PDM3, a pentatricopeptide repeat-containing protein, affects chloroplast development
PDM3, a pentatricopeptide repeat-containing protein, affects chloroplast development
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PDM3 是一种含有五肽重复序列的蛋白质，影响叶绿体发育
DOI：
10.1093/jxb/erx360
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发表时间：
2017
影响因子：
6.9
通讯作者：
Jianwei Xiao
中科院分区：
文献类型：
--
作者：
Jian Zhang;Jianwei Xiao
叶绿体作为植物光合作用的细胞器，在植物的发育过程中起着至关重要的作用。人们对叶绿体发育进行了广泛的研究，然而，相关的调控机制仍然是难以捉摸的。在这里，我们的特点是突变体有缺陷的叶绿体在拟南芥中，称为色素缺陷型突变体3（pdm 3），它表现出独特的白化病表型在叶片中，最终导致pdm 3幼苗的致死性在自养生长条件下。电子显微镜观察表明pdm 3突变体中类囊体的数量减少，结构被破坏，最终导致叶绿体破裂。序列分析表明，PDM 3编码一个由12个五肽重复结构域组成的叶绿体蛋白，属于P亚类。共聚焦显微镜分析和叶绿体蛋白质组分的免疫印迹均表明PDM 3位于基质中。此外，叶绿体基因的转录谱分析显示，质体编码的聚合酶依赖的转录水平显着降低，而核编码的聚合酶依赖的转录水平增加在pdm 3突变体。此外，我们发现，剪接的内含子在trnA，ndhB和clpP-1也受到影响，在pdm 3。综上所述，我们认为PDM 3在拟南芥叶绿体发育中起着重要作用。
The chloroplast, as the photosynthetic organelle of plants, plays a crucial role in plant development. Extensive studies have been conducted on chloroplast development; however, the related regulatory mechanism still remains elusive. Here, we characterized a mutant with defective chloroplasts in Arabidopsis, termed pigment-defective mutant3 (pdm3), which exhibits a distinct albino phenotype in leaves, eventually leading to pdm3 seedling lethality under autotrophic growth conditions. Electron microscopy demonstrated that the number of thylakoids was reduced and the structure of those thylakoids was disrupted in the pdm3 mutant, which eventually led to the breakdown of chloroplasts. Sequence analysis showed that PDM3 encodes a chloroplast protein consisting of 12 pentratricopeptide repeat domains that belongs to the P subgroup. Both confocal microscopic analysis and immunoblotting in the chloroplast protein fraction showed that PDM3 was located in the stroma. Furthermore, analysis of the transcript profiles of chloroplast genes revealed that plastid-encoded polymerase-dependent transcript levels were markedly reduced, while nuclear-encoded polymerase-dependent transcript levels were increased in pdm3 mutants. In addition, we found that the splicing of introns in trnA, ndhB, and clpP-1 is also affected in pdm3. Taken together, we propose that PDM3 plays an essential role in chloroplast development in Arabidopsis.