Contrasting effects of copper limitation on the photosynthetic apparatus in two strains of the open ocean diatom Thalassiosira oceanica.
Contrasting effects of copper limitation on the photosynthetic apparatus in two strains of the open ocean diatom Thalassiosira oceanica.
复制标题
铜限制对开放海洋硅藻塔拉西奥拉海洋两种菌株光合作用的对比影响。
DOI：
10.1371/journal.pone.0181753
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Maldonado MT
中科院分区：
文献类型：
--
作者：
Hippmann AA;Schuback N;Moon KM;McCrow JP;Allen AE;Foster LJ;Green BR;Maldonado MT
在硅藻中，铁（Fe）和铜（Cu）生理之间存在复杂的相互作用。然而，科普低铜的策略在很大程度上是未知的。本研究从生理和蛋白质水平揭示了低铜胁迫下海洋海链藻（Thalassiosira oceanica，CCMP 1003）光合机构的全面重组。重组的结果是从光化学的光捕获-最终用于碳固定-到光保护，减少碳固定和氧气释放。观察到的生理参数Fv/Fm、碳固定和氧释放的降低，伴随着触角吸收截面（σPSII）、非光化学猝灭（NPQ）和转换因子（φe：C/ηPSII）的增加，与已有的细胞对低Fe的反应一致。然而，由于低铜引起的潜在蛋白质组学变化与低铁引起的变化非常不同。低铜诱导含铜光合电子载体质体蓝素显着减少四倍。质体蓝素的减少导致光合电子传递链（ETC）内的瓶颈，最终导致实质性的化学计量变化。即，细胞色素b6 f复合物（cytb 6 f）和光系统II（PSII）减少2倍，富铁PSI没有变化，而可能参与活性氧解毒的蛋白质（铁氧还蛋白和铁氧还蛋白：NADP+还原酶）增加40倍和2倍。此外，我们确定了48个捕光复合物（LHC）蛋白在公开可用的基因组的T。并为其中33种提供了蛋白质组学证据。触角内LHC组成的变化对低Cu的反应强调了T. oceanica（CCMP1003）。有趣的是，我们还揭示了非常显著的种内菌株差异。另一株T.与CCMP 1003相比，Oceanica（CCMP 1005）需要显著更高的Cu浓度来维持其最大和最小生长速率。低铜胁迫下，CCMP 1005的生长速率、细胞大小、叶绿素a和细胞总蛋白均下降.我们认为，每个细胞蛋白质的减少是降低其细胞铜需求的主要策略，因为测试的其他参数均不受影响。两种菌株之间的差异，以及有据可查的响应低铁和这里提出的响应低铜之间的差异进行了讨论。
There is an intricate interaction between iron (Fe) and copper (Cu) physiology in diatoms. However, strategies to cope with low Cu are largely unknown. This study unveils the comprehensive restructuring of the photosynthetic apparatus in the diatom Thalassiosira oceanica (CCMP1003) in response to low Cu, at the physiological and proteomic level. The restructuring results in a shift from light harvesting for photochemistry—and ultimately for carbon fixation—to photoprotection, reducing carbon fixation and oxygen evolution. The observed decreases in the physiological parameters Fv/Fm, carbon fixation, and oxygen evolution, concomitant with increases in the antennae absorption cross section (σPSII), non-photochemical quenching (NPQ) and the conversion factor (φe:C/ηPSII) are in agreement with well documented cellular responses to low Fe. However, the underlying proteomic changes due to low Cu are very different from those elicited by low Fe. Low Cu induces a significant four-fold reduction in the Cu-containing photosynthetic electron carrier plastocyanin. The decrease in plastocyanin causes a bottleneck within the photosynthetic electron transport chain (ETC), ultimately leading to substantial stoichiometric changes. Namely, 2-fold reduction in both cytochrome b6f complex (cytb6f) and photosystem II (PSII), no change in the Fe-rich PSI and a 40- and 2-fold increase in proteins potentially involved in detoxification of reactive oxygen species (ferredoxin and ferredoxin:NADP+ reductase, respectively). Furthermore, we identify 48 light harvesting complex (LHC) proteins in the publicly available genome of T. oceanica and provide proteomic evidence for 33 of these. The change in the LHC composition within the antennae in response to low Cu underlines the shift from photochemistry to photoprotection in T. oceanica (CCMP1003). Interestingly, we also reveal very significant intra-specific strain differences. Another strain of T. oceanica (CCMP 1005) requires significantly higher Cu concentrations to sustain both its maximal and minimal growth rate compared to CCMP 1003. Under low Cu, CCMP 1005 decreases its growth rate, cell size, Chla and total protein per cell. We argue that the reduction in protein per cell is the main strategy to decrease its cellular Cu requirement, as none of the other parameters tested are affected. Differences between the two strains, as well as differences between the well documented responses to low Fe and those presented here in response to low Cu are discussed.
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影响因子：
56.9
作者：
Armbrust, EV;Berges, JA;Rokhsar, DS
通讯作者：
Rokhsar, DS
影响因子：
14.9
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Finn RD;Mistry J;Tate J;Coggill P;Heger A;Pollington JE;Gavin OL;Gunasekaran P;Ceric G;Forslund K;Holm L;Sonnhammer EL;Eddy SR;Bateman A
通讯作者：
Bateman A
影响因子：
4.5
作者：
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通讯作者：
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影响因子：
56.9
作者：
Field, CB;Behrenfeld, MJ;Falkowski, P
通讯作者：
Falkowski, P
影响因子：
14.9
作者：
Benson DA;Clark K;Karsch-Mizrachi I;Lipman DJ;Ostell J;Sayers EW
通讯作者：
Sayers EW