Schreiber U, Vidaver W
Biochim Biophys Acta. 1976 Jul 9;440(1):205-14. doi: 10.1016/0005-2728(76)90124-9.
The I-D transient in the chlorophyll fluorescence induction curve (kautsky effect) is investigated in the view of recently discovered rapid changes in energy distribution between the two photosystems (Schreiber, U. and Vidaver, W., FEBS Lett., in the press). Fluorescence induction curves differ appreciably depending on whether measured at lambda less than 690 nm, originating in pigment system II, or at lambda greater than 715 nm, which is in part from pigment system I. The differences occur as well in the rapid part of the induction curve (O-I-D-P) as in the slower P-S decay. Most significant changes in energy distribution are indicated in the region of the I-D dip, being induced by appropriate preillumination. The effect is studied by (a) comparing the individual fluorescence time courses at lambda less than 690 nm and lambda greather than 715, (b) plotting F less than 690 vs. F greater than 715 and (c) recording time courses of F less than 690/F greater than 715 ratios. In (a) the I and D characteristics are delayed at F greater than 715 relative to F less than 690, which is accompanied by periods close to I and D, where the two emissions follow inverse courses. In (b) the I-D dip corresponds to a loop. And in (c) it is shown that a rapid ratio decay, reflecting increasing excitation of System I pigments, is initiated before the I-D dip. These data indicate that the I-D transient is caused by a rapid switch of energy distribution in favor of System I and resulting stimulation of Q reoxidation via the electron transport chain. It is suggested that as with the slow fluorescence transients the rapid also can be understood as a composite of two different changes, (1) direct changes resulting from a switch in energy distribution, which are inverse for F less than 690 and F greater than 715, and (2) indirect changes due to stimulated Q reduction or Q oxidation, which are parallel for both emissions. The rapid ratio decay, correlated to I-D, persists and is even stimulated in the presence of electron transport inhibitors. This and the speed of the phenomenon make it improbable that the rapid energy distribution changes are affected by an ion flux-induced mechanism. It is proposed that the electrical field across the thylakoid membrane is involved in the energy switch mechanism.
从最近发现的两个光系统之间能量分布的快速变化角度（施赖伯，U.和维达弗，W.，《欧洲生物化学学会联合会快报》，即将发表），对叶绿素荧光诱导曲线（考茨基效应）中的I-D瞬变进行了研究。荧光诱导曲线根据测量波长的不同而有明显差异，在波长小于690纳米时测量，其源于色素系统II，而在波长大于715纳米时测量，这部分来自色素系统I。这种差异在诱导曲线的快速部分（O-I-D-P）以及较慢的P-S衰减中都存在。能量分布的最显著变化在I-D下降区域表现出来，并由适当的预照明诱导。通过以下方式研究该效应：（a）比较波长小于690纳米和大于715纳米时的个体荧光时间进程，（b）绘制F小于690与F大于715的关系图，以及（c）记录F小于690/F大于715比值的时间进程。在（a）中相对于F小于690，F大于715时I和D特征出现延迟，同时伴随着接近I和D的时期，此时两种发射呈现相反的进程。在（b）中I-D下降对应一个环。并且在（c）中表明，反映系统I色素激发增加的快速比值衰减在I-D下降之前就开始了。这些数据表明，I-D瞬变是由能量分布快速转向有利于系统I并通过电子传递链导致Q再氧化的刺激引起的。有人提出，与缓慢的荧光瞬变一样，快速瞬变也可以理解为两种不同变化的组合，（1）能量分布切换导致的直接变化，对于F小于690和F大于715是相反的，以及（2）由于刺激的Q还原或Q氧化导致的间接变化，对于两种发射是平行的。与I-D相关的快速比值衰减持续存在，甚至在存在电子传递抑制剂的情况下也会受到刺激。这种情况以及该现象的速度使得快速能量分布变化不太可能受到离子通量诱导机制的影响。有人提出，类囊体膜上的电场参与了能量切换机制。
