1
|
Paukszto Ł, Górski P, Krawczyk K, Maździarz M, Szczecińska M, Ślipiko M, Sawicki J. The organellar genomes of Pellidae (Marchantiophyta): the evidence of cryptic speciation, conflicting phylogenies and extraordinary reduction of mitogenomes in simple thalloid liverwort lineage. Sci Rep 2023; 13:8303. [PMID: 37221210 DOI: 10.1038/s41598-023-35269-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 05/15/2023] [Indexed: 05/25/2023] Open
Abstract
Organellar genomes of liverworts are considered as one of the most stable among plants, with rare events of gene loss and structural rearrangements. However, not all lineages of liverworts are equally explored in the field of organellar genomics, and subclass Pellidae is one of the less known. Hybrid assembly, using both short- and long-read technologies enabled the assembly of repeat-rich mitogenomes of Pellia and Apopellia revealing extraordinary reduction of length in the latter which impacts only intergenic spacers. The mitogenomes of Apopellia were revealed to be the smallest among all known liverworts-109 k bp, despite retaining all introns. The study also showed the loss of one tRNA gene in Apopellia mitogenome, although it had no impact on the codon usage pattern of mitochondrial protein coding genes. Moreover, it was revealed that Apopellia and Pellia differ in codon usage by plastome CDSs, despite identical tRNA gene content. Molecular identification of species is especially important where traditional taxonomic methods fail, especially within Pellidae where cryptic speciation is well recognized. The simple morphology of these species and a tendency towards environmental plasticity make them complicated in identification. Application of super-barcodes, based on complete mitochondrial or plastid genomes sequences enable identification of all cryptic lineages within Apopellia and Pellia genera, however in some particular cases, mitogenomes were more efficient in species delimitation than plastomes.
Collapse
Affiliation(s)
- Łukasz Paukszto
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Plac Łódzki 1, 10-727, Olsztyn, Poland.
| | - Piotr Górski
- Department of Botany, Poznań University of Life Sciences, ul. Wojska Polskiego 71C, 60-625, Poznań, Poland
| | - Katarzyna Krawczyk
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Plac Łódzki 1, 10-727, Olsztyn, Poland
| | - Mateusz Maździarz
- 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
| | - 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
| |
Collapse
|
2
|
Super-Mitobarcoding in Plant Species Identification? It Can Work! The Case of Leafy Liverworts Belonging to the Genus Calypogeia. Int J Mol Sci 2022; 23:ijms232415570. [PMID: 36555212 PMCID: PMC9779425 DOI: 10.3390/ijms232415570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/04/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022] Open
Abstract
Molecular identification of species is especially important where traditional taxonomic methods fail. The genus Calypogeia belongs to one of the tricky taxons. The simple morphology of these species and a tendency towards environmental plasticity make them complicated in identification. The finding of the universal single-locus DNA barcode in plants seems to be 'the Holy Grail'; therefore, researchers are increasingly looking for multiloci DNA barcodes or super-barcoding. Since the mitochondrial genome has low sequence variation in plants, species delimitation is usually based on the chloroplast genome. Unexpectedly, our research shows that super-mitobarcoding can also work! However, our outcomes showed that a single method of molecular species delimitation should be avoided. Moreover, it is recommended to interpret the results of molecular species delimitation alongside other types of evidence, such as ecology, population genetics or comparative morphology. Here, we also presented genetic data supporting the view that C. suecica is not a homogeneous species.
Collapse
|
3
|
Choi SS, Bakalin VA, Kwon W, Park J. The complete mitochondrial genome of Douinia plicata (Lindb.) Konstant. et. Vilnet (Scapaniaceae, Jungermanniales). Mitochondrial DNA B Resour 2021; 6:789-791. [PMID: 33763579 PMCID: PMC7954511 DOI: 10.1080/23802359.2021.1882901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 01/24/2021] [Indexed: 12/20/2022] Open
Abstract
Douinia plicata (Lindb.) Konstant. & Vilnet is the endemic species in Northeast Asia. Here, we reported complete mitochondrial genome of D. plicata. It is 144,206 bp long and includes 72 genes (42 protein-coding genes, three rRNAs, and 27 tRNAs). The overall GC content is 45.1%. Intergeneic variations against S. amplicata, which is slightly higher than intraspecific variations of S. ampliata and W. denudata. Phylogenetic trees show D. plicatum is clustered with three Scapania mitochondrial genomes with high supportive values, which is congruent with previous studies.
