scholarly journals Comparative analysis of chloroplast genomes of cultivars and wild species of sweetpotato (Ipomoea batatas [L.] Lam)

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Shizhuo Xiao ◽  
Pan Xu ◽  
Yitong Deng ◽  
Xibin Dai ◽  
Lukuan Zhao ◽  
...  

Abstract Background Sweetpotato (Ipomoea batatas [L.] Lam.) is an important food crop. However, the genetic information of the nuclear genome of this species is difficult to determine accurately because of its large genome and complex genetic background. This drawback has limited studies on the origin, evolution, genetic diversity and other relevant studies on sweetpotato. Results The chloroplast genomes of 107 sweetpotato cultivars were sequenced, assembled and annotated. The resulting chloroplast genomes were comparatively analysed with the published chloroplast genomes of wild species of sweetpotato. High similarity and certain specificity were found among the chloroplast genomes of Ipomoea spp. Phylogenetic analysis could clearly distinguish wild species from cultivars. Ipomoea trifida and Ipomoea tabascana showed the closest relationship with the cultivars, and different haplotypes of ycf1 could be used to distinguish the cultivars from their wild relatives. The genetic structure was analyzed using variations in the chloroplast genome. Compared with traditional nuclear markers, the chloroplast markers designed based on the InDels on the chloroplast genome showed significant advantages. Conclusions Comparative analysis of chloroplast genomes of 107 cultivars and several wild species of sweetpotato was performed to help analyze the evolution, genetic structure and the development of chloroplast DNA markers of sweetpotato.

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Shizhuo Xiao ◽  
Pan Xu ◽  
Yitong Deng ◽  
Xibin Dai ◽  
Lukuan Zhao ◽  
...  

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6563
Author(s):  
Jianying Sun ◽  
Xiaofeng Dong ◽  
Qinghe Cao ◽  
Tao Xu ◽  
Mingku Zhu ◽  
...  

Background Ipomoea is the largest genus in the family Convolvulaceae. The species in this genus have been widely used in many fields, such as agriculture, nutrition, and medicine. With the development of next-generation sequencing, more than 50 chloroplast genomes of Ipomoea species have been sequenced. However, the repeats and divergence regions in Ipomoea have not been well investigated. In the present study, we sequenced and assembled eight chloroplast genomes from sweet potato’s close wild relatives. By combining these with 32 published chloroplast genomes, we conducted a detailed comparative analysis of a broad range of Ipomoea species. Methods Eight chloroplast genomes were assembled using short DNA sequences generated by next-generation sequencing technology. By combining these chloroplast genomes with 32 other published Ipomoea chloroplast genomes downloaded from GenBank and the Oxford Research Archive, we conducted a comparative analysis of the repeat sequences and divergence regions across the Ipomoea genus. In addition, separate analyses of the Batatas group and Quamoclit group were also performed. Results The eight newly sequenced chloroplast genomes ranged from 161,225 to 161,721 bp in length and displayed the typical circular quadripartite structure, consisting of a pair of inverted repeat (IR) regions (30,798–30,910 bp each) separated by a large single copy (LSC) region (87,575–88,004 bp) and a small single copy (SSC) region (12,018–12,051 bp). The average guanine-cytosine (GC) content was approximately 40.5% in the IR region, 36.1% in the LSC region, 32.2% in the SSC regions, and 37.5% in complete sequence for all the generated plastomes. The eight chloroplast genome sequences from this study included 80 protein-coding genes, four rRNAs (rrn23, rrn16, rrn5, and rrn4.5), and 37 tRNAs. The boundaries of single copy regions and IR regions were highly conserved in the eight chloroplast genomes. In Ipomoea, 57–89 pairs of repetitive sequences and 39–64 simple sequence repeats were found. By conducting a sliding window analysis, we found six relatively high variable regions (ndhA intron, ndhH-ndhF, ndhF-rpl32, rpl32-trnL, rps16-trnQ, and ndhF) in the Ipomoea genus, eight (trnG, rpl32-trnL, ndhA intron, ndhF-rpl32, ndhH-ndhF, ccsA-ndhD, trnG-trnR, and pasA-ycf3) in the Batatas group, and eight (ndhA intron, petN-psbM, rpl32-trnL, trnG-trnR, trnK-rps16, ndhC-trnV, rps16-trnQ, and trnG) in the Quamoclit group. Our maximum-likelihood tree based on whole chloroplast genomes confirmed the phylogenetic topology reported in previous studies. Conclusions The chloroplast genome sequence and structure were highly conserved in the eight newly-sequenced Ipomoea species. Our comparative analysis included a broad range of Ipomoea chloroplast genomes, providing valuable information for Ipomoea species identification and enhancing the understanding of Ipomoea genetic resources.


