Search results for "OA"
showing 10 items of 22575 documents
An isoleucine residue within the carboxyl-transferase domain of multidomain acetyl-coenzyme A carboxylase is a major determinant of sensitivity to ar…
2003
Abstract A 3,300-bp DNA fragment encoding the carboxyl-transferase domain of the multidomain, chloroplastic acetyl-coenzyme A carboxylase (ACCase) was sequenced in aryloxyphenoxypropionate (APP)-resistant and -sensitive Alopecurus myosuroides (Huds.). No resistant plant contained an Ile-1,781-Leu substitution, previously shown to confer resistance to APPs and cyclohexanediones (CHDs). Instead, an Ile-2,041-Asn substitution was found in resistant plants. Phylogenetic analysis of the sequences revealed that Asn-2,041 ACCase alleles derived from several distinct origins. Allele-specific polymerase chain reaction associated the presence of Asn-2,041 with seedling resistance to APPs but not to C…
Involvement of Free Calcium in Action of Cryptogein, a Proteinaceous Elicitor of Hypersensitive Reaction in Tobacco Cells
1995
Treatment of suspension-cultured tobacco (Nicotiana tabacum var Xanthi) cells with cryptogein, a proteinaceous elicitor from Phytophthora cryptogea, induced a great stimulation of Ca2+ influx within the first minutes. Ca2+ influx is essential for the initiation of cryptogein-induced responses, since ethyleneglycol-bis([beta]-amino-ethyl ether)-N,N[prime]-tetraacetic acid or La3+, which block Ca2+ entrance, suppress cryptogein-induced responses such as extracellular alkalinization, active oxygen species, and phytoalexin production. Moreover, once initiated, these responses require sustained Ca2+ influx within the 1st h. A Ca2+ ionophore (A23187) was able to trigger an extracellular alkaliniz…
Real-time electrochemical detection of extracellular nitric oxide in tobacco cells exposed to cryptogein, an elicitor of defence responses
2008
International audience; It was previously reported that cryptogein, an elicitor of defence responses, induces an intracellular production of nitric oxide (NO) in tobacco. Here, the possibility was explored that cryptogein might also trigger an increase of NO extracellular content through two distinct approaches, an indirect method using the NO probe 4,5-diaminofluorescein (DAF-2) and an electrochemical method involving a chemically modified microelectrode probing free NO in biological media. While the chemical nature of DAF-2-reactive compound(s) is still uncertain, the electrochemical modified microelectrodes provide real-time evidence that cryptogein induces an increase of extracellular N…
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…
Universal primers for PCR-sequencing of grass chloroplastic acetyl-CoA carboxylase domains involved in resistance to herbicides
2005
Summary Primers were designed to amplify two regions involved in sensitivity to herbicides inhibiting the plastidic acetyl-CoA carboxylase (ACCase) from grasses (Poaceae). The first primer pair amplified a 551-bp amplicon containing a variable Ile/Leu codon at position 1781 in Alopecurus myosuroides sequence. The second primer pair amplified a 406-bp amplicon containing four variable codons (Trp/Cys, Ile/Asn, Asp/Gly, Gly/Ala) at positions 2027, 2041, 2078 and 2096, respectively, in A. myosuroides sequence. Both primer pairs amplified the targeted fragments from genes encoding plastidic ACCases, but not from the very similar genes encoding cytosolic ACCases. Clear DNA sequences were obtaine…
Valuable natural products from marine and freshwater macroalgae obtained from supercritical fluid extracts
2017
The biologically active compounds (fatty acids, pigments, phenolics, and flavonoid content) were studied in supercritical fluid extracts from the biomass of marine (Ulva clathrata, Cladophora glomerata, Polysiphonia fucoides, and their multi-species mixture) and freshwater (C. glomerata) macroalgae. Different extraction techniques were used in order to compare differences in the biologically active compound composition of the macroalgal extracts. The results indicated that the saturated and unsaturated fatty acids ranged from C9:0 to C22:0. The analysis of differences in the composition of unsaturated to saturated fatty acids in extracts showed that palmitic acid (C16:0) and oleic acid (C18…
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 …
Sensitive measure of prevalence and parasitaemia of haemosporidia from European blackbird (Turdus merula) populations: value of PCR-RFLP and quantita…
2006
8 pages; International audience; Haemosporidian parasites are common in birds in which they act as an important selective pressure. While most studies so far have focused on the effect of their prevalence on host life-history traits, no study has measured the effect of parasitaemia. We developed molecular methods to detect, identify and quantify haemosporidia in 2 natural populations of the Blackbird Turdus merula. Three different parasite genotypes were found - 1 Haemoproteus and 2 Plasmodium. A PCR-RFLP screening revealed that only approximately 3% of blackbirds were free of parasites, compared to the 34% of uninfected birds estimated by blood smear screening. A quantitative PCR (q-PCR) a…
The buffer effect of canopy-forming algae on vermetid reefs' functioning: A multiple stressor case study.
2021
Abstract Biodiversity plays a key role for our planet by buffering ongoing and future changes in environmental conditions. We tested if canopy-forming algae enhancing biodiversity (CEB) in a Mediterranean intertidal reef ecological community could alleviate the effect of stressors (heat waves and pollution from sewage) on community metabolic rates (as expressed by oxygen consumption) used as a proxy of community functioning. CEB exerted a buffering effect related to the properties of stressor: physical-pulsing (heat wave) and chronic-trophic (sewage). After a simulated heat wave, CEB was effective in buffering the impacts of detrimental temperatures on the functioning of the community. In r…
New national and regional bryophyte records, 44
2015
Syntrichia norvegica is a circumpolar arctic- montane species (Smith, 2004), rare at lower altitudes and in southern Europe (Frey et al., 2006). It is known from several south-eastern European countries (Sabovljevic et al., 2008) and now it is recorded for the first time in Croatia. Regarding its conservation status, S. norvegica is red listed in Great Britain (EN), Czech Republic (CR), Slovakia (VU), Bulgaria (NT), Hungary (DD), Romania (VU) and Estonia (VU) (Hodgetts, 2014). It was found in the northern Velebit Mountains, in an area with the most outstanding and extreme karst relief, with steep slopes, perpendicular rocks, screes and deep dolines. The locality is situated in the Pinus mug…