scholarly journals Ten Ostreobium (Ulvophyceae) strains from Great Barrier Reef corals as a resource for algal endolith biology and genomics

2021 ◽  
Author(s):  
Marisa M Pasella ◽  
Ming-Fen Eileen Lee ◽  
Vaness R Marcelino ◽  
Anusuya Willis ◽  
Heroen Verbruggen
Keyword(s):  
Great Barrier Reef ◽  
Phenotypic Diversity ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Barrier Reef ◽  
Low Light ◽  
Protein Coding ◽  
Reef Corals ◽  
Coral Skeletons ◽  
Chloroplast Genomes

Ostreobium is a genus of siphonous green algae that lives as an endolith in carbonate substrates under extremely limited light conditions and has recently been gaining attention due to its roles in reef carbonate budgets and its association with reef corals. Knowledge about this genus remains fairly limited due to the scarcity of strains available for physiological studies. Here, we report on 10 strains of Ostreobium isolated from coral skeletons from the Great Barrier Reef. Phenotypic diversity showed differences in the gross morphology and in few structures. Phylogenetic analyses of the tufA and rbcL put the strains in the context of the lineages identified previously through environmental sequencing. The chloroplast genomes of our strains are all around 80k bp in length and show that genome structure is highly conserved, with only a few insertions (some containing putative protein-coding genes) differing between the strains. The addition of these strains from the Great Barrier Reef to our toolkit will help develop Ostreobium as a model species for endolithic growth, low-light photosynthesis and coral-algal associations.

scholarly journals Analysis of Six Chloroplast Genomes Provides Insight into the Evolution of Chrysosplenium (Saxifragaceae)

2020 ◽  
Author(s):  
Zhihua Wu ◽  
Rui Liao ◽  
Tiange Yang ◽  
Xiang Dong ◽  
Deqing Lan ◽  
...  
Keyword(s):  
Positive Selection ◽  
Selective Pressure ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Gc Content ◽  
Light Conditions ◽  
Low Light ◽  
Plant Adaptation ◽  
Chloroplast Genomes ◽  
Pressure Estimation

Abstract Background: Chrysosplenium L. (Saxifragaceae) is a genus of plants widely distributed in Northern Hemisphere and usually found in moist, shaded valleys and mountain slopes. This genus is ideal for studying plant adaptation to low light conditions. Although some progress has been made in the systematics and biogeography of Chrysosplenium, its chloroplast genome evolution remains to be investigated. Results: To fill this gap, we sequenced the chloroplast genomes of six Chrysosplenium species and analyzed their genome structure, GC content, and nucleotide diversity. Moreover, we performed a phylogenetic analysis and calculated non-synonymous (Ka) /synonymous (Ks) substitution ratios using the combined protein-coding genes of 29 species within Saxifragales and two additional species as outgroups, as well as a pair-wise estimation for each gene within Chrysosplenium. Compared with the outgroups in Saxifragaceae, the six Chrysosplenium chloroplast genomes had lower GC contents; they also had conserved boundary regions and gene contents, as only the rpl32 gene was lost in four of the Chrysosplenium chloroplast genomes. Phylogenetic analyses suggested that the Chrysosplenium separated to two major clades (the opposite group and the alternate group). The selection pressure estimation (Ka/Ks ratios) of genes in the Chrysosplenium species showed that matK and ycf2 were subjected to positive selection.Conclusion: This study provides genetic resources for exploring the phylogeny of Chrysosplenium and sheds light on plant adaptation to low light conditions. The lower average GC content and the lacking gene of rpl32 indicated selective pressure in their unique habitats. Different from results previously reported, our selective pressure estimation suggested that the genes related to photosynthesis (such as ycf2) were under positive selection at sites in the coding region.

scholarly journals Comparison of Chloroplast Genomes among Species of Unisexual and Bisexual Clades of the Monocot Family Araceae

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 737 ◽  
Author(s):  
Abdullah ◽  
Claudia L. Henriquez ◽  
Furrukh Mehmood ◽  
Iram Shahzadi ◽  
Zain Ali ◽  
...  
Keyword(s):  
Chloroplast Genome ◽  
De Novo ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Trna Genes ◽  
Protein Coding ◽  
Chloroplast Genomes ◽  
History Of ◽  
And Bisexual ◽  
Contraction And Expansion

