156 research outputs found
Comparative pollen morphology of Calycanthaceae for their taxonomic implication
The pollen morphology of four species of Calycanthaceae is described based on the observation of scanning electron microscopy and light microscopy. All pollens are monad, large grain category. The pollen grain was elliptic with disulcate. Surface ornamentation is smooth. Pollen grains of each species are from the genus Sinocalycanthus, Calycanthus, Chimonanthus and Idiospermum. The basic shape of the pollen grains is elliptical. The pollen is spheroid in Calycanthaceae except in Idiospermum, which represent boat-shape. The circular shape was in polar views in Chimonanthus but equatorial shape in Sinocalycanthus. Idiospermum and Chimonanthus were smooth exine with micro-perforation but rugose exine in Sinocalycanthus and Chimonanthus.
DOI: http://dx.doi.org/10.5281/zenodo.376333
Comparative stem anatomy of four taxa of Calycanthaceae Lindl.
The anatomical character is potential value in Calycanthaceae for their taxonomic study. Four species of Calycanthaceae were collected for this experiment. The experiment was done using the resin methods for preparation of the permanent slide for anatomical studies. The anatomical character like two traces of the unilocular vascular bundle, in the primary vascular cylinder, contains four cortical vascular bundles in the stem, the unilocular structure of primary cylinder, the presence of numerous intercellular space in phloem, the presence of oil cell in the form of scatter in Calycanthus whereas small size in Chimonathus. Calycanthus possess boarder pit with circular aperture while Chimonanthus possess elliptical. The tracheid is a characteristic feature of the spiral band wider in Chimonanthus than that of Calycanthus and Sinocalycanthus. The noted sclerenchymatous cells are grouped of the colony which is a characteristic feature of Sinocalycanthus and Calycanthus but in case of Chimonanthus is the long chain with the layer of the cell. Collenchymatous cell was circular with an intercellular in Calycanthus; ovoid shape with the intercellular in Chimonanthus but in Sinocalycanthus is elongation with the minor regular shape. The different character of pith cells found in hexagonal and circular shape which is also distinguished feature in Calycanthaceae. The valu-able stem anatomical characters are the importance of their function, ontogeny, and phylogeny.
DOI: http://dx.doi.org/10.5281/zenodo.119957
Cladistics analysis of Calycanthaceae on the basis of morphological and anatomical characters
Cladistics analysis was carried out to find the correct phylogenetic relationship of the four genera of Calycanthaceae. Morphological and anatomical information from all aspect of the data were considered for the analysis. Siparuna guianensis (Siparunaceae) and Cinnamomum malabatrum (Lauraceae) were considered as out-group. Characters were selected mainly for reasonable argument of the similarity. Character-state transformation and discrimination of the genera were decided based upon the out-group comparison method. PAUP* (ver. 4.0) program was used for the dataset analysis and to make phylogenetic tree. The genera split into two separate genera Idiospermum + Chimonanthus and Sinocalycanthus + Calycanthus. Chimonanthus + Idiospermum are supported strict consensus tree with f-value calculation. Furthermore, Sinocalycanthus and Calycanthus are separated genera. Therefore, Calycanthaceae be redefined wide circumscriptions of the characters. The detailed investigation of the cladistics analysis revealed that the Sinocalycanthus and Calycanthus are the sole genus.
DOI: http://dx.doi.org/10.5281/zenodo.3908965
Keywords: Calycanthaceae, Characters and characters state, Cladistics, Out-group, Phylogen
Pericarp, seed coat anatomy and seed morphology of Calycanthaceae
Trichome morphology and seed coat anatomy display great feature of taxonomic value in the Calycanthaceae. The current Knowledge about the trichome and seed coat anatomy is mainly based on the external and internal observation. Detail anatomical study of the seed provide valuable information for further studied about their function, ontogeny and phylogeny. Therefore the goal of the study was to investigate trichome morphology and seed coat anatomy in Calycanthaceae species to provide more detail Characterization. We investigated trichome morphology and seed anatomy from 8 species of Calycanthaceae. Seed were collected and preserved in formalin -acetic acid-alcohol (FAA) solution. Alcohol series was applied after that proceeds for SEM and anatomical analysis. We found unicellular trichome hair in deferent density, seed surface was irregular and polygonal. Pericarp and seed coat anatomy was investigated, we found 3 layer in each as distinguished feature. The diversity of unicellular trichome morphology is common in all species in Calycanthaceae. Density of trichome is high in Calycanthus occidentalis, different variation of seed coat layer, Pericarp layer is a character of potential phylogenetic significance
Morphological Studies on Seeds of Scrophulariaceae s.l. and Their Systematic Significance
This study employed scanning electron microscopy and light microscopy to observe seed surface micromorphology and seed coat anatomy in the Scrophulariaceae s.l. to investigate seed characters of taxonomic importance. Seeds of 41 taxa corresponding to 13 genera of the family were carefully investigated. Seeds were minute and less than or slightly larger than 1 millimeter in length except for Melampyrum and Pedicularis species. The seed shape ranged from elliptical to broad elliptical and ovoid. In the studied species the surface sculpture was predominantly reticulate-striate, regular reticulate, sometimes colliculate, and rugose, or - rarely - ribbed, as in Lindernia procumbens and Paulownia coreana. Seed coats comprised the epidermis and the endothelium. Nevertheless, in all Melampyrum and some Veronica species the seed coat was very poorly represented and only formed by a papery layer of epidermis. According to correspondence analysis (CA) and unweighted pair group method with arithmetic mean (UPGMA) based cluster analysis the close affinities among the species of Scrophularia were well supported by their proximity to one another. Similarly, the proximity of Melampyrum species and Pedicularis species cannot be denied. In contrast, Veronica species were divided into two groups in CA plots and even three in the UPGMA tree. Regardless of the limited range taxa considered we found that similarities and differences in seed morphology between different genera could help us to understand the systematic relationships involved
