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Petrocosmea qinlingensis is a protected wild plant endemic in China, inhabiting low-light limestone cliffs but the complete chloroplast genome has not been reported. In this study, we first sequenced and assembled the complete chloroplast genome of P. qinlingensis. The total size of this genome was 153,865 bp, including a large single-copy (LSC) region (84,737 bp), a small single-copy (SSC) region (18,244 bp), and two inverted repeats (IRs) regions (25,442 bp). This genome encoded 111 uniquegenes, consisted of 77 protein-coding genes, four ribosomal RNA genes, and 30 transfer RNA genes. Phylogenomic analysis based on the chloroplast protein-coding genes and showed that the genus Petrocosmea was the closest relative to Raphiocarpus. Our results will support further phylogeographic, population genetic studies of this species. [ABSTRACT FROM AUTHOR]

Although more than 9100 plant plastomes have been sequenced, RNA editing sites of the whole plastome have been experimentally verified in only approximately 21 species, which seriously hampers the comprehensive evolutionary study of chloroplast RNA editing. We investigated the evolutionary pattern of chloroplast RNA editing sites in 19 species from all 13 families of gymnosperms based on a combination of genomic and transcriptomic data. We found that the chloroplast C-to-U RNA editing sites of gymnosperms shared many common characteristics with those of other land plants, but also exhibited many unique characteristics. In contrast to that noted in angiosperms, the density of RNA editing sites in ndh genes was not the highest in the sampled gymnosperms, and both loss and gain events at editing sites occurred frequently during the evolution of gymnosperms. In addition, GC content and plastomic size were positively correlated with the number of chloroplast RNA editing sites in gymnosperms, suggesting that the increase in GC content could provide more materials for RNA editing and facilitate the evolution of RNA editing in land plants or vice versa. Interestingly, novel G-to-A RNA editing events were commonly found in all sampled gymnosperm species, and G-to-A RNA editing exhibits many different characteristics from C-to-U RNA editing in gymnosperms. This study revealed a comprehensive evolutionary scenario for chloroplast RNA editing sites in gymnosperms, and reported that a novel type of G-to-A RNA editing is prevalent in gymnosperms. [ABSTRACT FROM AUTHOR]

Tribe Theeae, which includes some economically important and widely grown plants, such as beverage tea and a number of woody ornamentals, is the largest member of the Theaceae family. Using five genomic regions (chloroplast: atpI-H, matK, psbA5'R-ALS-11F, rbcL; nuclear: LEAFY) and 30 species representing four of the five genera in this tribe (Apterosperma, Camellia, Polyspora, and Pyrenaria s.l.), we investigated the phylogeny of Theeae and assessed the delimitation of genera in the tribe. Our results showed that Polyspora was monophyletic and the sister of the three other genera of Theeae investigated, Camellia was paraphyletic and Pyrenaria was polyphyletic. The inconsistent phylogenetic placement of some species of Theeae between the nuclear and chloroplast trees suggested widespread hybridization between Camellia and Pyrenaria, Polyspora and Parapyrenaria. These results indicate that hybridization, rather than morphological homoplasy, has confused the current classification of Theeae. In addition, the phylogenetic placement and possible allies of Laplacea are also discussed. [ABSTRACT FROM AUTHOR]

Corydalis DC., the largest genus of Papaveraceae, was recognized as one of the most taxonomically challenging plant taxa. Due to the lack of genetic information used in previous studies, species discrimination and taxonomic assignment in Corydalis have not been fully solved. Here, the complete chloroplast genomes were reported for Corydalis edulis Maxim. and Corydalis shensiana Liden, with their genome sizes being 154,395 and 155,938 bp, respectively. Both of the chloroplast genomes comprise two inverted repeat (IR) regions, separated by a large single-copy (LSC) region and a small single-copy (SSC) region, and encode 130 genes, including 85 protein-coding genes, 8 ribosomal RNA genes, 37 transfer RNA genes. Our study will provide novel insight into the molecular phylogeny and classification of Corydalis. [ABSTRACT FROM AUTHOR]