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Tao L, Duan H, Tao K, Luo Y, Li Q, Li L. Complete chloroplast genome structural characterization of two Phalaenopsis (Orchidaceae) species and comparative analysis with their alliance. BMC Genomics 2023; 24:359. [PMID: 37369999 DOI: 10.1186/s12864-023-09448-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
BACKGROUND The taxonomy and infrageneric delimitation of Phalaenopsis Blume has been significantly disputed due to some overlapping morphological features between species related, which needed further evidence for clarification. The structural characterization of complete chloroplast genomes of P. storbatiana and P. wilsonii were analyzed and compared with those of related taxa to provide a better understanding of their genomic information on taxonomy and phylogeny. RESULTS It was shown that chloroplast genomes of Phalaenopsis storbatiana and P. wilsonii had a typical quadripartite structure with conserved genome arrangements and moderate divergence. The chloroplast genomes of P. storbatiana and P. wilsonii were 145,885 bp and 145,445 bp in length, respectively, and shared a similar GC content of 36.8%. Gene annotations of two species revealed 109 single-copy genes consistently. In addition, 20 genes duplicated in the inverted regions, 16 genes each possessed one or more introns, and five ndh (NA (D)H dehydrogenase) genes were observed in both. Comparative analysis of the total cp genomes of P. storbatiana and P. wilsonii with those of other six related Phalaenopsis species confirmed the stable sequence identity for coding and non-coding regions and higher sequence variation in SC regions than IR regions. Most of their protein-coding genes had a high degree of codon preference. Moreover, 45 genes were discovered with significantly positive selection. However, different amplifications in IR regions were observed in these eight species. Phylogenetic analysis based on CDS from 60 species representing main clades in Orchidaceae indicated that Phalaenopsis species including P. stobartiana and P. wilsonii formed a monophyletic clade with high bootstrap nested in tribe Vandeae of Epidendroideae, which was consistent with those from previous studies. CONCLUSIONS The results could provide insight into understanding the plastome evolution and phylogenetic relationships of Phalaenopsis.
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Affiliation(s)
- Lei Tao
- Department of Biological Conservation, Southwest Forestry University, Kunming, Yunnan, 650224, China
- Department of Life Science, Southwest Forestry University, Kunming, Yunnan, 650224, China
| | - Hanning Duan
- Department of Biological Conservation, Southwest Forestry University, Kunming, Yunnan, 650224, China
| | - Kaifeng Tao
- Department of Biological Conservation, Southwest Forestry University, Kunming, Yunnan, 650224, China
| | - Yan Luo
- Department of Horticulture and Gardening, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, 666303, China
| | - Qingqing Li
- Department of Life Science, Southwest Forestry University, Kunming, Yunnan, 650224, China
- Kunming Xianghao Technology Co. Ltd., Kunming, Yunnan, 650204, China
| | - Lu Li
- Department of Biological Conservation, Southwest Forestry University, Kunming, Yunnan, 650224, China.
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Li C, Cai C, Tao Y, Sun Z, Jiang M, Chen L, Li J. Variation and Evolution of the Whole Chloroplast Genomes of Fragaria spp. (Rosaceae). FRONTIERS IN PLANT SCIENCE 2021; 12:754209. [PMID: 34721483 PMCID: PMC8551639 DOI: 10.3389/fpls.2021.754209] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/21/2021] [Indexed: 06/02/2023]
Abstract
Species identification is vital for protecting species diversity and selecting high-quality germplasm resources. Wild Fragaria spp. comprise rich and excellent germplasm resources; however, the variation and evolution of the whole chloroplast (cp) genomes in the genus Fragaria have been ignored. In the present study, 27 complete chloroplast genomes of 11 wild Fragaria species were sequenced using the Illumina platform. Then, the variation among complete cp genomes of Fragaria was analyzed, and phylogenetic relationships were reconstructed from those genome sequences. There was an overall high similarity of sequences, with some divergence. According to analysis with mVISTA, non-coding regions were more variable than coding regions. Inverted repeats (IRs) were observed to contract or expand to different degrees, which resulted in different sizes of cp genomes. Additionally, five variable loci, trnS-trnG, trnR-atpA, trnC-petN, rbcL-accD, and psbE-petL, were identified that could be used to develop DNA barcoding for identification of Fragaria species. Phylogenetic analyses based on the whole cp genomes supported clustering all species into two groups (A and B). Group A species were mainly distributed in western China, while group B contained several species from Europe and Americas. These results support allopolyploid origins of the octoploid species F. chiloensis and F. virginiana and the tetraploid species F. moupinensis and F. tibetica. The complete cp genomes of these Fragaria spp. provide valuable information for selecting high-quality Fragaria germplasm resources in the future.
