Complete chloroplast genome of Austral king fern Todea barbara (L.) Moore (Osmundaceae).

In this study, we determined the chloroplast genome sequence of the Austral king fern, Todea barbara (L.) Moore. The plastome of T. barbara is a typical circular form composed of 144,208 bp with two inverted repeats (IRs; 10,442 bp), a large single copy (LSC; 101,059 bp), and a small single copy (SSC; 22,265 bp). The complete sequence comprises 131 genes, namely 85 protein-coding genes, eight ribosomal RNAs, and 38 transfer RNAs. The guanine-cytosine (GC) content of the genome was found to be 39.9%. Additionally, U-to-C RNA editing sites were identified in eight genes: atpE, chlB, clpP, matK, rpl20, rpoB, rpoC1, and rpoC2. Phylogenetic analysis using 85 coding gene sequences revealed that the genera Todea and Osmunda form a clade and that the genus Osmundastrum is a sister genus to both.

Dynamic hybridization between two spleenworts, Asplenium incisum and Asplenium ruprechtii in Korea.

Natural hybridization between Asplenium incisum and A. ruprechtii has been observed in Northeast Asia and its allotetraploid species, A. castaneoviride, was reported. However, the hybridization process between the parental species and the origin of the allotetraploid taxon remains obscure. Additionally, the systematic affinities of the recently described hybrid A. bimixtum, considered to have originated from the hybridization of A. ruprechtii, A. trichomanes, and A. incisum, is unresolved owing to its similarity to A. castaneoviride. The goals of this study were to (1) investigate the hybridization between A. ruprechtii and A. incisum; (2) verify the origin of A. castaneoviride occurring in Korea, whether it independently arose from 2x sterile hybrids; and (3) elucidate the reliability of identifying A. bimixtum. Three genotypes, A. incisum, A. ruprechtii, and their hybrid, were identified based on the nuclear gene pgiC sequence and finally divided them into six types by ploidy levels: diploid A. incisum, A. ruprechtii, and four hybrid types (diploid A. × castaneoviride, triploid A. × castaneoviride, allotetraploid A. castaneoviride, and A. bimixtum). In the analyses of plastid DNA, all hybrids had an A. ruprechtii-type rbcL gene. In addition, the four plastomes of A. ruprechtii and the hybrids had high pairwise sequence identities greater than 98.48%. They increased up to 99.88% when a large deletion of A. x castaneoriviride (2x) collected from Buramsan populations was ignored. Notably, this large deletion was also found in triploid A. × castaneoviride and allotetraploid A. castaneoviride in the same populations. Sequence data of the nuclear and plastid genes showed that hybridization is unidirectional, and A. ruprechtii is the maternal parent. The large deletion of rpoC2-rps2 commonly found in the different ploidy hybrids of the Buramsan population suggests that the allotetraploid A. castaneoviride can be created independently from sterile hybrids. We assume that both polyploidization driving allopolyploidy and minority cytotype exclusion took place independently in the population, since A castaenoviride co-occurs with A. ruprechtii in small populations. Furthermore, it was also observed that an enlarged noncoding region in fern organelle (ENRIFO) of the plastome was found in the genus Asplenium.

The complete chloroplast genome sequence of Crepidomanes latealatum (Bosch) Copel.

The complete chloroplast genome sequence of Crepidomanes latealatum (Bosch) Copel. was determined in the present study. The genome is 145,943 base pairs (bp) in length and comprised two inverted repeats (32,990 bp) between a large single copy (92,170 bp) and a small single copy (20,783 bp). It contains 88 coding genes, 8 rRNA genes, 34 tRNA genes, and 1 pseudogene of trnL-UAA, and the GC content is 37.6%. Molecular phylogenetic analysis based on the plastid genome sequences of related taxa strongly supported the monophyly of the family Hymenophyllaceae, and the genus Vandenboschia was a sister group of Crepidomanes. In addition, compared to C. minutum, two large deletions of 453 bp and 878 bp were found in the IGS regions of petA-psbI and rrn16-trnV-GAC of C. latealatum cp genome, respectively.

The complete chloroplast genome sequence of the Korean maple tree (Acer pseudosieboldianum (Pax) Kom.).

