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Shan Y, Li J, Duan X, Zhang X, Yu J. Elucidating the multichromosomal structure within the Brasenia schreberi mitochondrial genome through assembly and analysis. BMC Genomics 2024; 25:422. [PMID: 38684976 PMCID: PMC11059650 DOI: 10.1186/s12864-024-10331-0] [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: 12/19/2023] [Accepted: 04/22/2024] [Indexed: 05/02/2024] Open
Abstract
Brasenia schreberi, a plant species traditionally utilized in Chinese medicine and cuisine, represents an early evolutionary stage among flowering plants (angiosperms). While the plastid genome of this species has been published, its mitochondrial genome (mitogenome) has not been extensively explored, with a notable absence of thorough comparative analyses of its organellar genomes. In our study, we had assembled the entire mitogenome of B. schreberi utilizing the sequencing data derived from both Illumina platform and Oxford Nanopore. The B. schreberi mitogenome mostly exists as six circular DNA molecules, with the largest being 628,257 base pairs (bp) and the smallest 110,220 bp, amounting to 1.49 megabases (Mb). Then we annotated the mitogenome of B. schreberi. The mitogenome encompasses a total of 71 genes: 40 of these are coding proteins genes (PCGs), 28 are genes for transfer RNA (tRNA), and the remaining 3 are genes for ribosomal RNA (rRNA). In the analysis of codon usage, we noted a unique codon preference specific to each amino acid. The most commonly used codons exhibited an average RSCU of 1.36, indicating a noticeable bias in codon selection. In the repeat sequence analysis, a total of 553 simple sequence repeats (SSRs) were identified, 1,822 dispersed repeats (comprising 1,015 forward and 807 palindromic repeats), and 608 long terminal repeats (LTRs). Additionally, in the analysis of homologous sequences between organelle genomes, we detected 38 homologous sequences derived from the plastid genome, each exceeding 500 bp, within the B. schreberi mitochondrial genome. Notably, ten tRNA genes (trnC-GCA, trnM-CAU, trnI-CAU, trnQ-UUG, trnN-GUU, trnT-GGU, trnW-CCA, trnA-UGC, trnI-GAU, and trnV-GAC) appear to have been completely transferred from the chloroplast to the mitogenome. Utilizing the Deepred-mt to predict the RNA editing sites in the mitogenome, we have identified 675 high-quality RNA editing sites in the 40 mitochondrial PCGs. In the final stage of our study, we performed an analysis of colinearity and inferred the phylogenetic relationship of B. schreberi with other angiosperms, utilizing the mitochondrial PCGs as a basis. The results showed that the non-coding regions of the B. schreberi mitogenome are characterized by an abundance of repetitive sequences and exogenous sequences, and B. schreberi is more closely related with Euryale ferox.
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Affiliation(s)
- Yuanyu Shan
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Jingling Li
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Xinmei Duan
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Xue Zhang
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Jie Yu
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China.
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Southwest University, Chongqing, 400715, China.
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Chen L, Dong X, Huang H, Xu H, Rono PC, Cai X, Hu G. Assembly and comparative analysis of the initial complete mitochondrial genome of Primulina hunanensis (Gesneriaceae): a cave-dwelling endangered plant. BMC Genomics 2024; 25:322. [PMID: 38561677 PMCID: PMC10983754 DOI: 10.1186/s12864-024-10247-9] [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: 12/30/2023] [Accepted: 03/22/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Primulina hunanensis, a troglobitic plant within the Primulina genus of Gesneriaceae family, exhibits robust resilience to arid conditions and holds great horticultural potential as an ornamental plant. The work of chloroplast genome (cpDNA) has been recently accomplished, however, the mitochondrial genome (mtDNA) that is crucial for plant evolution has not been reported. RESULTS In this study, we sequenced and assembled the P. hunanensis complete mtDNA, and elucidated its evolutionary and phylogenetic relationships. The assembled mtDNA spans 575,242 bp with 43.54% GC content, encompassing 60 genes, including 37 protein-coding genes (PCGs), 20 tRNA genes, and 3 rRNA genes. Notably, high number of repetitive sequences in the mtDNA and substantial sequence translocation from chloroplasts to mitochondria were observed. To determine the evolutionary and taxonomic positioning of P. hunanensis, a phylogenetic tree was constructed using mitochondrial PCGs from P. hunanensis and 32 other taxa. Furthermore, an exploration of PCGs relative synonymous codon usage, identification of RNA editing events, and an investigation of collinearity with closely related species were conducted. CONCLUSIONS This study reports the initial assembly and annotation of P. hunanensis mtDNA, contributing to the limited mtDNA repository for Gesneriaceae plants and advancing our understanding of their evolution for improved utilization and conservation.