2019 ◽  
Vol 42 (4) ◽  
pp. 601-611 ◽  
Author(s):  
Yan Li ◽  
Liukun Jia ◽  
Zhihua Wang ◽  
Rui Xing ◽  
Xiaofeng Chi ◽  
...  

Abstract Saxifraga sinomontana J.-T. Pan & Gornall belongs to Saxifraga sect. Ciliatae subsect. Hirculoideae, a lineage containing ca. 110 species whose phylogenetic relationships are largely unresolved due to recent rapid radiations. Analyses of complete chloroplast genomes have the potential to significantly improve the resolution of phylogenetic relationships in this young plant lineage. The complete chloroplast genome of S. sinomontana was de novo sequenced, assembled and then compared with that of other six Saxifragaceae species. The S. sinomontana chloroplast genome is 147,240 bp in length with a typical quadripartite structure, including a large single-copy region of 79,310 bp and a small single-copy region of 16,874 bp separated by a pair of inverted repeats (IRs) of 25,528 bp each. The chloroplast genome contains 113 unique genes, including 79 protein-coding genes, four rRNAs and 30 tRNAs, with 18 duplicates in the IRs. The gene content and organization are similar to other Saxifragaceae chloroplast genomes. Sixty-one simple sequence repeats were identified in the S. sinomontana chloroplast genome, mostly represented by mononucleotide repeats of polyadenine or polythymine. Comparative analysis revealed 12 highly divergent regions in the intergenic spacers, as well as coding genes of matK, ndhK, accD, cemA, rpoA, rps19, ndhF, ccsA, ndhD and ycf1. Phylogenetic reconstruction of seven Saxifragaceae species based on 66 protein-coding genes received high bootstrap support values for nearly all identified nodes, suggesting a promising opportunity to resolve infrasectional relationships of the most species-rich section Ciliatae of Saxifraga.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wei Tan ◽  
Han Gao ◽  
Weiling Jiang ◽  
Huanyu Zhang ◽  
Xiaolei Yu ◽  
...  

Abstract Chloroplast genomes have been widely considered an informative and valuable resource for molecular marker development and phylogenetic reconstruction in plant species. This study evaluated the complete chloroplast genomes of the traditional Chinese medicine Gleditsia sinensis and G. japonica, an adulterant of the former. The complete chloroplast genomes of G. sinensis and G. japonica were found to be of sizes 163,175 bp and 162,391 bp, respectively. A total of 111 genes were identified in each chloroplast genome, including 77 coding sequences, 30 tRNA, and 4 rRNA genes. Comparative analysis demonstrated that the chloroplast genomes of these two species were highly conserved in genome size, GC contents, and gene organization. Additionally, nucleotide diversity analysis of the two chloroplast genomes revealed that the two short regions of ycf1b were highly diverse, and could be treated as mini-barcode candidate regions. The mini-barcode of primers ZJ818F-1038R was proven to precisely discriminate between these two species and reflect their biomass ratio accurately. Overall, the findings of our study will shed light on the genetic evolution and guide species identification of G. sinensis and G. japonica.


