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Qu K, Liu D, Sun L, Li M, Xia T, Sun W, Xia Y. De novo assembly and comprehensive analysis of the mitochondrial genome of Taxus wallichiana reveals different repeats mediate recombination to generate multiple conformations. Genomics 2024; 116:110900. [PMID: 39067796 DOI: 10.1016/j.ygeno.2024.110900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Revised: 07/09/2024] [Accepted: 07/20/2024] [Indexed: 07/30/2024]
Abstract
Taxus plants are the exclusive source of paclitaxel, an anticancer drug with significant medicinal and economic value. Interspecies hybridization and gene introgression during evolution have obscured distinctions among Taxus species, complicating their phylogenetic classification. While the chloroplast genome of Taxus wallichiana, a widely distributed species in China, has been sequenced, its mitochondrial genome (mitogenome) remains uncharacterized.We sequenced and assembled the T. wallichiana mitogenome using BGI short reads and Nanopore long reads, facilitating comparisons with other gymnosperm mitogenomes. The T. wallichiana mitogenome spanning 469,949 bp, predominantly forms a circular configuration with a GC content of 50.51%, supplemented by 3 minor configurations mediated by one pair of LRs and two pairs of IntRs. It includes 32 protein-coding genes, 7 tRNA genes, and 3 rRNA genes, several of which exist in multiple copies.We detailed the mitogenome's structure, codon usage, RNA editing, and sequence migration between organelles, constructing a phylogenetic tree to elucidate evolutionary relationships. Unlike typical gymnosperm mitochondria, T. wallichiana shows no evidence of mitochondrial-plastid DNA transfer (MTPT), highlighting its unique genomic architecture. Synteny analysis indicated extensive genomic rearrangements in T. wallichiana, likely driven by recombination among abundant repetitive sequences. This study offers a high-quality T. wallichiana mitogenome, enhancing our understanding of gymnosperm mitochondrial evolution and supporting further cultivation and utilization of Taxus species.
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Affiliation(s)
- Kai Qu
- Shandong Provincial Center of Forest and Grass Germplasm Resources, Jinan 250102, China; National Engineering Laboratory of Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Dan Liu
- Shandong Provincial Center of Forest and Grass Germplasm Resources, Jinan 250102, China; National Engineering Laboratory of Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
| | - Limin Sun
- Forestry College of Shandong Agricultural University, Taian 271018, China
| | - Meng Li
- Shandong Provincial Center of Forest and Grass Germplasm Resources, Jinan 250102, China
| | - Tiantian Xia
- Shandong Jianzhu University, Jinan 250101, China
| | - Weixia Sun
- Shandong Provincial Center of Forest and Grass Germplasm Resources, Jinan 250102, China
| | - Yufei Xia
- National Engineering Laboratory of Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
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Li H, Akella S, Engstler C, Omini JJ, Rodriguez M, Obata T, Carrie C, Cerutti H, Mower JP. Recurrent evolutionary switches of mitochondrial cytochrome c maturation systems in Archaeplastida. Nat Commun 2024; 15:1548. [PMID: 38378784 PMCID: PMC10879542 DOI: 10.1038/s41467-024-45813-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 02/05/2024] [Indexed: 02/22/2024] Open
Abstract
Mitochondrial cytochrome c maturation (CCM) requires heme attachment via distinct pathways termed systems I and III. The mosaic distribution of these systems in Archaeplastida raises questions about the genetic mechanisms and evolutionary forces promoting repeated evolution. Here, we show a recurrent shift from ancestral system I to the eukaryotic-specific holocytochrome c synthase (HCCS) of system III in 11 archaeplastid lineages. Archaeplastid HCCS is sufficient to rescue mutants of yeast system III and Arabidopsis system I. Algal HCCS mutants exhibit impaired growth and respiration, and altered biochemical and metabolic profiles, likely resulting from deficient CCM and reduced cytochrome c-dependent respiratory activity. Our findings demonstrate that archaeplastid HCCS homologs function as system III components in the absence of system I. These results elucidate the evolutionary trajectory and functional divergence of CCM pathways in Archaeplastida, providing insight into the causes, mechanisms, and consequences of repeated cooption of an entire biological pathway.
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Affiliation(s)
- Huang Li
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Soujanya Akella
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Carina Engstler
- Department Biologie I-Botanik, Ludwig-Maximilians-Universität München, D-82152, Planegg-Martinsried, Germany
| | - Joy J Omini
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Moira Rodriguez
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Toshihiro Obata
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Chris Carrie
- School of Biological Sciences, University of Auckland, Auckland, 1142, New Zealand
| | - Heriberto Cerutti
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Jeffrey P Mower
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.
- Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA.
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Liu J, Hu JY, Li DZ. Remarkable mitochondrial genome heterogeneity in Meniocus linifolius (Brassicaceae). PLANT CELL REPORTS 2024; 43:36. [PMID: 38200362 DOI: 10.1007/s00299-023-03102-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/06/2023] [Indexed: 01/12/2024]
Abstract
KEY MESSAGE Detailed analyses of 16 genomes identified a remarkable acceleration of mutation rate, hence mitochondrial sequence and structural heterogeneity, in Meniocus linifolius (Brassicaceae). The powerhouse, mitochondria, in plants feature high levels of structural variation, while the encoded genes are normally conserved. However, the substitution rates and spectra of mitochondria DNA within the Brassicaceae, a family with substantial scientific and economic importance, have not been adequately deciphered. Here, by analyzing three newly assembled and 13 known mitochondrial genomes (mitogenomes), we report the highly variable genome structure and mutation rates in Brassicaceae. The genome sizes and GC contents are 196,604 bp and 46.83%, 288,122 bp and 44.79%, and 287,054 bp and 44.93%, for Meniocus linifolius (Mli), Crucihimalaya lasiocarpa (Cla), and Lepidium sativum (Lsa), respectively. In total, 29, 33, and 34 protein-coding genes (PCGs) and 14, 18, and 18 tRNAs are annotated for Mli, Cla, and Lsa, respectively, while all mitogenomes contain one complete circular molecule with three rRNAs and abundant RNA editing sites. The Mli mitogenome features four conformations likely mediated by the two pairs of long repeats, while at the same time seems to have an unusual evolutionary history due to higher GC content, loss of more genes and sequences, but having more repeats and plastid DNA insertions. Corroborating with these, an ambiguous phylogenetic position with long branch length and elevated synonymous substitution rate in nearly all PCGs are observed for Mli. Taken together, our results reveal a high level of mitogenome heterogeneity at the family level and provide valuable resources for further understanding the evolutionary pattern of organelle genomes in Brassicaceae.
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Affiliation(s)
- Jie Liu
- CAS Key Laboratory for Plant Diversity, Biogeography of East Asia, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jin-Yong Hu
- CAS Key Laboratory for Plant Diversity, Biogeography of East Asia, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China.
| | - De-Zhu Li
- Germplasm Bank of Wild Species, Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China.
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Cao Y, Yin D, Pang B, Li H, Liu Q, Zhai Y, Ma N, Shen H, Jia Q, Wang D. Assembly and phylogenetic analysis of the mitochondrial genome of endangered medicinal plant Huperzia crispata. Funct Integr Genomics 2023; 23:295. [PMID: 37691055 DOI: 10.1007/s10142-023-01223-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 08/08/2023] [Accepted: 08/28/2023] [Indexed: 09/12/2023]
Abstract
Huperzia crispata is a traditional Chinese herb plant and has attracted special attention in recent years for its products Hup A can serve as an acetylcholinesterase inhibitor (AChEI). Although the chloroplast (cp) genome of H. crispata has been studied, there are no reports regarding the Huperzia mitochondrial (mt) genome since the previously reported H. squarrosa has been revised as Phlegmariurus squarrosus. The mt genome of H. crispata was sequenced using a combination of long-read nanopore and Illumina sequencing platforms. The entire H. crispata mt genome was assembled in a circular with a length of 412,594 bp and a total of 91 genes, including 45 tRNAs, 6 rRNAs, 37 protein-coding genes (PCGs), and 3 pseudogenes. Notably, the rps8 gene was present in P. squarrosus and a pseudogene rps8 was presented in H. crispata, which was lacking in most of Pteridophyta and Gymnospermae. Intron-encoded maturase (mat-atp9i85 and mat-cobi787) genes were present in H. crispata and P. squarrosus, but lost in other examined lycophytes, ferns, and Gymnospermae plants. Collinearity analysis showed that the mt genome of H. crispata and P. squarrossus is highly conservative compared to other ferns. Relative synonymous codon usage (RSCU) analysis showed that the amino acids most frequently found were phenylalanine (Phe) (4.77%), isoleucine (Ile) (4.71%), lysine (Lys) (4.26%), while arginine (Arg) (0.32%), and histidine (His) (0.42%) were rarely found. Simple sequence repeats (SSR) analysis revealed that a total of 114 SSRs were identified in the mt genome of H. crispata and account for 0.35% of the whole mt genome. Monomer repeats were the majority types of SSRs and represent 91.89% of the total SSRs. In addition, a total of 1948 interspersed repeats (158 forward, 147 palindromic, and 5 reverse repeats) with a length ranging from 30 bp to 14,945 bp were identified in the H. crispata mt genome and the 30-39-bp repeats were the most abundant type. Gene transfer analysis indicated that a total of 12 homologous fragments were discovered between the cp and mt genomes of H. crispata, accounting for 0.93% and 2.48% of the total cp and mt genomes, respectively. The phylogenetic trees revealed that H. crispata was the sister of P. squarrosus. The Ka/Ks analysis results suggested that most PCGs, except atp6 gene, were subject to purification selection during evolution. Our study provides extensive information on the features of the H. crispata mt genome and will help unravel evolutionary relationships, and molecular identification within lycophytes.
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Affiliation(s)
- Yu Cao
- Key Laboratory of Plant Secondary Metabolism Regulation in Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Zhejiang, 310018, Hangzhou, China
| | - Dengpan Yin
- Key Laboratory of Plant Secondary Metabolism Regulation in Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Zhejiang, 310018, Hangzhou, China
| | - Bo Pang
- Key Laboratory of Plant Secondary Metabolism Regulation in Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Zhejiang, 310018, Hangzhou, China
| | - Haibo Li
- Yuyao Seedling Management Station, Ningbo, Zhejiang, 315400, China
| | - Qiao Liu
- Key Laboratory of Plant Secondary Metabolism Regulation in Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Zhejiang, 310018, Hangzhou, China
| | - Yufeng Zhai
- Key Laboratory of Plant Secondary Metabolism Regulation in Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Zhejiang, 310018, Hangzhou, China
| | - Nan Ma
- Key Laboratory of Plant Secondary Metabolism Regulation in Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Zhejiang, 310018, Hangzhou, China
| | - Hongjun Shen
- Ningbo Delai Medicinal Material Planting Co, Ltd, 315444, Ningbo, Zhejiang, 315444, China
| | - Qiaojun Jia
- Key Laboratory of Plant Secondary Metabolism Regulation in Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Zhejiang, 310018, Hangzhou, China
| | - Dekai Wang
- Key Laboratory of Plant Secondary Metabolism Regulation in Zhejiang Province, College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Zhejiang, 310018, Hangzhou, China.
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Yang Y, Ritzenhofen K, Otrzonsek J, Xie J, Schallenberg-Rüdinger M, Knoop V. Beyond a PPR-RNA recognition code: Many aspects matter for the multi-targeting properties of RNA editing factor PPR56. PLoS Genet 2023; 19:e1010733. [PMID: 37603555 PMCID: PMC10482289 DOI: 10.1371/journal.pgen.1010733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 09/06/2023] [Accepted: 07/30/2023] [Indexed: 08/23/2023] Open
Abstract
The mitochondrial C-to-U RNA editing factor PPR56 of the moss Physcomitrium patens is an RNA-binding pentatricopeptide repeat protein equipped with a terminal DYW-type cytidine deaminase domain. Transferred into Escherichia coli, PPR56 works faithfully on its two native RNA editing targets, nad3eU230SL and nad4eU272SL, and also converts cytidines into uridines at over 100 off-targets in the bacterial transcriptome. Accordingly, PPR56 is attractive for detailed mechanistic studies in the heterologous bacterial setup, allowing for scoring differential RNA editing activities of many target and protein variants in reasonable time. Here, we report (i) on the effects of numerous individual and combined PPR56 protein and target modifications, (ii) on the spectrum of off-target C-to-U editing in the bacterial background transcriptome for PPR56 and two variants engineered for target re-direction and (iii) on combinations of targets in tandem or separately at the 5'- and 3'-ends of large mRNAs. The latter experimentation finds enhancement of RNA editing at weak targets in many cases, including cox3eU290SF as a new candidate mitogenome target. We conclude that C-to-U RNA editing can be much enhanced by transcript features also outside the region ultimately targeted by PPRs of a plant editing factor, possibly facilitated by its enrichment or scanning along transcripts.