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Affiliation(s)
- Chenxin Li
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, China
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, China
| | - Chaonan Cai
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, China
- School of Advanced Study, Taizhou University, Taizhou, China
| | - Yutian Tao
- School of Advanced Study, Taizhou University, Taizhou, China
| | - Zhongshuai Sun
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, China
- School of Advanced Study, Taizhou University, Taizhou, China
| | - Ming Jiang
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, China
| | - Luxi Chen
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, China
| | - Junmin Li
- Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, China
- School of Advanced Study, Taizhou University, Taizhou, China
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Li M, Yang Y, Xu R, Mu W, Li Y, Mao X, Zheng Z, Bi H, Hao G, Li X, Xu X, Xi Z, Shrestha N, Liu J. A chromosome-level genome assembly for the tertiary relict plant Tetracentron sinense oliv. (trochodendraceae). Mol Ecol Resour 2021; 21:1186-1199. [PMID: 33486895 DOI: 10.1111/1755-0998.13334] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 12/01/2020] [Accepted: 01/18/2021] [Indexed: 12/13/2022]
Abstract
Tetracentron sinense and Trochodendron aralioides are two Tertiary relict species of large trees in the family Trochodendraceae with narrow distributions on the mainland and islands of eastern Asia. They belong to the order Trochodendrales, which is one of the four early-diverged eudicot lineages. These two relict species provide a good system in which to examine genomic changes that occurred as they survived during repeated climatic oscillations in the Quaternary. We sequenced the genome of Te. sinense and compared it with that of Tr. aralioides. We found that Te. sinense has a smaller genome size (986.3 Mb) than that of Tr. aralioides (1610 Mb). Repetitive elements made the major contribution to the contrasting genome sizes in the two species, with most bursts of repeats occurring within the past four million years when the climate oscillated greatly. These species share two rounds of whole-genome duplications. The mainland species Te. sinense had a larger effective population size than the island species Tr. aralioides after the largest glaciation during the Quaternary climatic oscillation. However, soon after this recovery stage, the effective population sizes of both species continued to decrease, although the current effective population size of Te. sinense is still larger than that of Tr. aralioides. We recovered three distinctly diverged clades through resequencing the genomes of 50 individuals across the distributional range of Te. sinense in China. Our results provide an important genomic resource with which to examine early trait evolution in the core eudicots and assist efforts to conserve this relict tree species.
