Insights into the function of PsbR protein in Arabidopsis thaliana
Insights into the function of PsbR protein in Arabidopsis thaliana
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DOI：
10.1016/j.bbabio.2007.01.011
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发表时间：
2007-06-01
影响因子：
4.3
通讯作者：
Aro, Eva-Mari
中科院分区：
文献类型：
--
作者：
Allahverdiyeva, Yagut;Mamedov, Fikret;Aro, Eva-Mari
对拟南芥PSBR T-DNA插入突变体的光系统II复合体的功能状态进行了研究。Delta PSBR类囊体的放氧量比WT低约34%，这与Y-D(OX)自由基EPR信号估计的PSII量有关。在DCMU存在和不存在的情况下，闪光荧光(FF)-弛豫慢相时间常数的增加和主要TL带峰位的上移证实了S(2)Q(A)(-)和S(2)Q(B)(-)电荷复合在Delta PSBR类囊体中是稳定的。此外，更多的暗氧化Cyt-b559和增加的荧光比例，在测量的100s时间范围内没有衰减，因此表明Y(D)(+)Q(A)(-)重组的量更高，这表明Delta PSBR中的给体侧修饰。电子顺磁共振测量表明，S-1-S-2-跃迁和S-2态多线信号不受突变的影响。在没有DCMU的情况下，FF松弛的快相明显减慢，并伴随着这一相的相对幅度的降低，这表明在Delta PSBR类囊体中Q(A)到Q(B)的电子传递发生了改变。结论：PSBR蛋白的缺失改变了PSII复合体的供体和受体侧。(C)2007 Elsevier B.V.保留所有权利。
The functional state of the Photosystem (PS) II complex in Arabidopsis psbR T-DNA insertion mutant was studied. The Delta PsbR thylakoids showed about 34% less oxygen evolution than WT, which correlates with the amounts of PSII estimated from Y-D(ox) radical EPR signal. The increased time constant of the slow phase of flash fluorescence (FF)-relaxation and upshift in the peak position of the main TL-bands, both in the presence and in the absence of DCMU, confirmed that the S(2)Q(A)(-) and S(2)Q(B)(-) charge recombinations were stabilized in Delta PsbR thylakoids. Furthermore, the higher amount of dark oxidized Cyt-b559 and the increased proportion of fluorescence, which did not decay during the 100s time span of the measurement thus indicating higher amount of Y(D)(+)Q(A)(-) recombination, pointed to the donor side modifications in Delta PsbR. EPR measurements revealed that S-1-to-S-2-transition and S-2-state multiline signal were not affected by mutation. The fast phase of the FF-relaxation in the absence of DCMU was significantly slowed down with concomitant decrease in the relative amplitude of this phase, indicating a modification in Q(A) to Q(B) electron transfer in Delta PsbR thylakoids. It is concluded that the lack of the PsbR protein modifies both the donor and the acceptor side of the PSII complex. (c) 2007 Elsevier B.V. All rights reserved.