Studies on the Anti-Angiogenic Activities of Wild and Cultivated Orostachys japonicus Extracts in Human Umbilical Vein Endothelial Cells.

Orostachys japonicus has traditionally been used as a food product and a fork medicine in Asia to treat various diseases. Angiogenesis is a critical process that contributes to various chronic diseases via excessive delivery of oxygen and nutrients. Common anti-angiogenic drugs have serious problems related to high costs and side effects; thus, natural products with low costs and no cytotoxicity have garnered increasing interest. In this study, we evaluated and compared the anti-angiogenic effects and phenolic compound contents between wild (WOEs) and cultivated O. japonicus extracts (COEs) prepared under various extract conditions. WOEs and COEs suppressed cell proliferation of human umbilical vein endothelial cells (HUVECs) and inhibited vascular endothelial growth factor-induced chemotactic migration, invasion, and capillary-like tube formation in HUVECs. Among COEs, that prepared by 70% EtOH (70% CE) showed the most effective anti-angiogenic activity in HUVECs. When compared to WOEs, total polyphenol and total flavonoid contents were 1.28 to 4.38 times higher in COEs, and 70% CE contained the greatest flavonoid contents (28.28 ± 0.93 mg%), as well as the highest levels of major phenolic compounds including gallic acid (21.84 µg/mL), epicatechin-gallate (6.58 µg/mL), kaempferol (6.32 µg/mL), and quercetin (8.55 µg/mL). Although further studies are required to identify the molecular mechanisms behind these anti-angiogenic effects, 70% CE could be used as an herbal medicine, functional food ingredient, and potent angiogenesis inhibitor. PRACTICAL APPLICATION: Environmental factors such as altitude, nutrients, exposure to sunlight, and temperature can influence the type and quantity of bioactive components in plants. The advantage of cultivated plants is that the above-mentioned factors can be artificially adjusted compared to wild plants. Based on economic efficiency, productivity, and consistent quality, anti-angiogenesis activity of cultivated O. japonicus is of greater commercial value as a functional food than wild O. japonicus.

Are there symplastic connections between the endosperm and embryo in some angiosperms?--a lesson from the Crassulaceae family.

It is believed that there is symplastic isolation between the embryo (new sporophyte) and the endosperm (maternal-parental origin tissue, which nourishes the embryo) in angiosperms. However, in embryological literature there are rare examples in which plasmodesmata between the embryo suspensor and endosperm cells have been recorded (three species from Fabaceae). This study was undertaken in order to test the hypothesis that plasmodesmata between the embryo suspensor and the endosperm are not so rare but also occur in other angiosperm families; in order to check this, we used the Crassulaceae family because embryogenesis in Crassulaceae has been studied extensively at an ultrastructure level recently and also we tread members of this family as model for suspensor physiology and function studies. These plasmodesmata even occurred between the basal cell of the two-celled proembryo and endosperm cells. The plasmodesmata were simple at this stage of development. During the development of the embryo proper and the suspensor, the structure of plasmodesmata changes. They were branched and connected with electron-dense material. Our results suggest that in Crassulaceae with plasmodesmata between the endosperm and suspensor, symplastic connectivity at this cell-cell boundary is still reduced or blocked at a very early stage of embryo development (before the globular stage). The occurrence of plasmodesmata between the embryo suspensor and endosperm cells suggests possible symplastic transport between these different organs, at least at a very early stage of embryo development. However, whether this transport actually occurs needs to be proven experimentally. A broader analysis of plants from various families would show whether the occurrence of plasmodesmata between the embryo suspensor and the endosperm are typical embryological characteristics and if this is useful in discussions about angiosperm systematic and evolution.

New data about the suspensor of succulent angiosperms: Ultrastructure and cytochemical study of the embryo-suspensor of Sempervivum arachnoideum L. and Jovibarba sobolifera (Sims) Opiz.

The development of the suspensor in two species - Sempervivum arachnoideum and Jovibarba sobolifera - was investigated using cytochemical methods, light and electron microscopy. Cytological processes of differentiation in the embryo-suspensor were compared with the development of embryo-proper. The mature differentiated suspensor consists of a large basal cell and three to four chalazal cells. The basal cell produces haustorial branched invading ovular tissues. The walls of the haustorium and the micropylar part of the basal cell form the wall ingrowths typical for a transfer cells. The ingrowths also partially cover the lateral wall and the chalazal wall separating the basal cell from the other embryo cells. The dense cytoplasm filling the basal cell is rich in: numerous polysomes lying free or covering rough endoplasmic reticulum (RER), active dictyosomes, microtubules, bundles of microfilaments, microbodies, mitochondria, plastids and lipid droplets. Cytochemical tests (including proteins, insoluble polysaccharides and lipids are distributed in the suspensor during different stages of embryo development) showed the presence of high amounts of macromolecules in the suspensor cells, particularly during the globular and heart-shaped phases of embryo development. The protein bodies and lipid droplets are the main storage products in the cells of the embryo-proper. The results of Auramine 0 indicate that a cuticular material is present only on the surface walls of the embryo-proper, but is absent from the suspensor cell wall. The ultrastructural features and cytochemical tests indicate that in the two species - S. arachnoideum and J. sobolifera - the embryo-suspensor is mainly involved in the absorption and transport of metabolites from the ovular tissues to the developing embryo-proper.

Rarity as a life-history correlate in Dudleya (Crassulaceae).

