scholarly journals Chloroplast phylogenomics and divergence times of Lagerstroemia (Lythraceae)

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Wenpan Dong ◽  
Chao Xu ◽  
Yanlei Liu ◽  
Jipu Shi ◽  
Wenying Li ◽  
...  

Abstract Background Crape myrtles, belonging to the genus Lagerstroemia L., have beautiful paniculate inflorescences and are cultivated as important ornamental tree species for landscaping and gardening. However, the phylogenetic relationships within Lagerstroemia have remained unresolved likely caused by limited sampling and the insufficient number of informative sites used in previous studies. Results In this study, we sequenced 20 Lagerstroemia chloroplast genomes and combined with 15 existing chloroplast genomes from the genus to investigate the phylogenetic relationships and divergence times within Lagerstroemia. The phylogenetic results indicated that this genus is a monophyletic group containing four clades. Our dating analysis suggested that Lagerstroemia originated in the late Paleocene (~ 60 Ma) and started to diversify in the middle Miocene. The diversification of most species occurred during the Pleistocene. Four variable loci, trnD-trnY-trnE, rrn16-trnI, ndhF-rpl32-trnL and ycf1, were discovered in the Lagerstroemia chloroplast genomes. Conclusions The chloroplast genome information was successfully utilized for molecular characterization of diverse crape myrtle samples. Our results are valuable for the global genetic diversity assessment, conservation and utilization of Lagerstroemia.

2019 ◽  
pp. 162-172
Author(s):  

The islands of the Gulf of California are divided into three categories – oceanic, continental, and landbridge – and were formed from the Middle Miocene to the Holocene. The species of the Crotalus genus are an important ecological element of the endemic fauna of these islands. This study is the first to include several island-endemic species in a phylogenetic framework. We seek to understand the phylogenetic relationships among these species, and in particular, whether these species are more related to the Baja California peninsula or continental Mexican species, and whether the divergence times for these relationships are consistent with the formation of the islands. We performed a phylogenetic analysis and estimated divergence times using Bayesian inference and two mitochondrial 12S and 16S genes. The analyses show a new relationship between Crotalus angelensis and C. pyrrhus. Crotalus lorenzoensis was nested with C. ruber individuals, making this species a paraphyletic species. A novel relationship was also detected in that C. estebanensis was sister to C. basiliscus. The divergence time for all island-endemic Crotalus species is consistent with the formation of these islands. In addition, the insular species are related to their congeners in the Baja California peninsula or mainland Mexico.


2021 ◽  
Vol 22 (4) ◽  
pp. 2104
Author(s):  
Pedro Robles ◽  
Víctor Quesada

Eleven published articles (4 reviews, 7 research papers) are collected in the Special Issue entitled “Organelle Genetics in Plants.” This selection of papers covers a wide range of topics related to chloroplasts and plant mitochondria research: (i) organellar gene expression (OGE) and, more specifically, chloroplast RNA editing in soybean, mitochondria RNA editing, and intron splicing in soybean during nodulation, as well as the study of the roles of transcriptional and posttranscriptional regulation of OGE in plant adaptation to environmental stress; (ii) analysis of the nuclear integrants of mitochondrial DNA (NUMTs) or plastid DNA (NUPTs); (iii) sequencing and characterization of mitochondrial and chloroplast genomes; (iv) recent advances in plastid genome engineering. Here we summarize the main findings of these works, which represent the latest research on the genetics, genomics, and biotechnology of chloroplasts and mitochondria.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria Alejandra Serna-Sánchez ◽  
Oscar A. Pérez-Escobar ◽  
Diego Bogarín ◽  
María Fernanda Torres-Jimenez ◽  
Astrid Catalina Alvarez-Yela ◽  
...  

