PDM4, a Pentatricopeptide Repeat Protein, Affects Chloroplast Gene Expression and Chloroplast Development inArabidopsis thaliana
PDM4, a Pentatricopeptide Repeat Protein, Affects Chloroplast Gene Expression and Chloroplast Development inArabidopsis thaliana
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PDM4，一种五肽重复蛋白，影响拟南芥叶绿体基因表达和叶绿体发育
DOI：
10.3389/fpls.2020.01198
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发表时间：
2020-08-11
影响因子：
5.6
通讯作者：
Xiao, Jianwei
中科院分区：
文献类型：
--
作者：
Wang, Xinwei;Zhao, Lirong;Xiao, Jianwei
对叶绿体基因表达和叶绿体发育进行了广泛的研究；然而，其调控机制在很大程度上仍是未知的。在这里，我们鉴定了色素缺陷突变4 (PDM4)，这是一种定位于叶绿体的p型PPR蛋白。pdm4突变体在异养生长条件下表现出幼苗致死和白化表型。透射电镜分析表明，pdm4突变体的类囊体结构完全被破坏，最终导致叶绿体的破坏。在pdm4突变体中，一些叶绿体和核编码蛋白的水平明显降低。此外，转录谱分析发现，pdm4突变体中质体编码RNA聚合酶依赖基因的表达受到明显影响，叶绿体rRNA加工也出现异常。此外，我们发现PDM4在II组内含子的剪接中起作用，也可能参与50S核糖体颗粒的组装。本研究结果表明，PDM4在拟南芥叶绿体基因表达和叶绿体发育中起重要作用。
Extensive studies have been carried out on chloroplast gene expression and chloroplast development; however, the regulatory mechanism is still largely unknown. Here, we characterized Pigment-Defective Mutant4 (PDM4), a P-type PPR protein localized in chloroplast. The pdm4 mutant showed seedling-lethal and albino phenotype under heterotrophic growth conditions. Transmission electron microscopic analysis revealed that thylakoid structure was totally disrupted in pdm4 mutant and eventually led to the breakdown of chloroplasts. The levels of several chloroplast- and nuclear-encoded proteins are strongly reduced in pdm4 mutant. Besides, transcript profile analysis detected that, in pdm4 mutant, the expression of plastid-encoded RNA polymerase-dependent genes was markedly affected, and deviant chloroplast rRNA processing was also observed. In addition, we found that PDM4 functions in the splicing of group II introns and may also be involved in the assembly of the 50S ribosomal particle. Our results demonstrate that PDM4 plays an important role in chloroplast gene expression and chloroplast development in Arabidopsis.