Morphological and genetic characteristics of Nicotiana langsdorffii, N. glauca and its hybrid
Plant tumors, including genetic tumors, are disorganized and proliferate in an uncontrolled fashion. In this report we describe the morphological, physiological and genetic properties of Nicotiana. langsdorffii and Nicotiana. glauca and their hybrids (Nicotiana. langsdorffii x Nicotiana. Glauca). Nicotiana. langsdorffii leaves are oblate and pubescent with winged petioles, while Nicotiana. glauca leaf-blades are rubbery and oval-to-heart-shaped. The hybrid plants are intermediate in leaf shape, with anisocytic stomata and well-developed trichomes. In addition, they produce tumors in the absence of bacteria and exogenous hormones. Tumor growth in the hybrid plants was not affected by indole-3-acetic acid or kinetin. Genetic polymorphism was analyzed by the randomly amplified polymorphic DNA technique in the parents (Nicotiana. langsdorffii and Nicotiana. glauca) and in the genetic tumors produced by the hybrids. A total of 128 randomly amplified polymorphic DNA fragments were scored from fifteen random primers, and pronounced differences were found between the genetic tumors and their parents. These observations show that randomly amplified polymorphic DNA markers are might informative about genetic similarities and dissimilarities
The C-Fern (Ceratopteris richardii) Genome: Insights Into Plant Genome Evolution With the First Partial Homosporous Fern Genome Assembly
Ferns are notorious for possessing large genomes and numerous chromosomes. Despite decades of speculation, the processes underlying the expansive genomes of ferns are unclear, largely due to the absence of a sequenced homosporous fern genome. The lack of this crucial resource has not only hindered investigations of evolutionary processes responsible for the unusual genome characteristics of homosporous ferns, but also impeded synthesis of genome evolution across land plants. Here, we used the model fern species Ceratopteris richardii to address the processes (e.g., polyploidy, spread of repeat elements) by which the large genomes and high chromosome numbers typical of homosporous ferns may have evolved and have been maintained. We directly compared repeat compositions in species spanning the green plant tree of life and a diversity of genome sizes, as well as both short- and long-read-based assemblies of Ceratopteris. We found evidence consistent with a single ancient polyploidy event in the evolutionary history of Ceratopteris based on both genomic and cytogenetic data, and on repeat proportions similar to those found in large flowering plant genomes. This study provides a major stepping-stone in the understanding of land plant evolutionary genomics by providing the first homosporous fern reference genome, as well as insights into the processes underlying the formation of these massive genomes
pH-responsive high-density lipoprotein-like nanoparticles to release paclitaxel at acidic pH in cancer chemotherapy
Jae-Yoon Shin,1,* Yoosoo Yang,1,* Paul Heo,1 Ji-Chun Lee,1 ByoungJae Kong,1 Jae Youl Cho,1 Keejung Yoon,1 Cheol-Su Shin,2 Jin-Ho Seo,3 Sung-Gun Kim,4 Dae-Hyuk Kweon11Department of Genetic Engineering, College of Biotechnology and Bioengineering, and Center for Human Interface Nano Technology, Sungkyunkwan University, 2APTech Research Center, Suwon, 3Department of Agricultural Biotechnology, Seoul National University, Seoul, 4Department of Biomedical Science, Youngdong University, Chungbuk, South Korea*These authors contributed equally to this workBackground: Nanoparticles undergoing physicochemical changes to release enclosed drugs at acidic pH conditions are promising vehicles for antitumor drug delivery. Among the various drug carriers, high-density lipoprotein (HDL)-like nanoparticles have been shown to be beneficial for cancer chemotherapy, but have not yet been designed to be pH-responsive.Methods and results: In this study, we developed a pH-responsive HDL-like nanoparticle that selectively releases paclitaxel, a model antitumor drug, at acidic pH. While the well known HDL-like nanoparticle containing phospholipids, phosphatidylcholine, and apolipoprotein A-I, as well as paclitaxel (PTX-PL-NP) was structurally robust at a wide range of pH values (3.8–10.0), the paclitaxel nanoparticle that only contained paclitaxel and apoA-I selectively released paclitaxel into the medium at low pH. The paclitaxel nanoparticle was stable at physiological and basic pH values, and over a wide range of temperatures, which is a required feature for efficient cancer chemotherapy. The homogeneous assembly enabled high paclitaxel loading per nanoparticle, which was 62.2% (w/w). The molar ratio of apolipoprotein A-I and paclitaxel was 1:55, suggesting that a single nanoparticle contained approximately 110 paclitaxel particles in a spherical structure with a 9.2 nm diameter. Among the several reconstitution methods applied, simple dilution following sonication enhanced the reconstitution yield of soluble paclitaxel nanoparticles, which was 0.66. As a result of the pH responsiveness, the anticancer effect of paclitaxel nanoparticles was much more potent than free paclitaxel or PTX-PL-NP.Conclusion: The anticancer efficacy of both paclitaxel nanoparticles and PTX-PL-NP was dependent on the expression of scavenger receptor class B type I, while the killing efficacy of free paclitaxel was independent of this receptor. We speculate that the pH responsiveness of paclitaxel nanoparticles enabled efficient endosomal escape of paclitaxel before lysosomal break down. This is the first report on pH-responsive nanoparticles that do not contain any synthetic polymer.Keywords: pH responsiveness, nanoparticle, apolipoprotein A-I, paclitaxe
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