Evidence from Phylogenomics and Morphology Provide Insights into the Phylogeny, Plastome Evolution, and Taxonomy of Kitagawia.

Kitagawia Pimenov is one of the segregate genera of Peucedanum sensu lato within the Apiaceae. The phylogenetic position and morphological delimitation of Kitagawia have been controversial. In this study, we used plastid genome (plastome) and nuclear ribosomal DNA (nrDNA) sequences to reconstruct the phylogeny of Kitagawia, along with comparative plastome and morphological analyses between Kitagawia and related taxa. The phylogenetic results identified that all examined Kitagawia species were divided into Subclade I and Subclade II within the tribe Selineae, and they were all distant from the representative members of Peucedanum sensu stricto. The plastomes of Kitagawia and related taxa showed visible differences in the LSC/IRa junction (JLA) and several hypervariable regions, which separated Subclade I and Subclade II from other taxa. Fruit anatomical and micromorphological characteristics, as well as general morphological characteristics, distinguished the four Kitagawia species within Subclade I from Subclade II and other related genera. This study supported the separation of Kitagawia from Peucedanum sensu lato, confirmed that Kitagawia belongs to Selineae, and two species (K. praeruptora and K. formosana) within Subclade II should be placed in a new genus. We believe that the "core" Kitagawia should be limited to Subclade I, and this genus can be distinguished by the association of a series of morphological characteristics. Overall, our study provides new insights into the phylogeny, plastome evolution, and taxonomy of Kitagawia.

The phylogeny of Seseli (Apiaceae, Apioideae): insights from molecular and morphological data.

BACKGROUND: The genus Seseli L., which consists of 125-140 species distributed in the Old World from western Europe and northwestern Africa to China and Japan, is one of the largest and most taxonomically difficult genera of Apiaceae Lindl. Although several previous studies have been conducted on Seseli based on limited morphological characteristics and molecular fragments, a robust and comprehensive phylogeny of Seseli remains elusive. Plastomes provide abundant genetic information and have been widely used in studying plant phylogeny and evolution. Consequently, we newly generated the complete plastomes of eleven Seseli taxa. We combined plastome data and morphological characteristics to investigate the phylogeny of Seseli. RESULTS: In our study, we observed that the genome length, gene numbers, IR/SC borders, and repeat composition of the eleven Seseli plastomes were variable. Several appropriate mutation hotspot regions may be developed as candidate DNA barcodes for evolution, phylogeny, and species identification of Seseli. The phylogenetic results identified that Seseli was not a monophyletic group. Moreover, the eleven newly sequenced Seseli taxa did not cluster with S. tortuosum (the type species of Seseli, belonging to the tribe Selineae), where S. delavayi clustered with Eriocycla belonging to the tribe Echinophoreae and the other ten belonged to Selineae. The comparative plastome and morphological characteristics analyses confirmed the reliability of the phylogenetic analyses and implied the complex evolution of Seseli. CONCLUSION: Combining molecular and morphological data is efficient and useful for studying the phylogeny of Seseli. We suggest that "a narrow sense" of Seseli will be meaningful for further study and the current taxonomic system of Seseli needs to be revised. In summary, our study can provide new insights into the phylogenetic relationships and taxonomic framework of Seseli.

Alliumheterophyllum (Amaryllidaceae), a new species from Henan, China.

Alliumheterophyllum D.F.Xie & X.J.He, sp. nov. (Amaryllidaceae), is a new species from Henan, China and is described based on morphological and molecular evidence. It is morphologically most similar to A.dumebuchum in the rhomboid scape in cross-section. However, distinctive differences were detected in perianth color, leaf shape and cross-section, flowers' density as well as flowering season. Similarly, the karyotype of A.heterophyllum is 2n = 2x = 16 and in A.dumebuchum is 2n = 4x = 32. Phylogenetic analysis based on nuclear ribosomal Internal Transcribed Spacers (ITS) and three cpDNA regions strongly supports that A.heterophyllum is a member of Allium section Rhizirideum and sister to the other species of this section (e.g. A.senescens, A.spirale, and A.prostratum). Currently, only one population and approximately 120 individuals were discovered; the development of scenic spots in this region may affect its growth and threaten this population. Therefore, this new species is preliminarily considered as Near Threatened (NT) according to criteria of the IUCN Red List.

