Identification of a functional respiratory complex in chloroplasts through analysis of tobacco mutants containing disrupted plastid ndh genes
Identification of a functional respiratory complex in chloroplasts through analysis of tobacco mutants containing disrupted plastid ndh genes
复制标题
DOI：
10.1093/emboj/17.4.868
复制
发表时间：
1998-02-16
期刊：
影响因子：
11.4
通讯作者：
Nixon, PJ
中科院分区：
文献类型：
--
作者：
Burrows, PA;Sazanov, LA;Nixon, PJ
几种植物的质体基因组含有编码NADH亚基的基因的同源物，称为ndh基因：辅酶Q氧化还原酶或线粒体和真细菌的复合物I。Ndh蛋白在高等植物中的功能意义是不确定的，我们在这里显示烟草叶绿体含有由至少三种ndh基因产物组成的550 kDa的蛋白复合物：NdhI、NdhJ和NdhK，我们已经构建了具有被破坏的ndhC、ndhK和ndhJ质体基因的突变烟草植物，表明Ndh复合物在最佳生长条件下对于植物生长是不可缺少的，叶绿素荧光分析表明，在体内Ndh复合物催化质体醌库的光照后还原，并且在光下优化了在物质胁迫条件下光合作用的诱导。我们得出结论，Ndh复合物使用基质还原剂催化质体醌库的还原，因此充当呼吸复合物。我们的数据与Ndh复合物在光下参与光系统I复合物周围的循环电子以及在黑暗中可能参与叶绿体呼吸链是一致的。
The plastid genomes of several plants contain homologues, termed ndh genes, of genes encoding subunits of the NADH:ubiquinone oxidoreductase or complex I of mitochondria and eubacteria. The functional significance of the Ndh proteins in higher plants is uncertain, We show here that tobacco chloroplasts contain a protein complex of 550 kDa consisting of at least three of the ndh gene products: NdhI, NdhJ and NdhK, We have constructed mutant tobacco plants with disrupted ndhC ndhK and ndhJ plastid genes, indicating that the Ndh complex is dispensible for plant growth under optimal growth conditions, Chlorophyll fluorescence analysis shows that in vivo the Ndh complex catalyses the post-illumination reduction of the plastoquinone pool and in the light optimizes the induction of photosynthesis under conditions of mater stress, We conclude that the Ndh complex catalyses the reduction of the plastoquinone pool using stromal reductant and so acts as a respiratory complex, Overall, our data are compatible with the participation of the Ndh complex in cyclic electron how around the photosystem I complex in the light and possibly in a chloroplast respiratory chain in the dark.