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Affiliation(s)
- Minjie Li
- State Key Laboratory of Grassland Agro-Ecosystem, Institute of Innovation Ecology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Yongzhi Yang
- State Key Laboratory of Grassland Agro-Ecosystem, Institute of Innovation Ecology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Renping Xu
- State Key Laboratory of Grassland Agro-Ecosystem, Institute of Innovation Ecology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Wenjie Mu
- State Key Laboratory of Grassland Agro-Ecosystem, Institute of Innovation Ecology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Ying Li
- State Key Laboratory of Grassland Agro-Ecosystem, Institute of Innovation Ecology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Xingxing Mao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Zeyu Zheng
- State Key Laboratory of Grassland Agro-Ecosystem, Institute of Innovation Ecology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Hao Bi
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Guoqian Hao
- Biodiversity Institute of Mount Emei, Mount Emei Scenic Area Management Committee, Leshan, China
| | - Xiaojie Li
- Emeishan Biological Resources Experimental Station, Emei, China
| | - Xiaoting Xu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Zhenxiang Xi
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Nawal Shrestha
- State Key Laboratory of Grassland Agro-Ecosystem, Institute of Innovation Ecology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Jianquan Liu
- State Key Laboratory of Grassland Agro-Ecosystem, Institute of Innovation Ecology, School of Life Sciences, Lanzhou University, Lanzhou, China.,Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
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Zhang H, Jin J, Moore MJ, Yi T, Li D. Plastome characteristics of Cannabaceae. PLANT DIVERSITY 2018; 40:127-137. [PMID: 30175293 PMCID: PMC6114266 DOI: 10.1016/j.pld.2018.04.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 04/11/2018] [Accepted: 04/18/2018] [Indexed: 05/02/2023]
Abstract
Cannabaceae is an economically important family that includes ten genera and ca. 117 accepted species. To explore the structure and size variation of their plastomes, we sequenced ten plastomes representing all ten genera of Cannabaceae. Each plastome possessed the typical angiosperm quadripartite structure and contained a total of 128 genes. The Inverted Repeat (IR) regions in five plastomes had experienced small expansions (330-983 bp) into the Large Single-Copy (LSC) region. The plastome of Chaetachme aristata has experienced a 942-bp IR contraction and lost rpl22 and rps19 in its IRs. The substitution rates of rps19 and rpl22 decreased after they shifted from the LSC to IR. A 270-bp inversion was detected in the Parasponia rugosa plastome, which might have been mediated by 18-bp inverted repeats. Repeat sequences, simple sequence repeats, and nucleotide substitution rates varied among these plastomes. Molecular markers with more than 13% variable sites and 5% parsimony-informative sites were identified, which may be useful for further phylogenetic analysis and species identification. Our results show strong support for a sister relationship between Gironniera and Lozanell (BS = 100). Celtis, Cannabis-Humulus, Chaetachme-Pteroceltis, and Trema-Parasponia formed a strongly supported clade, and their relationships were well resolved with strong support (BS = 100). The availability of these ten plastomes provides valuable genetic information for accurately identifying species, clarifying taxonomy and reconstructing the intergeneric phylogeny of Cannabaceae.
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Affiliation(s)
- Huanlei Zhang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- Kunming College of Life Sciences, University of Chinese Academy of Sciences, Kunming 650201, China
| | - Jianjun Jin
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- Kunming College of Life Sciences, University of Chinese Academy of Sciences, Kunming 650201, China
| | | | - Tingshuang Yi
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- Corresponding author.
| | - Dezhu Li
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- Corresponding author.
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The Complete Chloroplast Genome of Catha edulis: A Comparative Analysis of Genome Features with Related Species. Int J Mol Sci 2018; 19:ijms19020525. [PMID: 29425128 PMCID: PMC5855747 DOI: 10.3390/ijms19020525] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/03/2018] [Accepted: 02/06/2018] [Indexed: 11/17/2022] Open
Abstract
Qat (Catha edulis, Celastraceae) is a woody evergreen species with great economic and cultural importance. It is cultivated for its stimulant alkaloids cathine and cathinone in East Africa and southwest Arabia. However, genome information, especially DNA sequence resources, for C. edulis are limited, hindering studies regarding interspecific and intraspecific relationships. Herein, the complete chloroplast (cp) genome of Catha edulis is reported. This genome is 157,960 bp in length with 37% GC content and is structurally arranged into two 26,577 bp inverted repeats and two single-copy areas. The size of the small single-copy and the large single-copy regions were 18,491 bp and 86,315 bp, respectively. The C. edulis cp genome consists of 129 coding genes including 37 transfer RNA (tRNA) genes, 8 ribosomal RNA (rRNA) genes, and 84 protein coding genes. For those genes, 112 are single copy genes and 17 genes are duplicated in two inverted regions with seven tRNAs, four rRNAs, and six protein coding genes. The phylogenetic relationships resolved from the cp genome of qat and 32 other species confirms the monophyly of Celastraceae. The cp genomes of C. edulis, Euonymus japonicus and seven Celastraceae species lack the rps16 intron, which indicates an intron loss took place among an ancestor of this family. The cp genome of C. edulis provides a highly valuable genetic resource for further phylogenomic research, barcoding and cp transformation in Celastraceae.