The complete plastomes of seven Peucedanum plants: comparative and phylogenetic analyses for the Peucedanum genus.

BACKGROUND: The Peucedanum genus is the backbone member of Apiaceae, with many economically and medically important plants. Although the previous studies on Peucedanum provide us with a good research basis, there are still unclear phylogenetic relationships and many taxonomic problems in Peucedanum, and a robust phylogenetic framework of this genus still has not been obtained, which severely hampers the improvement and revision of taxonomic system for this genus. The plastid genomes possessing more variable characters have potential for reconstructing a robust phylogeny in plants. RESULTS: In the current study, we newly sequenced and assembled seven Peucedanum plastid genomes. Together with five previously published plastid genomes of Peucedanum, we performed a comprehensively comparative analyses for this genus. Twelve Peucedanum plastomes were similar in terms of genome structure, codon bias, RNA editing sites, and SSRs, but varied in genome size, gene content and arrangement, and border of SC/IR. Fifteen mutation hotspot regions were identified among plastid genomes that can serve as candidate DNA barcodes for species identification in Peucedanum. Our phylogenetic analyses based on plastid genomes generated a phylogeny with high supports and resolutions for Peucedanum that robustly supported the non-monophyly of genus Peucedanum. CONCLUSION: The plastid genomes of Peucedanum showed both conservation and diversity. The plastid genome data were efficient and powerful for improving the supports and resolutions of phylogeny for the complex Peucedanum genus. In summary, our study provides new sights into the plastid genome evolution, taxonomy, and phylogeny for Peucedanum species.

A pH-sensitive drug delivery system based on hyaluronic acid co-deliver doxorubicin and aminoferrocene for the combined application of chemotherapy and chemodynamic therapy.

Doxorubicin is a broad-spectrum antineoplastic drug used in tumor therapy, its clinical application is limited by side effects on normal tissues. In this article, a pH-responsive drug delivery system (NPs(DOX/AFc)) with co-delivers doxorubicin (DOX) and aminoferrocene (AFc) was prepared by a two-step synthesis method including the oxidation of hyaluronic acid and Schiff base reaction. NPs(DOX/AFc) can be used in combination therapy of chemodynamic therapy (CDT) and chemotherapy (CT), thus the dosage of the chemotherapeutic drug DOX was reduced. The drug release behavior of NPs(DOX/AFc) in vitro showed that acid-responsive drug releases under the endosomal/lysosomal environment were 56.5 % of DOX and 61.8 % of AFc. In vitro toxicity experiments showed that DOX and AFc had synergistic effects (CI = 0.878). The results of intracellular ROS measurement and the mitochondrial membrane potential analysis showed that in tumor cells NPs(DOX4/AFc) induced more production of reactive oxygen species and more loss of the mitochondrial membrane potential. In short, this co-delivery system based on polymer prodrugs provides a new idea for the combined application of CT and CDT.

A pH-sensitive oxidized-dextran based double drug-loaded hydrogel with high antibacterial properties.

Delayed healing or non-healing of wounds caused by bacterial infection is still a difficult medical problem. Nowadays, the topical application of antibiotics is a common treatment for infections. However, subinhibitory concentrations or high dose of antibiotics leads to the antibacterial effect counterproductive. So it's necessary to put forward an on-demand drug delivery to solve this tough issue. In this paper, a pH-responsive hydrogel was prepared by oxidized dextran (Dex-CHO), sulfadiazine (SD) and tobramycin (TOB). The hydrogel was designed by the environment in the early immature stage of biofilm (pH 5.0). Schiff bases can release drugs in slightly acidic environment. The hydrogel showed injectable, pH-sensitive drug release, and great biocompatibility. Released SD and TOB exhibited a synergistic effect therefore the hydrogel showed high antibacterial activity. This study provides an easy and promising strategy to develop smart hydrogels that aim at topical administration of antibiotics and come up with a new treatment of local bacterial infections.