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Affiliation(s)
- Yingying Yang
- IZMB–Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Bonn, Germany
| | - Kira Ritzenhofen
- IZMB–Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Bonn, Germany
| | - Jessica Otrzonsek
- IZMB–Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Bonn, Germany
| | - Jingchan Xie
- IZMB–Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Bonn, Germany
| | | | - Volker Knoop
- IZMB–Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Bonn, Germany
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6
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Wu Z, Yang T, Qin R, Liu H. Complete Mitogenome and Phylogenetic Analysis of the Carthamus tinctorius L. Genes (Basel) 2023; 14:genes14050979. [PMID: 37239339 DOI: 10.3390/genes14050979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/16/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
Carthamus tinctorius L. 1753 (Asteraceae), also called safflower, is a cash crop with both edible and medical properties. We analyzed and reported the safflower mitogenome based on combined short and long reads obtained from Illumina and Pacbio platforms, respectively. This safflower mitogenome mainly contained two circular chromosomes, with a total length of 321,872 bp, and encoded 55 unique genes, including 34 protein-coding genes (PCGs), 3 rRNA genes, and 18 tRNA genes. The total length of repeat sequences greater than 30 bp was 24,953 bp, accounting for 7.75% of the whole mitogenome. Furthermore, we characterized the RNA editing sites of protein-coding genes located in the safflower mitogenome, and the total number of RNA editing sites was 504. Then, we revealed partial sequence transfer events between plastid and mitochondria, in which one plastid-derived gene (psaB) remained intact in the mitogenome. Despite extensive arrangement events among the three mitogenomes of C. tinctorius, Arctium lappa, and Saussurea costus, the constructed phylogenetic tree based on mitogenome PCGs showed that C. tinctorius has a closer relationship with three Cardueae species, A. lappa, A. tomentosum, and S. costus, which is similar to the phylogeny constructed from the PCGs of plastid genomes. This mitogenome not only enriches the genetic information of safflower but also will be useful in the phylogeny and evolution study of the Asteraceae.
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Affiliation(s)
- Zhihua Wu
- College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China
| | - Tiange Yang
- Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central Minzu University, Wuhan 430074, China
| | - Rui Qin
- Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central Minzu University, Wuhan 430074, China
| | - Hong Liu
- Hubei Provincial Key Laboratory for Protection and Application of Special Plant Germplasm in Wuling Area of China, College of Life Sciences, South-Central Minzu University, Wuhan 430074, China
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Zumkeller S, Polsakiewicz M, Knoop V. Rickettsial DNA and a trans-splicing rRNA group I intron in the unorthodox mitogenome of the fern Haplopteris ensiformis. Commun Biol 2023; 6:296. [PMID: 36941328 PMCID: PMC10027690 DOI: 10.1038/s42003-023-04659-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 03/03/2023] [Indexed: 03/23/2023] Open
Abstract
Plant mitochondrial genomes can be complex owing to highly recombinant structures, lack of gene syntenies, heavy RNA editing and invasion of chloroplast, nuclear or even foreign DNA by horizontal gene transfer (HGT). Leptosporangiate ferns remained the last major plant clade without an assembled mitogenome, likely owing to a demanding combination of the above. We here present both organelle genomes now for Haplopteris ensiformis. More than 1,400 events of C-to-U RNA editing and over 500 events of reverse U-to-C edits affect its organelle transcriptomes. The Haplopteris mtDNA is gene-rich, lacking only the ccm gene suite present in ancestral land plant mitogenomes, but is highly unorthodox, indicating extraordinary recombinogenic activity. Although eleven group II introns known in disrupted trans-splicing states in seed plants exist in conventional cis-arrangements, a particularly complex structure is found for the mitochondrial rrnL gene, which is split into two parts needing reassembly on RNA level by a trans-splicing group I intron. Aside from ca. 80 chloroplast DNA inserts that complicated the mitogenome assembly, the Haplopteris mtDNA features as an idiosyncrasy 30 variably degenerated protein coding regions from Rickettiales bacteria indicative of heavy bacterial HGT on top of tRNA genes of chlamydial origin.
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Affiliation(s)
- Simon Zumkeller
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Monika Polsakiewicz
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Volker Knoop
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115, Bonn, Germany.
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8
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Tang JY, Wei R, Zhang XC, Xiang QP. Mitogenome-based phylogenomics provides insights into the positions of the enigmatic sinensis group and the sanguinolenta group in Selaginellaceae (Lycophyte). Mol Phylogenet Evol 2023; 179:107673. [PMID: 36528332 DOI: 10.1016/j.ympev.2022.107673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 10/14/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022]
Abstract
Spikemoss (Selaginellaceae) is one of the basal lineages of vascular plants. This family has a single genus Selaginella which consists of about 750 extant species. The phylogeny of Selaginellaceae has been extensively studied mainly based on plastid DNA and a few nuclear sequences. However, the placement of the enigmatic sinensis group is a long-term controversy because of the long branch in the plastid DNA phylogeny. The sanguinolenta group is also a phylogenetically problematic clade owing to two alternative positions resulted from different datasets. Here, we newly sequenced 34 mitochondrial genomes (mitogenomes) of individuals representing all seven subgenera and major clades in Selaginellaceae. We assembled the draft mitogenomes and annotated the genes and performed phylogenetic analyses based on the shared 17 mitochondrial genes. Our major results include: (1) all the assembled mitogenomes have complicated structures, unparalleled high GC content and a small gene content set, and the positive correlations among GC content, substitution rates and the number of RNA editing sites hold; (2) the sinensis group was well supported as a member of subg. Stachygynandrum; (3) the sanguinolenta group was strongly resolved as sister to all other Selaginella species except for subg. Selaginella. This study demonstrates the potential of mitogenome data in providing novel insights into phylogenetically recalcitrant problems.
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Affiliation(s)
- Jun-Yong Tang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ran Wei
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Xian-Chun Zhang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
| | - Qiao-Ping Xiang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
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Zhang H, Zheng Y, Zhang G, Miao Y, Liu C, Huang L. A Bibliometric Study for Plant RNA Editing Research: Trends and Future Challenges. Mol Biotechnol 2022:10.1007/s12033-022-00641-7. [PMID: 36562872 DOI: 10.1007/s12033-022-00641-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
RNA editing is a post-transcriptional process that introduces changes in RNA sequences encoded by nuclear, mitochondrial, or plastid genomes. To understand the research progress of plant RNA editing, we comprehensively analyze the articles on plant RNA editing from 2001 to 2022 through bibliometric methods. Nucleic Acids Research, Plant Journal and Plant cell are the journals that deserve attention with their high production, total local citation scores (TLCS), and h-indexes. The USA, China, and Germany are the top three countries with highly productive publications. Ulm University, Cornell University, and Chinese Acad Sci are excellent cooperative institutions with a high level of influence in the field, and KNOOP V and TAKENAKA M are good partnership. Plant RNA editing researches concentrate on the subject categories of Biochemistry & Molecular Biology, Plant Sciences, Genetics & Heredity, etc. Plant mitochondria, genome editing and messenger-RNA may be the research hotspots in the future. The main plant RNA editing research tools are JACUSA, SPRINT, and REDO, and the main databases are REDIdb, PED, and dbRES. At present, the research streams are (1) RNA editing sites; (2) Pentapeptide repeat protein (PPR) involved in RNA editing; (3) RNA editing factors. Overall, this article summarizes the research overview of plant RNA editing until 2022 and provides theoretical implications for its possible future directions.
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Affiliation(s)
- Huihui Zhang
- Key Laboratory of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100193, China
- Jiangxi University of Chinese Medicine, Nanchang, 330000, Jiangxi, China
| | - Yan Zheng
- Key Laboratory of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100193, China
- Jiangxi University of Chinese Medicine, Nanchang, 330000, Jiangxi, China
| | - Guoshuai Zhang
- Key Laboratory of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100193, China
| | - Yujing Miao
- Key Laboratory of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100193, China
| | - Chang Liu
- Key Laboratory of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100193, China.
| | - Linfang Huang
- Key Laboratory of Chinese Medicine Resources Conservation, State Administration of Traditional Chinese Medicine of China, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, 100193, China.
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Ogaji YO, Lee RC, Sawbridge TI, Cocks BG, Daetwyler HD, Kaur S. De Novo Long-Read Whole-Genome Assemblies and the Comparative Pan-Genome Analysis of Ascochyta Blight Pathogens Affecting Field Pea. J Fungi (Basel) 2022; 8:jof8080884. [PMID: 36012871 PMCID: PMC9410150 DOI: 10.3390/jof8080884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/12/2022] [Accepted: 08/15/2022] [Indexed: 11/16/2022] Open
Abstract
Ascochyta Blight (AB) is a major disease of many cool-season legumes globally. In field pea, three fungal pathogens have been identified to be responsible for this disease in Australia, namely Peyronellaea pinodes, Peyronellaea pinodella and Phoma koolunga. Limited genomic resources for these pathogens have been generated, which has hampered the implementation of effective management strategies and breeding for resistant cultivars. Using Oxford Nanopore long-read sequencing, we report the first high-quality, fully annotated, near-chromosome-level nuclear and mitochondrial genome assemblies for 18 isolates from the Australian AB complex. Comparative genome analysis was performed to elucidate the differences and similarities between species and isolates using phylogenetic relationships and functional diversity. Our data indicated that P. pinodella and P. koolunga are heterothallic, while P. pinodes is homothallic. More homology and orthologous gene clusters are shared between P. pinodes and P. pinodella compared to P. koolunga. The analysis of the repetitive DNA content showed differences in the transposable repeat composition in the genomes and their expression in the transcriptomes. Significant repeat expansion in P. koolunga’s genome was seen, with strong repeat-induced point mutation (RIP) activity being evident. Phylogenetic analysis revealed that genetic diversity can be exploited for species marker development. This study provided the much-needed genetic resources and characterization of the AB species to further drive research in key areas such as disease epidemiology and host–pathogen interactions.
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Affiliation(s)
- Yvonne O. Ogaji
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Melbourne, VIC 3083, Australia
- School of Applied Systems Biology, La Trobe University, Melbourne, VIC 3086, Australia
| | - Robert C. Lee
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA 6102, Australia
| | - Tim I. Sawbridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Melbourne, VIC 3083, Australia
- School of Applied Systems Biology, La Trobe University, Melbourne, VIC 3086, Australia
| | - Benjamin G. Cocks
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Melbourne, VIC 3083, Australia
- School of Applied Systems Biology, La Trobe University, Melbourne, VIC 3086, Australia
| | - Hans D. Daetwyler
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Melbourne, VIC 3083, Australia
- School of Applied Systems Biology, La Trobe University, Melbourne, VIC 3086, Australia
| | - Sukhjiwan Kaur
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Melbourne, VIC 3083, Australia
- Correspondence:
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11
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Xiang QP, Tang JY, Yu JG, Smith DR, Zhu YM, Wang YR, Kang JS, Yang J, Zhang XC. The evolution of extremely diverged plastomes in Selaginellaceae (lycophyte) is driven by repeat patterns and the underlying DNA maintenance machinery. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:768-784. [PMID: 35648423 DOI: 10.1111/tpj.15851] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/25/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Two factors are proposed to account for the unusual features of organellar genomes: the disruptions of organelle-targeted DNA replication, repair, and recombination (DNA-RRR) systems in the nuclear genome and repetitive elements in organellar genomes. Little is known about how these factors affect organellar genome evolution. The deep-branching vascular plant family Selaginellaceae is known to have a deficient DNA-RRR system and convergently evolved organellar genomes. However, we found that the plastid genome (plastome) of Selaginella sinensis has extremely accelerated substitution rates, a low GC content, pervasive repeat elements, a dynamic network structure, and it lacks direct or inverted repeats. Unexpectedly, its organelle DNA-RRR system is short of a plastid-targeted Recombinase A1 (RecA1) and a mitochondrion-targeted RecA3, in line with other explored Selaginella species. The plastome contains a large collection of short- and medium-sized repeats. Given the absence of RecA1 surveillance, we propose that these repeats trigger illegitimate recombination, accelerated mutation rates, and structural instability. The correlations between repeat quantity and architectural complexity in the Selaginella plastomes support these conclusions. We, therefore, hypothesize that the interplay of the deficient DNA-RRR system and the high repeat content has led to the extraordinary divergence of the S. sinensis plastome. Our study not only sheds new light on the mechanism of plastome divergence by emphasizing the power of cytonuclear integration, but it also reconciles the longstanding contradiction on the effects of DNA-RRR system disruption on genome structure evolution.