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Oueslati A, Ollitrault F, Baraket G, Salhi-Hannachi A, Navarro L, Ollitrault P. Towards a molecular taxonomic key of the Aurantioideae subfamily using chloroplastic SNP diagnostic markers of the main clades genotyped by competitive allele-specific PCR. BMC Genet 2016; 17:118. [PMID: 27539067 PMCID: PMC4991024 DOI: 10.1186/s12863-016-0426-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 08/11/2016] [Indexed: 11/28/2022] Open
Abstract
Background Chloroplast DNA is a primary source of molecular variations for phylogenetic analysis of photosynthetic eukaryotes. However, the sequencing and analysis of multiple chloroplastic regions is difficult to apply to large collections or large samples of natural populations. The objective of our work was to demonstrate that a molecular taxonomic key based on easy, scalable and low-cost genotyping method should be developed from a set of Single Nucleotide Polymorphisms (SNPs) diagnostic of well-established clades. It was applied to the Aurantioideae subfamily, the largest group of the Rutaceae family that includes the cultivated citrus species. Results The publicly available nucleotide sequences of eight plastid genomic regions were compared for 79 accessions of the Aurantioideae subfamily to search for SNPs revealing taxonomic differentiation at the inter-tribe, inter-subtribe, inter-genus and interspecific levels. Diagnostic SNPs (DSNPs) were found for 46 of the 54 clade levels analysed. Forty DSNPs were selected to develop KASPar markers and their taxonomic value was tested by genotyping 108 accessions of the Aurantioideae subfamily. Twenty-seven markers diagnostic of 24 clades were validated and they displayed a very high rate of transferability in the Aurantioideae subfamily (only 1.2 % of missing data on average). The UPGMA from the validated markers produced a cladistic organisation that was highly coherent with the previous phylogenetic analysis based on the sequence data of the eight plasmid regions. In particular, the monophyletic origin of the “true citrus” genera plus Oxanthera was validated. However, some clarification remains necessary regarding the organisation of the other wild species of the Citreae tribe. Conclusions We validated the concept that with well-established clades, DSNPs can be selected and efficiently transformed into competitive allele-specific PCR markers (KASPar method) allowing cost-effective highly efficient cladistic analysis in large collections at subfamily level. The robustness of this genotyping method is an additional decisive advantage for network collaborative research. The availability of WGS data for the main “true citrus” species should soon make it possible to develop a set of DSNP markers allowing very fine resolution of this very important horticultural group. Electronic supplementary material The online version of this article (doi:10.1186/s12863-016-0426-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Amel Oueslati
- Laboratoire de Génétique Moléculaire, Immunologie et Biotechnologie LR99ES12, Faculté des Sciences de Tunis (FST), Université de Tunis El Manar, Campus Universitaire, El Manar-Tunis, 2092, Tunisia.,UMR Agap, CIRAD, Petit-Bourg, F-97170, Guadeloupe, France
| | - Frederique Ollitrault
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Moncada, 46113, Valencia, Spain
| | - Ghada Baraket
- Laboratoire de Génétique Moléculaire, Immunologie et Biotechnologie LR99ES12, Faculté des Sciences de Tunis (FST), Université de Tunis El Manar, Campus Universitaire, El Manar-Tunis, 2092, Tunisia
| | - Amel Salhi-Hannachi
- Laboratoire de Génétique Moléculaire, Immunologie et Biotechnologie LR99ES12, Faculté des Sciences de Tunis (FST), Université de Tunis El Manar, Campus Universitaire, El Manar-Tunis, 2092, Tunisia
| | - Luis Navarro
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Moncada, 46113, Valencia, Spain
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Gu C, Tembrock LR, Johnson NG, Simmons MP, Wu Z. The Complete Plastid Genome of Lagerstroemia fauriei and Loss of rpl2 Intron from Lagerstroemia (Lythraceae). PLoS One 2016; 11:e0150752. [PMID: 26950701 PMCID: PMC4780714 DOI: 10.1371/journal.pone.0150752] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 02/17/2016] [Indexed: 11/19/2022] Open