2019 ◽  
Author(s):  
Tapan Kumar Mohanta ◽  
Awdhesh Kumar Mishra ◽  
Adil Khan ◽  
Abeer Hashem ◽  
Elsayed Fathi Abd_Allah ◽  
...  

AbstractChloroplasts are unique organelles within the plant cells and are responsible for sustaining life forms on the earth due to their ability to conduct photosynthesis. Multiple functional genes within the chloroplast are responsible for a variety of metabolic processes that occur in the chloroplast. Considering its fundamental role in sustaining life on the earth, it is important to identify the level of diversity present in the chloroplast genome, what genes and genomic content have been lost, what genes have been transferred to the nuclear genome, duplication events, and the overall origin and evolution of the chloroplast genome. Our analysis of 2511 chloroplast genomes indicated that the genome size and number of coding DNA sequences (CDS) in the chloroplasts genome of algae are higher relative to other lineages. Approximately 10.31% of the examined species have lost the inverted repeats (IR) in the chloroplast genome that span across all the lineages. Genome-wide analyses revealed the loss of the Rbcl gene in parasitic and heterotrophic plants occurred approximately 56 Ma ago. PsaM, Psb30, ChlB, ChlL, ChlN, and Rpl21 were found to be characteristic signature genes of the chloroplast genome of algae, bryophytes, pteridophytes, and gymnosperms; however, none of these genes were found in the angiosperm or magnoliid lineage which appeared to have lost them approximately 203–156 Ma ago. A variety of chloroplast-encoded genes were lost across different species lineages throughout the evolutionary process. The Rpl20 gene, however, was found to be the most stable and intact gene in the chloroplast genome and was not lost in any of the analyzed species, suggesting that it is a signature gene of the plastome. Our evolutionary analysis indicated that chloroplast genomes evolved from multiple common ancestors ~1293 Ma ago and have undergone vivid recombination events across different taxonomic lineages.


2020 ◽  
Author(s):  
Tapan Kumar Mohanta ◽  
Adil Khan ◽  
Abdul Latif Khan ◽  
Abeer Hashem ◽  
Elsayed Fathi Abd_Allah ◽  
...  

Abstract Chloroplasts are unique organelles within plant cells and are ultimately responsible for sustaining life forms on the earth due to their ability to conduct photosynthesis. Multiple functional genes within the chloroplast are responsible for a variety of metabolic processes that occur in the chloroplast. Considering its fundamental role in sustaining life on earth, it is important to identify the level of diversity present in the chloroplast genome, what genes and genomic content have been lost, what genes have been transferred to the nuclear genome, duplication events, and the overall origin and evolution of the chloroplast genome. Our analysis of 2511 chloroplast genomes indicated that the genome size and number of CDS in the chloroplasts of algae are higher relative to other lineages. Approximately 10.31% of the examined species have lost the inverted repeats (IR) that span across the lineages that comprise algae, bryophytes, pteridophytes, gymnosperm, angiosperms, magnoliids, and protists. Genome-wide analyses revealed that the loss of the Rbcl gene in parasitic and heterotrophic plant species occurred approximately 56 Ma ago. PsaM, Psb30, ChlB, ChlL, ChlN, and Rpl21 were found to be characteristic signature genes of chloroplast genome of algae, bryophytes, pteridophytes, and gymnosperms; while none of these genes were found in the angiosperm or magnoliid lineage which appeared to have lost them approximately 203-156 Ma ago. A variety of chloroplast encoding genes were lost across different species lineages throughout the evolutionary process. The Rpl20 gene, however, was found to be the most stable and intact gene in the chloroplast genome and was not lost in any of the analysed species; suggesting that it is a signature gene of the plastome. Our evolutionary analysis indicated that chloroplast genomes evolved from multiple common ancestors ~1293 Ma ago and have undergone vivid recombination events across different taxonomic lineages. Additionally, our findings support the hypothesis that these recombination events are the most probable cause behind the dynamic loss of chloroplast genes and inverted repeats in different species.


