Time course of the photochemical reflectance index (PRI) during photosynthetic induction: its relationship with the photochemical yield of photosystem II
Time course of the photochemical reflectance index (PRI) during photosynthetic induction: its relationship with the photochemical yield of photosystem II
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光合诱导过程中光化学反射指数（PRI）的时程：与光系统II光化学产率的关系
DOI：
10.1111/ppl.12745
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发表时间：
2018
影响因子：
6.4
通讯作者：
Ibaraki Yasuomi
中科院分区：
文献类型：
--
作者：
Murakami Keach;Ibaraki Yasuomi
比较了黄瓜叶片在暗-光过渡过程中光化学反射指数（PRI）与光系统II （YII）光化学产率的变化过程，探讨了PRI成像技术用于估算光合光能利用效率的可行性。我们分别使用脉冲幅度调制叶绿素荧光仪和低成本成像系统（由数码相机和带通滤波器组成）对iiand PRI进行了评估。在不同的光子通量密度下，跃迁发生后，光子密度立即减小，然后增大。虽然在弱光条件下PRI相对于ii表现出延迟的时间过程，但在强光条件下PRI单调下降。在稳态光合作用下，i i与转化后立即的PRI （ΔPRI）变化没有相关性，i i与ΔPRI相关。这些结果表明，在波动光下，基于稳态得到的回归，用PRI估计yii可能会高估yii。该成像系统还应用于评价叶片内PRI的空间分布。未处理或再次处理水的叶区PRI在弱光条件下先下降后上升，在强光条件下单调下降，而抑制剂（二氯苯基二甲基脲）处理的叶区PRI没有任何变化。该抑制剂可能抑制了管腔酸化，从而导致PRI降低。这表明，基于PRI的估算可能高估了光合电子传递异常的叶片的ii值。
Time courses of photochemical reflectance index (PRI) of an attached cucumber leaf during a dark–light transition were compared with those of photochemical yields of photosystem II (YII) to discuss the feasibility of PRI imaging for estimating the efficiency of photosynthetic light use.YIIand PRI were simultaneously evaluated with a pulse‐amplitude modulation chlorophyll fluorometer and a low‐cost imaging system consisting of digital cameras and band‐pass filters, respectively.YIIdecreased immediately after the transition and then increased under various photon flux densities. Although PRI exhibited delayed time courses with respect toYIIunder low light conditions, PRI decreased monotonically under high light conditions. There was no correlation betweenYIIand the changes in PRI (ΔPRI) immediately after the transition butYIIwas correlated with ΔPRI under the steady‐state photosynthesis. These results indicate that the use of PRI to estimateYIIunder fluctuating light based on the regression obtained at steady state can overestimateYII. The imaging system was also applied to evaluate the spatial PRI distribution within a leaf. While PRI of leaf areas that remained untreated, or had been treated with H2O again, first dropped and then rose under low light and monotonically decreased under high light conditions, leaf areas treated with inhibitor (dichlorophenyl dimethylurea) did not exhibit any changes. It is likely that the inhibitor suppressed lumen acidification, which triggers a decrease in PRI. It was suggested thatYIIof leaves with malfunctions in the photosynthetic electron transport can be overestimated by the PRI‐based estimation.