Correction: Understanding plastome evolution in Hemiparasitic Santalales: Complete chloroplast genomes of three species, Dendrotrophe varians, Helixanthera parasitica, and Macrosolen cochinchinensis.

[This corrects the article DOI: 10.1371/journal.pone.0200293.].

Understanding plastome evolution in Hemiparasitic Santalales: Complete chloroplast genomes of three species, Dendrotrophe varians, Helixanthera parasitica, and Macrosolen cochinchinensis.

Santalales is a large order, with over 2200 species, most of which are root or aerial (stem) hemiparasites. In this study, we report the newly assembled chloroplast genome of Dendrotrophe varians (140,666 bp) in the family Amphorogynaceae and the cp genomes of Helixanthera parasitica (124,881 bp) and Macrosolen cochinchinensis (122,986 bp), both in the family Loranthaceae. We compared the cp genomes of 11 Santalales including eight currently available cp genomes. Santalales cp genomes are slightly or not reduced in size (119-147 kb), similar to other hemiparasitic species, when compared with typical angiosperm cp genomes (120-170 kb). In a phylogeny examining gene content, the NADH dehydrogenase gene group is the only one among eight functional gene groups that lost complete functionally in all examined Santalales. This supports the idea that the functional loss of ndh genes is the initial stage in the evolution of the plastome of parasitic plants, but the loss has occurred independently multiple times in angiosperms, while they are not found in some parasites. This suggests that the functional loss of ndh genes is not essential for the transition from autotroph to parasite. We additionally examined the correlation between gene content and type of parasitism (obligate/facultative and stem/root parasites) of all hemiparasitic species in which cp genomes have been reported to date. Correlation was not found in any types of parasitism.

Molecular Identification of Mycorrhizae of Cymbidium kanran (Orchidaceae) on Jeju Island, Korea.

A fungal internal transcribed spacer region was used to identify the mycorrhizae of Cymbidium kanran. The family Russulaceae was found to be the most frequently occurring group in both root and soil samples. In phylogenetic analyses, the majority of the Russulaceae clones were clustered with Russula brevipes and R. cyanoxantha. Therefore, C. kanran may form symbiotic relationships with the genus Russula.

Phylogeny and comparative seed morphology of epiphytic and terrestrial species of Liparis (Orchidaceae) in Japan.

To elucidate the evolution of epiphytes in Liparis section Liparis, we examined the phylogenetic relationships of 16 species by using internal transcribed spacer regions of 18S-26S nuclear ribosomal DNA (ITS) and three chloroplast DNA regions (trnS-trnG spacer, trnL with trnL-trnF spacer, and partial matK). Results showed that the epiphytic L. fujisanensis is sister to the terrestrial L. koreana and L. kumokiri, while another epiphyte, L. truncata, is sister to the terrestrial L. krameri. Therefore, the two epiphytic species evolved from terrestrial species independently in section Liparis. Comparative seed morphology revealed that the epiphytes have larger embryos than their closely related terrestrial counterparts. A similar trend toward the increase of embryo size in the two epiphytic species belonging to closely related, but distinct clades suggests that the large embryo may have an advantage in the epiphytic lifestyle. The two epiphytic species share another character state, smaller air spaces in the seed than that of closely related terrestrial species, suggesting possible low dispersibility of the epiphytes.

Cytotoxic constituents from the whole plant of Corydalis pallida.

Here we report the cytotoxic activity of three known compounds isolated for the first time from Corydalis pallida (Papaveraceae). An isoquinoline alkaloid, berberine, exhibited cytototoxic activity against two human cancer cell lines, HT-1080 (human fibrosarcoma) and SNU-638 (human stomach adenocarcinoma), with IC50 values of 3.2 and 3.4 microg/mL, respectively. N-trans-feruloyltyramine and N-trans-feruloylmethoxytyramine were also isolated from this plant but were inactive.

Molecular evidence for the taxonomic identity of Korean Adonis (Ranunculaceae).

Although Korean Adonis has been traditionally recognized as Adonis amurensis Regel and Radde with various infraspecific taxa described, its taxonomic identity is still in dispute. We investigated the genetic variation in 60 individuals from 12 populations in Korea to elucidate the taxonomic identity of the Korean Adonis complex. Random amplified polymorphic DNA (RAPD) analysis revealed that Korean Adonis comprises three species: A. amurensis, A. pseudoamurensis, and A. multiflora. Adonis amurensis is distributed in northern central inland regions of Korea and A. pseudoamurensis is found in southern parts of the Korean peninsula. Adonis multiflora grows only on Cheju Island, which is the southernmost part of Korea. Phylogenetic analysis of nuclear ribosomal internal transcribed spacer (ITS) sequences partially supported the presence of three Adonis taxa in Korea as detected by RAPD analysis. The Adonis population on Jangbong Island located in the West Sea, which was referred to as A. pseudoamurensison the basis of morphological examination, was separated from the other populations of A. pseudoamurensis. Otherwise, the molecular evidence is well congruent with the recent morphological study that proposes that Korean Adonis consists of these three species.