The complete chloroplast genome sequence of Acer pseudosieboldianum (Sapindaceae) was determined. The chloroplast genome of A. pseudosieboldianum is 157,053 bp in length with two inverted repeats (26,747 bp) between a large single-copy (85,391 bp) and a small single-copy (18,168 bp). The GC content was 37.8% and it was composed of 86 coding genes, eight rRNA genes, 37 tRNA genes, and two pseudogenes, rps2, and ycf1. Molecular phylogenetic analysis based on the plastid genome sequences strongly supported the hypothesis that A. pseudosieboldianum was embedded in the series Palmata of section Palmata. However, the phylogenetic positions of A. ukurunduense and A. buergerianum, which are a members of the series Penninervia of sections Palmata and Pentaphylla, respectively, were incongruent with the recent sectional classification system.

Asplenium pseudocapillipes (Aspleniaceae), a New Fern Species from South Korea.

A new allotetraploid species of the genus Asplenium, A. pseudocapillipes, originated from the hybridization between A. capillipes and A. tenuicaule, has been newly discovered in two limestone areas of South Korea. A molecular phylogenetic analysis using one chloroplast region (rbcL) and three single- or low-copy nuclear regions (AK1, gapCp, pgiC) and a cytological analysis, including genome size measurements, were conducted to characterize this new species. From these results, the maternal origin of A. pseudocapillipes was confirmed to be A. capillipes, which has never been reported in Korea. All three nuclear data showed that this new species had genotypes of both A. capillipes and A. tenuicaule. The quantitative characteristics of the leaves showed values intermediate between the two parental species. The absence of gemma accorded with its paternal origin from A. tenuicaule, and 32 spores per sporangium accorded with its maternal origin from A. capillipes. Although A. pseudocapillipes has 32 spores per sporangium, it is considered to be a sexually reproducing, not an apomitic, fern.

The complete chloroplast genome of Ziziphus jujuba cv. Bokjo (Rhamnaceae).

We have sequenced the Ziziphus jujuba cv. Bokjo chloroplast genome by de novo assembly using next-generation sequencing. The complete circular chloroplast genome consisted of 161,714 bp and contained four parts: a large single-copy (LSC) region of 89,323 bp, a small single-copy (SSC) region of 19,361 bp, and two inverted repeat regions (IRa and IRb) of 26,515 bp each. The genome annotation predicted a total of 110 genes, including 76 protein-coding genes, 30 tRNA genes, and four rRNA genes. Phylogenetic analysis demonstrated the close taxonomic relationship between Z. jujuba cv. Bokjo and two other members of the Ziziphus genus, Z. spina-christi and Z. mauritiana. We found 135 polymorphic loci, 63 single nucleotide polymorphism (SNP) and 72 insertion-deletion (InDel), from the comparison of Z. jujuba cultivar Bokjo and Z. jujuba reference (NC_030299). The polymorphic loci could be used for the differentiation of Z. jujuba genetic resources and for breeding in the future.

The complete chloroplast genome sequence of Haplopteris flexuosa (Fée) E.H. Crane.

The complete chloroplast genome sequence of Haplopteris flexuosa, a member of Vittarioideae (family Pteridaceae), was determined. The chloroplast genome of H. flexuosa was 165,664 bp in length with two inverted repeats (32,556 bp) between a large single copy (79,996 bp) and a small single copy (20,556 bp). The GC content was higher than that of related taxa H. elongate, and it was caused by high GC content of expanded regions by insertion of mobile open reading frames in fern organelles (MORFFO) found in the family Pteridaceae. And also, we found that rrn5-rps12 enlarged region of H. flexuosa was similar to MORFFOs of other Pteridaceae.

Structural Mutations in the Organellar Genomes of Valeriana sambucifolia f. dageletiana (Nakai. ex Maekawa) Hara Show Dynamic Gene Transfer.

Valeriana sambucifolia f. dageletiana (Nakai. ex Maekawa) Hara is a broad-leaved valerian endemic to Ulleung Island, a noted hot spot of endemism in Korea. However, despite its widespread pharmacological use, this plant remains comparatively understudied. Plant cells generally contain two types of organellar genomes (the plastome and the mitogenome) that have undergone independent evolution, which accordingly can provide valuable information for elucidating the phylogenetic relationships and evolutionary histories of terrestrial plants. Moreover, the extensive mega-data available for plant genomes, particularly those of plastomes, can enable researchers to gain an in-depth understanding of the transfer of genes between different types of genomes. In this study, we analyzed two organellar genomes (the 155,179 bp plastome and the 1,187,459 bp mitogenome) of V. sambucifolia f. dageletiana and detected extensive changes throughout the plastome sequence, including rapid structural mutations associated with inverted repeat (IR) contraction and genetic variation. We also described features characterizing the first reported mitogenome sequence obtained for a plant in the order Dipsacales and confirmed frequent gene transfer in this mitogenome. We identified eight non-plastome-originated regions (NPRs) distributed within the plastome of this endemic plant, for six of which there were no corresponding sequences in the current nucleotide sequence databases. Indeed, one of these unidentified NPRs unexpectedly showed certain similarities to sequences from bony fish. Although this is ostensibly difficult to explain, we suggest that this surprising association may conceivably reflect the occurrence of gene transfer from a bony fish to the plastome of an ancestor of V. sambucifolia f. dageletiana mediated by either fungi or bacteria.