The chloroplast genome provides insight into the evolution of plant species. We de novo assembled and annotated chloroplast genomes of four genera representing three subfamilies of Araceae: Lasia spinosa (Lasioideae), Stylochaeton bogneri, Zamioculcas zamiifolia (Zamioculcadoideae), and Orontium aquaticum (Orontioideae), and performed comparative genomics using these chloroplast genomes. The sizes of the chloroplast genomes ranged from 163,770 bp to 169,982 bp. These genomes comprise 113 unique genes, including 79 protein-coding, 4 rRNA, and 30 tRNA genes. Among these genes, 17–18 genes are duplicated in the inverted repeat (IR) regions, comprising 6–7 protein-coding (including trans-splicing gene rps12), 4 rRNA, and 7 tRNA genes. The total number of genes ranged between 130 and 131. The infA gene was found to be a pseudogene in all four genomes reported here. These genomes exhibited high similarities in codon usage, amino acid frequency, RNA editing sites, and microsatellites. The oligonucleotide repeats and junctions JSB (IRb/SSC) and JSA (SSC/IRa) were highly variable among the genomes. The patterns of IR contraction and expansion were shown to be homoplasious, and therefore unsuitable for phylogenetic analyses. Signatures of positive selection were seen in three genes in S. bogneri, including ycf2, clpP, and rpl36. This study is a valuable addition to the evolutionary history of chloroplast genome structure in Araceae.

scholarly journals Analysis of six chloroplast genomes provides insight into the evolution of Chrysosplenium (Saxifragaceae)

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhihua Wu ◽  
Rui Liao ◽  
Tiange Yang ◽  
Xiang Dong ◽  
Deqing Lan ◽  
...  
Keyword(s):  
Positive Selection ◽  
Selective Pressure ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Gc Content ◽  
Light Conditions ◽  
Low Light ◽  
Plant Adaptation ◽  
Chloroplast Genomes ◽  
Pressure Estimation

Abstract Background Chrysosplenium L. (Saxifragaceae) is a genus of plants widely distributed in Northern Hemisphere and usually found in moist, shaded valleys and mountain slopes. This genus is ideal for studying plant adaptation to low light conditions. Although some progress has been made in the systematics and biogeography of Chrysosplenium, its chloroplast genome evolution remains to be investigated. Results To fill this gap, we sequenced the chloroplast genomes of six Chrysosplenium species and analyzed their genome structure, GC content, and nucleotide diversity. Moreover, we performed a phylogenetic analysis and calculated non-synonymous (Ka) /synonymous (Ks) substitution ratios using the combined protein-coding genes of 29 species within Saxifragales and two additional species as outgroups, as well as a pair-wise estimation for each gene within Chrysosplenium. Compared with the outgroups in Saxifragaceae, the six Chrysosplenium chloroplast genomes had lower GC contents; they also had conserved boundary regions and gene contents, as only the rpl32 gene was lost in four of the Chrysosplenium chloroplast genomes. Phylogenetic analyses suggested that the Chrysosplenium separated to two major clades (the opposite group and the alternate group). The selection pressure estimation (Ka/Ks ratios) of genes in the Chrysosplenium species showed that matK and ycf2 were subjected to positive selection. Conclusion This study provides genetic resources for exploring the phylogeny of Chrysosplenium and sheds light on plant adaptation to low light conditions. The lower average GC content and the lacking gene of rpl32 indicated selective pressure in their unique habitats. Different from results previously reported, our selective pressure estimation suggested that the genes related to photosynthesis (such as ycf2) were under positive selection at sites in the coding region.

scholarly journals Analysis of Six Chloroplast Genomes Provides Insight into the Evolution of Chrysosplenium (Saxifragaceae)

2020 ◽  
Author(s):  
Zhihua Wu ◽  
Rui Liao ◽  
Tiange Yang ◽  
Xiang Dong ◽  
Deqing Lan ◽  
...  
Keyword(s):  
Selective Pressure ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Gc Content ◽  
Light Conditions ◽  
Coding Region ◽  
Low Light ◽  
Additional Species ◽  
Plant Adaptation ◽  
Chloroplast Genomes

