, U
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5.7
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3.3
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通讯作者：
STRAUS, NA
影响因子：
2.1
作者：
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通讯作者：
Kawai, S