Robert Hill Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, P.O. Box 594, S10 2UH, Sheffield, UK.
Photosynth Res. 1993 May;36(2):119-39. doi: 10.1007/BF00016277.
The components of non-photochemical chlorophyll fluorescence quenching (qN) in barley leaves have been quantified by a combination of relaxation kinetics analysis and 77 K fluorescence measurements (Walters RG and Horton P 1991). Analysis of the behaviour of chlorophyll fluorescence parameters and oxygen evolution at low light (when only state transitions - measured as qNt - are present) and at high light (when only photoinhibition - measured as qNi - is increasing) showed that the parameter qNt represents quenching processes located in the antenna and that qNi measures quenching processes located in the reaction centre but which operate significantly only when those centres are closed. The theoretical predictions of a variety of models describing possible mechanisms for high-energy-state quenching, measured as the residual quenching, qNe, were then tested against the experimental data for both fluorescence quenching and quantum yield of oxygen evolution. Only one model was found to agree with these data, one in which antennae exist in two states, efficient in either energy transfer or energy dissipation, and in which those photosynthetic units in a dissipative state are unable to exchange energy with non-dissipative units.
大麦叶片中非光化学叶绿素荧光猝灭（qN）的组成部分已通过弛豫动力学分析和 77 K 荧光测量的组合进行了定量（Walters RG 和 Horton P 1991）。对低光下（仅存在状态转换 - 以 qNt 测量）和高光下（仅光抑制 - 以 qNi 测量）叶绿素荧光参数和氧气演化行为的分析表明，参数 qNt 代表位于天线中的猝灭过程，而 qNi 测量位于反应中心的猝灭过程，但仅在这些中心关闭时才会显著起作用。然后，根据荧光猝灭和氧气演化量子产率的实验数据，对各种描述高能态猝灭（以残余猝灭 qNe 测量）可能机制的模型的理论预测进行了测试。只有一个模型与这些数据相符，该模型认为天线存在两种状态，在能量转移或能量耗散方面都有效，并且处于耗散状态的那些光合作用单元无法与非耗散单元交换能量。