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Affiliation(s)
- Qiao-Ping Xiang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
| | - Jun-Yong Tang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ji-Gao Yu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - David Roy Smith
- Department of Biology, University of Western Ontario, London, N6A 5B7, Ontario, Canada
| | - Yan-Mei Zhu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
| | - Ya-Rong Wang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
| | - Jong-Soo Kang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
| | - Jie Yang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xian-Chun Zhang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, Beijing, 100093, China
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12
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Szandar K, Krawczyk K, Myszczyński K, Ślipiko M, Sawicki J, Szczecińska M. Breaking the limits - multichromosomal structure of an early eudicot Pulsatilla patens mitogenome reveals extensive RNA-editing, longest repeats and chloroplast derived regions among sequenced land plant mitogenomes. BMC PLANT BIOLOGY 2022; 22:109. [PMID: 35264098 PMCID: PMC8905907 DOI: 10.1186/s12870-022-03492-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND The mitogenomes of vascular plants are one of the most structurally diverse molecules. In the present study we characterize mitogenomes of a rare and endangered species Pulsatilla patens. We investigated the gene content and its RNA editing potential, repeats distribution and plastid derived sequences. RESULTS The mitogenome structure of early divergent eudicot, endangered Pulsatilla patens does not support the master chromosome hypothesis, revealing the presence of three linear chromosomes of total length 986 613 bp. The molecules are shaped by the presence of extremely long, exceeding 87 kbp repeats and multiple chloroplast-derived regions including nearly complete inverted repeat. Since the plastid IR content of Ranunculales is very characteristic, the incorporation into mitogenome could be explained rather by intracellular transfer than mitochondrial HGT. The mitogenome contains almost a complete set of genes known from other vascular plants with exception of rps10 and sdh3, the latter being present but pseudogenized. Analysis of long ORFs enabled the identification of genes which are rarely present in plant mitogenomes, including RNA and DNA polymerases, albeit their presence even at species level is variable. Mitochondrial transcripts of P. patens were edited with a high frequency, which exceeded the level known in other analyzed angiosperms, despite the strict qualification criteria of counting the editing events and taking into analysis generally less frequently edited leaf transcriptome. The total number of edited sites was 902 and nad4 was identified as the most heavily edited gene with 65 C to U changes. Non-canonical, reverse U to C editing was not detected. Comparative analysis of mitochondrial genes of three Pulsatilla species revealed a level of variation comparable to chloroplast CDS dataset and much higher infrageneric differentiation than in other known angiosperm genera. The variation found in CDS of mitochondrial genes is comparable to values found among Pulsatilla plastomes. Despite the complicated mitogenome structure, 14 single copy regions of 329 kbp, not splitted by repeats or plastid-derived sequences (MTPT), revealed the potential for phylogenetic, phylogeographic and population genetics studies by revealing intra- and interspecific collinearity. CONCLUSIONS This study provides valuable new information about mitochondrial genome of early divergent eudicots, Pulsatilla patens, revealed multi-chromosomal structure and shed new light on mitogenomics of early eudicots.
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Affiliation(s)
- Kamil Szandar
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Plac Łódzki 1, 10-727, Olsztyn, Poland.
| | - Katarzyna Krawczyk
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Plac Łódzki 1, 10-727, Olsztyn, Poland.
| | - Kamil Myszczyński
- Laboratory of Translational Oncology, Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Dębinki 1, 80-211, Gdańsk, Poland.
| | - Monika Ślipiko
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Plac Łódzki 1, 10-727, Olsztyn, Poland.
| | - Jakub Sawicki
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Plac Łódzki 1, 10-727, Olsztyn, Poland.
| | - Monika Szczecińska
- Department of Ecology and Environmental Protection, University of Warmia and Mazury in Olsztyn, Plac Łódzki 3, 10- 727, Olsztyn, Poland.
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13
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Lin Y, Li P, Zhang Y, Akhter D, Pan R, Fu Z, Huang M, Li X, Feng Y. Unprecedented organelle genomic variations in morning glories reveal independent evolutionary scenarios of parasitic plants and the diversification of plant mitochondrial complexes. BMC Biol 2022; 20:49. [PMID: 35172831 PMCID: PMC8851834 DOI: 10.1186/s12915-022-01250-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 02/08/2022] [Indexed: 01/01/2023] Open
Abstract
Background The morning glories (Convolvulaceae) are distributed worldwide and produce economically important crops, medicinal herbs, and ornamentals. Members of this family are diverse in morphological characteristics and trophic modes, including the leafless parasitic Cuscuta (dodders). Organelle genomes were generally used for studying plant phylogeny and genomic variations. Notably, plastomes in parasitic plants always show non-canonical features, such as reduced size and accelerated rates. However, few organelle genomes of this group have been sequenced, hindering our understanding of their evolution, and dodder mitogenome in particular. Results We assembled 22 new mitogenomes and 12 new plastomes in Convolvulaceae. Alongside previously known ones, we totally analyzed organelle genomes of 23 species in the family. Our sampling includes 16 leafy autotrophic species and 7 leafless parasitic dodders, covering 8 of the 12 tribes. Both the plastid and mitochondrial genomes of these plants have encountered variations that were rarely observed in other angiosperms. All of the plastomes possessed atypical IR boundaries. Besides the gene and IR losses in dodders, some leafy species also showed gene and intron losses, duplications, structural variations, and insertions of foreign DNAs. The phylogeny reconstructed by plastid protein coding sequences confirmed the previous relationship of the tribes. However, the monophyly of ‘Merremieae’ and the sister group of Cuscuta remained uncertain. The mitogenome was significantly inflated in Cuscuta japonica, which has exceeded over 800 kb and integrated massive DNAs from other species. In other dodders, mitogenomes were maintained in small size, revealing divergent evolutionary strategies. Mutations unique to plants were detected in the mitochondrial gene ccmFc, which has broken into three fragments through gene fission and splicing shift. The unusual changes likely initially happened to the common ancestor of the family and were caused by a foreign insertion from rosids followed by double-strand breaks and imprecise DNA repairs. The coding regions of ccmFc expanded at both sides after the fission, which may have altered the protein structure. Conclusions Our family-scale analyses uncovered unusual scenarios for both organelle genomes in Convolvulaceae, especially in parasitic plants. The data provided valuable genetic resources for studying the evolution of Convolvulaceae and plant parasitism. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01250-1.
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Affiliation(s)
- Yanxiang Lin
- College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China
| | - Pan Li
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Yuchan Zhang
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, Zhejiang, China
| | - Delara Akhter
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, Zhejiang, China.,Department of Genetics and Plant Breeding, Sylhet Agricultural University, Sylhet Division 3100, Sylhet, Bangladesh
| | - Ronghui Pan
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, Zhejiang, China.,ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
| | - Zhixi Fu
- College of Life Science, Sichuan Normal University, Chengdu, 610101, Sichuan, China
| | - Mingqing Huang
- College of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China
| | - Xiaobo Li
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, 310024, Zhejiang, China.,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, 310024, Zhejiang, China
| | - Yanlei Feng
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, 310024, Zhejiang, China. .,Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, 310024, Zhejiang, China.
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14
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OTP970 Is Required for RNA Editing of Chloroplast ndhB Transcripts in Arabidopsis thaliana. Genes (Basel) 2022; 13:genes13010139. [PMID: 35052479 PMCID: PMC8774829 DOI: 10.3390/genes13010139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/09/2022] [Accepted: 01/10/2022] [Indexed: 11/19/2022] Open
Abstract
RNA editing is essential for compensating for defects or mutations in haploid organelle genomes and is regulated by numerous trans-factors. Pentatricopeptide repeat (PPR) proteins are the prime factors that are involved in RNA editing; however, many have not yet been identified. Here, we screened the plastid-targeted PLS-DYW subfamily of PPR proteins belonging to Arabidopsis thaliana and identified ORGANELLE TRANSCRIPT PROCESSING 970 (OTP970) as a key player in RNA editing in plastids. A loss-of-function otp970 mutant was impaired in RNA editing of ndhB transcripts at site 149 (ndhB-C149). RNA-immunoprecipitation analysis indicated that OTP970 was associated with the ndhB-C149 site. The complementation of the otp970 mutant with OTP970 lacking the DYW domain (OTP970∆DYW) failed to restore the RNA editing of ndhB-C149. ndhB gene encodes the B subunit of the NADH dehydrogenase-like (NDH) complex; however, neither NDH activity and stability nor NDH-PSI supercomplex formation were affected in otp970 mutant compared to the wild type, indicating that alteration in amino acid sequence is not necessary for NdhB function. Together, these results suggest that OTP970 is involved in the RNA editing of ndhB-C149 and that the DYW domain is essential for its function.
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15
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Fauskee BD, Sigel EM, Pryer KM, Grusz AL. Variation in frequency of plastid RNA editing within Adiantum implies rapid evolution in fern plastomes. AMERICAN JOURNAL OF BOTANY 2021; 108:820-827. [PMID: 33969475 DOI: 10.1002/ajb2.1649] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
PREMISE Recent studies of plant RNA editing have demonstrated that the number of editing sites can vary widely among large taxonomic groups (orders, families). Yet, very little is known about intrageneric variation in frequency of plant RNA editing, and no study has been conducted in ferns. METHODS We determined plastid RNA-editing counts for two species of Adiantum (Pteridaceae), A. shastense and A. aleuticum, by implementing a pipeline that integrated read-mapping and SNP-calling software to identify RNA-editing sites. We then compared the edits found in A. aleuticum and A. shastense with previously published edits from A. capillus-veneris by generating alignments for each plastid gene. RESULTS We found direct evidence for 505 plastid RNA-editing sites in A. aleuticum and 509 in A. shastense, compared with 350 sites in A. capillus-veneris. We observed striking variation in the number and location of the RNA-editing sites among the three species, with reverse (U-to-C) editing sites showing a higher degree of conservation than forward (C-to-U) sites. Additionally, sites involving start and stop codons were highly conserved. CONCLUSIONS Variation in the frequency of RNA editing within Adiantum implies that RNA-editing sites can be rapidly gained or lost throughout evolution. However, varying degrees of conservation between both C-to-U and U-to-C sites and sites in start or stop codons, versus other codons, hints at the likely independent origin of both types of edits and a potential selective advantage conferred by RNA editing.
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Affiliation(s)
- Blake D Fauskee
- Department of Biology, Duke University, Durham, NC, 27708, USA
| | - Erin M Sigel
- Department of Biological Sciences, University of New Hampshire, Durham, NH, 03824, USA
| | | | - Amanda L Grusz
- Department of Biology, University of Minnesota Duluth, Duluth, MN, 55812, USA
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16
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Filip E, Skuza L. Horizontal Gene Transfer Involving Chloroplasts. Int J Mol Sci 2021; 22:ijms22094484. [PMID: 33923118 PMCID: PMC8123421 DOI: 10.3390/ijms22094484] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 02/04/2023] Open
Abstract
Horizontal gene transfer (HGT)- is defined as the acquisition of genetic material from another organism. However, recent findings indicate a possible role of HGT in the acquisition of traits with adaptive significance, suggesting that HGT is an important driving force in the evolution of eukaryotes as well as prokaryotes. It has been noted that, in eukaryotes, HGT is more prevalent than originally thought. Mitochondria and chloroplasts lost a large number of genes after their respective endosymbiotic events occurred. Even after this major content loss, organelle genomes still continue to lose their own genes. Many of these are subsequently acquired by intracellular gene transfer from the original plastid. The aim of our review was to elucidate the role of chloroplasts in the transfer of genes. This review also explores gene transfer involving mitochondrial and nuclear genomes, though recent studies indicate that chloroplast genomes are far more active in HGT as compared to these other two DNA-containing cellular compartments.
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Affiliation(s)
- Ewa Filip
- Institute of Biology, University of Szczecin, 13 Wąska, 71-415 Szczecin, Poland;
- The Centre for Molecular Biology and Biotechnology, University of Szczecin, 13 Wąska, 71-415 Szczecin, Poland
- Correspondence:
| | - Lidia Skuza
- Institute of Biology, University of Szczecin, 13 Wąska, 71-415 Szczecin, Poland;
- The Centre for Molecular Biology and Biotechnology, University of Szczecin, 13 Wąska, 71-415 Szczecin, Poland
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17
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Guo W, Zhu A, Fan W, Adams RP, Mower JP. Extensive Shifts from Cis- to Trans-splicing of Gymnosperm Mitochondrial Introns. Mol Biol Evol 2021; 37:1615-1620. [PMID: 32027368 DOI: 10.1093/molbev/msaa029] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Hundreds of plant mitogenomes have been sequenced from angiosperms, but relatively few mitogenomes are available from its sister lineage, gymnosperms. To examine mitogenomic diversity among extant gymnosperms, we generated draft mitogenomes from 11 diverse species and compared them with four previously published mitogenomes. Examined mitogenomes from Pinaceae and cycads retained all 41 protein genes and 26 introns present in the common ancestor of seed plants, whereas gnetophyte and cupressophyte mitogenomes experienced extensive gene and intron loss. In Pinaceae and cupressophyte mitogenomes, an unprecedented number of exons are distantly dispersed, requiring trans-splicing of 50-70% of mitochondrial introns to generate mature transcripts. RNAseq data confirm trans-splicing of these dispersed exons in Pinus. The prevalence of trans-splicing in vascular plant lineages with recombinogenic mitogenomes suggests that genomic rearrangement is the primary cause of shifts from cis- to trans-splicing in plant mitochondria.
