Involvement of cyclic electron flow in irradiance stress responding and its potential regulation of the mechanisms in Pyropia yezoensis
Involvement of cyclic electron flow in irradiance stress responding and its potential regulation of the mechanisms in Pyropia yezoensis
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DOI：
10.1007/s00343-016-4236-9
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发表时间：
2016-04
影响因子：
--
通讯作者：
J. Niu;Jianhua Feng;Xiujun Xie;Shan Gao;Guangce Wang
中科院分区：
文献类型：
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作者：
J. Niu;Jianhua Feng;Xiujun Xie;Shan Gao;Guangce Wang
条斑甲藻（Pyropia yezoensis）在2011年以前属于紫菜属（Porphyra），它栖息在光照变化剧烈的潮间带岩石上，这意味着这种海藻已经获得了在恶劣环境中生存的某些机制。利用Dual-PAM-100光合仪测定了藻体在不同光强胁迫下的光合特性和电子流的变化。当接近辐照饱和时，PS I周围的CEF变得至关重要，因为添加抑制剂通常会导致非光化学猝灭的增加。抑制剂实验表明，Py中至少存在三种不同的CEF途径。这些途径相互补偿。除了维持ATP/NAD（P）H的适当比例以支持有效的光合作用外，CEF的潜在作用还可能包括调节Py中不同的光保护机制。yezoensis。在CEF的调控下，氯呼吸将电子从还原的质体醌（PQ）库转移到氧气中，以减轻电子转移链中的还原。当辐射强度达到高强度胁迫时，CEF的相对值开始下降，说明NADP+库或PQ+库很小，电子从还原型PS I转移到了氧。清除酶可能被激活，水-水循环可能成为去除辐射胁迫Py产生的活性氧的有效手段。yezoensis。我们认为，不同的机制可以组成光保护网络，让Py。yezoensisfor生存在一个高度可变的光胁迫栖息地，这可能会启发科学家在未来的研究辐照胁迫在其他藻类物种。
Pyropia yezoensis, belongs to the genus ofPorphyrabefore 2011, inhabit on intertidal zone rocks where irradiation changes dramatically, implying that the seaweed has gained certain mechanisms to survive a harsh environment. Based on the photosynthetic parameters with or without the inhibitors determined by a Dual-PAM-100 apparatus, we investigated the photosynthetic performance and the changes in electron flow that occurred during the algae were stressed with different light intensities previously. When the irradiation saturation was approaching, the CEF around PS I became crucial since the addition of inhibitors usually led to an increase in non-photochemical quenching. The inhibitor experiments showed that there were at least three different CEF pathways inPy. yezoensisand these pathways compensated each other. In addition to maintaining a proper ratio of ATP/NAD(P)H to support efficient photosynthesis, the potential roles of CEF might also include the regulation of different photoprotective mechanisms inPy. yezoensis. Under the regulation of CEF, chlororespiration is thought to transport electrons from the reduced plastoquinone (PQ) pool to oxygen in order to mitigate the reduction in the electron transfer chain. When irradiation was up to the high-grade stress conditions, the relative value of CEF began to decrease, which implied that the NADP+pool or PQ+pool was very small and that the electrons were transferred from reduced PS I to oxygen. The scavenging enzymes might be activated and the water-water cycle probably became an effective means of removing the active oxygen produced by the irradiation stressedPy. yezoensis. We believe that the different mechanisms could make up the photoprotective network to allowPy. yezoensisfor survival in a highly variable light stress habitat, which may enlighten scientists in future studies on irradiance stress in other algae species.