A Small Number of Gametophytes with Gametangia and Stunted Sporophytes of Antrophyum obovatum Baker (Pteridaceae): The Suppression of Functional Sporophyte Production by Prezygotic and Postzygotic Sterility.

Ferns have conspicuous sporophytes as the dominant phase in their life cycle; however, the gametophytes are completely separated from the sporophytes and supply their own nutrition, unlike in bryophytes and seed plants. Among the gametophytes, some maintain their populations in the gametophyte phase without progressing to sporophyte production and are known as independent gametophytes. Independent gametophytes of Antrophyum obovatum Baker were recently reported in one population on Jeju Island, Korea. In the present study, we surveyed more places to find new independent gametophyte populations of A. obovatum using the rbcL gene sequence-based DNA barcoding technique. We identified two new sites inhabited by independent gametophytes. Archegonia and juvenile sporophytes were independently observed in each location under slightly different environmental conditions. Consequently, in the case of this species, functional sporophyte production is likely suppressed by prezygotic and postzygotic sterility, depending on microenvironmental factors.

Study of the independent gametophytes found on Jeju Island in South Korea and the first record of the obligate independent gametophyte of Antrophyum obovatum Baker.

Fern gametophytes have often been neglected in research; however, studies on gametophytes are crucial for a better understanding of the evolution of ferns. During their life cycle, some gametophytes produce large and long-lived populations without producing sporophytes and reproduce independently through asexual means, such as through the formation of gemmae. In this study, we investigated independent gametophytes on the Jeju Island of Korea, which was located on the land bridge between East China and Japan during the glacial periods. Fourteen gametophyte populations were collected from seven sites, of which 13 populations were clearly identified as belonging to four fern species known to occur in Jeju Island with BLAST searches using rbcL and trnL-F sequences. Surprisingly, the last remaining population constituted undescribed taxa in Korea. We presented the first report of the independent gametophytes of Antrophyum obovatum Baker which has not been previously recorded in Korea. It has been supposed that many ferns sought suitable habitat throughout the land bridge between China and Japan. However, Jeju Island might be unsuitable for vittarioid ferns that prefer a tropical or subtropical environment. Consequently, only two species of vittariod ferns (A. obovatum and Haplopteris flexuosa (Fée) E.H. Crane) in the form of a gametophyte and sporophyte, respectively, exist on Jeju Island. Therefore, this gametophyte population must be protected and managed from a conservation perspective. In the case of the independent gametophyte of Hymenophyllum wrightii Bosch, haplotype analysis was conducted based on the rbcL sequences and the result supported that the North American populations were migrated from Japan through land bridge during the glacial periods and Jeju populations were recently established by long-distance dispersal of the Japanese populations.

The dynamic evolution of mobile open reading frames in plastomes of Hymenophyllum Sm. and new insight on Hymenophyllum coreanum Nakai.

In this study, four plastomes of Hymenophyllum, distributed in the Korean peninsula, were newly sequenced and phylogenomic analysis was conducted to reveal (1) the evolutionary history of plastomes of early-diverging fern species at the species level, (2) the importance of mobile open reading frames in the genus, and (3) plastome sequence divergence providing support for H. coreanum to be recognized as an independent species distinct from H. polyanthos. In addition, 1C-values of H. polyanthos and H. coreanum were measured to compare the genome size of both species and to confirm the diversification between them. The rrn16-trnV intergenic regions in the genus varied in length caused by Mobile Open Reading Frames in Fern Organelles (MORFFO). We investigated enlarged noncoding regions containing MORFFO throughout the fern plastomes and found that they were strongly associated with tRNA genes or palindromic elements. Sequence identity between plastomes of H. polyanthos and H. coreanum is quite low at 93.35% in the whole sequence and 98.13% even if the variation in trnV-rrn16 intergenic spacer was ignored. In addition, different genome sizes were found for these species based on the 1C-value. Consequently, there is no reason to consider them as a conspecies.

A Molecular Phylogenetic Study of the Genus Phedimus for Tracing the Origin of "Tottori Fujita" Cultivars.