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Affiliation(s)
- Wenhu Guo
- Center for Plant Science Innovation, University of Nebraska, Lincoln, NE.,School of Biological Sciences, University of Nebraska, Lincoln, NE
| | - Andan Zhu
- Center for Plant Science Innovation, University of Nebraska, Lincoln, NE.,Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE.,Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Weishu Fan
- Center for Plant Science Innovation, University of Nebraska, Lincoln, NE.,Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE.,Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | | | - Jeffrey P Mower
- Center for Plant Science Innovation, University of Nebraska, Lincoln, NE.,Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE
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18
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Comparative analysis of nuclear, chloroplast, and mitochondrial genomes of watermelon and melon provides evidence of gene transfer. Sci Rep 2021; 11:1595. [PMID: 33452307 PMCID: PMC7811005 DOI: 10.1038/s41598-020-80149-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 12/17/2020] [Indexed: 11/08/2022] Open
Abstract
During plant evolution, there is genetic communication between organelle and nuclear genomes. A comparative analysis was performed on the organelle and nuclear genomes of the watermelon and melon. In the watermelon, chloroplast-derived sequences accounted for 7.6% of the total length of the mitochondrial genome. In the melon, chloroplast-derived sequences accounted for approximately 2.73% of the total mitochondrial genome. In watermelon and melon, the chloroplast-derived small-fragment sequences are either a subset of large-fragment sequences or appeared multiple times in the mitochondrial genome, indicating that these fragments may have undergone multiple independent migration integrations or emerged in the mitochondrial genome after migration, replication, and reorganization. There was no evidence of migration from the mitochondria to chloroplast genome. A sequence with a total length of about 73 kb (47%) in the watermelon chloroplast genome was homologous to a sequence of about 313 kb in the nuclear genome. About 33% of sequences in the watermelon mitochondrial genome was homologous with a 260 kb sequence in the nuclear genome. A sequence with a total length of about 38 kb (25%) in the melon chloroplast genome was homologous with 461 sequences in the nuclear genome, with a total length of about 301 kb. A 3.4 Mb sequence in the nuclear genome was homologous with a melon mitochondrial sequence. These results indicate that, during the evolution of watermelon and melon, a large amount of genetic material was exchanged between the nuclear genome and the two organelle genomes in the cytoplasm.
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19
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Fan K, Peng Y, Ren Z, Li D, Zhen S, Hey S, Cui Y, Fu J, Gu R, Wang J, Wang G, Li L. Maize Defective Kernel605 Encodes a Canonical DYW-Type PPR Protein that Edits a Conserved Site of nad1 and Is Essential for Seed Nutritional Quality. PLANT & CELL PHYSIOLOGY 2020; 61:1954-1966. [PMID: 32818255 DOI: 10.1093/pcp/pcaa110] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
Pentatricopeptide repeat (PPR) proteins involved in mitochondrial RNA cytidine (C)-to-uridine (U) editing mostly result in stagnant embryo and endosperm development upon loss of function. However, less is known about PPRs that are involved in farinaceous endosperm formation and maize quality. Here, we cloned a maize DYW-type PPR Defective Kernel605 (Dek605). Mutation of Dek605 delayed seed and seedling development. Mitochondrial transcript analysis of dek605 revealed that loss of DEK605 impaired C-to-U editing at the nad1-608 site and fails to alter Ser203 to Phe203 in NAD1 (dehydrogenase complex I), disrupting complex I assembly and reducing NADH dehydrogenase activity. Meanwhile, complexes III and IV in the cytochrome pathway, as well as AOX2 in the alternative respiratory pathway, are dramatically increased. Interestingly, the dek605 mutation resulted in opaque endosperm and increased levels of the free amino acids alanine, aspartic acid and phenylalanine. The down- and upregulated genes mainly involved in stress response-related and seed dormancy-related pathways, respectively, were observed after transcriptome analysis of dek605 at 12 d after pollination. Collectively, these results indicate that Dek605 specifically affects the single nad1-608 site and is required for normal seed development and resulted in nutritional quality relevant amino acid accumulation.
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Affiliation(s)
- Kaijian Fan
- Seed Science and Technology Research Center, Beijing Innovation Center for Seed Technology (MOA), Beijing Key Laboratory for Crop Genetic Improvement, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Yixuan Peng
- Institute of Crop Sciences, Chinese Academy of Agricultural iences, Beijing 100081, China
| | - Zhenjing Ren
- Seed Science and Technology Research Center, Beijing Innovation Center for Seed Technology (MOA), Beijing Key Laboratory for Crop Genetic Improvement, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
- Institute of Crop Sciences, Chinese Academy of Agricultural iences, Beijing 100081, China
| | - Delin Li
- Institute of Crop Sciences, Chinese Academy of Agricultural iences, Beijing 100081, China
| | - Sihan Zhen
- Institute of Crop Sciences, Chinese Academy of Agricultural iences, Beijing 100081, China
| | - Stefan Hey
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA
| | - Yu Cui
- Seed Science and Technology Research Center, Beijing Innovation Center for Seed Technology (MOA), Beijing Key Laboratory for Crop Genetic Improvement, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Junjie Fu
- Seed Science and Technology Research Center, Beijing Innovation Center for Seed Technology (MOA), Beijing Key Laboratory for Crop Genetic Improvement, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Riliang Gu
- Institute of Crop Sciences, Chinese Academy of Agricultural iences, Beijing 100081, China
| | - Jianhua Wang
- Institute of Crop Sciences, Chinese Academy of Agricultural iences, Beijing 100081, China
| | - Guoying Wang
- Seed Science and Technology Research Center, Beijing Innovation Center for Seed Technology (MOA), Beijing Key Laboratory for Crop Genetic Improvement, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Li Li
- Institute of Crop Sciences, Chinese Academy of Agricultural iences, Beijing 100081, China
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Kang JS, Zhang HR, Wang YR, Liang SQ, Mao ZY, Zhang XC, Xiang QP. Distinctive evolutionary pattern of organelle genomes linked to the nuclear genome in Selaginellaceae. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:1657-1672. [PMID: 33073395 DOI: 10.1111/tpj.15028] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 08/21/2020] [Accepted: 10/02/2020] [Indexed: 06/11/2023]
Abstract
Plastids and mitochondria are endosymbiotic organelles that store genetic information. The genomes of these organelles generally exhibit contrasting patterns regarding genome architecture and genetic content. However, they have similar genetic features in Selaginellaceae, and little is known about what causes parallel evolution. Here, we document the multipartite plastid genomes (plastomes) and the highly divergent mitochondrial genomes (mitogenomes) from spikemoss obtained by combining short- and long-reads. The 188-kb multipartite plastome has three ribosomal operon copies in the master genomic conformation, creating the alternative subgenomic conformation composed of 110- and 78-kb subgenomes. The long-read data indicated that the two different genomic conformations were present in almost equal proportions in the plastomes of Selaginella nipponica. The mitogenome of S. nipponica was assembled into 27 contigs with a total size of 110 kb. All contigs contained directly arranged repeats at both ends, which introduced multiple conformations. Our results showed that plastomes and mitogenomes share high tRNA losses, GC-biased nucleotides, elevated substitution rates and complicated organization. The exploration of nuclear-encoded organelle DNA replication, recombination and repair proteins indicated that, several single-targeted proteins, particularly plastid-targeted recombinase A1, have been lost in Selaginellaceae; conversely, the dual-targeted proteins remain intact. According to the reported function of recombinase A1, we propose that the plastomes of spikemoss often fail to pair homologous sequences during recombination, and the dual-targeted proteins play a key role in the convergent genetic features of plastomes and mitogenomes. Our results provide a distinctive evolutionary pattern of the organelle genomes in Selaginellaceae and evidence of their convergent evolution.
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Affiliation(s)
- Jong-Soo Kang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hong-Rui Zhang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Ya-Rong Wang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Si-Qi Liang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhi-Yuan Mao
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Xian-Chun Zhang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Qiao-Ping Xiang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
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21
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Deng Y, Zhang X, Xie B, Lin L, Hsiang T, Lin X, Lin Y, Zhang X, Ma Y, Miao W, Ming R. Intra-specific comparison of mitochondrial genomes reveals host gene fragment exchange via intron mobility in Tremella fuciformis. BMC Genomics 2020; 21:426. [PMID: 32580700 PMCID: PMC7315562 DOI: 10.1186/s12864-020-06846-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 06/17/2020] [Indexed: 01/21/2023] Open
Abstract
Background Mitochondrial genomic sequences are known to be variable. Comparative analyses of mitochondrial genomes can reveal the nature and extent of their variation. Results Draft mitochondrial genomes of 16 Tremella fuciformis isolates (TF01-TF16) were assembled from Illumina and PacBio sequencing data. Mitochondrial DNA contigs were extracted and assembled into complete circular molecules, ranging from 35,104 bp to 49,044 bp in size. All mtDNAs contained the same set of 41 conserved genes with identical gene order. Comparative analyses revealed that introns and intergenic regions were variable, whereas genic regions (including coding sequences, tRNA, and rRNA genes) were conserved. Among 24 introns detected, 11 were in protein-coding genes, 3 in tRNA genes, and the other 10 in rRNA genes. In addition, two mobile fragments were found in intergenic regions. Interestingly, six introns containing N-terminal duplication of the host genes were found in five conserved protein-coding gene sequences. Comparison of genes with and without these introns gave rise to the following proposed model: gene fragment exchange with other species can occur via gain or loss of introns with N-terminal duplication of the host genes. Conclusions Our findings suggest a novel mechanism of fungal mitochondrial gene evolution: partial foreign gene replacement though intron mobility.
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Affiliation(s)
- Youjin Deng
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.,Department of Plant Biology, University of Illinois at Urbana-Champaign, 1201 W. Gregory Drive, Urbana, IL, 61801, USA
| | - Xunxiao Zhang
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Baogui Xie
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Longji Lin
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Tom Hsiang
- Environmental Sciences, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Xiangzhi Lin
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yiying Lin
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xingtan Zhang
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yanhong Ma
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Wenjing Miao
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Ray Ming
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. .,Department of Plant Biology, University of Illinois at Urbana-Champaign, 1201 W. Gregory Drive, Urbana, IL, 61801, USA.
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22
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Mower JP. Variation in protein gene and intron content among land plant mitogenomes. Mitochondrion 2020; 53:203-213. [PMID: 32535166 DOI: 10.1016/j.mito.2020.06.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 05/24/2020] [Accepted: 06/08/2020] [Indexed: 12/20/2022]
Abstract
The functional content of the mitochondrial genome (mitogenome) is highly diverse across eukaryotes. Among land plants, our understanding of the variation in mitochondrial gene and intron content is improving from concerted efforts to densely sample mitogenomes from diverse land plants. Here I review the current state of knowledge regarding the diversity in content of protein genes and introns in the mitogenomes of all major land plant lineages. Mitochondrial protein gene content is largely conserved among mosses and liverworts, but it varies substantially among and within other land plant lineages due to convergent losses of genes encoding ribosomal proteins and, to a lesser extent, genes for proteins involved in cytochrome c maturation and oxidative phosphorylation. Mitochondrial intron content is fairly stable within each major land plant lineage, but highly variable among lineages, resulting from occasional gains and many convergent losses over time. Trans-splicing has evolved dozens of times in various vascular plant lineages, particularly those with relatively higher rates of mitogenomic rearrangement. Across eukaryotes, mitochondrial protein gene and intron content has been shaped massive convergent evolution.
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Affiliation(s)
- Jeffrey P Mower
- Center for Plant Science Innovation and Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE.
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23
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Zumkeller S, Gerke P, Knoop V. A functional twintron, 'zombie' twintrons and a hypermobile group II intron invading itself in plant mitochondria. Nucleic Acids Res 2020; 48:2661-2675. [PMID: 31915815 PMCID: PMC7049729 DOI: 10.1093/nar/gkz1194] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/26/2019] [Accepted: 12/11/2019] [Indexed: 02/06/2023] Open
Abstract
The occurrence of group II introns in plant mitochondrial genomes is strikingly different between the six major land plant clades, contrasting their highly conserved counterparts in chloroplast DNA. Their present distribution likely reflects numerous ancient intron gains and losses during early plant evolution before the emergence of seed plants. As a novelty for plant organelles, we here report on five cases of twintrons, introns-within-introns, in the mitogenomes of lycophytes and hornworts. An internal group II intron interrupts an intron-borne maturase of an atp9 intron in Lycopodiaceae, whose splicing precedes splicing of the external intron. An invasive, hypermobile group II intron in cox1, has conquered nine further locations including a previously overlooked sdh3 intron and, most surprisingly, also itself. In those cases, splicing of the external introns does not depend on splicing of the internal introns. Similar cases are identified in the mtDNAs of hornworts. Although disrupting a group I intron-encoded protein in one case, we could not detect splicing of the internal group II intron in this ‘mixed’ group I/II twintron. We suggest the name ‘zombie’ twintrons (half-dead, half-alive) for such cases where splicing of external introns does not depend any more on prior splicing of fossilized internal introns.