AbstractRecent phylogenomic analyses based on the maternally inherited plastid organelle have enlightened evolutionary relationships between the subfamilies of Orchidaceae and most of the tribes. However, uncertainty remains within several subtribes and genera for which phylogenetic relationships have not ever been tested in a phylogenomic context. To address these knowledge-gaps, we here provide the most extensively sampled analysis of the orchid family to date, based on 78 plastid coding genes representing 264 species, 117 genera, 18 tribes and 28 subtribes. Divergence times are also provided as inferred from strict and relaxed molecular clocks and birth–death tree models. Our taxon sampling includes 51 newly sequenced plastid genomes produced by a genome skimming approach. We focus our sampling efforts on previously unplaced clades within tribes Cymbidieae and Epidendreae. Our results confirmed phylogenetic relationships in Orchidaceae as recovered in previous studies, most of which were recovered with maximum support (209 of the 262 tree branches). We provide for the first time a clear phylogenetic placement for Codonorchideae within subfamily Orchidoideae, and Podochilieae and Collabieae within subfamily Epidendroideae. We also identify relationships that have been persistently problematic across multiple studies, regardless of the different details of sampling and genomic datasets used for phylogenetic reconstructions. Our study provides an expanded, robust temporal phylogenomic framework of the Orchidaceae that paves the way for biogeographical and macroevolutionary studies.


Gene ◽  
2021 ◽  
pp. 145715
Author(s):  
Ying Zhang ◽  
Zhengfeng Wang ◽  
Yanan Guo ◽  
Sheng Chen ◽  
Xianyi Xu ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bobby Lim-Ho Kong ◽  
Hyun-Seung Park ◽  
Tai-Wai David Lau ◽  
Zhixiu Lin ◽  
Tae-Jin Yang ◽  
...  

AbstractIlex is a monogeneric plant group (containing approximately 600 species) in the Aquifoliaceae family and one of the most commonly used medicinal herbs. However, its taxonomy and phylogenetic relationships at the species level are debatable. Herein, we obtained the complete chloroplast genomes of all 19 Ilex types that are native to Hong Kong. The genomes are conserved in structure, gene content and arrangement. The chloroplast genomes range in size from 157,119 bp in Ilex graciliflora to 158,020 bp in Ilex kwangtungensis. All these genomes contain 125 genes, of which 88 are protein-coding and 37 are tRNA genes. Four highly varied sequences (rps16-trnQ, rpl32-trnL, ndhD-psaC and ycf1) were found. The number of repeats in the Ilex genomes is mostly conserved, but the number of repeating motifs varies. The phylogenetic relationship among the 19 Ilex genomes, together with eight other available genomes in other studies, was investigated. Most of the species could be correctly assigned to the section or even series level, consistent with previous taxonomy, except Ilex rotunda var. microcarpa, Ilex asprella var. tapuensis and Ilex chapaensis. These species were reclassified; I. rotunda was placed in the section Micrococca, while the other two were grouped with the section Pseudoaquifolium. These studies provide a better understanding of Ilex phylogeny and refine its classification.


2019 ◽  
Vol 4 (2) ◽  
pp. 2614-2616 ◽  
Author(s):  
Yong-Yan Zhang ◽  
Fan Liu ◽  
Na Tian ◽  
Jing-Ru Che ◽  
Xue-Li Sun ◽  
...  

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1042
Author(s):  
Cheepudom ◽  
Lin ◽  
Lee ◽  
Meng

Thermobifida fusca is of biotechnological interest due to its ability to produce an array of plant cell wall hydrolytic enzymes. Nonetheless, only one T. fusca bacteriophage with genome information has been reported to date. This study was aimed at discovering more relevant bacteriophages to expand the existing knowledge of phage diversity for this host species. With this end in view, a thermostable T. fusca bacteriophage P318, which belongs to the Siphoviridae family, was isolated and characterized. P318 has a double-stranded DNA genome of 48,045 base pairs with 3′-extended COS ends, on which 52 putative ORFs are organized into clusters responsible for the order of genome replication, virion morphogenesis, and the regulation of the lytic/lysogenic cycle. In comparison with T. fusca and the previously discovered bacteriophage P1312, P318 has a much lower G+C content in its genome except at the region encompassing ORF42, which produced a protein with unknown function. P1312 and P318 share very few similarities in their genomes except for the regions encompassing ORF42 of P318 and ORF51 of P1312 that are homologous. Thus, acquisition of ORF42 by lateral gene transfer might be an important step in the evolution of P318.


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