It is very important to confirm and understand the genetic background of cultivated plants used in multiple applications. The genetic background is the history of crossing between maternal and paternal plants to generate a cultivated plant. If the plant in question was generated from a simple origin and not complicated crossing, we can easily confirm the history using a phylogenetic tree based on molecular data. This study was conducted to trace the origin of "Tottori Fujita 1gou" and "Tottori Fujita 2gou", which are registered as cultivars originating from Phedimus kamtschaticus. To investigate the phylogenetic position of these cultivars, the backbone tree of the genus Phedimus needed to be further constructed because it retains inarticulate phylogenetic relationships among the wild species. We performed molecular phylogenetic analysis for P. kamtschaticus, Phedimus takesimensis, Phedimus aizoon, and Phedimus middendorffianus, which are assumed as the species of origin for "Tottori Fujita 1gou" and "Tottori Fujita 2gou". The molecular phylogenetic tree based on the internal transcribed spacer (ITS) and psbA-trnH sequences showed the monophyly of the genus Phedimus, with P. takesimensis forming a single clade. However, P. kamtschaticus and P. aizoon were scattered in the tree. It was verified that "Tottori Fujita 1gou" and "Tottori Fujita 2gou" were embedded in a clade with P. takesimensis and not P. kamtschaticus. Therefore, origination from P. takesimensis was strongly supported. Based on these results, molecular phylogenetic analysis is suggested as a powerful tool for clearly tracing the origin of cultivated plants.

The complete chloroplast genome sequence of Thymus quinquecostatus var. japonicus (Lamiaceae), an endemic to Ullenung Island of Korea.

The complete chloroplast (cp) genome sequence of Thymus quinquecostatus var. japonicus, an endemic species to Ulleung Island of Korea and used as plant material for folk remedies, was firstly analyzed in this study. It showed a typical circular structure composed of 151,782 bp in length and comprised of a large single-copy region (82,903bp) and a small single-copy region (17,667 bp) which were separated by two inverted repeat regions (25,606 bp). From the phylogenetic analyses of related taxa using the complete chloroplast genome sequences, it was proved that T. quinquecostatus var. japonicus is sister to the member of genus Mentha within the subfamily Nepetoideae.

The complete chloroplast genome sequence of Ajania pacifica (Nakai) Bremer & Humphries.

The complete chloroplast (cp) genome sequence of Ajania pacifica, called as golden and silver chrysanthemum, was newly analyzed in this study. It was 151,059 bp in length and was a typical circular structure composed of and comprised of a large single copy region (82,857 bp) and a small single copy region (18,294 bp) which were separated by two inverted repeat regions (24,954 bp). The molecular phylogenetic analyses of A. pacifica and its related taxa was conducted based on the complete chloroplast genome sequences, and it was proved that the genus Ajania is embedded in the genus Chrysanthemum clade as well as a monotypic genus Opisthopappus. In the other hand, the genus Artemisia was divided into two group in the tribe Anthemideae.

The complete chloroplast genome sequence of Leucanthemella linearis (Matsum. ex Matsum.) Tzvelev (Asteraceae), endangered plant of Korea.

The complete chloroplast (cp) genome sequence of LHeucanthemella linearis was newly analyzed in this study. It was 151,395 bp in length and was a typical circular structure composed of a large single-copy region (LSC) (83,080 bp) and a small single-copy (SSC) region (18,391 bp) which were separated by two inverted repeat regions (24,962 bp). It was totally 6 bp shorter than the Chinese L. linearis cp genome and was composed of 132 genes. There were four regional specific Indels between them in the LSC region as well as 20 bp insertion in the intergenic spacer region excluding poly-A/T sequence variation. And it was clear that both of Luecanthemella linearis were sister to Chrysanthemum - Artemisia groups and their phylogenetic relationship from this study.

New Insights on Lilium Phylogeny Based on a Comparative Phylogenomic Study Using Complete Plastome Sequences.

The genus Lilium L. is widely distributed in the cold and temperate regions of the Northern Hemisphere and is one of the most valuable plant groups in the world. Regarding the classification of the genus Lilium, Comber's sectional classification, based on the natural characteristics, has been primarily used to recognize species and circumscribe the sections within the genus. Although molecular phylogenetic approaches have been attempted using different markers to elucidate their phylogenetic relationships, there still are unresolved clades within the genus. In this study, we constructed the species tree for the genus using 28 Lilium species plastomes, including three currently determined species (L. candidum, L. formosanum, and L. leichtlinii var. maximowiczii). We also sought to verify Comber's classification and to evaluate all loci for phylogenetic molecular markers. Based on the results, the genus was divided into two major lineages, group A and B, consisting of eastern Asia + Europe species and Hengduan Mountains + North America species, respectively. Sectional relationships revealed that the ancestor Martagon diverged from Sinomartagon species and that Pseudolirium and Leucolirion are polyphyletic. Out of all loci in that Lilium plastome, ycf1, trnF-ndhJ, and trnT-psbD regions are suggested as evaluated markers with high coincidence with the species tree. We also discussed the biogeographical diversification and long-distance dispersal event of the genus.