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Affiliation(s)
- Simon Zumkeller
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, D-53115 Bonn, Germany
| | - Philipp Gerke
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, D-53115 Bonn, Germany
| | - Volker Knoop
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, D-53115 Bonn, Germany
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24
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Petersen G, Anderson B, Braun HP, Meyer EH, Møller IM. Mitochondria in parasitic plants. Mitochondrion 2020; 52:173-182. [DOI: 10.1016/j.mito.2020.03.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/05/2020] [Accepted: 03/23/2020] [Indexed: 02/06/2023]
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25
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Abstract
Ever since its discovery, the double-stranded DNA contained in the mitochondria of eukaryotes has fascinated researchers because of its bacterial endosymbiotic origin, crucial role in encoding subunits of the respiratory complexes, compact nature, and specific inheritance mechanisms. In the last few years, high-throughput sequencing techniques have accelerated the sequencing of mitochondrial genomes (mitogenomes) and uncovered the great diversity of organizations, gene contents, and modes of replication and transcription found in living eukaryotes. Some early divergent lineages of unicellular eukaryotes retain certain synteny and gene content resembling those observed in the genomes of alphaproteobacteria (the inferred closest living group of mitochondria), whereas others adapted to anaerobic environments have drastically reduced or even lost the mitogenome. In the three main multicellular lineages of eukaryotes, mitogenomes have pursued diverse evolutionary trajectories in which different types of molecules (circular versus linear and single versus multipartite), gene structures (with or without self-splicing introns), gene contents, gene orders, genetic codes, and transfer RNA editing mechanisms have been selected. Whereas animals have evolved a rather compact mitochondrial genome between 11 and 50 Kb in length with a highly conserved gene content in bilaterians, plants exhibit large mitochondrial genomes of 66 Kb to 11.3 Mb with large intergenic repetitions prone to recombination, and fungal mitogenomes have intermediate sizes of 12 to 236 Kb.
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Affiliation(s)
- Rafael Zardoya
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain
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26
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Warren JM, Sloan DB. Interchangeable parts: The evolutionarily dynamic tRNA population in plant mitochondria. Mitochondrion 2020; 52:144-156. [PMID: 32184120 DOI: 10.1016/j.mito.2020.03.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 03/06/2020] [Accepted: 03/11/2020] [Indexed: 01/31/2023]
Abstract
Transfer RNAs (tRNAs) remain one of the very few classes of genes still encoded in the mitochondrial genome. These key components of the protein translation system must interact with a large enzymatic network of nuclear-encoded gene products to maintain mitochondrial function. Plants have an evolutionarily dynamic mitochondrial tRNA population, including ongoing tRNA gene loss and replacement by both horizontal gene transfer from diverse sources and import of nuclear-expressed tRNAs from the cytosol. Thus, plant mitochondria represent an excellent model for understanding how anciently divergent genes can act as "interchangeable parts" during the evolution of complex molecular systems. In particular, understanding the integration of the mitochondrial translation system with elements of the corresponding machinery used in cytosolic protein synthesis is a key area for eukaryotic cellular evolution. Here, we review the increasingly detailed phylogenetic data about the evolutionary history of mitochondrial tRNA gene loss, transfer, and functional replacement that has created extreme variation in mitochondrial tRNA populations across plant species. We describe emerging tRNA-seq methods with promise for refining our understanding of the expression and subcellular localization of tRNAs. Finally, we summarize current evidence and identify open questions related to coevolutionary changes in nuclear-encoded enzymes that have accompanied turnover in mitochondrial tRNA populations.
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Affiliation(s)
- Jessica M Warren
- Department of Biology, Colorado State University, Fort Collins, CO, USA.
| | - Daniel B Sloan
- Department of Biology, Colorado State University, Fort Collins, CO, USA
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27
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Hein A, Brenner S, Polsakiewicz M, Knoop V. The dual-targeted RNA editing factor AEF1 is universally conserved among angiosperms and reveals only minor adaptations upon loss of its chloroplast or its mitochondrial target. PLANT MOLECULAR BIOLOGY 2020; 102:185-198. [PMID: 31797248 DOI: 10.1007/s11103-019-00940-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/26/2019] [Indexed: 06/10/2023]
Abstract
Upon loss of either its chloroplast or mitochondrial target, a uniquely dual-targeted factor for C-to-U RNA editing in angiosperms reveals low evidence for improved molecular adaptation to its remaining target. RNA-binding pentatricopeptide repeat (PPR) proteins specifically recognize target sites for C-to-U RNA editing in the transcriptomes of plant chloroplasts and mitochondria. Among more than 80 PPR-type editing factors that have meantime been characterized, AEF1 (or MPR25) is a special case given its dual targeting to both organelles and addressing an essential mitochondrial (nad5eU1580SL) and an essential chloroplast (atpFeU92SL) RNA editing site in parallel in Arabidopsis. Here, we explored the angiosperm-wide conservation of AEF1 and its two organelle targets. Despite numerous independent losses of the chloroplast editing site by C-to-T conversion and at least four such conversions at the mitochondrial target site in other taxa, AEF1 remains consistently conserved in more than 120 sampled angiosperm genomes. Not a single case of simultaneous loss of the chloroplast and mitochondrial editing target or of AEF1 disintegration or loss could be identified, contrasting previous findings for editing factors targeted to only one organelle. Like in most RNA editing factors, the PPR array of AEF1 reveals potential for conceptually "improved fits" to its targets according to the current PPR-RNA binding code. Surprisingly, we observe only minor evidence for adaptation to the mitochondrial target also after deep losses of the chloroplast target among Asterales, Caryophyllales and Poales or, vice versa, for the remaining chloroplast target after a deep loss of the mitochondrial target among Malvales. The evolutionary observations support the notion that PPR-RNA mismatches may be essential for proper function of editing factors.
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Affiliation(s)
- Anke Hein
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Sarah Brenner
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Monika Polsakiewicz
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Volker Knoop
- IZMB - Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee 1, 53115, Bonn, Germany.
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28
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Ishibashi K, Small I, Shikanai T. Evolutionary Model of Plastidial RNA Editing in Angiosperms Presumed from Genome-Wide Analysis of Amborella trichopoda. PLANT & CELL PHYSIOLOGY 2019; 60:2141-2151. [PMID: 31150097 DOI: 10.1093/pcp/pcz111] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 05/21/2019] [Indexed: 05/08/2023]
Abstract
Amborella trichopoda is placed close to the base of the angiosperm lineage (basal angiosperm). By genome-wide RNA sequencing, we identified 184C-to-U RNA editing sites in the plastid genome of Amborella. This number is much higher than that observed in other angiosperms including maize (44 sites), rice (39 sites) and grape (115 sites). Despite the high frequency of RNA editing, the biased distribution of RNA editing sites in the genome, target codon preference and nucleotide preference adjacent to the edited cytidine are similar to that in other angiosperms, suggesting a common editing machinery. Consistent with this idea, the Amborella nuclear genome encodes 2-3 times more of the E- and DYW-subclass members of pentatricopeptide repeat proteins responsible for RNA editing site recognition in plant organelles. Among 165 editing sites in plastid protein coding sequences in Amborella, 100 sites were conserved at least in one out of 38 species selected to represent key branching points of the angiosperm phylogenetic tree. We assume these 100 sites represent at least a subset of the sites in the plastid editotype of ancestral angiosperms. We then mapped the loss and gain of editing sites on the phylogenetic tree of angiosperms. Our results support the idea that the evolution of angiosperms has led to the loss of RNA editing sites in plastids.
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Affiliation(s)
- Kota Ishibashi
- Department of Botany, Graduate School of Science, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto, Japan
| | - Ian Small
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto, Japan
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29
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Chi SI, Dahl M, Emblem Å, Johansen SD. Giant group I intron in a mitochondrial genome is removed by RNA back-splicing. BMC Mol Biol 2019; 20:16. [PMID: 31153363 PMCID: PMC6545197 DOI: 10.1186/s12867-019-0134-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 05/23/2019] [Indexed: 01/29/2023] Open
Abstract
Background The mitochondrial genomes of mushroom corals (Corallimorpharia) are remarkable for harboring two complex group I introns; ND5-717 and COI-884. How these autocatalytic RNA elements interfere with mitochondrial RNA processing is currently not known. Here, we report experimental support for unconventional processing events of ND5-717 containing RNA. Results We obtained the complete mitochondrial genome sequences and corresponding mitochondrial transcriptomes of the two distantly related corallimorpharian species Ricordea yuma and Amplexidiscus fenestrafer. All mitochondrial genes were found to be expressed at the RNA-level. Both introns were perfectly removed by autocatalytic splicing, but COI-884 excision appeared more efficient than ND5-717. ND5-717 was organized into giant group I intron elements of 18.1 kb and 19.3 kb in A. fenestrafer and R. yuma, respectively. The intron harbored almost the entire mitochondrial genome embedded within the P8 peripheral segment. Conclusion ND5-717 was removed by group I intron splicing from a small primary transcript that contained a permutated intron–exon arrangement. The splicing pathway involved a circular exon-containing RNA intermediate, which is a hallmark of RNA back-splicing. ND5-717 represents the first reported natural group I intron that becomes excised by back-splicing from a permuted precursor RNA. Back-splicing may explain why Corallimorpharia mitochondrial genomes tolerate giant group I introns. Electronic supplementary material The online version of this article (10.1186/s12867-019-0134-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sylvia Ighem Chi
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Mikael Dahl
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Åse Emblem
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Steinar D Johansen
- Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway. .,Genomics Group, Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway.
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30
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Mower JP, Ma P, Grewe F, Taylor A, Michael TP, VanBuren R, Qiu Y. Lycophyte plastid genomics: extreme variation in GC, gene and intron content and multiple inversions between a direct and inverted orientation of the rRNA repeat. THE NEW PHYTOLOGIST 2019; 222:1061-1075. [PMID: 30556907 PMCID: PMC6590440 DOI: 10.1111/nph.15650] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 12/10/2018] [Indexed: 05/02/2023]
Abstract
Lycophytes are a key group for understanding vascular plant evolution. Lycophyte plastomes are highly distinct, indicating a dynamic evolutionary history, but detailed evaluation is hindered by the limited availability of sequences. Eight diverse plastomes were sequenced to assess variation in structure and functional content across lycophytes. Lycopodiaceae plastomes have remained largely unchanged compared with the common ancestor of land plants, whereas plastome evolution in Isoetes and especially Selaginella is highly dynamic. Selaginella plastomes have the highest GC content and fewest genes and introns of any photosynthetic land plant. Uniquely, the canonical inverted repeat was converted into a direct repeat (DR) via large-scale inversion in some Selaginella species. Ancestral reconstruction identified additional putative transitions between an inverted and DR orientation in Selaginella and Isoetes plastomes. A DR orientation does not disrupt the activity of copy-dependent repair to suppress substitution rates within repeats. Lycophyte plastomes include the most archaic examples among vascular plants and the most reconfigured among land plants. These evolutionary trends correlate with the mitochondrial genome, suggesting shared underlying mechanisms. Copy-dependent repair for DR-localized genes indicates that recombination and gene conversion are not inhibited by the DR orientation. Gene relocation in lycophyte plastomes occurs via overlapping inversions rather than transposase/recombinase-mediated processes.