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Affiliation(s)
- Lingling Chen
- Department of Botany, College of Life Sciences, Hunan Normal University, Changsha, 410081, China
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Xiang Dong
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hang Huang
- Department of Botany, College of Life Sciences, Hunan Normal University, Changsha, 410081, China
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Haixia Xu
- Department of Botany, College of Life Sciences, Hunan Normal University, Changsha, 410081, China
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Peninah Cheptoo Rono
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Xiuzhen Cai
- Department of Botany, College of Life Sciences, Hunan Normal University, Changsha, 410081, China.
| | - Guangwan Hu
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China.
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Hubei Jiangxia Laboratory, Wuhan, 430200, China.
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Sanchez-Puerta MV, Ceriotti LF, Gatica-Soria LM, Roulet ME, Garcia LE, Sato HA. Invited Review Beyond parasitic convergence: unravelling the evolution of the organellar genomes in holoparasites. ANNALS OF BOTANY 2023; 132:909-928. [PMID: 37503831 PMCID: PMC10808021 DOI: 10.1093/aob/mcad108] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/27/2023] [Indexed: 07/29/2023]
Abstract
BACKGROUND The molecular evolution of organellar genomes in angiosperms has been studied extensively, with some lineages, such as parasitic ones, displaying unique characteristics. Parasitism has emerged 12 times independently in angiosperm evolution. Holoparasitism is the most severe form of parasitism, and is found in ~10 % of parasitic angiosperms. Although a few holoparasitic species have been examined at the molecular level, most reports involve plastomes instead of mitogenomes. Parasitic plants establish vascular connections with their hosts through haustoria to obtain water and nutrients, which facilitates the exchange of genetic information, making them more susceptible to horizontal gene transfer (HGT). HGT is more prevalent in the mitochondria than in the chloroplast or nuclear compartments. SCOPE This review summarizes current knowledge on the plastid and mitochondrial genomes of holoparasitic angiosperms, compares the genomic features across the different lineages, and discusses their convergent evolutionary trajectories and distinctive features. We focused on Balanophoraceae (Santalales), which exhibits extraordinary traits in both their organelles. CONCLUSIONS Apart from morphological similarities, plastid genomes of holoparasitic plants also display other convergent features, such as rampant gene loss, biased nucleotide composition and accelerated evolutionary rates. In addition, the plastomes of Balanophoraceae have extremely low GC and gene content, and two unexpected changes in the genetic code. Limited data on the mitochondrial genomes of holoparasitic plants preclude thorough comparisons. Nonetheless, no obvious genomic features distinguish them from the mitochondria of free-living angiosperms, except for a higher incidence of HGT. HGT appears to be predominant in holoparasitic angiosperms with a long-lasting endophytic stage. Among the Balanophoraceae, mitochondrial genomes exhibit disparate evolutionary paths with notable levels of heteroplasmy in Rhopalocnemis and unprecedented levels of HGT in Lophophytum. Despite their differences, these Balanophoraceae share a multichromosomal mitogenome, a feature also found in a few free-living angiosperms.