Author(s):  
Tapan Kumar Mohanta ◽  
Adil Khan ◽  
Abdul Latif Khan ◽  
Abeer Hashem ◽  
Elsayed Fathi Abd_Allah ◽  
...  

Abstract Chloroplasts are unique organelles within plant cells and are ultimately responsible for sustaining life forms on the earth due to their ability to conduct photosynthesis. Multiple functional genes within the chloroplast are responsible for a variety of metabolic processes that occur in the chloroplast. Considering its fundamental role in sustaining life on earth, it is important to identify the level of diversity present in the chloroplast genome, what genes and genomic content have been lost, what genes have been transferred to the nuclear genome, duplication events, and the overall origin and evolution of the chloroplast genome. Our analysis of 2511 chloroplast genomes indicated that the genome size and number of CDS in the chloroplasts of algae are higher relative to other lineages. Approximately 10.31% of the examined species have lost the inverted repeats (IR) that span across the lineages that comprise algae, bryophytes, pteridophytes, gymnosperm, angiosperms, magnoliids, and protists. Genome-wide analyses revealed that the loss of the RBCL gene in parasitic and heterotrophic plant species occurred approximately 56 Ma ago. PsaM, Psb30, ChlB, ChlL, ChlN, and RPL21 were found to be characteristic signature genes of chloroplast genome of algae, bryophytes, pteridophytes, and gymnosperms; while none of these genes were found in the angiosperm or magnoliid lineage which appeared to have lost them approximately 203-156 Ma ago. A variety of chloroplast encoding genes were lost across different species lineages throughout the evolutionary process. The Rpl20 gene, however, was found to be the most stable and intact gene in the chloroplast genome and was not lost in any of the analysed species; suggesting that it is a signature gene of the plastome. Our evolutionary analysis indicated that chloroplast genomes evolved from multiple common ancestors ~1293 Ma ago and have undergone vivid recombination events across different taxonomic lineages. Additionally, our findings support the hypothesis that these recombination events are the most probable cause behind the dynamic loss of chloroplast genes and inverted repeats in different species.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Ying Zhang ◽  
Hai-Li Li ◽  
Jun-Di Zhong ◽  
Yun Wang ◽  
Chang-Chun Yuan

In the Combretaceae family, only two species of Lumnitzera and one species of Laguncularia belong to mangroves. Among them, Lumnitzera littorea (Jack) Voigt. is an endangered mangrove plant in China for the limited occurrence and seed abortion. In contrast, Lumnitzera racemosa Willd. is known as the most widespread mangrove plant in China. Laguncularia racemosa C. F. Gaertn., an exotic mangrove in China, has the fast growth and high adaptation ability. To better understand the phylogenetic positions of these mangroves in Combretaceae and in Myrtales and to provide information for studies on evolutionary adaptation for intertidal habitat, the complete chloroplast (cp) genomes of Lu. racemosa and La. racemosa were sequenced. Furthermore, we present here the results from the assembly and annotation of the two cp genomes, which were further subjected to the comparative analysis with Lu. littorea cp genomes we published before and other eleven closely related species within Myrtales. The chloroplast genomes of the three Combretaceae mangrove species: Lu. littorea, Lu. racemosa, and La. racemosa are 159,687 bp, 159,473 bp, and 158,311 bp in size. All three cp genomes host 130 genes including 85 protein-coding genes, 37 tRNAs, and 4 rRNAs. A comparative analysis of those three genomes revealed the high similarity of genes in coding-regions and conserved gene order in the IR and LSC/SSC regions. The differences between Lumnitzera and Laguncularia cp genomes are the locations of rps19 and rpl2 genes in the IR/SC boundary regions. Investigating the effects of selection events on shared protein-coding genes showed a relaxed selection had acted on the ycf2, ycf1, and matK genes of Combretaceae mangroves compared to the nonmangrove species Eucalyptus aromaphloia. The phylogenetic analysis based on the whole chloroplast genome sequence with one outgroup species strongly supported three Combretaceae mangroves together with other two Combretaceae species formed a cluster in Combretaceae. This study is the first report on the comparative analysis of three Combretaceae mangrove chloroplast genomes, which will provide the significant information for understanding photosynthesis and evolution in Combretaceae mangrove plants.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haonan Cui ◽  
Zhuo Ding ◽  
Qianglong Zhu ◽  
Yue Wu ◽  
Boyan Qiu ◽  
...  