Abstract Background Chrysosplenium L. (Saxifragaceae) is a genus of plants widely distributed in China and usually found in moist, shaded valleys and mountain slopes. This genus is ideal for studying plant adaptation to low-light conditions. Although some progress has been made in the systematics and biogeography of Chrysosplenium, its chloroplast genome evolution remains to be investigated. Results To fill this gap, we sequenced the chloroplast genomes of six Chrysosplenium species and analyzed their genome structure, GC content, and nucleotide diversity. Moreover, we performed a phylogenetic analysis and calculated non-synonymous (Ka)/synonymous (Ks) substitution ratios using the combined protein-coding genes of 29 species within Saxifragales and two additional species as outgroups, as well as a pair-wise estimation for each gene within Chrysosplenium. Compared with the outgroups in Saxifragaceae, the six Chrysosplenium chloroplast genomes had lower GC contents; they also had conserved boundary regions and gene contents, as only the rpl32 gene was lost in four of the Chrysosplenium chloroplast genomes. Phylogenetic analyses suggested that the Chrysosplenium separated to two major clades (the opposite group and the alternate group). The pair-wise Ka/Ks ratios of genes in the Chrysosplenium species showed that matK and ycf2 were subjected to relatively relaxed selection. Conclusion This study provides genetic resources for exploring the phylogeny of Chrysosplenium and sheds light on plant adaptation to low-light conditions. The lower average GC content and the lacking gene of rpl32 indicating selective pressure in their unique habitats. Different from results previously reported, our selective pressure estimation suggested that the genes related to photosynthesis (such as ycf2) were under positive selection at sites in the coding region.

scholarly journals Analysis of Six Chloroplast Genomes Provides Insight into the Evolution of Chrysosplenium (Saxifragaceae)

2020 ◽  
Author(s):  
Zhihua Wu ◽  
Rui Liao ◽  
Tiange Yang ◽  
Xiang Dong ◽  
Deqing Lan ◽  
...  
Keyword(s):  
Positive Selection ◽  
Selective Pressure ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Gc Content ◽  
Light Conditions ◽  
Low Light ◽  
Plant Adaptation ◽  
Chloroplast Genomes ◽  
Pressure Estimation

Abstract Background: Chrysosplenium L. (Saxifragaceae) is a genus of plants widely distributed in Northern Hemisphere and usually found in moist, shaded valleys and mountain slopes. This genus is ideal for studying plant adaptation to low-light conditions. Although some progress has been made in the systematics and biogeography of Chrysosplenium, its chloroplast genome evolution remains to be investigated. Results: To fill this gap, we sequenced the chloroplast genomes of six Chrysosplenium species and analyzed their genome structure, GC content, and nucleotide diversity. Moreover, we performed a phylogenetic analysis and calculated non-synonymous (Ka) /synonymous (Ks) substitution ratios using the combined protein-coding genes of 29 species within Saxifragales and two additional species as outgroups, as well as a pair-wise estimation for each gene within Chrysosplenium. Compared with the outgroups in Saxifragaceae, the six Chrysosplenium chloroplast genomes had lower GC contents; they also had conserved boundary regions and gene contents, as only the rpl32 gene was lost in four of the Chrysosplenium chloroplast genomes. Phylogenetic analyses suggested that the Chrysosplenium separated to two major clades (the opposite group and the alternate group). The selection pressure estimation (Ka/Ks ratios) of genes in the Chrysosplenium species showed that matK and ycf2 were subjected to positive selection.Conclusion: This study provides genetic resources for exploring the phylogeny of Chrysosplenium and sheds light on plant adaptation to low-light conditions. The lower average GC content and the lacking gene of rpl32 indicated selective pressure in their unique habitats. Different from results previously reported, our selective pressure estimation suggested that the genes related to photosynthesis (such as ycf2) were under positive selection at sites in the coding region.

scholarly journals Analysis of Six Chloroplast Genomes Provides Insight into the Evolution of Chrysosplenium (Saxifragaceae)

2020 ◽  
Author(s):  
Zhihua Wu ◽  
Rui Liao ◽  
Tiange Yang ◽  
Xiang Dong ◽  
Deqing Lan ◽  
...  
Keyword(s):  
Positive Selection ◽  
Selective Pressure ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Gc Content ◽  
Light Conditions ◽  
Low Light ◽  
Plant Adaptation ◽  
Chloroplast Genomes ◽  
Pressure Estimation

Abstract Background: Chrysosplenium L. (Saxifragaceae) is a genus of plants widely distributed in Northern Hemisphere and usually found in moist, shaded valleys and mountain slopes. This genus is ideal for studying plant adaptation to low light conditions. Although some progress has been made in the systematics and biogeography of Chrysosplenium, its chloroplast genome evolution remains to be investigated. Results: To fill this gap, we sequenced the chloroplast genomes of six Chrysosplenium species and analyzed their genome structure, GC content, and nucleotide diversity. Moreover, we performed a phylogenetic analysis and calculated non-synonymous (Ka) /synonymous (Ks) substitution ratios using the combined protein-coding genes of 29 species within Saxifragales and two additional species as outgroups, as well as a pair-wise estimation for each gene within Chrysosplenium. Compared with the outgroups in Saxifragaceae, the six Chrysosplenium chloroplast genomes had lower GC contents; they also had conserved boundary regions and gene contents, as only the rpl32 gene was lost in four of the Chrysosplenium chloroplast genomes. Phylogenetic analyses suggested that the Chrysosplenium separated to two major clades (the opposite group and the alternate group). The selection pressure estimation (Ka/Ks ratios) of genes in the Chrysosplenium species showed that matK and ycf2 were subjected to positive selection.Conclusion: This study provides genetic resources for exploring the phylogeny of Chrysosplenium and sheds light on plant adaptation to low light conditions. The lower average GC content and the lacking gene of rpl32 indicated selective pressure in their unique habitats. Different from results previously reported, our selective pressure estimation suggested that the genes related to photosynthesis (such as ycf2) were under positive selection at sites in the coding region.

