Sukhova Ekaterina, Gromova Ekaterina, Yudina Lyubov, Kior Anastasiia, Vetrova Yana, Ilin Nikolay, Mareev Evgeny, Vodeneev Vladimir, Sukhov Vladimir
Department of Biophysics, N.I. Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia.
Earth's Electromagnetic Environment Laboratory, Institute of Applied Physics of Russian Academy of Sciences, 603600 Nizhny Novgorod, Russia.
Plants (Basel). 2021 Oct 18;10(10):2207. doi: 10.3390/plants10102207.
Natural and artificial extremely low-frequency magnetic fields (ELFMFs) are important factors influencing physiological processes in living organisms including terrestrial plants. Earlier, it was experimentally shown that short-term and long-term treatments by ELFMFs with Schumann resonance frequencies (7.8, 14.3, and 20.8 Hz) influenced parameters of photosynthetic light reactions in wheat leaves. The current work is devoted to an analysis of potential ways of this ELFMF influence on the light reactions. Only a short-term wheat treatment by 14.3 Hz ELFMF was used in the analysis. First, it was experimentally shown that ELFMF-induced changes (an increase in the effective quantum yield of photosystem II, a decrease in the non-photochemical quenching of chlorophyll fluorescence, a decrease in time of changes in these parameters, etc.) were observed under the action of ELFMF with widely ranging magnitudes (from 3 to 180 µT). In contrast, the potential quantum yield of photosystem II and time of relaxation of the energy-dependent component of the non-photochemical quenching were not significantly influenced by ELFMF. Second, it was shown that the ELFMF treatment decreased the proton gradient across the thylakoid membrane. In contrast, the H conductivity increased under this treatment. Third, an analysis of the simplest mathematical model of an H transport across the thylakoid membrane, which was developed in this work, showed that changes in H fluxes related to activities of the photosynthetic electron transport chain and the H-ATP synthase were not likely a mechanism of the ELFMF influence. In contrast, changes induced by an increase in an additional H flux (probably, through the proton leakage and/or through the H/Ca antiporter activity in the thylakoid membrane) were in good accordance with experimental results. Thus, we hypothesized that this increase is the mechanism of the 14.3 Hz ELFMF influence (and, maybe, influences of other low frequencies) on photosynthetic light reactions in wheat.
天然和人工极低频磁场（ELFMFs）是影响包括陆生植物在内的生物体生理过程的重要因素。此前，实验表明，用舒曼共振频率（7.8、14.3和20.8赫兹）的ELFMFs进行短期和长期处理会影响小麦叶片光合光反应的参数。当前的工作致力于分析这种ELFMF对光反应的潜在影响方式。分析中仅使用了14.3赫兹ELFMF对小麦进行短期处理。首先，实验表明，在幅度范围广泛（从3到180微特斯拉）的ELFMF作用下，观察到了ELFMF诱导的变化（光合系统II有效量子产率增加、叶绿素荧光非光化学猝灭降低、这些参数变化时间缩短等）。相比之下，光合系统II的潜在量子产率和非光化学猝灭的能量依赖成分的弛豫时间不受ELFMF的显著影响。其次，结果表明，ELFMF处理降低了类囊体膜两侧的质子梯度。相比之下，这种处理下H电导率增加。第三，对本工作中建立的类囊体膜H运输最简单数学模型的分析表明，与光合电子传递链和H - ATP合酶活性相关的H通量变化不太可能是ELFMF影响的机制。相比之下，额外H通量增加（可能通过质子泄漏和/或类囊体膜中H/Ca反向转运体活性）引起的变化与实验结果高度吻合。因此，我们假设这种增加是14.3赫兹ELFMF（也许还有其他低频）对小麦光合光反应影响的机制。