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Affiliation(s)
- Jeffrey P. Mower
- Center for Plant Science InnovationUniversity of NebraskaLincolnNE68588USA
- Department of Agronomy and HorticultureUniversity of NebraskaLincolnNE68583USA
| | - Peng‐Fei Ma
- Center for Plant Science InnovationUniversity of NebraskaLincolnNE68588USA
- Germplasm Bank of Wild SpeciesKunming Institute of BotanyChinese Academy of SciencesKunmingYunnan650201China
| | - Felix Grewe
- Grainger Bioinformatics Center, Science and EducationField Museum of Natural HistoryChicagoIL60605USA
| | - Alex Taylor
- Department of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMI48109USA
| | | | - Robert VanBuren
- Department of HorticultureMichigan State UniversityEast LansingMI48824USA
| | - Yin‐Long Qiu
- Department of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMI48109USA
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31
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Lu X, Yin Z, Wang J, Chen X, Wang D, Wang S, Guo L, Fan W, Chen C, Wang X, Cui R, Zhang B, Han M, Yang X, Ye W. Identification and function analysis of drought-specific small RNAs in Gossypium hirsutum L. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 280:187-196. [PMID: 30823997 DOI: 10.1016/j.plantsci.2018.11.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 11/23/2018] [Accepted: 11/23/2018] [Indexed: 05/24/2023]
Abstract
Cotton production is severely constrained by drought, especially if encountered during the seedling stage or the fiber initiation and elongation stage, but the regulatory mechanisms underlying the effects of drought remain unclear. Therefore, characterization and functional analysis of microRNA-mediated stress regulatory networks are critical to deciphering plant drought response. In this study, 357, 379 and 377 miRNAs with annotations were obtained using the drought-resistant cotton variety ZhongH177 under three treatments, CK, drought and re-watering, and divided into 73 miRNA families with varying copy numbers from 1 to 24. 136 differential expressed genes (DEGs) with significant expression changes were found, of which only 33 DEGs were upregulated, while 103 DEGs were downregulated under drought stress. However, most DEGs recovered their initial expression states when the plants were re-watered. In total, 2657 targets were identified and found to be mainly enriched in the pathways plant-pathogen interaction, plant hormone signal transduction and biosynthesis of amino acids. Drought tolerance was significantly enhanced in 2 transgenic Arabidopsis lines, showing that miRNAs were involved in cotton drought response. Analysis of the expression patterns of 2 miRNA precursors and methylation alterations of 2 targets suggested that these miRNAs or miRNA precursors may be involved in the regulation of target methylation states. Our study provides evidence of transcriptional responses to drought stress, which will be helpful for the research of drought-resistance mechanisms in the future.
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Affiliation(s)
- Xuke Lu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Zujun Yin
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Junjuan Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Xiugui Chen
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Delong Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Shuai Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Lixue Guo
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Weili Fan
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Chao Chen
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Xiaoge Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Ruifeng Cui
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Binglei Zhang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Mingge Han
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Xiaomin Yang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
| | - Wuwei Ye
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Key Laboratory for Cotton Genetic Improvement, Ministry of Agriculture, Anyang 455000, Henan, China.
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Repeats of Unusual Size in Plant Mitochondrial Genomes: Identification, Incidence and Evolution. G3-GENES GENOMES GENETICS 2019; 9:549-559. [PMID: 30563833 PMCID: PMC6385970 DOI: 10.1534/g3.118.200948] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Plant mitochondrial genomes have excessive size relative to coding capacity, a low mutation rate in genes and a high rearrangement rate. They also have abundant non-tandem repeats often including pairs of large repeats which cause isomerization of the genome by recombination, and numerous repeats of up to several hundred base pairs that recombine only when the genome is stressed by DNA damaging agents or mutations in DNA repair pathway genes. Early work on mitochondrial genomes led to the suggestion that repeats in the size range from several hundred to a few thousand base pair are underrepresented. The repeats themselves are not well-conserved between species, and are not always annotated in mitochondrial sequence assemblies. We systematically identified and compared these repeats, which are important clues to mechanisms of DNA maintenance in mitochondria. We developed a tool to find and curate non-tandem repeats larger than 50bp and analyzed the complete mitochondrial sequences from 157 plant species. We observed an interesting difference between taxa: the repeats are larger and more frequent in the vascular plants. Analysis of closely related species also shows that plant mitochondrial genomes evolve in dramatic bursts of breakage and rejoining, complete with DNA sequence gain and loss. We suggest an adaptive explanation for the existence of the repeats and their evolution.
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Wang Q, Tang G. The mitochondrial genomes of two walnut pests, Gastrolina depressa depressa and G. depressa thoracica (Coleoptera: Chrysomelidae), and phylogenetic analyses. PeerJ 2018; 6:e4919. [PMID: 29888134 PMCID: PMC5993032 DOI: 10.7717/peerj.4919] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 05/16/2018] [Indexed: 11/20/2022] Open
Abstract
In this study, the mitochondrial genomes (mitogenomes) of two walnut leaf insect pests, Gastrolina depressa depressa and G. depressa thoracica, were sequenced by Sanger sequencing technology. The mitogenome of G. depressa thoracica was complete at 16,109 bp in length, while the mitogenome of G. depressa depressa (14,277 bp) was partial. The genomic analyses indicated that both mitogenomes have the typical gene content and arrangement. The formerly identified elements, 'TAGTA' between trnSer(UCN) and nad2, and 'ATGATAA' between atp8 and atp6, were more conserved than that between nad4L and nad4, which was 'ATGTTAA' in Coleoptera excluding Polyphaga. Phylogenetic analyses of the 13 protein-coding genes from 36 coleopteran species well supported a close affinity between the subfamily Chrysomelinae including G. depressa thoracica and G. depressa depressa and Galerucinae, as well as a sister relationship of ((Eumolpinae + Cryptocephalinae) + Cassidinae) within Chrysomelidae.
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Affiliation(s)
- Qiqi Wang
- Key Laboratory of State Forestry Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, Shaanxi, China.,Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Guanghui Tang
- Key Laboratory of State Forestry Administration on Management of Western Forest Bio-Disaster, College of Forestry, Northwest A&F University, Yangling, Shaanxi, China
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Edera AA, Gandini CL, Sanchez-Puerta MV. Towards a comprehensive picture of C-to-U RNA editing sites in angiosperm mitochondria. PLANT MOLECULAR BIOLOGY 2018; 97:215-231. [PMID: 29761268 DOI: 10.1007/s11103-018-0734-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 05/02/2018] [Indexed: 06/08/2023]
Abstract
Our understanding of the dynamic and evolution of RNA editing in angiosperms is in part limited by the few editing sites identified to date. This study identified 10,217 editing sites from 17 diverse angiosperms. Our analyses confirmed the universality of certain features of RNA editing, and offer new evidence behind the loss of editing sites in angiosperms. RNA editing is a post-transcriptional process that substitutes cytidines (C) for uridines (U) in organellar transcripts of angiosperms. These substitutions mostly take place in mitochondrial messenger RNAs at specific positions called editing sites. By means of publicly available RNA-seq data, this study identified 10,217 editing sites in mitochondrial protein-coding genes of 17 diverse angiosperms. Even though other types of mismatches were also identified, we did not find evidence of non-canonical editing processes. The results showed an uneven distribution of editing sites among species, genes, and codon positions. The analyses revealed that editing sites were conserved across angiosperms but there were some species-specific sites. Non-synonymous editing sites were particularly highly conserved (~ 80%) across the plant species and were efficiently edited (80% editing extent). In contrast, editing sites at third codon positions were poorly conserved (~ 30%) and only partially edited (~ 40% editing extent). We found that the loss of editing sites along angiosperm evolution is mainly occurring by replacing editing sites with thymidines, instead of a degradation of the editing recognition motif around editing sites. Consecutive and highly conserved editing sites had been replaced by thymidines as result of retroprocessing, by which edited transcripts are reverse transcribed to cDNA and then integrated into the genome by homologous recombination. This phenomenon was more pronounced in eudicots, and in the gene cox1. These results suggest that retroprocessing is a widespread driving force underlying the loss of editing sites in angiosperm mitochondria.
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Affiliation(s)
- Alejandro A Edera
- IBAM, Facultad de Ciencias Agrarias, CONICET, Universidad Nacional de Cuyo, M5528AHB, Chacras de Coria, Argentina.
| | - Carolina L Gandini
- IBAM, Facultad de Ciencias Agrarias, CONICET, Universidad Nacional de Cuyo, M5528AHB, Chacras de Coria, Argentina
| | - M Virginia Sanchez-Puerta
- IBAM, Facultad de Ciencias Agrarias, CONICET, Universidad Nacional de Cuyo, M5528AHB, Chacras de Coria, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, 5500, Mendoza, Argentina
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Frailey DC, Chaluvadi SR, Vaughn JN, Coatney CG, Bennetzen JL. Gene loss and genome rearrangement in the plastids of five Hemiparasites in the family Orobanchaceae. BMC PLANT BIOLOGY 2018; 18:30. [PMID: 29409454 PMCID: PMC5801802 DOI: 10.1186/s12870-018-1249-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 01/30/2018] [Indexed: 05/09/2023]
Abstract
BACKGROUND The chloroplast genomes (plastome) of most plants are highly conserved in structure, gene content, and gene order. Parasitic plants, including those that are fully photosynthetic, often contain plastome rearrangements. These most notably include gene deletions that result in a smaller plastome size. The nature of gene loss and genome structural rearrangement has been investigated in several parasitic plants, but their timing and contributions to the adaptation of these parasites requires further investigation, especially among the under-studied hemi-parasites. RESULTS De novo sequencing, assembly and annotation of the chloroplast genomes of five photosynthetic parasites from the family Orobanchaceae were employed to investigate plastome dynamics. Four had major structural rearrangements, including gene duplications and gene losses, that differentiated the taxa. The facultative parasite Aureolaria virginica had the most similar genome content to its close non-parasitic relative, Lindenbergia philippensis, with similar genome size and organization, and no differences in gene content. In contrast, the facultative parasite Buchnera americana and three obligate parasites in the genus Striga all had enlargements of their plastomes, primarily caused by expansion within the large inverted repeats (IRs) that are a standard plastome feature. Some of these IR increases were shared by multiple investigated species, but others were unique to particular lineages. Gene deletions and pseudogenization were also both shared and lineage-specific, with particularly frequent and independent loss of the ndh genes involved in electron recycling. CONCLUSIONS Five new plastid genomes were fully assembled and compared. The results indicate that plastome instability is common in parasitic plants, even those that retain the need to perform essential plastid functions like photosynthesis. Gene losses were slow and not identical across taxa, suggesting that different lineages had different uses or needs for some of their plastome gene content, including genes involved in some aspects of photosynthesis. Recent repeat region extensions, some unique to terminal species branches, were observed after the divergence of the Buchnera/Striga clade, suggesting that this otherwise rare event has some special value in this lineage.
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Affiliation(s)
| | | | - Justin N. Vaughn
- Department of Genetics, University of Georgia, Athens, GA 30677 USA
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Yang Y, Zhu G, Li R, Yan S, Fu D, Zhu B, Tian H, Luo Y, Zhu H. The RNA Editing Factor SlORRM4 Is Required for Normal Fruit Ripening in Tomato. PLANT PHYSIOLOGY 2017; 175:1690-1702. [PMID: 29061908 PMCID: PMC5717740 DOI: 10.1104/pp.17.01265] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 10/20/2017] [Indexed: 05/19/2023]
Abstract
RNA editing plays a key posttranscriptional role in gene expression. Existing studies on cytidine-to-uridine RNA editing in plants have focused on maize (Zea mays), rice (Oryza sativa), and Arabidopsis (Arabidopsis thaliana). However, the importance and regulation of RNA editing in several critical agronomic processes are not well understood, a notable example of which is fruit ripening. Here, we analyzed the expression profile of 33 RNA editing factors and identified 11 putative tomato (Solanum lycopersicum) fruit ripening-related factors. A rapid virus-induced gene silencing assay indicated that the organelle RNA recognition motif-containing protein SlORRM4 affected tomato fruit ripening. Knocking out SlORRM4 expression using a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 genome editing strategy delayed tomato fruit ripening by lowering respiratory rate and ethylene production. Additionally, the expression of numerous genes associated with fruit ripening and mitochondrial functions changed significantly when SlORRM4 was knocked out. Moreover, the loss of SlORRM4 function significantly reduced RNA editing of many mitochondrial transcripts, leading to low-level expression of some core subunits that are critical for mitochondrial complex assembly (i.e. Nad3, Cytc1, and COX II). Taken together, these results indicate that SlORRM4 is involved in RNA editing of transcripts in ripening fruit that influence mitochondrial function and key aspects of fruit ripening.
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Affiliation(s)
- Yongfang Yang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Guoning Zhu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Rui Li
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Shijie Yan
- College of Food Science and Biological Engineering, Tianjin Agricultural University, Tianjin 300384, China
| | - Daqi Fu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Benzhong Zhu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Huiqin Tian
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Yunbo Luo
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Hongliang Zhu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
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Dong Y, Gao X, Zhao Y, Wei M, Xu L, Yang G, Liu L. Semi‑random mutagenesis profile of BCR‑ABL during imatinib resistance acquirement in K562 cells. Mol Med Rep 2017; 16:9409-9414. [PMID: 29152650 PMCID: PMC5779997 DOI: 10.3892/mmr.2017.7835] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 09/01/2017] [Indexed: 01/14/2023] Open
Abstract
Although imatinib is effective in chronic myeloid leukemia treatment, imatinib resistance due to the T315I mutation and/or other mutations is a challenge to be overcome. However, how DNA mutation occurs, particularly the T315I mutation, remains unclear. In the current study, the mutagenesis of BCR-ABL was analyzed via focusing on the process of drug resistance, rather than the final results. Clone sequencing of the BCR-ABL gene and other control genes was applied in two imatinib-resistant cell models. The results have indicated that imatinib actively and selectively causes sporadic mutations in the BCR-ABL gene, however not in the control genes. The majority of the mutations of BCR-ABL were not the clinically observed T315I mutation, suggesting that the T315I mutation may be due to clonal expansion of cells with survival advantages. Taken together, the results of the current study elucidated the mutagenesis process during drug resistance and thus aids in the management of chemotherapy.