Abstract
Lagerstroemia (crape myrtle) is an important plant genus used in ornamental horticulture in temperate regions worldwide. As such, numerous hybrids have been developed. However, DNA sequence resources and genome information for Lagerstroemia are limited, hindering evolutionary inferences regarding interspecific relationships. We report the complete plastid genome of Lagerstroemia fauriei. To our knowledge, this is the first reported whole plastid genome within Lythraceae. This genome is 152,440 bp in length with 38% GC content and consists of two single-copy regions separated by a pair of 25,793 bp inverted repeats. The large single copy and the small single copy regions span 83,921 bp and 16,933 bp, respectively. The genome contains 129 genes, including 17 located in each inverted repeat. Phylogenetic analysis of genera sampled from Geraniaceae, Myrtaceae, and Onagraceae corroborated the sister relationship between Lythraceae and Onagraceae. The plastid genomes of L. fauriei and several other Lythraceae species lack the rpl2 intron, which indicating an early loss of this intron within the Lythraceae lineage. The plastid genome of L. fauriei provides a much needed genetic resource for further phylogenetic research in Lagerstroemia and Lythraceae. Highly variable markers were identified for application in phylogenetic, barcoding and conservation genetic applications.
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Affiliation(s)
- Cuihua Gu
- School of Landscape and Architecture, Zhejiang Agriculture and Forestry University, Hangzhou 311300, P.R. China
- Department of Biology, Colorado State University, Fort Collins, Colorado, 80523, United States of America
| | - Luke R. Tembrock
- Department of Biology, Colorado State University, Fort Collins, Colorado, 80523, United States of America
| | - Nels G. Johnson
- National Institute for Mathematical and Biological Synthesis, University of Tennessee, Knoxville, 37996, Tennessee, United States of America
| | - Mark P. Simmons
- Department of Biology, Colorado State University, Fort Collins, Colorado, 80523, United States of America
| | - Zhiqiang Wu
- Department of Biology, Colorado State University, Fort Collins, Colorado, 80523, United States of America
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Barthet MM, Moukarzel K, Smith KN, Patel J, Hilu KW. Alternative translation initiation codons for the plastid maturase MatK: unraveling the pseudogene misconception in the Orchidaceae. BMC Evol Biol 2015. [PMID: 26416561 DOI: 10.1186/s12862-015-0491-491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/24/2023] Open
Abstract
BACKGROUND The plastid maturase MatK has been implicated as a possible model for the evolutionary "missing link" between prokaryotic and eukaryotic splicing machinery. This evolutionary implication has sparked investigations concerning the function of this unusual maturase. Intron targets of MatK activity suggest that this is an essential enzyme for plastid function. The matK gene, however, is described as a pseudogene in many photosynthetic orchid species due to presence of premature stop codons in translations, and its high rate of nucleotide and amino acid substitution. RESULTS Sequence analysis of the matK gene from orchids identified an out-of-frame alternative AUG initiation codon upstream from the consensus initiation codon used for translation in other angiosperms. We demonstrate translation from the alternative initiation codon generates a conserved MatK reading frame. We confirm that MatK protein is expressed and functions in sample orchids currently described as having a matK pseudogene using immunodetection and reverse-transcription methods. We demonstrate using phylogenetic analysis that this alternative initiation codon emerged de novo within the Orchidaceae, with several reversal events at the basal lineage and deep in orchid history. CONCLUSION These findings suggest a novel evolutionary shift for expression of matK in the Orchidaceae and support the function of MatK as a group II intron maturase in the plastid genome of land plants including the orchids.