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Affiliation(s)
- M Virginia Sanchez-Puerta
- IBAM, Universidad Nacional de Cuyo, CONICET, Facultad de Ciencias Agrarias, Almirante Brown 500, Chacras de Coria, M5528AHB, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Padre Jorge Contreras 1300, Universidad Nacional de Cuyo, M5502JMA, Mendoza, Argentina
| | - Luis F Ceriotti
- IBAM, Universidad Nacional de Cuyo, CONICET, Facultad de Ciencias Agrarias, Almirante Brown 500, Chacras de Coria, M5528AHB, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Padre Jorge Contreras 1300, Universidad Nacional de Cuyo, M5502JMA, Mendoza, Argentina
| | - Leonardo M Gatica-Soria
- IBAM, Universidad Nacional de Cuyo, CONICET, Facultad de Ciencias Agrarias, Almirante Brown 500, Chacras de Coria, M5528AHB, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Padre Jorge Contreras 1300, Universidad Nacional de Cuyo, M5502JMA, Mendoza, Argentina
| | - M Emilia Roulet
- IBAM, Universidad Nacional de Cuyo, CONICET, Facultad de Ciencias Agrarias, Almirante Brown 500, Chacras de Coria, M5528AHB, Mendoza, Argentina
| | - Laura E Garcia
- IBAM, Universidad Nacional de Cuyo, CONICET, Facultad de Ciencias Agrarias, Almirante Brown 500, Chacras de Coria, M5528AHB, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Padre Jorge Contreras 1300, Universidad Nacional de Cuyo, M5502JMA, Mendoza, Argentina
| | - Hector A Sato
- Facultad de Ciencias Agrarias, Cátedra de Botánica General–Herbario JUA, Alberdi 47, Universidad Nacional de Jujuy, 4600 Jujuy, Argentina
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Zhang J, Zhang C, Zan T, Nan P, Li L, Song Z, Zhang W, Yang J, Wang Y. Host shift promotes divergent evolution between closely related holoparasitic species. Mol Phylogenet Evol 2023:107842. [PMID: 37321361 DOI: 10.1016/j.ympev.2023.107842] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/27/2023] [Accepted: 06/02/2023] [Indexed: 06/17/2023]
Abstract
Distinct hosts have been hypothesized to possess the potential for affecting species differentiation and genome evolution of parasitic organisms. However, what host shift history is experienced by the closely related parasites and whether disparate evolution of their genomes occur remain largely unknown. Here, we screened horizontal gene transfer (HGT) events in a pair of sister species of holoparasitic Boschniakia (Orobanchaceae) having obligate hosts from distinct families to recall the former host-parasite associations and performed a comparative analysis to investigate the difference of their organelle genomes. Except those from the current hosts (Ericaceae and Betulaceae), we identified a number of HGTs from Rosaceae supporting the occurrence of unexpected ancient host shifts. Different hosts transfer functional genes which changed nuclear genomes of this sister species. Likewise, different donors transferred sequences to their mitogenomes, which vary in size due to foreign and repetitive elements rather than other factors found in other parasites. The plastomes are both severely reduced, and the degree of difference in reduction syndrome reaches the intergeneric level. Our findings provide new insights into the genome evolution of parasites adapting to different hosts and extend the mechanism of host shift promoting species differentiation to parasitic plant lineages.
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Affiliation(s)
- Jiayin Zhang
- Ecological Engineering and State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai 200438, China.
| | - Chi Zhang
- Ecological Engineering and State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai 200438, China.
| | - Ting Zan
- Ecological Engineering and State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai 200438, China.
| | - Peng Nan
- Ecological Engineering and State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai 200438, China.
| | - Linfeng Li
- Ecological Engineering and State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai 200438, China.
| | - Zhiping Song
- Ecological Engineering and State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai 200438, China.
| | - Wenju Zhang
- Ecological Engineering and State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai 200438, China.
| | - Ji Yang
- Ecological Engineering and State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai 200438, China.
| | - Yuguo Wang
- Ecological Engineering and State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, School of Life Sciences, Fudan University, Shanghai 200438, China.
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Cao P, Huang Y, Zong M, Xu Z. De Novo Assembly and Comparative Analysis of the Complete Mitochondrial Genome of Chaenomeles speciosa (Sweet) Nakai Revealed the Existence of Two Structural Isomers. Genes (Basel) 2023; 14:526. [PMID: 36833452 PMCID: PMC9957484 DOI: 10.3390/genes14020526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 02/01/2023] [Accepted: 02/17/2023] [Indexed: 02/22/2023] Open
Abstract
As a valuable Chinese traditional medicinal species, Chaenomeles speciosa (Sweet) Nakai (C. speciosa) is a natural resource with significant economic and ornamental value. However, its genetic information is not well understood. In this study, the complete mitochondrial genome of C. speciosa was assembled and characterized to explore the repeat sequences, recombination events, rearrangements, and IGT, to predict RNA editing sites, and to clarify the phylogenetic and evolutionary relationship. The C. speciosa mitochondrial genome was found to have two circular chromosomes as its major conformation, with a total length of 436,464 bp and 45.2% GC content. The mitochondrial genome contained 54 genes, including 33 unique protein-coding genes, 18 tRNAs, and 3 rRNA genes. Seven pairs of repeat sequences involving recombination events were analyzed. Both the repeat pairs, R1 and R2, played significant roles in mediating the major and minor conformations. In total, 18 MTPTs were identified, 6 of which were complete tRNA genes. There were 454 RNA editing sites in the 33 protein-coding sequences predicted by the PREPACT3 program. A phylogenetic analysis based on 22 species of mitochondrial genomes was constructed and indicated highly conserved PCG sequences. Synteny analyses showed extensive genomic rearrangements in the mitochondrial genome of C. speciosa and closely related species. This work is the first to report the C. speciosa mitochondrial genome, which is of great significance for conducting additional genetic studies on this organism.
