Department of Biophysics, Faculty of Science, Palacký University, Šlechtitelů 241/27, 77900, Olomouc, Czech Republic.
Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141, Institut de Biologie Physico-Chimique, Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, Paris, France.
Plant Physiol Biochem. 2024 Dec;217:109138. doi: 10.1016/j.plaphy.2024.109138. Epub 2024 Sep 21.
Alternating electric current and alternating electromagnetic fields revolutionized physics and engineering and led to many technologies that shape modern life. Despite these undisputable achievements that have been reached using stimulation by harmonic oscillations over centuries, applications in biology remain rare. Photosynthesis research is uniquely suited to unleash this potential because light can be modulated as a harmonic function, here sinus. Understanding the response of photosynthetic organisms to sinusoidal light is hindered by the complexity of dynamics that such light elicits, and by the mathematical apparatus required for understanding the signals in the frequency domain which, although well-established and simple, is outside typical curricula in biology. Here, we approach these challenges by presenting a mathematical model that was designed specifically to simulate the response of photosynthetic light reactions to light which oscillates with periods that often occur in nature. The independent variables of the model are the plastoquinone pool, the photosystem I donors, lumen pH, ATP, and the chlorophyll fluorescence (ChlF) quencher that is responsible for the qE non-photochemical quenching. Dynamics of ChlF emission, rate of oxygen evolution, and non-photochemical quenching are approximated by dependent model variables. The model is used to explain the essentials of the frequency-domain approaches up to the level of presenting Bode plots of frequency-dependence of ChlF. The model simulations were found satisfactory when compared with the Bode plots of ChlF response of the green alga Chlamydomonas reinhardtii to light that was oscillating with a small amplitude and frequencies between 7.8 mHz and 64 Hz.
交流电和交变电磁场彻底改变了物理学和工程学，并催生了许多塑造现代生活的技术。尽管在过去几个世纪中，通过谐波振荡刺激已经取得了这些无可争议的成就，但在生物学中的应用仍然很少。光合作用研究非常适合释放这种潜力，因为光可以作为谐波函数（这里是正弦函数）进行调制。理解光合作用生物体对正弦光的响应受到激发光引发的动力学复杂性以及理解频域信号所需的数学仪器的限制，尽管这些信号在生物学领域已经得到很好的确立和简化，但它们通常不在生物学课程的范围内。在这里，我们通过提出一个专门设计的数学模型来解决这些挑战，该模型旨在模拟光合作用光反应对以自然界中经常出现的周期振荡的光的响应。该模型的独立变量是质体醌池、光系统 I 供体、腔室 pH 值、ATP 和负责 qE 非光化学猝灭的叶绿素荧光（ChlF）猝灭剂。ChlF 发射的动力学、氧释放的速率和非光化学猝灭由依赖模型的变量来近似。该模型用于解释频域方法的要点，直至呈现叶绿素荧光对频率依赖性的 Bode 图。当将模型模拟与小球藻对振幅小且频率在 7.8 mHz 和 64 Hz 之间的振荡光的 ChlF 响应的 Bode 图进行比较时，发现模型模拟结果令人满意。