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Affiliation(s)
- Yan Dong
- Department of Hematology, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
| | - Xiaotong Gao
- Department of Hematology, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
| | - Yingxin Zhao
- Department of Hematology, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
| | - Mengying Wei
- Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Lingmin Xu
- Department of Hematology, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
| | - Guodong Yang
- Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Li Liu
- Department of Hematology, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710038, P.R. China
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Hassani D, Khalid M, Bilal M, Zhang YD, Huang D. Pentatricopeptide Repeat-directed RNA Editing and Their Biomedical Applications. INT J PHARMACOL 2017. [DOI: 10.3923/ijp.2017.762.772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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39
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Functional divergence and origin of the DAG-like gene family in plants. Sci Rep 2017; 7:5688. [PMID: 28720816 PMCID: PMC5515838 DOI: 10.1038/s41598-017-05961-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 06/06/2017] [Indexed: 01/08/2023] Open
Abstract
The nuclear-encoded DAG-like (DAL) gene family plays critical roles in organelle C-to-U RNA editing in Arabidopsis thaliana. However, the origin, diversification and functional divergence of DAL genes remain unclear. Here, we analyzed the genomes of diverse plant species and found that: DAL genes are specific to spermatophytes, all DAL genes share a conserved gene structure and protein similarity with the inhibitor I9 domain of subtilisin genes found in ferns and mosses, suggesting that DAL genes likely arose from I9-containing proproteases via exon shuffling. Based on phylogenetic inference, DAL genes can be divided into five subfamilies, each composed of putatively orthologous and paralogous genes from different species, suggesting that all DAL genes originated from a common ancestor in early seed plants. Significant type I functional divergence was observed in 6 of 10 pairwise comparisons, indicating that shifting functional constraints have contributed to the evolution of DAL genes. This inference is supported by the finding that functionally divergent amino acids between subfamilies are predominantly located in the DAL domain, a critical part of the RNA editosome. Overall, these findings shed light on the origin of DAL genes in spermatophytes and outline functionally important residues involved in the complexity of the RNA editosome.
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Yang YZ, Ding S, Wang HC, Sun F, Huang WL, Song S, Xu C, Tan BC. The pentatricopeptide repeat protein EMP9 is required for mitochondrial ccmB and rps4 transcript editing, mitochondrial complex biogenesis and seed development in maize. THE NEW PHYTOLOGIST 2017; 214:782-795. [PMID: 28121385 DOI: 10.1111/nph.14424] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 12/02/2016] [Indexed: 05/02/2023]
Abstract
Pentatricopeptide repeat (PPR) proteins comprise a large family of sequence-specific RNA binding proteins in land plants. Because of its large family size and frequent embryo lethality in the mutants, molecular functions and physiological roles of many PPR proteins are unknown. Through characterization of an empty pericarp9 (emp9) mutant in maize (Zea mays), we defined the functions of EMP9 in mitochondrial RNA editing, respiratory complex formation and seed development. Mu insertions in different regions of Emp9 facilitated dissection of the domain functions of the EMP9. Through genetic and functional analyses of multiple alleles, we showed that deletions of two N-terminal PPR motifs and partial E+ domain do not eliminate the editing function of EMP9. Emp9 encodes an E+ subclass PPR protein that is localized in mitochondria. Loss of EMP9 function abolishes the C-to-U editing of ccmB-43 and rps4-335 sites in mitochondria. The loss of editing at ccmB-43 and rps4-335 affects the maturation of cytochrome c and impairs the biogenesis of mitochondrial respiratory complexes, particularly complex III. This work extends our understanding of PPR-E+ protein in editing function and seed development, and provides insights into the molecular function of mitochondrial CcmB protein in higher plants.
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Affiliation(s)
- Yan-Zhuo Yang
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Shuo Ding
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Hong-Chun Wang
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Feng Sun
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Wen-Long Huang
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Shu Song
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Chunhui Xu
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
| | - Bao-Cai Tan
- Key Lab of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
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41
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Schallenberg-Rüdinger M, Oldenkott B, Hiss M, Trinh PL, Knoop V, Rensing SA. A Single-Target Mitochondrial RNA Editing Factor of Funaria hygrometrica Can Fully Reconstitute RNA Editing at Two Sites in Physcomitrella patens. PLANT & CELL PHYSIOLOGY 2017; 58:496-507. [PMID: 28394399 DOI: 10.1093/pcp/pcw229] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 12/21/2016] [Indexed: 05/26/2023]
Abstract
Nuclear-encoded pentatricopeptide repeat (PPR) proteins are key factors for site-specific RNA editing, converting cytidines into uridines in plant mitochondria and chloroplasts. All editing factors in the model moss Physcomitrella patens have a C-terminal DYW domain with similarity to cytidine deaminase. However, numerous editing factors in flowering plants lack such a terminal DYW domain, questioning its immediate role in the pyrimidine base conversion process. Here we further investigate the Physcomitrella DYW-type PPR protein PPR_78, responsible for mitochondrial editing sites cox1eU755SL and rps14eU137SL. Complementation assays with truncated proteins demonstrate that the DYW domain is essential for full PPR_78 editing functionality. The DYW domain can be replaced, however, with its counterpart from another editing factor, PPR_79. The PPR_78 ortholog of the related moss Funaria hygrometrica fully complements the Physcomitrella mutant for editing at both sites, although the editing site in rps14 is lacking in Funaria. Editing factor orthologs in different taxa may thus retain editing capacity for multiple sites despite the absence of editing requirement.
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Affiliation(s)
- Mareike Schallenberg-Rüdinger
- Plant Cell Biology, Faculty of Biology, University of Marburg, Karl-von-Frisch-Str, Marburg, Germany
- IZMB-Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee, Bonn, Germany
| | - Bastian Oldenkott
- IZMB-Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee, Bonn, Germany
| | - Manuel Hiss
- Plant Cell Biology, Faculty of Biology, University of Marburg, Karl-von-Frisch-Str, Marburg, Germany
| | - Phuong Le Trinh
- IZMB-Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee, Bonn, Germany
- Key Laboratory of Enzyme and Protein Technology (KLEPT), VNU University of Science, Nguyen Trai, Thanh Xuan, Hanoi, Vietnam
| | - Volker Knoop
- IZMB-Institut für Zelluläre und Molekulare Botanik, Abteilung Molekulare Evolution, Universität Bonn, Kirschallee, Bonn, Germany
| | - Stefan A Rensing
- Plant Cell Biology, Faculty of Biology, University of Marburg, Karl-von-Frisch-Str, Marburg, Germany
- BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
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Identification of Symmetrical RNA Editing Events in the Mitochondria of Salvia miltiorrhiza by Strand-specific RNA Sequencing. Sci Rep 2017; 7:42250. [PMID: 28186130 PMCID: PMC5301482 DOI: 10.1038/srep42250] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 01/08/2017] [Indexed: 01/08/2023] Open
Abstract
Salvia miltiorrhiza is one of the most widely-used medicinal plants. Here, we systematically analyzed the RNA editing events in its mitochondria. We developed a pipeline using REDItools to predict RNA editing events from stand-specific RNA-Seq data. The predictions were validated using reverse transcription, RT-PCR amplification and Sanger sequencing experiments. Putative sequences motifs were characterized. Comparative analyses were carried out between S. miltiorrhiza, Arabidopsis thaliana and Oryza sativa. We discovered 1123 editing sites, including 225 “C to U” sites in the protein-coding regions. Fourteen of sixteen (87.5%) sites were validated. Three putative DNA motifs were identified around the predicted sites. The nucleotides on both strands at 115 of the 225 sites had undergone RNA editing, which we called symmetrical RNA editing (SRE). Four of six these SRE sites (66.7%) were experimentally confirmed. Re-examination of strand-specific RNA-Seq data from A. thaliana and O. sativa identified 327 and 369 SRE sites respectively. 78, 20 and 13 SRE sites were found to be conserved among A. thaliana, O. sativa and S. miltiorrhiza respectively. This study provides a comprehensive picture of RNA editing events in the mitochondrial genome of S. miltiorrhiza. We identified SREs for the first time, which may represent a universal phenomenon.
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Guo W, Zhu A, Fan W, Mower JP. Complete mitochondrial genomes from the ferns Ophioglossum californicum and Psilotum nudum are highly repetitive with the largest organellar introns. THE NEW PHYTOLOGIST 2017; 213:391-403. [PMID: 27539928 DOI: 10.1111/nph.14135] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/06/2016] [Indexed: 05/07/2023]
Abstract
Currently, complete mitochondrial genomes (mitogenomes) are available from all major land plant lineages except ferns. Sequencing of fern mitogenomes could shed light on the major evolutionary transitions that established mitogenomic diversity among extant lineages. In this study, we generated complete mitogenomes from the adder's tongue fern (Ophioglossum californicum) and the whisk fern (Psilotum nudum). The Psilotum mitogenome (628 kb) contains a rich complement of genes and introns, some of which are the largest of any green plant organellar genome. In the Ophioglossum mitogenome (372 kb), gene and intron content is slightly reduced, including the loss of all four mitochondrial ccm genes. Transcripts of nuclear Ccm genes also were not detected, suggesting loss of the entire mitochondrial cytochrome c maturation pathway from Ophioglossum. Both fern mitogenomes are highly repetitive, yet they show extremely low levels of active recombination. Transcriptomic sequencing uncovered ˜1000 sites of C-to-U RNA editing in both species, plus a small number (< 60) of U-to-C edit sites. Overall, the first mitochondrial genomes of ferns show a mix of features shared with lycophytes and/or seed plants and several novel genomic features, enabling a robust reconstruction of the mitogenome in the common ancestor of vascular plants.
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Affiliation(s)
- Wenhu Guo
- Center for Plant Science Innovation, University of Nebraska, Lincoln, NE, 68588, USA
- School of Biological Sciences, University of Nebraska, Lincoln, NE, 68588, USA
- ACGT Inc., Wheeling, IL, 60090, USA
| | - Andan Zhu
- Center for Plant Science Innovation, University of Nebraska, Lincoln, NE, 68588, USA
- Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE, 68583, USA
| | - Weishu Fan
- Center for Plant Science Innovation, University of Nebraska, Lincoln, NE, 68588, USA
- Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE, 68583, USA
| | - Jeffrey P Mower
- Center for Plant Science Innovation, University of Nebraska, Lincoln, NE, 68588, USA
- Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE, 68583, USA
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Knie N, Grewe F, Knoop V. Monilophyte mitochondrial rps1 genes carry a unique group II intron that likely originated from an ancient paralog in rpl2. RNA (NEW YORK, N.Y.) 2016; 22:1338-48. [PMID: 27354706 PMCID: PMC4986890 DOI: 10.1261/rna.056572.116] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 05/19/2016] [Indexed: 05/10/2023]
Abstract
Intron patterns in plant mitochondrial genomes differ significantly between the major land plant clades. We here report on a new, clade-specific group II intron in the rps1 gene of monilophytes (ferns). This intron, rps1i25g2, is strikingly similar to rpl2i846g2 previously identified in the mitochondrial rpl2 gene of seed plants, ferns, and the lycophyte Phlegmariurus squarrosus Although mitochondrial ribosomal protein genes are frequently subject to endosymbiotic gene transfer among plants, we could retrieve the mitochondrial rps1 gene in a taxonomically wide sampling of 44 monilophyte taxa including basal lineages such as the Ophioglossales, Psilotales, and Marattiales with the only exception being the Equisetales (horsetails). Introns rps1i25g2 and rpl2i846g2 were likewise consistently present with only two exceptions: Intron rps1i25g2 is lost in the genus Ophioglossum and intron rpl2i846g2 is lost in Equisetum bogotense Both intron sequences are moderately affected by RNA editing. The unprecedented primary and secondary structure similarity of rps1i25g2 and rpl2i846g2 suggests an ancient retrotransposition event copying rpl2i846g2 into rps1, for which we suggest a model. Our phylogenetic analysis adding the new rps1 locus to a previous data set is fully congruent with recent insights on monilophyte phylogeny and further supports a sister relationship of Gleicheniales and Hymenophyllales.