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Affiliation(s)
- Pei Cao
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Yuan Huang
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Mei Zong
- College of Life Sciences, Anqing Normal University, Anqing 246133, China
| | - Zilong Xu
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
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Zhong Y, Yu R, Chen J, Liu Y, Zhou R. Highly active repeat-mediated recombination in the mitogenome of the holoparasitic plant Aeginetia indica. FRONTIERS IN PLANT SCIENCE 2022; 13:988368. [PMID: 36212306 PMCID: PMC9532969 DOI: 10.3389/fpls.2022.988368] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 09/07/2022] [Indexed: 06/16/2023]
Abstract
Mitogenomes of most flowering plants evolve slowly in sequence, but rapidly in structure. The rearrangements in structure are mainly caused by repeat-mediated recombination. However, patterns of repeat-mediated recombination vary substantially among plants, and to provide a comprehensive picture, characterization of repeat-mediated recombination should extend to more plant species, including parasitic plants with a distinct heterotrophic lifestyle. Here we assembled the mitogenome of the holoparasitic plant Aeginetia indica (Orobanchaceae) using Illumina sequencing reads. The mitogenome was assembled into a circular chromosome of 420,362 bp, 18,734 bp longer than that of another individual of A. indica which was assembled before as a linear molecule. Synteny analysis between the two mitogenomes revealed numerous rearrangements, unique regions of each individual and 0.2% sequence divergence in their syntenic regions. The A. indica mitogenome contains a gene content typical of flowering plants (33 protein-coding, 3 rRNA, and 17 tRNA genes). Repetitive sequences >30 bp in size totals 57,060 bp, representing 13.6% of the mitogenome. We examined recombination mediated by repeats >100 bp in size and found highly active recombination for all the repeats, including a very large repeat of ~16 kb. Recombination between these repeats can form much smaller subgenomic circular chromosomes, which may lead to rapid replication of mitochondrial DNA and thus be advantageous for A. indica with a parasitic lifestyle. In addition, unlike some other parasitic plants, A. indica shows no evidence for horizontal gene transfer of protein-coding genes in its mitogenome.
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Affiliation(s)
- Yan Zhong
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Runxian Yu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, The Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jingfang Chen
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Ying Liu
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Renchao Zhou
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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Li J, Li J, Ma Y, Kou L, Wei J, Wang W. The complete mitochondrial genome of okra (Abelmoschus esculentus): using nanopore long reads to investigate gene transfer from chloroplast genomes and rearrangements of mitochondrial DNA molecules. BMC Genomics 2022; 23:481. [PMID: 35768783 PMCID: PMC9245263 DOI: 10.1186/s12864-022-08706-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/13/2022] [Indexed: 12/12/2022] Open
Abstract
Background Okra (Abelmoschus esculentus L. Moench) is an economically important crop and is known for its slimy juice, which has significant scientific research value. The A. esculentus chloroplast genome has been reported; however, the sequence of its mitochondrial genome is still lacking. Results We sequenced the plastid and mitochondrial genomes of okra based on Illumina short reads and Nanopore long reads and conducted a comparative study between the two organelle genomes. The plastid genome of okra is highly structurally conserved, but the mitochondrial genome of okra has been confirmed to have abundant subgenomic configurations. The assembly results showed that okra’s mitochondrial genome existed mainly in the form of two independent molecules, which could be divided into four independent molecules through two pairs of long repeats. In addition, we found that four pairs of short repeats could mediate the integration of the two independent molecules into one complete molecule at a low frequency. Subsequently, we also found extensive sequence transfer between the two organelles of okra, where three plastid-derived genes (psaA, rps7 and psbJ) remained intact in the mitochondrial genome. Furthermore, psbJ, psbF, psbE and psbL were integrated into the mitochondrial genome as a conserved gene cluster and underwent pseudogenization as nonfunctional genes. Only psbJ retained a relatively complete sequence, but its expression was not detected in the transcriptome data, and we speculate that it is still nonfunctional. Finally, we characterized the RNA editing events of protein-coding genes located in the organelle genomes of okra. Conclusions In the current study, our results not only provide high-quality organelle genomes for okra but also advance our understanding of the gene dialogue between organelle genomes and provide information to breed okra cultivars efficiently. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08706-2.
