Quantifying light response of photosynthesis: addressing the long-standing limitations of non-rectangular hyperbolic model
Quantifying light response of photosynthesis: addressing the long-standing limitations of non-rectangular hyperbolic model
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DOI：
10.32615/ps.2021.009
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发表时间：
2021-03
期刊：
影响因子：
2.7
通讯作者：
Z. Ye;S. Duan;X. M. Chen;H. Duan;C. Gao;H. Kang;T. An;S. Zhou
中科院分区：
文献类型：
--
作者：
Z. Ye;S. Duan;X. M. Chen;H. Duan;C. Gao;H. Kang;T. An;S. Zhou
光强度（I）波动迅速，是影响光合作用最重要的环境因素。准确表征叶尺度光合作用的光响应曲线（PN-I曲线）是理解全植物和生态系统尺度的PN-I关系的基础。稳健的 PN-I 模型应该能够准确地再现光限制、光饱和和光抑制 I 水平上的 PN-I 曲线，并理想地返回定义曲线的关键数量性状，包括初始增加斜率 (α)、暗呼吸速率 (RD)、最大净光合速率 (PNmax) 和相应的饱和强度 (Isat)。我们需要改进 (1) 低 I 水平下的 PN-I 反应和 (2) 广泛报道的光抑制 I 水平下 PN 下降的模型再现。我们的观察模型比较（由广泛使用的非矩形双曲线模型显示）导致（1）低估 RD，（2）高估 PNmax，以及（3）当我超过品种特定的 Isat 时，无法重现光抑制反应。相比之下，我们的模型很好地解决了上述限制。结果突出了我们模型的准确性和鲁棒性，特别是在 (1) 返回定义曲线的关键特征和 (2) 在低 [即 0-50 μmol(photon) m-2 s-1] 和光抑制 I 水平（即超出 Isat）上重现曲线。
Light intensity (I) fluctuates rapidly and is the most important environmental factor affecting photosynthesis. Accurate characterization of light-response curve of leaf-scale photosynthesis (PN-I curve) is fundamental for understanding PN-I relations at the whole-plant and ecosystem scales. A robust PN-I model should be accurate in reproducing PN-I curves over light-limited, light-saturated, and photoinhibitory I levels, and ideally returning key quantitative traits defining the curves, including initial slope of increase (α), dark respiration rate (RD), the maximum net photosynthetic rate (PNmax), and the corresponding saturation intensity (Isat). We need to improve a model reproduction of (1) PN-I responses over low I levels and (2) the widely reported decline of PN at photoinhibitory I levels. Our observation-modelling comparison, shown by the widely used non-rectangular hyperbolic model, led to (1) underestimation of RD, (2) overestimation of PNmax, and (3) failure in reproducing the photoinhibitory response when I surpassed the cultivar-specific Isat. In contrast, our model addressed the above limitations extremely well. The results highlighted the accuracy and robustness of our model, especially in (1) returning key traits defining the curve and (2) reproducing the curve over both low [i.e., 0-50 μmol(photon) m-2 s-1] and photoinhibitory I levels (i.e., beyond Isat).