A nucleus-encoded factor, CRR2, is essential for the expression of chloroplast ndhB in Arabidopsis
A nucleus-encoded factor, CRR2, is essential for the expression of chloroplast ndhB in Arabidopsis
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DOI：
10.1046/j.1365-313x.2003.01900.x
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发表时间：
2003-11-01
期刊：
影响因子：
7.2
通讯作者：
Shikanai, T
中科院分区：
文献类型：
--
作者：
Hashimoto, M;Endo, T;Shikanai, T
叶绿体NDH复合物NAD（P）H脱氢酶以非光化学方式减少质体醌库，并参与光系统I（PSI）周围的循环电子流。关闭光化光后叶绿素荧光的瞬时增加是NDH活性的结果。本研究利用叶绿素荧光成像技术，对拟南芥叶绿体NDH活性的这种细微变化进行了研究，以筛选出影响叶绿体NDH活性的核突变体。crr 2 -1和crr 2 -2（氯呼吸减少）是隐性突变等位基因，其中NDH复合物的积累受损。除了NDH活性的缺陷，光合电子传递不受影响。CRR 2编码植物组合和模块蛋白（PCMP）家族的成员，该家族由拟南芥中的200多个基因组成。CRR 2在rps 7和ndhB之间的叶绿体RNA的基因间加工中起作用，这可能是ndhB翻译所必需的。我们已经确定了PCMP家族成员的功能，表明该家族与参与细胞器RNA成熟步骤的pentatrico肽PPR蛋白密切相关。
The chloroplast NDH complex, NAD(P)H dehydrogenase, reduces the plastoquinone pool non-photochemically and is involved in cyclic electron flow around photosystem I (PSI). A transient increase in chlorophyll fluorescence after turning off actinic light is a result of NDH activity. We focused on this subtle change in chlorophyll fluorescence to isolate nuclear mutants affected in chloroplast NDH activity in Arabidopsis by using chlorophyll fluorescence imaging. crr2-1 and crr2-2 (chlororespiratory reduction) are recessive mutant alleles in which accumulation of the NDH complex is impaired. Except for the defect in NDH activity, photosynthetic electron transport was unaffected. CRR2 encodes a member of the plant combinatorial and modular protein (PCMP) family consisting of more than 200 genes in Arabidopsis. CRR2 functions in the intergenic processing of chloroplast RNA between rps7 and ndhB, which is possibly essential for ndhB translation. We have determined the function of a PCMP family member, indicating that the family is closely related to pentatrico-peptide PPR proteins involved in the maturation steps of organellar RNA.