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Affiliation(s)
- Jihan Li
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Jingling Li
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Yubo Ma
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Lu Kou
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China
| | - Juanjuan Wei
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China.,Key Laboratory of Horticulture Science for Southern Mountainous Regions from Ministry of Education, No.2 Tiansheng Road, Beibei District, Chongqing, 400716, China
| | - Weixing Wang
- College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China. .,Key Laboratory of Horticulture Science for Southern Mountainous Regions from Ministry of Education, No.2 Tiansheng Road, Beibei District, Chongqing, 400716, China.
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8
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Lin Q, Banerjee A, Stefanović S. Mitochondrial phylogenomics of Cuscuta (Convolvulaceae) reveals a potentially functional horizontal gene transfer from the host. Genome Biol Evol 2022; 14:evac091. [PMID: 35700229 PMCID: PMC9234195 DOI: 10.1093/gbe/evac091] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 06/06/2022] [Accepted: 06/09/2022] [Indexed: 11/14/2022] Open
Abstract
Horizontal gene transfers (HGTs) from host or other organisms have been reported in mitochondrial genomes of parasitic plants. Genes transferred in this fashion have usually been found non-functional. Several examples of HGT from the mitochondrial genome of parasitic Cuscuta (Convolvulaceae) to its hosts have been reported, but not vice versa. Here we used 31 protein-coding mitochondrial genes to infer the phylogeny of Cuscuta, and compared it with previous nuclear and plastid phylogenetic estimates. We also investigated the presence of HGTs within these lineages. Unlike in plastid genomes, we did not find extensive gene loss in their mitochondrial counterparts. Our results reveal the first example of organellar HGT from host to Cuscuta. Mitochondrial atp1 genes of South African subgenus Pachystigma were inferred to be transferred from Lamiales, with high support. Moreover, the horizontally transferred atp1 gene has functionally replaced the native, vertically transmitted copy, has an intact open reading frame, and is under strong purifying selection, all of which suggests that this xenolog remains functional. The mitochondrial phylogeny of Cuscuta is generally consistent with previous plastid and nuclear phylogenies, except for the misplacement of Pachystigma when atp1 is included. This incongruence may be caused by the HGT mentioned above. No example of HGT was found within mitochondrial genes of three other, independently evolved parasitic lineages we sampled: Cassytha/Laurales, Krameria/Zygophyllales, and Lennooideae/Boraginales.
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Affiliation(s)
- Qianshi Lin
- Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
- Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 2Z9, Canada
| | - Arjan Banerjee
- Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
- Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 2Z9, Canada
| | - Saša Stefanović
- Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
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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: 11] [Impact Index Per Article: 5.5] [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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The minicircular and extremely heteroplasmic mitogenome of the holoparasitic plant Rhopalocnemis phalloides. Curr Biol 2021; 32:470-479.e5. [PMID: 34906352 DOI: 10.1016/j.cub.2021.11.053] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/25/2021] [Accepted: 11/22/2021] [Indexed: 12/14/2022]
Abstract
The plastid and nuclear genomes of parasitic plants exhibit deeply altered architectures,1-13 whereas the few examined mitogenomes range from deeply altered to conventional.14-20 To provide further insight on mitogenome evolution in parasitic plants, we report the highly modified mitogenome of Rhopalocnemis phalloides, a holoparasite in Balanophoraceae. Its mitogenome is uniquely arranged in 21 minicircular chromosomes that vary in size from 4,949 to 7,861 bp, with a total length of only 130,713 bp. All chromosomes share an identical 896 bp conserved region, with a large stem-loop that acts as the origin of replication, flanked on each side by hypervariable and semi-conserved regions. Similar minicircular structures with shared and unique regions have been observed in parasitic animals and free-living protists,21-24 suggesting convergent structural evolution. Southern blots confirm both the minicircular structure and the replication origin of the mitochondrial chromosomes. PacBio reads provide evidence for chromosome recombination and rolling-circle replication for the R. phalloides mitogenome. Despite its small size, the mitogenome harbors a typical set of genes and introns within the unique regions of each chromosome, yet introns are the smallest among seed plants and ferns. The mitogenome also exhibits extreme heteroplasmy, predominantly involving short indels and more complex variants, many of which cause potential loss-of-function mutations for some gene copies. All heteroplasmic variants are transcribed, and functional and nonfunctional protein-coding variants are spliced and RNA edited. Our findings offer a unique perspective into how mitogenomes of parasitic plants can be deeply altered and shed light on plant mitogenome replication.
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