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Affiliation(s)
- Michelle M Barthet
- Department of Biology, Coastal Carolina University, Conway, SC, 29526, USA.
- School of Biological Sciences, University of Sydney, Sydney, NSW, 2006, Australia.
| | - Keenan Moukarzel
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, 24061, USA.
| | - Kayla N Smith
- Department of Biology, Coastal Carolina University, Conway, SC, 29526, USA.
| | - Jaimin Patel
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, 24061, USA.
| | - Khidir W Hilu
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, 24061, USA.
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Barthet MM, Moukarzel K, Smith KN, Patel J, Hilu KW. Alternative translation initiation codons for the plastid maturase MatK: unraveling the pseudogene misconception in the Orchidaceae. BMC Evol Biol 2015; 15:210. [PMID: 26416561 PMCID: PMC4587860 DOI: 10.1186/s12862-015-0491-1] [Citation(s) in RCA: 12] [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] [Received: 07/14/2015] [Accepted: 09/20/2015] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The plastid maturase MatK has been implicated as a possible model for the evolutionary "missing link" between prokaryotic and eukaryotic splicing machinery. This evolutionary implication has sparked investigations concerning the function of this unusual maturase. Intron targets of MatK activity suggest that this is an essential enzyme for plastid function. The matK gene, however, is described as a pseudogene in many photosynthetic orchid species due to presence of premature stop codons in translations, and its high rate of nucleotide and amino acid substitution. RESULTS Sequence analysis of the matK gene from orchids identified an out-of-frame alternative AUG initiation codon upstream from the consensus initiation codon used for translation in other angiosperms. We demonstrate translation from the alternative initiation codon generates a conserved MatK reading frame. We confirm that MatK protein is expressed and functions in sample orchids currently described as having a matK pseudogene using immunodetection and reverse-transcription methods. We demonstrate using phylogenetic analysis that this alternative initiation codon emerged de novo within the Orchidaceae, with several reversal events at the basal lineage and deep in orchid history. CONCLUSION These findings suggest a novel evolutionary shift for expression of matK in the Orchidaceae and support the function of MatK as a group II intron maturase in the plastid genome of land plants including the orchids.
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Affiliation(s)
- Michelle M Barthet
- Department of Biology, Coastal Carolina University, Conway, SC, 29526, USA.
- School of Biological Sciences, University of Sydney, Sydney, NSW, 2006, Australia.
| | - Keenan Moukarzel
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, 24061, USA.
| | - Kayla N Smith
- Department of Biology, Coastal Carolina University, Conway, SC, 29526, USA.
| | - Jaimin Patel
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, 24061, USA.
| | - Khidir W Hilu
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, 24061, USA.
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Hilu KW, Black CM, Oza D. Impact of gene molecular evolution on phylogenetic reconstruction: a case study in the rosids (Superorder Rosanae, Angiosperms). PLoS One 2014; 9:e99725. [PMID: 24932884 PMCID: PMC4059714 DOI: 10.1371/journal.pone.0099725] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 05/18/2014] [Indexed: 11/19/2022] Open
Abstract
Rate of substitution of genomic regions is among the most debated intrinsic features that impact phylogenetic informativeness. However, this variable is also coupled with rates of nonsynonymous substitutions that underscore the nature and degree of selection on the selected genes. To empirically address these variables, we constructed four completely overlapping data sets of plastid matK, atpB, rbcL, and mitochondrial matR genes and used the rosid lineage (angiosperms) as a working platform. The genes differ in combinations of overall rates of nucleotide and amino acid substitutions. Tree robustness, homoplasy, accuracy in contrast to a reference tree, and phylogenetic informativeness are evaluated. The rapidly evolving/unconstrained matK faired best, whereas remaining genes varied in degrees of contribution to rosid phylogenetics across the lineage's 108 million years evolutionary history. Phylogenetic accuracy was low with the slowly evolving/unconstrained matR despite least amount of homoplasy. Third codon positions contributed the highest amount of parsimony informative sites, resolution and informativeness, but magnitude varied with gene mode of evolution. These findings are in clear contrast with the views that rapidly evolving regions and the 3rd codon position have inevitable negative impact on phylogenetic reconstruction at deep historic level due to accumulation of multiple hits and subsequent elevation in homoplasy and saturation. Relaxed evolutionary constraint in rapidly evolving genes distributes substitutions across codon positions, an evolutionary mode expected to reduce the frequency of multiple hits. These findings should be tested at deeper evolutionary histories.
