Yi Xiaoping, Hargett Stefan R, Frankel Laurie K, Bricker Terry M
Division of Biochemistry and Molecular Biology, Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
Photosynth Res. 2008 Oct-Dec;98(1-3):439-48. doi: 10.1007/s11120-008-9352-8. Epub 2008 Sep 9.
Interfering RNA was used to suppress simultaneously the expression of the four genes which encode the PsbO and PsbP proteins of Photosystem II in Arabidopsis (PsbO: At5g66570, At3g50820 and PsbP: At1g06680, At2g30790). A phenotypic series of transgenic plants was obtained that expressed variable amounts of the PsbO proteins and undetectable amounts of the PsbP proteins. Immunological studies indicated that the loss of PsbP expression was correlated with the loss of expression of the PsbQ, D2, and CP47 proteins, while the loss of PsbO expression was correlated with the loss of expression of the D1 and CP43 proteins. Q(A)(-) reoxidation kinetics in the absence of DCMU indicated that the slowing of electron transfer from Q(A)(-) to Q(B) was correlated with the loss of the PsbP protein. Q(A)(-) reoxidation kinetics in the presence of DCMU indicated that charge recombination between Q(A)(-) and donor side components of the photosystem was retarded in all of the mutants. Decreasing amounts of the PsbO protein in the absence of the PsbP component also led to a progressive loss of variable fluorescence yield (F(V)/F(M)). During fluorescence induction, the loss of PsbP was correlated with a more rapid O to J transition and a loss of the J to I transition. These results indicate that the losses of the PsbO and PsbP proteins differentially affect separate protein components and different PS II functions and can do so, apparently, in the same plant.
干扰RNA被用于同时抑制拟南芥中编码光系统II的PsbO和PsbP蛋白的四个基因的表达（PsbO：At5g66570、At3g50820，PsbP：At1g06680、At2g30790）。获得了一系列转基因植物，它们表达不同量的PsbO蛋白且检测不到PsbP蛋白。免疫学研究表明，PsbP表达的缺失与PsbQ、D2和CP47蛋白表达的缺失相关，而PsbO表达的缺失与D1和CP43蛋白表达的缺失相关。在不存在二氯苯基二甲基脲（DCMU）的情况下，Q(A)(-)再氧化动力学表明，从Q(A)(-)到Q(B)的电子传递减慢与PsbP蛋白的缺失相关。在存在DCMU的情况下，Q(A)(-)再氧化动力学表明，在所有突变体中，Q(A)(-)与光系统供体侧组分之间的电荷复合受到阻碍。在不存在PsbP组分的情况下，PsbO蛋白量的减少也导致可变荧光产量（F(V)/F(M)）逐渐丧失。在荧光诱导期间，PsbP的缺失与更快的O到J转变以及J到I转变的丧失相关。这些结果表明，PsbO和PsbP蛋白的缺失对不同的蛋白质组分和不同的PS II功能有不同的影响，并且显然可以在同一植物中发生。