Collapse
Affiliation(s)
- Seung Se Choi
- Team of National Ecosystem Survey, National Institute of Ecology, Seocheon, Republic of Korea
| | - Vadim A. Bakalin
- Laboratory of Cryptogamic Biota, Botanical Garden-Institute FEB RAS, Vladivostok, Russia
| | - Woochan Kwon
- InfoBoss Inc., Seoul, Republic of Korea
- InfoBoss Research Center, Seoul, Republic of Korea
| | - Jongsun Park
- InfoBoss Inc., Seoul, Republic of Korea
- InfoBoss Research Center, Seoul, Republic of Korea
| |
Collapse
|
4
|
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: 61] [Impact Index Per Article: 15.3] [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.
Collapse
Affiliation(s)
- Jeffrey P Mower
- Center for Plant Science Innovation and Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE.
| |
Collapse
|
5
|
Ślipiko M, Myszczyński K, Buczkowska K, Bączkiewicz A, Szczecińska M, Sawicki J. Molecular delimitation of European leafy liverworts of the genus Calypogeia based on plastid super-barcodes. BMC PLANT BIOLOGY 2020; 20:243. [PMID: 32466772 PMCID: PMC7257191 DOI: 10.1186/s12870-020-02435-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 05/10/2020] [Indexed: 05/20/2023]
Abstract
BACKGROUND Molecular research revealed that some of the European Calypogeia species described on the basis of morphological criteria are genetically heterogeneous and, in fact, are species complexes. DNA barcoding is already commonly used for correct identification of difficult to determine species, to disclose cryptic species, or detecting new taxa. Among liverworts, some DNA fragments, recommend as universal plant DNA barcodes, cause problems in amplification. Super-barcoding based on genomic data, makes new opportunities in a species identification. RESULTS On the basis of 22 individuals, representing 10 Calypogeia species, plastid genome was tested as a super-barcode. It is not effective in 100%, nonetheless its success of species discrimination (95.45%) is still conspicuous. It is not excluded that the above outcome may have been upset by cryptic speciation in C. suecica, as our results indicate. Having the sequences of entire plastomes of European Calypogeia species, we also discovered that the ndhB and ndhH genes and the trnT-trnL spacer identify species in 100%. CONCLUSIONS This study shows that even if a super-barcoding is not effective in 100%, this method does not close the door to a traditional single- or multi-locus barcoding. Moreover, it avoids many complication resulting from the need to amplify selected DNA fragments. It seems that a good solution for species discrimination is a development of so-called "specific barcodes" for a given taxonomic group, based on plastome data.
Collapse
Affiliation(s)
- Monika Ślipiko
- Department of Botany and Nature Protection, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland.
| | - Kamil Myszczyński
- Department of Botany and Nature Protection, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Katarzyna Buczkowska
- Department of Biology, Institute of Experimental Biology, Adam Mickiewicz University in Poznań, Poznań, Poland
| | - Alina Bączkiewicz
- Department of Biology, Institute of Experimental Biology, Adam Mickiewicz University in Poznań, Poznań, Poland
| | - Monika Szczecińska
- Department of Botany and Nature Protection, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Jakub Sawicki
- Department of Botany and Nature Protection, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| |
Collapse
|
6
|
Kan SL, Shen TT, Gong P, Ran JH, Wang XQ. The complete mitochondrial genome of Taxus cuspidata (Taxaceae): eight protein-coding genes have transferred to the nuclear genome. BMC Evol Biol 2020; 20:10. [PMID: 31959109 PMCID: PMC6971862 DOI: 10.1186/s12862-020-1582-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 01/13/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Gymnosperms represent five of the six lineages of seed plants. However, most sequenced plant mitochondrial genomes (mitogenomes) have been generated for angiosperms, whereas mitogenomic sequences have been generated for only six gymnosperms. In particular, complete mitogenomes are available for all major seed plant lineages except Conifer II (non-Pinaceae conifers or Cupressophyta), an important lineage including six families, which impedes a comprehensive understanding of the mitogenomic diversity and evolution in gymnosperms. RESULTS Here, we report the complete mitogenome of Taxus cuspidata in Conifer II. In comparison with previously released gymnosperm mitogenomes, we found that the mitogenomes of Taxus and Welwitschia have lost many genes individually, whereas all genes were identified in the mitogenomes of Cycas, Ginkgo and Pinaceae. Multiple tRNA genes and introns also have been lost in some lineages of gymnosperms, similar to the pattern observed in angiosperms. In general, gene clusters could be less conserved in gymnosperms than in angiosperms. Moreover, fewer RNA editing sites were identified in the Taxus and Welwitschia mitogenomes than in other mitogenomes, which could be correlated with fewer introns and frequent gene losses in these two species. CONCLUSIONS We have sequenced the Taxus cuspidata mitogenome, and compared it with mitogenomes from the other four gymnosperm lineages. The results revealed the diversity in size, structure, gene and intron contents, foreign sequences, and mutation rates of gymnosperm mitogenomes, which are different from angiosperm mitogenomes.