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Affiliation(s)
- Khidir W. Hilu
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Chelsea M. Black
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Dipan Oza
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
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Gitsopoulos TK, Vasilakoglou I, Tsoktouridis G. Persicaria Amphibia, a Serious Terrestrial Weed in Northern Greece: A Combined Molecular and Morphological Approach to Identification and Taxonomy. BIOTECHNOL BIOTEC EQ 2013. [DOI: 10.5504/bbeq.2013.0088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Dong W, Liu J, Yu J, Wang L, Zhou S. Highly variable chloroplast markers for evaluating plant phylogeny at low taxonomic levels and for DNA barcoding. PLoS One 2012; 7:e35071. [PMID: 22511980 PMCID: PMC3325284 DOI: 10.1371/journal.pone.0035071] [Citation(s) in RCA: 353] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Accepted: 03/13/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND At present, plant molecular systematics and DNA barcoding techniques rely heavily on the use of chloroplast gene sequences. Because of the relatively low evolutionary rates of chloroplast genes, there are very few choices suitable for molecular studies on angiosperms at low taxonomic levels, and for DNA barcoding of species. METHODOLOGY/PRINCIPAL FINDINGS We scanned the entire chloroplast genomes of 12 genera to search for highly variable regions. The sequence data of 9 genera were from GenBank and 3 genera were of our own. We identified nearly 5% of the most variable loci from all variable loci in the chloroplast genomes of each genus, and then selected 23 loci that were present in at least three genera. The 23 loci included 4 coding regions, 2 introns, and 17 intergenic spacers. Of the 23 loci, the most variable (in order from highest variability to lowest) were intergenic regions ycf1-a, trnK, rpl32-trnL, and trnH-psbA, followed by trnS(UGA)-trnG(UCC), petA-psbJ, rps16-trnQ, ndhC-trnV, ycf1-b, ndhF, rpoB-trnC, psbE-petL, and rbcL-accD. Three loci, trnS(UGA)-trnG(UCC), trnT-psbD, and trnW-psaJ, showed very high nucleotide diversity per site (π values) across three genera. Other loci may have strong potential for resolving phylogenetic and species identification problems at the species level. The loci accD-psaI, rbcL-accD, rpl32-trnL, rps16-trnQ, and ycf1 are absent from some genera. To amplify and sequence the highly variable loci identified in this study, we designed primers from their conserved flanking regions. We tested the applicability of the primers to amplify target sequences in eight species representing basal angiosperms, monocots, eudicots, rosids, and asterids, and confirmed that the primers amplified the desired sequences of these species. SIGNIFICANCE/CONCLUSIONS Chloroplast genome sequences contain regions that are highly variable. Such regions are the first consideration when screening the suitable loci to resolve closely related species or genera in phylogenetic analyses, and for DNA barcoding.
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Affiliation(s)
- Wenpan Dong
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Landscape Architecture, Northeast Forestry University, Harbin, China
| | - Jing Liu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Graduate University of Chinese Academy of Sciences, Beijing, China
| | - Jing Yu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Graduate University of Chinese Academy of Sciences, Beijing, China
| | - Ling Wang
- College of Landscape Architecture, Northeast Forestry University, Harbin, China
| | - Shiliang Zhou
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- * E-mail:
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Kuo LY, Li FW, Chiou WL, Wang CN. First insights into fern matK phylogeny. Mol Phylogenet Evol 2011; 59:556-66. [DOI: 10.1016/j.ympev.2011.03.010] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 02/19/2011] [Accepted: 03/05/2011] [Indexed: 10/18/2022]
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