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Affiliation(s)
- Nils Knie
- Abteilung Molekulare Evolution, IZMB-Institut für Zelluläre und Molekulare Botanik, Universität Bonn, D-53115 Bonn, Germany
| | - Felix Grewe
- Abteilung Molekulare Evolution, IZMB-Institut für Zelluläre und Molekulare Botanik, Universität Bonn, D-53115 Bonn, Germany
| | - Volker Knoop
- Abteilung Molekulare Evolution, IZMB-Institut für Zelluläre und Molekulare Botanik, Universität Bonn, D-53115 Bonn, Germany
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Zumkeller SM, Knoop V, Knie N. Convergent Evolution of Fern-Specific Mitochondrial Group II Intron atp1i361g2 and Its Ancient Source Paralogue rps3i249g2 and Independent Losses of Intron and RNA Editing among Pteridaceae. Genome Biol Evol 2016; 8:2505-19. [PMID: 27492234 PMCID: PMC5010907 DOI: 10.1093/gbe/evw173] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2016] [Indexed: 01/01/2023] Open
Abstract
Mitochondrial intron patterns are highly divergent between the major land plant clades. An intron in the atp1 gene, atp1i361g2, is an example for a group II intron specific to monilophytes (ferns). Here, we report that atp1i361g2 is lost independently at least 4 times in the fern family Pteridaceae. Such plant organelle intron losses have previously been found to be accompanied by loss of RNA editing sites in the flanking exon regions as a consequence of genomic recombination of mature cDNA. Instead, we now observe that RNA editing events in both directions of pyrimidine exchange (C-to-U and U-to-C) are retained in atp1 exons after loss of the intron in Pteris argyraea/biaurita and in Actiniopteris and Onychium We find that atp1i361g2 has significant similarity with intron rps3i249g2 present in lycophytes and gymnosperms, which we now also find highly conserved in ferns. We conclude that atp1i361g2 may have originated from the more ancestral rps3i249g2 paralogue by a reverse splicing copy event early in the evolution of monilophytes. Secondary structure elements of the two introns, most characteristically their domains III, show strikingly convergent evolution in the monilophytes. Moreover, the intron paralogue rps3i249g2 reveals relaxed evolution in taxa where the atp1i361g2 paralogue is lost. Our findings may reflect convergent evolution of the two related mitochondrial introns exerted by co-evolution with an intron-binding protein simultaneously acting on the two paralogues.
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Affiliation(s)
- Simon Maria Zumkeller
- Abteilung Molekulare Evolution, IZMB-Institut Für Zelluläre Und Molekulare Botanik, Universität Bonn, Kirschallee 1, D-53115 Bonn, Germany
| | - Volker Knoop
- Abteilung Molekulare Evolution, IZMB-Institut Für Zelluläre Und Molekulare Botanik, Universität Bonn, Kirschallee 1, D-53115 Bonn, Germany
| | - Nils Knie
- Abteilung Molekulare Evolution, IZMB-Institut Für Zelluläre Und Molekulare Botanik, Universität Bonn, Kirschallee 1, D-53115 Bonn, Germany
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Cuenca A, Ross TG, Graham SW, Barrett CF, Davis JI, Seberg O, Petersen G. Localized Retroprocessing as a Model of Intron Loss in the Plant Mitochondrial Genome. Genome Biol Evol 2016; 8:2176-89. [PMID: 27435795 PMCID: PMC4987113 DOI: 10.1093/gbe/evw148] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2016] [Indexed: 12/23/2022] Open
Abstract
Loss of introns in plant mitochondrial genes is commonly explained by retroprocessing. Under this model, an mRNA is reverse transcribed and integrated back into the genome, simultaneously affecting the contents of introns and edited sites. To evaluate the extent to which retroprocessing explains intron loss, we analyzed patterns of intron content and predicted RNA editing for whole mitochondrial genomes of 30 species in the monocot order Alismatales. In this group, we found an unusually high degree of variation in the intron content, even expanding the hitherto known variation among angiosperms. Some species have lost some two-third of the cis-spliced introns. We found a strong correlation between intron content and editing frequency, and detected 27 events in which intron loss is consistent with the presence of nucleotides in an edited state, supporting retroprocessing. However, we also detected seven cases of intron loss not readily being explained by retroprocession. Our analyses are also not consistent with the entire length of a fully processed cDNA copy being integrated into the genome, but instead indicate that retroprocessing usually occurs for only part of the gene. In some cases, several rounds of retroprocessing may explain intron loss in genes completely devoid of introns. A number of taxa retroprocessing seem to be very common and a possibly ongoing process. It affects the entire mitochondrial genome.
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Affiliation(s)
- Argelia Cuenca
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - T Gregory Ross
- Department of Botany, 6270 University Boulevard, University of British Columbia, Vancouver, British Columbia, Canada UBC Botanical Garden & Centre for Plant Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sean W Graham
- Department of Botany, 6270 University Boulevard, University of British Columbia, Vancouver, British Columbia, Canada UBC Botanical Garden & Centre for Plant Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Craig F Barrett
- Department of Biological Sciences, California State University, Los Angeles, California
| | - Jerrold I Davis
- L.H. Bailey Hortorium and Plant Biology Section, Cornell University, Ithaca, New York
| | - Ole Seberg
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Gitte Petersen
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
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Jonathan Shaw A, Devos N, Liu Y, Cox CJ, Goffinet B, Flatberg KI, Shaw B. Organellar phylogenomics of an emerging model system: Sphagnum (peatmoss). ANNALS OF BOTANY 2016; 118:185-96. [PMID: 27268484 PMCID: PMC4970357 DOI: 10.1093/aob/mcw086] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 01/11/2016] [Accepted: 03/28/2016] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Sphagnum-dominated peatlands contain approx. 30 % of the terrestrial carbon pool in the form of partially decomposed plant material (peat), and, as a consequence, Sphagnum is currently a focus of studies on biogeochemistry and control of global climate. Sphagnum species differ in ecologically important traits that scale up to impact ecosystem function, and sequencing of the genome from selected Sphagnum species is currently underway. As an emerging model system, these resources for Sphagnum will facilitate linking nucleotide variation to plant functional traits, and through those traits to ecosystem processes. A solid phylogenetic framework for Sphagnum is crucial to comparative analyses of species-specific traits, but relationships among major clades within Sphagnum have been recalcitrant to resolution because the genus underwent a rapid radiation. Herein a well-supported hypothesis for phylogenetic relationships among major clades within Sphagnum based on organellar genome sequences (plastid, mitochondrial) is provided. METHODS We obtained nucleotide sequences (273 753 nucleotides in total) from the two organellar genomes from 38 species (including three outgroups). Phylogenetic analyses were conducted using a variety of methods applied to nucleotide and amino acid sequences. The Sphagnum phylogeny was rooted with sequences from the related Sphagnopsida genera, Eosphagnum and Flatbergium KEY RESULTS Phylogenetic analyses of the data converge on the following subgeneric relationships: (Rigida (((Subsecunda) (Cuspidata)) ((Sphagnum) (Acutifolia))). All relationships were strongly supported. Species in the two major clades (i.e. Subsecunda + Cuspidata and Sphagnum + Acutifolia), which include >90 % of all Sphagnum species, differ in ecological niches and these differences correlate with other functional traits that impact biogeochemical cycling. Mitochondrial intron presence/absence are variable among species and genera of the Sphagnopsida. Two new nomenclatural combinations are made, in the genera Eosphagnum and Flatbergium CONCLUSIONS Newly resolved relationships now permit phylogenetic analyses of morphological, biochemical and ecological traits among Sphagnum species. The results clarify long-standing disagreements about subgeneric relationships and intrageneric classification.
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Affiliation(s)
- A Jonathan Shaw
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Nicolas Devos
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Yang Liu
- Department of Ecology and Evolutionary Biology, 75 North Eagleville Road, Storrs, CT 06269, USA
| | - Cymon J Cox
- Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, Edif. 7, 8005-139 Faro, Portugal
| | - Bernard Goffinet
- Department of Ecology and Evolutionary Biology, 75 North Eagleville Road, Storrs, CT 06269, USA
| | - Kjell Ivar Flatberg
- NTNU University Museum, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
| | - Blanka Shaw
- Department of Biology, Duke University, Durham, NC 27708, USA
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Knie N, Grewe F, Fischer S, Knoop V. Reverse U-to-C editing exceeds C-to-U RNA editing in some ferns - a monilophyte-wide comparison of chloroplast and mitochondrial RNA editing suggests independent evolution of the two processes in both organelles. BMC Evol Biol 2016; 16:134. [PMID: 27329857 PMCID: PMC4915041 DOI: 10.1186/s12862-016-0707-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 06/09/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND RNA editing by C-to-U conversions is nearly omnipresent in land plant chloroplasts and mitochondria, where it mainly serves to reconstitute conserved codon identities in the organelle mRNAs. Reverse U-to-C RNA editing in contrast appears to be restricted to hornworts, some lycophytes, and ferns (monilophytes). A well-resolved monilophyte phylogeny has recently emerged and now allows to trace the side-by-side evolution of both types of pyrimidine exchange editing in the two endosymbiotic organelles. RESULTS Our study of RNA editing in four selected mitochondrial genes show a wide spectrum of divergent RNA editing frequencies including a dominance of U-to-C over the canonical C-to-U editing in some taxa like the order Schizaeales. We find that silent RNA editing leaving encoded amino acids unchanged is highly biased with more than ten-fold amounts of silent C-to-U over U-to-C edits. In full contrast to flowering plants, RNA editing frequencies are low in early-branching monilophyte lineages but increase in later emerging clades. Moreover, while editing rates in the two organelles are usually correlated, we observe uncoupled evolution of editing frequencies in fern mitochondria and chloroplasts. Most mitochondrial RNA editing sites are shared between the recently emerging fern orders whereas chloroplast editing sites are mostly clade-specific. Finally, we observe that chloroplast RNA editing appears to be completely absent in horsetails (Equisetales), the sister clade of all other monilophytes. CONCLUSIONS C-to-U and U-to-C RNA editing in fern chloroplasts and mitochondria follow disinct evolutionary pathways that are surprisingly different from what has previously been found in flowering plants. The results call for careful differentiation of the two types of RNA editing in the two endosymbiotic organelles in comparative evolutionary studies.
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Affiliation(s)
- Nils Knie
- Abteilung Molekulare Evolution, IZMB - Institut für Zelluläre und Molekulare Botanik, Universität Bonn, Kirschallee 1, D-53115, Bonn, Germany
| | - Felix Grewe
- Present address: Department of Science and Education, Field Museum of Natural History, Integrative Research Center, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA
| | - Simon Fischer
- Present address: Protrans medizinisch diagnostische Produkte GmbH, Ketschau 2, D-68766, Hockenheim, Germany
| | - Volker Knoop
- Abteilung Molekulare Evolution, IZMB - Institut für Zelluläre und Molekulare Botanik, Universität Bonn, Kirschallee 1, D-53115, Bonn, Germany.
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Nadimi M, Daubois L, Hijri M. Mitochondrial comparative genomics and phylogenetic signal assessment of mtDNA among arbuscular mycorrhizal fungi. Mol Phylogenet Evol 2016; 98:74-83. [DOI: 10.1016/j.ympev.2016.01.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 12/16/2015] [Accepted: 01/14/2016] [Indexed: 11/29/2022]
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Kamikawa R, Shiratori T, Ishida KI, Miyashita H, Roger AJ. Group II Intron-Mediated Trans-Splicing in the Gene-Rich Mitochondrial Genome of an Enigmatic Eukaryote, Diphylleia rotans. Genome Biol Evol 2016; 8:458-66. [PMID: 26833505 PMCID: PMC4779616 DOI: 10.1093/gbe/evw011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Although mitochondria have evolved from a single endosymbiotic event, present day mitochondria of diverse eukaryotes display a great range of genome structures, content and features. Group I and group II introns are two features that are distributed broadly but patchily in mitochondrial genomes across branches of the tree of eukaryotes. While group I intron-mediated trans-splicing has been reported from some lineages distantly related to each other, findings of group II intron-mediated trans-splicing has been restricted to members of the Chloroplastida. In this study, we found the mitochondrial genome of the unicellular eukaryote Diphylleia rotans possesses currently the second largest gene repertoire. On the basis of a probable phylogenetic position of Diphylleia, which is located within Amorphea, current mosaic gene distribution in Amorphea must invoke parallel gene losses from mitochondrial genomes during evolution. Most notably, although the cytochrome c oxidase subunit (cox) 1 gene was split into four pieces which located at a distance to each other, we confirmed that a single mature mRNA that covered the entire coding region could be generated by group II intron-mediated trans-splicing. This is the first example of group II intron-mediated trans-splicing outside Chloroplastida. Similar trans-splicing mechanisms likely work for bipartitely split cox2 and nad3 genes to generate single mature mRNAs. We finally discuss origin and evolution of this type of trans-splicing in D. rotans as well as in eukaryotes.
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Affiliation(s)
- Ryoma Kamikawa
- Graduate School of Human and Environmental Studies, Kyoto University, Japan Graduate School of Global Environmental Studies, Kyoto University, Japan
| | - Takashi Shiratori
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
| | - Ken-Ichiro Ishida
- Faculty of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
| | - Hideaki Miyashita
- Graduate School of Human and Environmental Studies, Kyoto University, Japan Graduate School of Global Environmental Studies, Kyoto University, Japan
| | - Andrew J Roger
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada Program in Integrated Microbial Biodiversity, Canadian Institute for Advanced Research, Halifax, Nova Scotia, Canada
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