Collapse
Affiliation(s)
- Sheng-Long Kan
- 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
| | - Ting-Ting Shen
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Ping Gong
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Jin-Hua Ran
- 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.
| | - Xiao-Quan Wang
- 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
| |
Collapse
|
7
|
Dong S, Zhao C, Zhang S, Zhang L, Wu H, Liu H, Zhu R, Jia Y, Goffinet B, Liu Y. Mitochondrial genomes of the early land plant lineage liverworts (Marchantiophyta): conserved genome structure, and ongoing low frequency recombination. BMC Genomics 2019; 20:953. [PMID: 31818248 PMCID: PMC6902596 DOI: 10.1186/s12864-019-6365-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 12/02/2019] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND In contrast to the highly labile mitochondrial (mt) genomes of vascular plants, the architecture and composition of mt genomes within the main lineages of bryophytes appear stable and invariant. The available mt genomes of 18 liverwort accessions representing nine genera and five orders are syntenous except for Gymnomitrion concinnatum whose genome is characterized by two rearrangements. Here, we expanded the number of assembled liverwort mt genomes to 47, broadening the sampling to 31 genera and 10 orders spanning much of the phylogenetic breadth of liverworts to further test whether the evolution of the liverwort mitogenome is overall static. RESULTS Liverwort mt genomes range in size from 147 Kb in Jungermanniales (clade B) to 185 Kb in Marchantiopsida, mainly due to the size variation of intergenic spacers and number of introns. All newly assembled liverwort mt genomes hold a conserved set of genes, but vary considerably in their intron content. The loss of introns in liverwort mt genomes might be explained by localized retroprocessing events. Liverwort mt genomes are strictly syntenous in genome structure with no structural variant detected in our newly assembled mt genomes. However, by screening the paired-end reads, we do find rare cases of recombination, which means multiple concurrent genome structures may exist in the vegetative tissues of liverworts. Our phylogenetic analyses of the nuclear encoded double stand break repair protein families revealed liverwort-specific subfamilies expansions. CONCLUSIONS The low repeat recombination level, selection, along with the intensified nuclear surveillance, might together shape the structural evolution of liverwort mt genomes.
Collapse
Affiliation(s)
- Shanshan Dong
- Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen & Chinese Academy of Sciences, Shenzhen, 518004 China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642 China
| | - Chaoxian Zhao
- Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen & Chinese Academy of Sciences, Shenzhen, 518004 China
- Department of Biology, School of Life Sciences, East China Normal University, Shanghai, 200241 China
| | - Shouzhou Zhang
- Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen & Chinese Academy of Sciences, Shenzhen, 518004 China
| | - Li Zhang
- Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen & Chinese Academy of Sciences, Shenzhen, 518004 China
| | - Hong Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642 China
| | - Huan Liu
- BGI-Shenzhen, Shenzhen, 518083 China
| | - Ruiliang Zhu
- Department of Biology, School of Life Sciences, East China Normal University, Shanghai, 200241 China
| | - Yu Jia
- State Key Laboratory of Systematic and Evolutionary Botany, Chinese Academy of Sciences, Institute of Botany, Beijing, 100093 China
| | - Bernard Goffinet
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269-3043 USA
| | - Yang Liu
- Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen & Chinese Academy of Sciences, Shenzhen, 518004 China
- BGI-Shenzhen, Shenzhen, 518083 China
| |
Collapse
|
8
|
Myszczyński K, Ślipiko M, Sawicki J. Potential of Transcript Editing Across Mitogenomes of Early Land Plants Shows Novel and Familiar Trends. Int J Mol Sci 2019; 20:E2963. [PMID: 31216623 PMCID: PMC6627324 DOI: 10.3390/ijms20122963] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 06/15/2019] [Accepted: 06/17/2019] [Indexed: 01/04/2023] Open
Abstract
RNA editing alters the identity of nucleotides in an RNA sequence so that the mature transcript differs from the template defined in the genome. This process has been observed in chloroplasts and mitochondria of both seed and early land plants. However, the frequency of RNA editing in plant mitochondria ranges from zero to thousands of editing sites. To date, analyses of RNA editing in mitochondria of early land plants have been conducted on a small number of genes or mitochondrial genomes of a single species. This study provides an overview of the mitogenomic RNA editing potential of the main lineages of these two groups of early land plants by predicting the RNA editing sites of 33 mitochondrial genes of 37 species of liverworts and mosses. For the purpose of the research, we newly assembled seven mitochondrial genomes of liverworts. The total number of liverwort genera with known complete mitogenome sequences has doubled and, as a result, the available complete mitogenome sequences now span almost all orders of liverworts. The RNA editing site predictions revealed that C-to-U RNA editing in liverworts and mosses is group-specific. This is especially evident in the case of liverwort lineages. The average level of C-to-U RNA editing appears to be over three times higher in liverworts than in mosses, while the C-to-U editing frequency of the majority of genes seems to be consistent for each gene across bryophytes.
