Search results for "Plant stem"
showing 10 items of 40 documents
Structural characterization and primary in vitro cell culture of locust male germline stem cells and their niche
2011
AbstractThe establishment of in vitro culture systems to expand stem cells and to elucidate the niche/stem cell interaction is among the most sought-after culture systems of our time. To further investigate niche/stem cell interactions, we evaluated in vitro cultures of isolated intact male germline–niche complexes (i.e., apical complexes), complexes with empty niche spaces, and completely empty niches (i.e., isolated apical cells) from the testes of Locusta migratoria and the interaction of these complexes with isolated germline stem cells, spermatogonia (of transit-amplifying stages), cyst progenitor cells, cyst progenitor cell-like cells, cyst cells, and follicle envelope cells. The stru…
Inhibition of Trypanosoma cruzi by plant extracts used in Chinese medicine.
2004
In this work, we assessed the effect of extracts obtained from 17 plants used in traditional Chinese medicine. These extracts were tested in vitro with the epimastigote form of Trypanosoma cruzi, clone Bra C(15) C(2), at 27 degrees C in F-29 medium at a concentration of 100 microg/ml in axenic cultures. Allopurinol was used as reference drug. Seven plant extracts showed inhibitory activities lower than 25%. Pueraria lobata, Mahonia beaei, Dictamus dasycarpus, Kochia scoparia, Sophora flavescens and Ligustrum lucidum showed effects with inhibition values between 25% and 60%, whereas Lithospermum erythrorhizon, Saussurea lappa, Melia toosendan and Cinnamomum cassia showed the greatest inhibit…
Evaluation of genotoxicity and DNA protective effects of mangiferin, a glucosylxanthone isolated from Mangifera indica L. stem bark extract.
2012
Abstract Mangiferin is a glucosylxantone isolated from Mangifera indica L. stem bark. Several studies have shown its pharmacological properties which make it a promising candidate for putative therapeutic use. This study was focused to investigate the in vitro genotoxic effects of mangiferin in the Ames test, SOS Chromotest and Comet assay. The genotoxic effects in bone marrow erythrocytes from NMRI mice orally treated with mangiferin (2000 mg/kg) were also evaluated. Additionally, its potential antimutagenic activity against several mutagens in the Ames test and its effects on CYP1A1 activity were assessed. Mangiferin (50–5000 μg/plate) did not increased the frequency of reverse mutations …
3-acetylaltholactone and related styryl-lactones, mitochondrial respiratory chain inhibitors.
2000
A novel furano-pyrone, 3-acetylaltholactone, and two other known styryl-lactones, altholactone and 5-acetoxyisogoniothalamin oxide, have been isolated from Goniothalamus arvensis (Annonaceae) stem bark. We report here the isolation and structural elucidation of these compounds with furane-pyrone and styryl-pyrone skeletons, postulating also for the first time their mechanism of cytotoxicity based on inhibition on mammalian mitochondrial respiratory chain.
Microbial community structure in soils with decomposing residues from plants with genetic modifications to lignin biosynthesis
2006
Lignin is a major determinant of the decomposition of plant materials in soils. Advances in transgenic technology have led to the possibility of modifying lignin to improve the pulping properties of plant materials for papermaking. Previous studies have shown that lignin modifications also affect the rate of plant material decay in soil. The aim of this work was to investigate short-term changes in soil microbial community structures when tobacco residues with reduced activity of enzymes in the monolignol pathway decompose. The residues from lignin-modified plants all decomposed faster than unmodified plant materials. The relative proportions of some of the structural groups of microbial ph…
A New Aromatic Compound from the Stem Bark of Terminalia catappa
2015
A new aromatic compound 3,4,5-trimethoxyphenyl-1- O-(4-sulfo)-β-D-glucopyranoside (1), in addition to two triterpenoid saponins (chebuloside II, arjunoglucoside II), two triterpenes (arjunolic acid and 3-betulinic acid) and sitosterol-3- O-β-D-glucopyranoside have been isolated from the barks of Terminalia catappa. Their structures have been established on the basis of spectroscopic techniques (1D/2D NMR) and MS. Their cytotoxicity and anti-inflammatory activity, together with the antioxidant capacity of compound 1 were also evaluated.
A portable NMR sensor to measure dynamic changes in the amount of water in living stems or fruit and its potential to measure sap flow.
2014
Nuclear magnetic resonance (NMR) and NMR imaging (magnetic resonance imaging) offer the possibility to quantitatively and non-invasively measure the presence and movement of water. Unfortunately, traditional NMR hardware is expensive, poorly suited for plants, and because of its bulk and complexity, not suitable for use in the field. But does it need to be? We here explore how novel, small-scale portable NMR devices can be used as a flow sensor to directly measure xylem sap flow in a poplar tree (Populus nigra L.), or in a dendrometer-like fashion to measure dynamic changes in the absolute water content of fruit or stems. For the latter purpose we monitored the diurnal pattern of growth, ex…
Uniform climate sensitivity in tree-ring stable isotopes across species and sites in a mid-latitude temperate forest.
2014
Tree-ring stable isotopes, providing insight into drought-induced eco-physiological mechanisms, are frequently used to reconstruct past changes in growing season temperature and precipitation. Their climatic response is, however, still not fully understood, particularly for data originating from non-extreme, mid-latitude environments with differing ecological conditions. Here, we assess the response of δ(13)C, δ(18)O and tree-ring width (TRW) from a temperate mountain forest in the Austrian pre-Alps to climate and specific drought events. Variations in stem growth and isotopic composition of Norway spruce, common beech and European larch from dry, medium and moist sites are compared with re…
Effects of indole-3-acetic acid on Sinorhizobium meliloti survival and on symbiotic nitrogen fixation and stem dry weight production
2009
We evaluated the effects of the main auxin phytohormone, indole-3-acetic acid (IAA), on the central metabolism of Sinorhizobium meliloti strain 1021. We either treated the Sinorhizobium meliloti 1021 strain with 0.5 mM IAA (1021+) or use a derivative, RD64, of the same strain harbouring a pathway for IAA biosynthesis converting tryptophan into IAA via indoleacetamide. We assayed the activity of key enzymes in the major energy-yielding pathways (Entner-Doudoroff, Embden-Meyerhof-Parnas, pentose phosphate, glyoxylate bypass and tricarboxylic acid cycle). We found that activity of two main regulative tricarboxylic acid (TCA) cycle enzymes was increased. Citrate synthase (CS) activity, as compa…
Reducing electric and thermal energy needs in buildings by using innovative envelope materials - Laboratory results of bio-composites embodying tomat…
2018
The life style of building occupants is continuously arising towards conditions that are more comfortable involving, on turn, the growing of the electric energy consumptions for climatization purposes. This calls for the improvement of the efficiencies of equipment along with environmental performance of building materials. Laboratory analyses of samples of mixed materials, utilizing tomato stems harvested in Sicily and Cataluña, have been conducted Thermal conductance and mechanical properties have been detected for different rates of bio-component and inert materials. First results of the thermal properties seem to situate such bio-composites among the insulating building materials, for a…