Historically, two modeling approaches have been developed independently to describe photosynthetic electron transport (PET) from water to plastoquinone within Photosystem II (PSII): Markov models account for losses from finite redox transition probabilities but predict no reaction kinetics, and ordinary differential equation (ODE) models account for kinetics but not for redox inefficiencies. We have developed an ODE mathematical framework to calculate Markov inefficiencies of transition probabilities as defined in Joliot–Kok-type catalytic cycles. We adapted a previously published ODE model for PET within PSII that accounts for 238 individual steps to enable calculation of the four photochemical inefficiency parameters (miss, double hit, inactivation, backward transition) and the four redox accumulation states (S-states) that are predicted by the most advanced of the Joliot–Kok-type models (VZAD). Using only reaction kinetic parameters without other assumptions, the RODE-calculated time-averaged (e.g., equilibrium) inefficiency parameters and equilibrium S-state populations agree with those calculated by time-independent Joliot–Kok models. RODE also predicts their time-dependent values during transient photochemical steps for all 96 microstates involving PSII redox cofactors. We illustrate applications to two cyanobacteria, Arthrospira maxima and Synechococcus sp. 7002, where experimental data exists for the inefficiency parameters and the S-state populations, and historical data for plant chloroplasts as benchmarks. Significant findings: RODE predicts the microstates responsible for period-4 and period-2 oscillations of O₂ and fluorescence yields and the four inefficiency parameters; the latter parameters are not constant for each S state nor in time, in contrast to predictions from Joliot–Kok models; some of the recombination pathways that contribute to the backward transition parameter are identified and found to contribute when their rates exceed the oxidation rate of the terminal acceptor pool (PQH₂); prior reports based on the assumptions of Joliot–Kok parameters may require reinterpretation.

从历史上看，已经独立开发了两种建模方法来描述光系统 II (PSII) 内从水到质体醌的光合电子传递 (PET)：马尔可夫模型解释了有限氧化还原转变概率的损失，但没有预测反应动力学，以及常微分方程 (ODE) ) 模型解释了动力学，但不考虑氧化还原效率低下。我们开发了一个 ODE 数学框架来计算 Joliot-Kok 型催化循环中定义的转换概率的马尔可夫低效率。我们在 PSII 中调整了之前发布的 PET ODE 模型，该模型包含 238 个单独的步骤，以计算四个光化学低效率参数（未命中、双击、失活、反向过渡）和四种氧化还原积累状态（S-状态），由最先进的 Joliot-Kok 型模型（VZAD）预测。使用只有反应动力学参数没有其他假设，RODE计算的时间平均（例如，平衡）无效率参数和平衡 S 状态人口与时间无关的 Joliot-Kok 模型计算的一致。RODE还预测了涉及 PSII 氧化还原辅因子的所有 96 种微状态的瞬态光化学步骤中它们的时间相关值。我们说明了对两种蓝藻、Arthrospira maxima和Synechococcus sp的应用。7002，其中存在低效率参数和 S 状态种群的实验数据，以及作为基准的植物叶绿体的历史数据。重要发现：RODE_{预测导致 O 2}的第 4 周期和第 2 周期振荡的微观状态以及荧光产量和四个低效率参数；与 Joliot-Kok 模型的预测相比，后一个参数对于每个 S 状态和时间都不是恒定的；_{当它们的速率超过末端受体池 (PQH 2} )的氧化速率时，一些有助于反向过渡参数的重组途径被确定并被发现；基于 Joliot-Kok 参数假设的先前报告可能需要重新解释。