Collapse
Affiliation(s)
- Kamil Myszczyński
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Plac Łódzki 1, 10-727 Olsztyn, 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.
| |
Collapse
|
9
|
Myszczyński K, Górski P, Ślipiko M, Sawicki J. Sequencing of organellar genomes of Gymnomitrion concinnatum (Jungermanniales) revealed the first exception in the structure and gene order of evolutionary stable liverworts mitogenomes. BMC PLANT BIOLOGY 2018; 18:321. [PMID: 30509184 PMCID: PMC6276189 DOI: 10.1186/s12870-018-1558-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 11/22/2018] [Indexed: 05/29/2023]
Abstract
BACKGROUND Comparative analyses of chloroplast and mitochondrial genomes have shown that organelle genomes in bryophytes evolve slowly. However, in contrast to seed plants, the organellar genomes are yet poorly explored in bryophytes, especially among liverworts. Discovering another organellar genomes of liverwort species by sequencing provides new conclusions on evolution of bryophytes. RESULTS In this work, the organellar genomes of Gymnomitrion concinnatum liverwort were sequenced, assembled and annotated for the first time. The chloroplast genome displays, typical for most plants, quadripartite structure containing large single copy region (81,701 bp), two inverted repeat regions (8704 bp each) and small single copy region (20,179 bp). The gene order and content of chloroplast are very similar to other liverworts with minor differences observed. A total number of 739 and 222 RNA editing sites were predicted in chloroplast and mitochondrial genes of G. concinnatum. The mitochondrial genome gene content is also in accordance with liverworts except few alterations such as: intron loss in cox1 and atp1 genes. Nonetheless the analysis revealed that G. concinnatum mitogenome structure and gene order are rearranged in comparison with other mitogenomes of liverworts. The causes underlying such mitogenomic rearrangement were investigated and the probable model of recombination was proposed. CONCLUSIONS This study provide the overview of mitochondrial and chloroplast genome structure and gene order diversity of Gymnomitrion concinnatum against the background of known organellar genomes of liverworts. The obtained results cast doubt on the idea that mitogenome structure of early land plants is highly conserved as previous studies suggested. In fact is the very first case of recombination within, evolutionary stable, mitogenomes of liverworts.
Collapse
Affiliation(s)
- Kamil Myszczyński
- Department of Botany and Nature Protection, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Piotr Górski
- Department of Botany, Poznań University of Life Sciences, Poznań, Poland
| | - Monika Ślipiko
- Department of Botany and Nature Protection, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Jakub Sawicki
- Department of Botany and Nature Protection, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| |
Collapse
|
10
|
Reddemann A, Horn R. Recombination Events Involving the atp9 Gene Are Associated with Male Sterility of CMS PET2 in Sunflower. Int J Mol Sci 2018; 19:E806. [PMID: 29534485 PMCID: PMC5877667 DOI: 10.3390/ijms19030806] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/05/2018] [Accepted: 03/06/2018] [Indexed: 12/18/2022] Open
Abstract
Cytoplasmic male sterility (CMS) systems represent ideal mutants to study the role of mitochondria in pollen development. In sunflower, CMS PET2 also has the potential to become an alternative CMS source for commercial sunflower hybrid breeding. CMS PET2 originates from an interspecific cross of H. petiolaris and H. annuus as CMS PET1, but results in a different CMS mechanism. Southern analyses revealed differences for atp6, atp9 and cob between CMS PET2, CMS PET1 and the male-fertile line HA89. A second identical copy of atp6 was present on an additional CMS PET2-specific fragment. In addition, the atp9 gene was duplicated. However, this duplication was followed by an insertion of 271 bp of unknown origin in the 5' coding region of the atp9 gene in CMS PET2, which led to the creation of two unique open reading frames orf288 and orf231. The first 53 bp of orf288 are identical to the 5' end of atp9. Orf231 consists apart from the first 3 bp, being part of the 271-bp-insertion, of the last 228 bp of atp9. These CMS PET2-specific orfs are co-transcribed. All 11 editing sites of the atp9 gene present in orf231 are fully edited. The anther-specific reduction of the co-transcript in fertility-restored hybrids supports the involvement in male-sterility based on CMS PET2.
Collapse
Affiliation(s)
- Antje Reddemann
- Institut für Biowissenschaften, Abt. Pflanzengenetik, Universität Rostock, Albert-Einstein-Straße 3, D-18059 Rostock, Germany
| | - Renate Horn
- Institut für Biowissenschaften, Abt. Pflanzengenetik, Universität Rostock, Albert-Einstein-Straße 3, D-18059 Rostock, Germany.
| |
Collapse
|