PREMISE OF THE STUDY: Differences in rarity among species can be caused by adaptation to local conditions along with correlated evolution in characters that limit geographic range size. For this kind of divergence, the resulting species differ in their ability to thrive in varying environments. Because rare species are more prone to extinction than widespread species, trade-offs in life history predispose the resulting lineages to clade selection. METHODS: Nine Dudleya species live in the Santa Monica Mountains: five neoendemics, one species intermediate in rarity, and three with broader ranges. Life-history traits were correlated against one another. To understand habitat dependence, the species were grown in an inland garden and in a coastal garden, and the disparity in growth and reproduction in the two gardens was compared among species. KEY RESULTS: Rare species reproduced earlier and grew to be smaller than common species. The small body size of the rare species was correlated with small reproductive outputs compared with those of the large-bodied common species. The growth disparity between plants in the two gardens was greatest for the rare species. The rare species had a lower tolerance for hot, dry conditions compared with the common species. In the Santa Monica Mountains, the habitat conditions required by the rare species are not as prevalent as those of the common species. CONCLUSIONS: The data are consistent with the view that differences in life histories constrained by trade-offs affect range size. Such differences in rarity become the grist for clade selection at the scale of macroevolution.

A search for growth related genes in Kalanchoë blossfeldiana.

Differential display of mRNA from four sets of contrasting phenotypes were carried out in order to identify and isolate genes associated with elongating growth of Kalanchoë blossfeldiana. A total of 17 unique differential expressed cDNA fragments were sequenced and 12 showed homology to genes in other plant species. Three genes were subsequently tested for growth related activity by Virus Induced Gene Silencing (VIGS) in Nicotiana benthamiana. One gene fragment (13C) resulted in plants with significantly reduced growth (N = 20, P = 0.05, one-tailed students t-test) from day 25 after virus infection. Full-length cDNA and genomic DNA sequences were obtained by inverse PCR and thermal asymmetric interlaced (TAIL) PCR and the gene was named KbORF1. The predicted gene is 2244 bp long with three exons of 411 bp in total encoding a protein of 137 amino acid residues with homologs widespread among plants. The protein has no known function, but its expression has been confirmed in a proteomic study of Arabidopsis. Southern blot analysis shows two hybridizing fragments in agreement with the tetraploid nature of K. blossfeldiana. Fragment 13C comprises 446 bp of the gene, and the portion of 13C conferring growth retardation by VIGS is located 10 bp into the second intron indicating a regulatory function of this part of the KbORF1 mRNA. Differential display in combination with VIGS as a screening method proved to be a good functional approach not only to search for genes of interest, but also to isolate expressed genetic regulatory domains.

Complexation and toxicity of copper in higher plants. I. Characterization of copper accumulation, speciation, and toxicity in Crassula helmsii as a new copper accumulator.

The amphibious water plant Crassula helmsii is an invasive copper (Cu)-tolerant neophyte in Europe. It now turned out to accumulate Cu up to more than 9,000 ppm in its shoots at 10 microm (=0.6 ppm) Cu(2+) in the nutrient solution, indicating that it is a Cu hyperaccumulator. We investigated uptake, binding environment, and toxicity of Cu in this plant under emerged and submerged conditions. Extended x-ray absorption fine structure measurements on frozen-hydrated samples revealed that Cu was bound almost exclusively by oxygen ligands, likely organic acids, and not any sulfur ligands. Despite significant differences in photosynthesis biochemistry and biophysics between emerged and submerged plants, no differences in Cu ligands were found. While measurements of tissue pH confirmed the diurnal acid cycle typical for Crassulacean acid metabolism, Delta(13)C measurements showed values typical for regular C3 photosynthesis. Cu-induced inhibition of photosynthesis mainly affected the photosystem II (PSII) reaction center, but with some unusual features. Most obviously, the degree of light saturation of electron transport increased during Cu stress, while maximal dark-adapted PSII quantum yield did not change and light-adapted quantum yield of PSII photochemistry decreased particularly in the first 50 s after onset of actinic irradiance. This combination of changes, which were strongest in submerged cultures, shows a decreasing number of functional reaction centers relative to the antenna in a system with high antenna connectivity. Nonphotochemical quenching, in contrast, was modified by Cu mainly in emerged cultures. Pigment concentrations in stressed plants strongly decreased, but no changes in their ratios occurred, indicating that cells either survived intact or died and bleached quickly.

Cytokinins inhibit epiphyllous plantlet development on leaves of Bryophyllum (Kalanchoë) marnierianum.

When leaves of Bryophyllum marnierianum are detached from the plant, plantlets develop from primordia located at their margins. Leaves excised with a piece of stem attached do not produce plantlets. Severing the major leaf veins overcomes the inhibitory effect of the attached stem, indicating that the control agent is transmitted through the vascular system. A possible mechanism is that an inhibitory substance, possibly a known plant hormone, transported from the stem to the leaf, suppresses plantlet development. A number of hormones were tested for their ability to inhibit plantlet primordium development in whole isolated leaves. Auxins had no effect, indicating that apical dominance is not involved. The cytokinins zeatin, kinetin, and benzylaminopurine (BAP) strongly inhibited plantlet development, suggesting that they may be the or a factor involved in maintenance of plantlet primordium dormancy when the leaf is attached to the plant. This hypothesis was strongly supported by the finding that treatment of leaves attached to stems with a cytokinin antagonist (purine riboside) released the primordia from inhibition. In contrast to whole leaves, plantlet primordium development on leaf explants incubated on Murashige Skoog medium containing 3% sucrose was strongly stimulated by cytokinins. A possible explanation of these observations is that in whole leaves the cytokinin signal is transduced into an inhibitory signal whereas in the isolated primordium cytokinin has a direct stimulatory effect. The inhibitory cytokinin pathway must be dominant as long as the leaf is attached to the plant. A model is proposed which could explain these findings. This study points to a novel role of cytokinins in the maintenance of foliar plantlet primordium dormancy.