Photosynthesis occurs mainly in chloroplasts,whose development is regulated by proteins encoded by nuclear genes.Among them,pentapeptide repeat(PPR)proteins participate in organelle RNA editing.Although there are more...Photosynthesis occurs mainly in chloroplasts,whose development is regulated by proteins encoded by nuclear genes.Among them,pentapeptide repeat(PPR)proteins participate in organelle RNA editing.Although there are more than 450 members of the PPR protein family in rice,only a few affect RNA editing in rice chloroplasts.Gene editing technology has created new rice germplasm and mutants,which could be used for rice breeding and gene function study.This study evaluated the functions of OsPPR9 in chloroplast RNA editing in rice.The osppr9 mutants were obtained by CRISPR/Cas9,which showed yellowing leaves and a lethal phenotype,with suppressed expression of genes associated with chloroplast development and accumulation of photosynthetic-related proteins.In addition,loss of OsPPR9 protein function reduces the editing efficiency of rps8-C182,rpoC2-C4106,rps14-C80,and ndhB-C611 RNA editing sites,which affects chloroplast growth and development in rice.Our data showed that OsPPR9 is highly expressed in rice leaves and encodes a DYW-PPR protein localized in chloroplasts.Besides,the OsPPR9 protein was shown to interact with OsMORF2 and OsMORF9.Together,our findings provide insights into the role of the PPR protein in regulating chloroplast development in rice.展开更多
Pentatricopeptide repeat(PPR) proteins function in post-transcriptional regulation of organellar gene expression. Although several PPR proteins are known to function in chloroplast development in rice(Oryza sativa), t...Pentatricopeptide repeat(PPR) proteins function in post-transcriptional regulation of organellar gene expression. Although several PPR proteins are known to function in chloroplast development in rice(Oryza sativa), the detailed molecular functions of many PPR proteins remain unclear.Here, we characterized a rice young leaf white stripe(ylws) mutant, which has defective chloroplast development during early seedling growth.Map-based cloning revealed that YLWS encodes a novel P-type chloroplast-targeted PPR protein with 11 PPR motifs. Further expression analyses showed that many nuclear-and plastid-encoded genes in the ylws mutant were significantly changed at the RNA and protein levels. The ylws mutant was impaired in chloroplast ribosome biogenesis and chloroplast development under low-temperature conditions. The ylws mutation causes defects in the splicing of atpF, ndhA, rpl2,and rps12, and editing of ndhA, ndhB, and rps14transcripts. YLWS directly binds to specific sites in the atpF, ndhA, and rpl2 pre-mRNAs. Our results suggest that YLWS participates in chloroplast RNA group II intron splicing and plays an important role in chloroplast development during early leaf development.展开更多
RNA editing is a posttranscriptional process that is important in mitochondria and plastids of higher plants. All RNA editing-specific trans-factors reported so far belong to PLS-class of pentatricopeptide repeat(PPR)...RNA editing is a posttranscriptional process that is important in mitochondria and plastids of higher plants. All RNA editing-specific trans-factors reported so far belong to PLS-class of pentatricopeptide repeat(PPR)proteins. Here, we report the map-based cloning and molecular characterization of a defective kernel mutant dek39 in maize. Loss of Dek39 function leads to delayed embryogenesis and endosperm development, reduced kernel size, and seedling lethality. Dek39 encodes an E subclass PPR protein that targets to both mitochondria and chloroplasts, and is involved in RNA editing in mitochondrial NADH dehydrogenase3(nad3) at nad3-247 and nad3-275. C-to-U editing of nad3-275 is not conserved and even lost in Arabidopsis, consistent with the idea that no close DEK39 homologs are present in Arabidopsis. However, the amino acids generated by editing nad3-247 and nad3-275 are highly conserved in many other plant species, and the reductions of editing at these two sites decrease the activity of mitochondria NADH dehydrogenase complex I,indicating that the alteration of amino acid sequence is necessary for Nad3 function. Our results indicate that Dek39 encodes an E sub-class PPR protein that is involved in RNA editing of multiple sites and is necessary for seed development of maize.展开更多
Pentatricopeptide repeat (PPR) proteins,containing tandem repeats of degenerate 35 amino acid motifs,are important for post-transcriptional chloroplast gene expression. In this study,we report the characterization of ...Pentatricopeptide repeat (PPR) proteins,containing tandem repeats of degenerate 35 amino acid motifs,are important for post-transcriptional chloroplast gene expression. In this study,we report the characterization of a pigment-deficient mutant 1 (pdm1) in Arabidopsis,which displays the albino phenotype. PDM1 contains 5 PPR motifs followed by a PLS domain. The levels of plastid-encoded polymerase-dependent chloroplast genes were reduced dramatically,whereas those of nucleus-encoded polymerase-dependent chloroplast genes increased in the mutant. In addition,the pattern of rpoA pre-mRNA was altered and the rpoA transcript was absent in pdm1. Thus,these results suggest that PDM1 is required for processing of rpoA pre-mRNA in Arabidop-sis.展开更多
基金funded by the Central Public-Interest Scientific Institution Basal Research Fund,China(CPSIBRF-CNRRI-202111 and CPSIBRF-CNRRI-202110)the Agricultural Science and Technology Innovation Program,Chinese Academy of Agricultural Sciences(ASTIP)+1 种基金the Project of State Key Laboratory of Rice Biology,China(2020ZZKT10205)the Key Research and Development Project of China Rice Research Institute(CNRRI-2020-01)。
文摘Photosynthesis occurs mainly in chloroplasts,whose development is regulated by proteins encoded by nuclear genes.Among them,pentapeptide repeat(PPR)proteins participate in organelle RNA editing.Although there are more than 450 members of the PPR protein family in rice,only a few affect RNA editing in rice chloroplasts.Gene editing technology has created new rice germplasm and mutants,which could be used for rice breeding and gene function study.This study evaluated the functions of OsPPR9 in chloroplast RNA editing in rice.The osppr9 mutants were obtained by CRISPR/Cas9,which showed yellowing leaves and a lethal phenotype,with suppressed expression of genes associated with chloroplast development and accumulation of photosynthetic-related proteins.In addition,loss of OsPPR9 protein function reduces the editing efficiency of rps8-C182,rpoC2-C4106,rps14-C80,and ndhB-C611 RNA editing sites,which affects chloroplast growth and development in rice.Our data showed that OsPPR9 is highly expressed in rice leaves and encodes a DYW-PPR protein localized in chloroplasts.Besides,the OsPPR9 protein was shown to interact with OsMORF2 and OsMORF9.Together,our findings provide insights into the role of the PPR protein in regulating chloroplast development in rice.
