scholarly journals Evolutionary Analysis of Unicellular Species in Chlamydomonadales Through Chloroplast Genome Comparison With the Colonial Volvocine Algae

2019 ◽  
Vol 10 ◽  
Author(s):  
Yuxin Hu ◽  
Weiyue Xing ◽  
Huiyin Song ◽  
Huan Zhu ◽  
Guoxiang Liu ◽  
...  
2021 ◽  
Author(s):  
LI li ◽  
Yunfei Hu ◽  
Min He ◽  
Bo Zhang ◽  
Wei Wu ◽  
...  

Abstract Background: Chloroplast genome resources can provide useful information for the evolution of plant species. Tea plant (Camellia sinensis) is among the most economically valuable member of Camellia. Here, we determined the chloroplast genome of the first natural triploid Chinary type tea (‘Wuyi narcissus’ cultivar of Camellia sinensis var. sinensis, CWN) and conducted the genome comparison with the diploid Chinary type tea (Camellia sinensis var. sinensis, CSS) and two types of diploid Assamica type teas (Camellia sinensis var. assamica: Chinese Assamica type tea, CSA and Indian Assamica type tea, CIA). Further, the evolutionary mechanism of the chloroplast genome of Camellia sinensis and the relationships of Camellia species based on chloroplast genome were discussed.Results: Comparative analysis showed the evolutionary dynamics of chloroplast genome of Camellia sinensis were the repeats and insertion-deletions (indels), and distribution of the repeats, indels and substitutions were significantly correlated. Chinese tea and Indian tea had significant differences in the structural characteristic and the codon usage of the chloroplast genome. Analysis of sequence characterized amplified region (SCAR) using sequences of the intergenic spacers (trnE/trnT) showed none of 292 different Camellia sinensis cultivars had similar sequence characteristic to triploid CWN, but the other four Camellia species did. Estimations of the divergence time showed that CIA diverged from the common ancestor of two Assamica type teas about 6.2 Mya (CI: 4.4-8.1 Mya). CSS and CSA diverged to each other about 0.8 Mya (CI: 0.4-1.5 Mya). Moreover, phylogenetic clustering was not exactly consistent with the current taxonomy of Camellia.Conclusions: The repeat-induced and indel-induced mutations were two important dynamics contributed to the diversification of the chloroplast genome in Camellia sinensis, which were not mutually exclusive. Chinese tea and Indian tea might have undergone different selection pressures. Chloroplast transfer occurred during the polyploid evolution in Camellia sinensis. In addition, our results supported the three different domestication origins of Chinary type tea, Chinese Assamica type tea and Indian Assamica type tea. And, the current classification of some Camellia species might need to be further discussed.


2019 ◽  
Vol 20 (11) ◽  
pp. 2726 ◽  
Author(s):  
Inkyu Park ◽  
Jun-Ho Song ◽  
Sungyu Yang ◽  
Wook Jin Kim ◽  
Goya Choi ◽  
...  

The genus Cuscuta (Convolvulaceae) comprises well-known parasitic plants. Cuscuta species are scientifically valuable, as their life style causes extensive crop damage. Furthermore, dried seeds of C. chinensis are used as a Korean traditional herbal medicine. Despite the importance of Cuscuta species, it is difficult to distinguish these plants by the naked eye. Moreover, plastid sequence information available for Cuscuta species is limited. In this study, we distinguished between C. chinensis and C. japonica using morphological characterisation of reproductive organs and molecular characterisation of chloroplast genomes. The differences in morphological characteristics of reproductive organs such as style, stigma, infrastaminal scale, seed shape and testa ornamentation were useful for distinguishing between C. japonica and C. chinensis. Analysis of chloroplast genomes revealed drastic differences in chloroplast genome length and gene order between the two species. Although both species showed numerous gene losses and genomic rearrangements, chloroplast genomes showed highly similar structure within subgenera. Phylogenetic analysis of Cuscuta chloroplast genomes revealed paraphyletic groups within subgenera Monogynella and Grammica, which is consistent with the APG IV system of classification. Our results provide useful information for the taxonomic, phylogenetic and evolutionary analysis of Cuscuta and accurate identification of herbal medicine.


2019 ◽  
Author(s):  
Qiwen Zhong ◽  
Shipeng Yang ◽  
Xuemei Sun ◽  
Lihui Wang ◽  
Yi Li

