Dynamic interplay between photodamage and photoprotection in photosystem II.
Dynamic interplay between photodamage and photoprotection in photosystem II.
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DOI：
10.1111/pce.13107
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发表时间：
2018-05
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影响因子：
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通讯作者：
Alexandra J. Townsend;Maxwell A. Ware;A. Ruban
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作者：
Alexandra J. Townsend;Maxwell A. Ware;A. Ruban
光抑制是光引起的光合作用效率降低，通常与 D1 光系统 II (PSII) 反应中心蛋白的损伤有关。这种损伤必须通过 PSII 修复周期进行修复，或者首先通过非光化学猝灭 (NPQ) 来预防。 NPQ 和 D1 修复都有助于提高耐光性，因为它们确保长期维持 PSII 的最高量子产率。然而，每个过程的相对贡献仍有待阐明。脉冲幅度调制荧光方法（称为保护性 NPQ）的应用使我们能够评估该过程的保护有效性。在这项研究中，通过使用已知影响每个过程的抑制剂和突变体，阐明了 NPQ 和 D1 修复对拟南芥光保护能力的贡献。我们得出的结论是，在短时间光照下，NPQ 比 D1 修复对维持高 PSII 产量的贡献更大。这项研究进一步支持了 NPQ 的保护性成分在光波动期间的作用，以及保护性 NPQ 和 qPd 作为明确荧光参数的价值，而不是 qI 和 Fv /Fm ，用于量化反应中心 II 的光失活和光合生物的光耐受性。
Photoinhibition is the light-induced reduction in photosynthetic efficiency and is usually associated with damage to the D1 photosystem II (PSII) reaction centre protein. This damage must either be repaired, through the PSII repair cycle, or prevented in the first place by nonphotochemical quenching (NPQ). Both NPQ and D1 repair contribute to light tolerance because they ensure the long-term maintenance of the highest quantum yield of PSII. However, the relative contribution of each of these processes is yet to be elucidated. The application of a pulse amplitude modulation fluorescence methodology, called protective NPQ, enabled us to evaluate of the protective effectiveness of the processes. Within this study, the contribution of NPQ and D1 repair to the photoprotective capacity of Arabidopsis thaliana was elucidated by using inhibitors and mutants known to affect each process. We conclude that NPQ contributes a greater amount to the maintenance of a high PSII yield than D1 repair under short periods of illumination. This research further supports the role of protective components of NPQ during light fluctuations and the value of protective NPQ and qPd as unambiguous fluorescence parameters, as opposed to qI and Fv /Fm , for quantifying photoinactivation of reaction centre II and light tolerance of photosynthetic organisms.