基金supported by the Key Laboratory of Biology, GeneticsBreeding of Japonica Rice in the Mid-lower Yangtze River, Ministry of Agriculture, China+5 种基金Jiangsu Plant Gene Engineering Research CenterJiangsu Collaborative Innovation Center for Modern Crop ProductionThis research was also supported by grants from the National Natural Science Foundation (92035301)Jiangsu Science and Technology Development Program (BE2021360)Jiangsu Agricultural Science and Technology Innovation Fund Project (SCX (19)1079)the Fundamental Research Funds for the Central Universities (JCQY201902)。
文摘Pentatricopeptide repeat(PPR) proteins function in post-transcriptional regulation of organellar gene expression. Although several PPR proteins are known to function in chloroplast development in rice(Oryza sativa), the detailed molecular functions of many PPR proteins remain unclear.Here, we characterized a rice young leaf white stripe(ylws) mutant, which has defective chloroplast development during early seedling growth.Map-based cloning revealed that YLWS encodes a novel P-type chloroplast-targeted PPR protein with 11 PPR motifs. Further expression analyses showed that many nuclear-and plastid-encoded genes in the ylws mutant were significantly changed at the RNA and protein levels. The ylws mutant was impaired in chloroplast ribosome biogenesis and chloroplast development under low-temperature conditions. The ylws mutation causes defects in the splicing of atpF, ndhA, rpl2,and rps12, and editing of ndhA, ndhB, and rps14transcripts. YLWS directly binds to specific sites in the atpF, ndhA, and rpl2 pre-mRNAs. Our results suggest that YLWS participates in chloroplast RNA group II intron splicing and plays an important role in chloroplast development during early leaf development.
基金supported by the National Natural Science Foundation of China (91435206 31421005)+1 种基金National Key Technologies Research & Development ProgramSeven Major Crops Breeding Project (2016YFD0101803, 2016YFD0100404)the 948 project (2016-X33)
文摘RNA editing is a posttranscriptional process that is important in mitochondria and plastids of higher plants. All RNA editing-specific trans-factors reported so far belong to PLS-class of pentatricopeptide repeat(PPR)proteins. Here, we report the map-based cloning and molecular characterization of a defective kernel mutant dek39 in maize. Loss of Dek39 function leads to delayed embryogenesis and endosperm development, reduced kernel size, and seedling lethality. Dek39 encodes an E subclass PPR protein that targets to both mitochondria and chloroplasts, and is involved in RNA editing in mitochondrial NADH dehydrogenase3(nad3) at nad3-247 and nad3-275. C-to-U editing of nad3-275 is not conserved and even lost in Arabidopsis, consistent with the idea that no close DEK39 homologs are present in Arabidopsis. However, the amino acids generated by editing nad3-247 and nad3-275 are highly conserved in many other plant species, and the reductions of editing at these two sites decrease the activity of mitochondria NADH dehydrogenase complex I,indicating that the alteration of amino acid sequence is necessary for Nad3 function. Our results indicate that Dek39 encodes an E sub-class PPR protein that is involved in RNA editing of multiple sites and is necessary for seed development of maize.
基金supported by the National Basic Research Program of China (2006CB910300)the National Natural Science Foundation of China (30725003)
文摘Pentatricopeptide repeat (PPR) proteins,containing tandem repeats of degenerate 35 amino acid motifs,are important for post-transcriptional chloroplast gene expression. In this study,we report the characterization of a pigment-deficient mutant 1 (pdm1) in Arabidopsis,which displays the albino phenotype. PDM1 contains 5 PPR motifs followed by a PLS domain. The levels of plastid-encoded polymerase-dependent chloroplast genes were reduced dramatically,whereas those of nucleus-encoded polymerase-dependent chloroplast genes increased in the mutant. In addition,the pattern of rpoA pre-mRNA was altered and the rpoA transcript was absent in pdm1. Thus,these results suggest that PDM1 is required for processing of rpoA pre-mRNA in Arabidop-sis.