Jerusalem artichoke (Helianthus tuberosus L.) is widely cultivated in Northwest China which has become an emerging economic crop with rapid development. Because of its elevated inulin content and high resistance, it is widely used in functional food, inulin processing, feed, and ecological management. In this study, Illumina sequencing technology was utilized to assemble and annotate the complete chloroplast genome sequences of Jerusalem artichoke. The total length was 151,431 bp, including four conserved regions: A pair of reverse repeat regions (IRa 24,568 bp and IRb 24,603 bp), a large single-copy region (LSC, 83,981 bp), and a small single-copy region (SSC, 18,279 bp). The genome had a total of 115 genes, with 19 present in the reverse direction in the IR region. 36 simple sequence repeats (SSRs) were identified in the coding and non-coding regions, most of which were biased towards A/T bases. 32 SSRs were distributed in the non-coding regions. Comparative analysis of the chloroplast genome sequence of Jerusalem artichoke and other species of the composite family revealed the chloroplast genome sequences of plants of the composite family to be highly conserved. Differences were observed in 24 gene loci in the coding region, with the degree of differentiation of the ycf2 gene being the most obvious. Phylogenetic analysis showed Helianthus petiolaris subsp. fallax had the closest relationship with Jerusalem artichoke, both members of the Helianthus genus. Selective locus detection of the ycf2 gene in eight species of the composite family was performed to explore adaptive evolution traits of the ycf2 gene in Jerusalem artichoke. The results show that there are significant and extremely significant positive selection sites at the 1239N and 1518R loci, respectively, indicating that the ycf2 gene has been subject to adaptive evolution and has the potential to be used as a phylogenetic reconstruction locus in the composite family. Insights from our assessment of the complete chloroplast genome sequences of Jerusalem artichoke will aid in the in-depth study of the evolutionary relationship of the composite family, and provide significant sequencing information for the genetic improvement of Jerusalem artichoke.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4186 ◽  
Author(s):  
Yanqiang Ding ◽  
Yang Fang ◽  
Ling Guo ◽  
Zhidan Li ◽  
Kaize He ◽  
...  

Background Phylogenetic relationship within different genera of Lemnoideae, a kind of small aquatic monocotyledonous plants, was not well resolved, using either morphological characters or traditional markers. Given that rich genetic information in chloroplast genome makes them particularly useful for phylogenetic studies, we used chloroplast genomes to clarify the phylogeny within Lemnoideae. Methods DNAs were sequenced with next-generation sequencing. The duckweeds chloroplast genomes were indirectly filtered from the total DNA data, or directly obtained from chloroplast DNA data. To test the reliability of assembling the chloroplast genome based on the filtration of the total DNA, two methods were used to assemble the chloroplast genome of Landoltia punctata strain ZH0202. A phylogenetic tree was built on the basis of the whole chloroplast genome sequences using MrBayes v.3.2.6 and PhyML 3.0. Results Eight complete duckweeds chloroplast genomes were assembled, with lengths ranging from 165,775 bp to 171,152 bp, and each contains 80 protein-coding sequences, four rRNAs, 30 tRNAs and two pseudogenes. The identity of L. punctata strain ZH0202 chloroplast genomes assembled through two methods was 100%, and their sequences and lengths were completely identical. The chloroplast genome comparison demonstrated that the differences in chloroplast genome sizes among the Lemnoideae primarily resulted from variation in non-coding regions, especially from repeat sequence variation. The phylogenetic analysis demonstrated that the different genera of Lemnoideae are derived from each other in the following order: Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia. Discussion This study demonstrates potential of whole chloroplast genome DNA as an effective option for phylogenetic studies of Lemnoideae. It also showed the possibility of using chloroplast DNA data to elucidate those phylogenies which were not yet solved well by traditional methods even in plants other than duckweeds.


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):  
Ying-min Zhang ◽  
Li-jun Han ◽  
Ying-Ying Liu ◽  
Cong-wei Yang ◽  
Xing Tian ◽  
...  

Abstract Background: Veratrum is a genus of perennial herbs that are widely used as traditional Chinese medicine for emetic, resolving blood stasis and relieve pain. However, the species classification and the phylogenetic relationship of the genus Veratrum have long been controversial due to the complexity of morphological variations. Knowledge on the infrageneric relationships of the genus Veratrum can be obtained from their chloroplast genome sequences and increase the taxonomic and phylogenetic resolution.Methods: Total DNA was extracted from ten species of Veratrum and subjected to next-generation sequencing. The cp genome was assembled by NOVOPlasty. Genome annotation was conducted using the online tool DOGMA and subsequently corrected by Geneious Prime. Then, genomic characterization of the Veratrum plastome and genome comparison with closely related species was analyzed by corresponding software. Moreover, phylogenetical trees were reconstructed, based on the 29 plastomes by maximum likelihood (ML) and Bayesian inference (BI) methods.Results: The whole plastomes of Veratrum species possess a typical quadripartite structure, ranging from 151,597 bp to 153,711 bp in size and comprising 135 genes. The gene order, content, and genome structure were nearly identical with a few exceptions across the Veratrum chloroplast genomes. The total number of simple sequence repeats (SSRs) ranged from 31 to 35, and of large sequence repeats (LSRs) ranged from 65 to 71. Seven highly divergent regions (rpoB-trnC, trnT-trnL, trnS-trnG, psbC-psbZ, psbI, ycf1, and ndhF) were identified that can be used for DNA barcoding in the genus of Veratrum. Phylogenetic analyses based on 29 plastomes strongly supported the monophyly of Veratrum. The circumscription and relationships of infrageneric taxa of Veratrum were well evaluated with high resolutions. Conclusions: Our study identified and analyzed the cp genome features of ten Veratrum species, and suggested high effectivity of chloroplast complete genome in resolving generic circumscription in Veratrum. These results will facilitate the identification, taxonomy, and utilization of Veratrum plants as well as the phylogenetic study of Melanthiaceae simultaneously.


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.


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