AbstractDuring plant evolution, there is genetic communication between organelle and nuclear genomes. A comparative analysis was performed on the organelle and nuclear genomes of the watermelon and melon. In the watermelon, chloroplast-derived sequences accounted for 7.6% of the total length of the mitochondrial genome. In the melon, chloroplast-derived sequences accounted for approximately 2.73% of the total mitochondrial genome. In watermelon and melon, the chloroplast-derived small-fragment sequences are either a subset of large-fragment sequences or appeared multiple times in the mitochondrial genome, indicating that these fragments may have undergone multiple independent migration integrations or emerged in the mitochondrial genome after migration, replication, and reorganization. There was no evidence of migration from the mitochondria to chloroplast genome. A sequence with a total length of about 73 kb (47%) in the watermelon chloroplast genome was homologous to a sequence of about 313 kb in the nuclear genome. About 33% of sequences in the watermelon mitochondrial genome was homologous with a 260 kb sequence in the nuclear genome. A sequence with a total length of about 38 kb (25%) in the melon chloroplast genome was homologous with 461 sequences in the nuclear genome, with a total length of about 301 kb. A 3.4 Mb sequence in the nuclear genome was homologous with a melon mitochondrial sequence. These results indicate that, during the evolution of watermelon and melon, a large amount of genetic material was exchanged between the nuclear genome and the two organelle genomes in the cytoplasm.


2020 ◽  
Author(s):  
Jiao Peng ◽  
Yunlin Zhao ◽  
Meng Dong ◽  
Shiquan Liu ◽  
Zhiyuan Hu ◽  
...  

Abstract Background: The cultivated tea is one of the most important economic and ecological trees distributing worldwide. The cultivated tea suffered from long-term targeted selection of traits and overexploitation of habitats by human beings, which may change the genetic structure. Chloroplast is an organelle with a conserved cyclic structure, and can help us better understand the evolutionary relationship of Camellia plants.Results: The study conducted comparative analysis and evolution analysis between cultivated tea and wild tea, and detected the evolution characteristic in cultivated tea. Chloroplast genome sizes of cultivated tea were slightly different, ranged from 157,025 bp to 157,085 bp. These cultivated species were more conservative than wild species, in terms of the genome length, genes number, genes arrangement and GC contents. However, the IRs length of cultivated species was about 20 bp shorter than that of C. sinensis var. sisnensis. We also found that the nucleotide diversity of 14 sequences in cultivated tea was higher than that of wild tea. These results provided the evidence on the variation of chloroplast genomes of cultivated tea. Detail analysis on the chloroplast genome variation and evolution of cultivated tea showed that 67 SNPs and 46 indels and 16 protein coding genes had nucleotide substitutions. The most comment variation gene was ycf1. It has the largest number of nucleotide substitutions. At the same time, in ycf1, five amino acid sites were exhibiting site-specific selection, and a 9 bp sequence insertion was found in the C. sinensis cultivar. Anhua. The phylogenetic tree constructed by ycf1 sequence shows that two cultivated tea were not completely clustered, and the evolutionary relationship between C. sinensis var. sisnensis and C. sinensis cultivar. Longjing is closer than that of C. sinensis cultivar. Anhua.Conclusions: The cultivated species were more conservative than wild species in terms of architecture and linear sequence order. The variation of chloroplast genome of cultivated tea was mainly manifested in the nucleotide polymorphism of some sequences. The ycf1 gene played an important role in the adaptive evolution of cultivated tea. These results provided evidence regarding the influence of human activities on tea.


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