Search results for "LEM"
showing 10 items of 23327 documents
Guaianolides from the Aerial Parts of Centaurea Hololeuca
2006
Seven guaianolides were isolated from the acetone extract of the aerial parts of Centaurea hololeuca Boiss. The antifeedant activity of the natural compounds (1–7) and of four chloro derivatives (8–11), synthesized from repin (1) and janerin (3) were tested against larvae of Spodoptera littoralis. Cebellin J (6) and chlorojanerin (11) showed significant antifeedant activity at 100 ppm, whereas at this concentration cebellin G (4) and 15-deschloro-15-hydroxychlorojanerin (7) stimulated feeding. Cebellin G (4) stimulated larvae of S. littoralis to feed at low concentration, but deterred feeding at high concentrations. The addition of chlorine to repin (1) resulted in an increase in antifeeda…
Mycotheca of Edible and Medicinal Mushrooms at Herbarium SAF as a Potential Source of Nutraceuticals and Cultivated Mushrooms
2018
Basidiomycetes strains (n = 39) belonging to 9 genera in 8 families are kept in the mycotheca of the Department of Agricultural, Food and Forest Sciences at the University of Palermo (Palermo, Italy). All of the strains are medicinal mushrooms, and some are of great commercial and nutraceutical interest.
In vitro interactions between calcium, zinc, copper and iron in milk- and soy-based infant formulas / Interacciones in vitro entre calcio, cinc, cobr…
2000
Interactions among calcium, zinc, copper and iron in milk- and soy-based infant formulas were as sessed in order to evaluate the influence of supplementation with one trace element on the bioavailability of the others. The criterion used to estimate the bioavailability is the percentage of dialysis, estimated by applying an in vitro method. Infant formulas were supplemented with CaCl2, ZnO, CuCO3 Cu(OH) 22H2O and FeSO4 7H2O at two levels (maximum (+) and minimum (-) allowed by the European Union). A factorial design at two levels with three factors (Zn, Cu and Fe addition) was carried out. The main effects and the second-order interactions of the studied factors on the bioavailability of a…
The grapevine flagellin receptor VvFLS2 differentially recognizes flagellin-derived epitopes from the endophytic growth-promoting bacterium Burkholde…
2014
International audience; The role of flagellin perception in the context of plant beneficial bacteria still remains unclear. Here, we characterized the flagellin sensing system flg22-FLAGELLIN SENSING 2 (FLS2) in grapevine, and analyzed the flagellin perception in the interaction with the endophytic plant growth-promoting rhizobacterium (PGPR) Burkholderia phytofirmans. The functionality of the grapevine FLS2 receptor, VvFLS2, was demonstrated by complementation assays in the Arabidopsis thaliana fls2 mutant, which restored flg22-induced H2O2 production and growth inhibition. Using synthetic flg22 peptides from different bacterial origins, we compared recognition specificities between VvFLS2…
Membrane glycerolipid remodeling triggered by nitrogen and phosphorus starvation in Phaeodactylum tricornutum.
2014
International audience; Diatoms constitute a major phylum of phytoplankton biodiversity in ocean water and freshwater ecosystems. They are known to respond to some chemical variations of the environment by the accumulation of triacylglycerol, but the relative changes occurring in membrane glycerolipids have not yet been studied. Our goal was first to define a reference for the glycerolipidome of the marine model diatom Phaeodactylum tricornutum, a necessary prerequisite to characterize and dissect the lipid metabolic routes that are orchestrated and regulated to build up each subcellular membrane compartment. By combining multiple analytical techniques, we determined the glycerolipid profil…
Molecular determinants of the Arabidopsis AKT1 K+ channel ionic selectivity investigated by expression in yeast of randomly mutated channels
1999
International audience; The Avabidopsis thaliana K+ channel AKT1 was expressed in a yeast strain defective for K+ uptake at low K+ concentrations (<3 mM). Besides restoring K+ transport in this strain, AKT1 expression increased its tolerance to salt (NaCl or LiCl), whatever the external K+ concentration used (50 mu M, 5 mM, or 50 mM), We took advantage of the latter phenomenon for screening a library of channels randomly mutated in the region that shares homologies with the pore forming domain (the so-called P domain) of animal K+ channels (Shaker family). Cassette mutagenesis was performed using a degenerate oligonucleotide that was designed to ensure, theoretically, a single mutation per …
Current view of nitric oxide-responsive genes in plants
2009
International audience; Significant efforts have been directed towards the identification of genes differentially regulated through nitric oxide (NO)-dependent processes. These efforts comprise the use of medium- and large-scale transcriptomic analyses including microarray and cDNA-amplification fragment length polymorphism (AFLP) approaches. Numerous putative NO-responsive genes have been identified in plant tissues and cell suspensions with transcript levels altered by artificially released NO, or endogenously produced. Comparative analysis of the data from such transcriptomic analyses in Arabidopsis reveals that a significant part of these genes encode proteins related to plant adaptive …
Mycorrhizae differentially influence the transfer of nitrogen among associated plants and their competitive relationships
2021
Abstract The formation of a common mycorrhizal network among roots of different plant species growing close to each other can influence plant community dynamics, regulating plant relationships through the differential transfer of nutrients from one plant to another. However, knowledge of the mechanisms that regulate this process is poor. Here we quantify the contribution of arbuscular mycorrhizae to the transfer of N among heterospecific plants growing adjacent to each other and examine whether the differential transfer of N within the plant community via mycorrhizae can alter competitive relationships among plant species. Plants of four species (wheat, pea, flax, and chicory) were grown in…
Ecological and conceptual consequences of Arctic pollution
2020
Although the effect of pollution on forest health and decline received much attention in the 1980s, it has not been considered to explain the ‘Divergence Problem’ in dendroclimatology; a decoupling of tree growth from rising air temperatures since the 1970s. Here we use physical and biogeochemical measurements of hundreds of living and dead conifers to reconstruct the impact of heavy industrialisation around Norilsk in northern Siberia. Moreover, we develop a forward model with surface irradiance forcing to quantify long‐distance effects of anthropogenic emissions on the functioning and productivity of Siberia’s taiga. Downwind from the world’s most polluted Arctic region, tree mortality ra…
Spatial distribution, contamination assessment and potential ecological risk of some trace metals in the surface sediments of the Gulf of Tunis, Nort…
2021
To evaluate the trace metals contamination status in the Gulf of Tunis, forty one sediment samples were analyzed using different approaches. According to certain contamination and ecological risk indices (Contamination Factor, Geoaccumulation index and Ecological risk index), Hg has the highest contamination level while pollution by Ni, Pb, Cd and Cr was absent. The highest concentrations of trace metals were found in sediments collected from the offshore and coastal areas located opposite the main exchange points with the gulf particularly, the Mejerda and Meliane Rivers, the Khalij Channel, Ghar El Melh and El Malah lagoons, Tunis Lake and Sebkhat Ariana. However, further ecological indic…