Transcriptomic Identification and Biochemical Characterization of HmpA, a Nitric Oxide Dioxygenase, Essential for Pathogenesis of Vibrio vulnificus.

Nitric oxide (NO) and its derivatives are important effectors of host innate immunity, disrupting cellular function of infecting pathogens. Transcriptome analysis of Vibrio vulnificus, an opportunistic human pathogen, identified a set of genes induced upon exposure to NO. Among them, VvhmpA (V. vulnificus hmpA), encoding a multidomain NO dioxygenase, was the most greatly induced upon exposure to NO and was thus further characterized. Absorption spectra demonstrated that VvHmpA is a heme protein in which the heme iron can exist in either reduced, NO-bound, or oxidized state. Biochemical studies revealed that VvHmpA is a flavohemoglobin containing equimolar amounts of heme and FAD as cofactors. The K M and k cat values of VvHmpA for NO at 37°C, the temperature encountered by V. vulnificus in the host, were greater than those at 30°C, indicating that VvHmpA detoxifies high levels of NO effectively during infection. Compared with the wild type, the VvhmpA mutant exhibited a lower NO-decomposition activity and impaired growth in the presence of NO in vitro. Also, the cytotoxicity and survival of the VvhmpA mutant infecting the NO-producing murine macrophage cells were lower than those of the wild type. Furthermore, the mouse lethality of the VvhmpA mutant was reduced compared to that of the parental wild type. The combined results revealed that VvHmpA is a potent virulence factor that is induced upon exposure to NO and important for the survival and pathogenesis of V. vulnificus during infection.

The complete plastid genome sequence of Chrysanthemum lucidum (Asteraceae): an endemic species of Ulleung Island of Korea.

The characteristic of complete chloroplast (cp) genome sequence of Chrysanthemum lucidum, one of famous insular plant and an endemic to Ulleung Island of Korea, was firstly introduced in the present study. It was 150,985 bp and contained a large single copy region (82,786 bp) and a small single copy region (18,281 bp) which were separated by two inverted repeat regions (24,959 bp). In total, 131 genes were identified and they were consisted of 76 coding genes, eight rRNA genes, and 36 tRNA genes. Comparing to the previously reported Chrysanthemum indicum and C. x morifolium cp genomes, we found complete inversion of SSC region in this taxa. rpoC1 gene was pseudogenes due to 1 bp insertion of poly-A sequence in the 3' of exon 2.

The complete chloroplast genome sequence of Hydrangea luteovenosa (Hydrangeaceae).

Hydrangea luteovenosa is a member of the family Hydrangeaceae. The complete chloroplast genome sequence of H. luteovenosa was characterized from MiSeq (Illumina Co.) pair-end sequencing data. The chloroplast genome of H. luteovenosa was 157,494 bp in length with a pair of inverted repeats (IRs) (25,126 bp) which were separated by a large single-copy (LSC) (86,596 bp) and a small single-copy regions (SSC) (18,646 bp). It contained 129 genes including 85 protein-coding genes, 36 tRNA genes, and 8 ribosomal RNA genes. The maximum-likelihood phylogenetic analysis with the previously reported chloroplast genomes showed that H. luteovenosa is most closely related to the tribe Hydrangeeae.

The complete plastid genome sequence of Rheum wittrockii (Polygonaceae), endangered species of Kazakhstan.

The complete chloroplast (cp) genome sequence of Rheum wittrockii, an endangered and medicinal plant of Kazakhstan, was firstly determined in the present study. It was 159,051 bp and contained a large single copy region (84,750 bp) and a small single copy region (12,999 bp) which were separated by two inverted repeat regions (30,651 bp). In total, 131 genes were identified and they were consisted of 79 coding genes, 8 rRNA genes, and 36 tRNA genes. rpl23 was pseudogenes due to sequence substitution. Among 23 genes containing introns, rps12 and ycf3 contained two introns and the rest had just one intron. Comparing to Chinese R. palmatum chloroplast genome, rpl32 and rpoA gene were shortened due to 1bp and 7bp deletion at poly-T and poly-A, respectively.