The Pentratricopeptide Repeat Protein Pigment-Defective Mutant2 is Involved in the Regulation of Chloroplast Development and Chloroplast Gene Expression in Arabidopsis. (31st January 2017)

• Record Type: Journal Article
• Authors: Du, Liang; Zhang, Jian; Qu, Shaofeng; Zhao, Yuanyuan; Su, Bodan; Lv, Xueqin; Li, Ruili; Wan, Yinglang; Xiao, Jianwei
• Is Part Of: Plant & cell physiology. Volume 58:Number 4(2017:Apr.)
• Page Start: 747
• Page End: 759
• Publication Date: 2017-01-31
• Subjects: Arabidopsis -- Chloroplast -- Development -- Pentatricopeptide repeat protein -- Pigment-Defective Mutant2; Plant physiology -- Periodicals; Microbiology -- Periodicals; Cytology -- Periodicals; Cell Physiology -- Periodicals; Plant Physiological Phenomena -- Periodicals; Cytology; Microbiology; Plant physiology; Periodicals; 571.205
• DOI: 10.1093/pcp/pcx004
• Languages: English
• ISSNs: 0032-0781

Abstract

Abstract : The development of functional chloroplasts, which is assisted by a series of nuclear-encoded auxiliary protein factors, is essential for plant autotrophic growth and development. To understand the molecular mechanisms underlying chloroplast development, we isolated and characterized a pigment-defective mutant, pdm2, and its corresponding variegated RNA interference (RNAi) lines in Arabidopsis. Sequence analysis revealed that PDM2 encodes a pentatricopeptide repeat protein that belongs to the P subgroup. Confocal microscopic analysis and immunoblotting of the chloroplast protein fraction showed that PDM2 was located in the stroma. In RNAi plants, protein-related photosynthesis was severely compromised. Furthermore, analysis of the transcript profile of chloroplast genes revealed that plastid-encoded polymerase-dependent transcript levels were markedly reduced, while nuclear-encoded polymerase-dependent transcript levels were increased, in RNAi plants. In addition, PDM2 affects plastid RNA editing efficiency in most editing sites, apparently by directly interacting with multiple organellar RNA editing factor 2 (MORF2) and MORF9. Thus, our results demonstrate that PDM2 is probably involved in the regulation of plastid gene expression required for normal chloroplast development.