scholarly journals Analysis of Six Chloroplast Genomes Provides Insight into the Evolution of Chrysosplenium (Saxifragaceae)

2020 ◽  
Author(s):  
Zhihua Wu ◽  
Rui Liao ◽  
Tiange Yang ◽  
Xiang Dong ◽  
Deqing Lan ◽  
...  
Keyword(s):  
Selective Pressure ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Gc Content ◽  
Light Conditions ◽  
Coding Region ◽  
Low Light ◽  
Plant Adaptation ◽  
Chloroplast Genomes ◽  
Pressure Estimation

Abstract Background: Chrysosplenium L. (Saxifragaceae) is a genus of plants widely distributed in Northern Hemisphere and usually found in moist, shaded valleys and mountain slopes. This genus is ideal for studying plant adaptation to low-light conditions. Although some progress has been made in the systematics and biogeography of Chrysosplenium , its chloroplast genome evolution remains to be investigated.Results: To fill this gap, we sequenced the chloroplast genomes of six Chrysosplenium species and analyzed their genome structure, GC content, and nucleotide diversity. Moreover, we performed a phylogenetic analysis and calculated non-synonymous (Ka) /synonymous (Ks) substitution ratios using the combined protein-coding genes of 29 species within Saxifragales and two additional species as outgroups, as well as a pair-wise estimation for each gene within Chrysosplenium . Compared with the outgroups in Saxifragaceae, the six Chrysosplenium chloroplast genomes had lower GC contents; they also had conserved boundary regions and gene contents, as only the rpl32 gene was lost in four of the Chrysosplenium chloroplast genomes. Phylogenetic analyses suggested that the Chrysosplenium separated to two major clades (the opposite group and the alternate group). The selection pressure estimation (Ka/Ks ratios) of genes in the Chrysosplenium species showed that matK and ycf2 were subjected to positive selection.Conclusion: This study provides genetic resources for exploring the phylogeny of Chrysosplenium and sheds light on plant adaptation to low-light conditions. The lower average GC content and the lacking gene of rpl32 indicated selective pressure in their unique habitats. Different from results previously reported, our selective pressure estimation suggested that the genes related to photosynthesis (such as ycf2 ) were under positive selection at sites in the coding region.

scholarly journals Comparison among the first representative chloroplast genomes of Orontium, Lasia, Zamioculcas, and Stylochaeton of the plant family Araceae: inverted repeat dynamics are not linked to phylogenetic signaling

2020 ◽  
Author(s):  
Abdullah ◽  
Claudia L. Henriquez ◽  
Furrukh Mehmood ◽  
Iram Shahzadi ◽  
Zain Ali ◽  
...  
Keyword(s):  
Chloroplast Genome ◽  
De Novo ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Trna Genes ◽  
Protein Coding ◽  
Chloroplast Genomes ◽  
History Of ◽  
Contraction And Expansion ◽  
Insight Into

AbstractThe chloroplast genome provides insight into the evolution of plant species. We de novo assembled and annotated chloroplast genomes of the first representatives of four genera representing three subfamilies: Lasia spinosa (Lasioideae), Stylochaeton bogneri, Zamioculcas zamiifolia (Zamioculcadoideae), and Orontium aquaticum (Orontioideae), and performed comparative genomics using the plastomes. The size of the chloroplast genomes ranged from 163,770–169,982 bp. These genomes comprise 114 unique genes, including 80 protein-coding, 4 rRNA, and 30 tRNA genes. These genomes exhibited high similarities in codon usage, amino acid frequency, RNA editing sites, and microsatellites. The junctions JSB (IRb/SSC) and JSA (SSC/IRa) are highly variable, as is oligonucleotide repeats content among the genomes. The patterns of inverted repeats contraction and expansion were shown to be homoplasious and therefore unsuitable for phylogenetic analyses. Signatures of positive selection were shown for several genes in S. bogneri. This study is a valuable addition to the evolutionary history of chloroplast genome structure in Araceae.

scholarly journals The Conservation of Chloroplast Genome Structure and Improved Resolution of Infrafamilial Relationships of Crassulaceae

2021 ◽  
Vol 12 ◽  
Author(s):  
Hong Chang ◽  
Lei Zhang ◽  
Huanhuan Xie ◽  
Jianquan Liu ◽  
Zhenxiang Xi ◽  
...  
Keyword(s):  
Chloroplast Genome ◽  
Phylogenetic Analyses ◽  
Genome Structure ◽  
Gene Organization ◽  
Ratio Test ◽  
Protein Coding ◽  
Branch Site ◽  
Chloroplast Genomes ◽  
The Family ◽  
And Function

Crassulaceae are the largest family in the angiosperm order Saxifragales. Species of this family are characterized by succulent leaves and a unique photosynthetic pathway known as Crassulacean acid metabolism (CAM). Although the inter- and intrageneric relationships have been extensively studied over the last few decades, the infrafamilial relationships of Crassulaceae remain partially obscured. Here, we report nine newly sequenced chloroplast genomes, which comprise several key lineages of Crassulaceae. Our comparative analyses and positive selection analyses of Crassulaceae species indicate that the overall gene organization and function of the chloroplast genome are highly conserved across the family. No positively selected gene was statistically supported in Crassulaceae lineage using likelihood ratio test (LRT) based on branch-site models. Among the three subfamilies of Crassulaceae, our phylogenetic analyses of chloroplast protein-coding genes support Crassuloideae as sister to Kalanchoideae plus Sempervivoideae. Furthermore, within Sempervivoideae, our analyses unambiguously resolved five clades that are successively sister lineages, i.e., Telephium clade, Sempervivum clade, Aeonium clade, Leucosedum clade, and Acre clade. Overall, this study enhances our understanding of the infrafamilial relationships and the conservation of chloroplast genomes within Crassulaceae.

scholarly journals Comparative Chloroplast Genomics of Litsea Lam. (Lauraceae) and Its Phylogenetic Implications

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 744
Author(s):  
Yunyan Zhang ◽  
Yongjing Tian ◽  
David Y. P. Tng ◽  
Jingbo Zhou ◽  
Yuntian Zhang ◽  
...  
Keyword(s):  
Chloroplast Genome ◽  
Phylogenetic Analyses ◽  
Eastern China ◽  
Chloroplast Microsatellites ◽  
Endangered Tree ◽  
Protein Coding ◽  
Intergenic Spacers ◽  
Chloroplast Genomes ◽  
Phylogenetic Implications ◽  
Chloroplast Genome Sequence

Litsea Lam. is an ecological and economic important genus of the “core Lauraceae” group in the Lauraceae. The few studies to date on the comparative chloroplast genomics and phylogenomics of Litsea have been conducted as part of other studies on the Lauraceae. Here, we sequenced the whole chloroplast genome sequence of Litsea auriculata, an endangered tree endemic to eastern China, and compared this with previously published chloroplast genome sequences of 11 other Litsea species. The chloroplast genomes of the 12 Litsea species ranged from 152,132 (L. szemaois) to 154,011 bp (L. garrettii) and exhibited a typical quadripartite structure with conserved genome arrangement and content, with length variations in the inverted repeat regions (IRs). No codon usage preferences were detected within the 30 codons used in the chloroplast genomes, indicating a conserved evolution model for the genus. Ten intergenic spacers (psbE–petL, trnH–psbA, petA–psbJ, ndhF–rpl32, ycf4–cemA, rpl32–trnL, ndhG–ndhI, psbC–trnS, trnE–trnT, and psbM–trnD) and five protein coding genes (ndhD, matK, ccsA, ycf1, and ndhF) were identified as divergence hotspot regions and DNA barcodes of Litsea species. In total, 876 chloroplast microsatellites were located within the 12 chloroplast genomes. Phylogenetic analyses conducted using the 51 additional complete chloroplast genomes of “core Lauraceae” species demonstrated that the 12 Litsea species grouped into four sub-clades within the Laurus-Neolitsea clade, and that Litsea is polyphyletic and closely related to the genera Lindera and Laurus. Our phylogeny strongly supported the monophyly of the following three clades (Laurus–Neolitsea, Cinnamomum–Ocotea, and Machilus–Persea) among the above investigated “core Lauraceae” species. Overall, our study highlighted the taxonomic utility of chloroplast genomes in Litsea, and the genetic markers identified here will facilitate future studies on the evolution, conservation, population genetics, and phylogeography of L. auriculata and other Litsea species.

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