Search results for "physiology"
showing 10 items of 8671 documents
Protein phosphorylation is induced in tobacco cells by the elicitor cryptogein
1994
Changes in plasmalemma ion fluxes were observed when tobacco (Nicotiana tabacum) cells were treated with cryptogein, a proteinaceous elicitor from Phytophthora cryptogea. A strong alkalization of the culture medium, accompanied by a leakage of potassium, was induced within a few minutes of treatment. These effects reached a maximum after 30 to 40 min and lasted for several hours. This treatment also resulted in a rapid, but transient, production of activated oxygen species. All these physiological responses were fully sensitive to staurosporine, a known protein kinase inhibitor. Furthermore, a study of protein phosphorylation showed that cryptogein induced a staurosporine-sensitive phosphor…
Nuclear protein kinases: still enigmatic components in plant cell signalling
2010
International audience; Plants constantly face changing conditions in their environment. Unravelling the transduction mechanisms from signal perception at the plasma membrane level down to gene expression in the nucleus is a fascinating challenge. Protein phosphorylation, catalysed by protein kinases, is one of the major posttranslational modifications involved in the specificity, kinetic(s) and intensity of a signal transduction pathway. Although commonly assumed, the involvement of nuclear protein kinases in signal transduction is often poorly characterized. In particular, both their regulation and mode of action remain to be elucidated and may lead to the unveiling of new original mechan…
Multitrophic interactions in the rhizosphere Rhizosphere microbiology: at the interface of many disciplines and expertises.
2008
The rhizosphere – the soil compartment influenced by the root, including the root itself – is the most-active microbial habitat in soils. Indeed, the release by plant roots of a significant part of their photosynthates promotes microbial abundance and activities in the rhizosphere. This investment made by plants is paid back by microbial functions, which contribute to plant nutrition and protection against soil-borne diseases. Indeed, rhizosphere microorganisms play a major role in plant growth and health and, …
Resource profitability, but not caffeine, affects individual and collective foraging in the stingless beePlebeia droryana
2019
ABSTRACT Plants and pollinators form beneficial relationships, with plants offering resources in return for pollination services. Some plants, however, add compounds to nectar to manipulate pollinators. Caffeine is a secondary plant metabolite found in some nectars that affects foraging in pollinators. In honeybees, caffeine increases foraging and recruitment to mediocre food sources, which might benefit the plant, but potentially harms the colonies. For the largest group of social bees, the stingless bees, the effect of caffeine on foraging behaviour has not been tested yet, despite their importance for tropical ecosystems. More generally, recruitment and foraging dynamics are not well und…
Are the effects of an invasive crayfish on lake littoral macroinvertebrate communities consistent over time?
2016
Management of invasive species requires assessment of their effects on recipient ecosystems. However, impact assessment of invasive species commonly lacks a long-term perspective which can potentially lead to false conclusions. We examined the effects of the invasive signal crayfish (Pacifastacus leniusculus Dana) on the stony littoral macroinvertebrate communities of a large boreal lake and assessed the extent to which the patterns observed in previous short-term studies were stable over time. We used temporal macroinvertebrate data collected in five consecutive years from a site with a well-established crayfish population, a site with no crayfish and a site where crayfish had been recentl…
Aflatoxins and A. flavus Reduction in Loaf Bread through the Use of Natural Ingredients
2018
In this study, the antifungal activity of yellow mustard (YMF) and oriental mustard (OMF) meal extracts against 14 strains of fungi was tested on a solid medium. The results obtained with the YMF were next confirmed in liquid medium determining the minimum inhibitory concentration (MIC) and the minimum fungicide concentration (MFC). Finally, the use of YMF as a natural preservative to extend the useful life of bread was evaluated. Breads with different concentrations of YMF (2, 4, 6 and 8 g/kg) were prepared and contaminated with Aspergillus flavus ISPA 8111 and Penicillium nordicum CECT 2320. For 10 days the formation of mycelium was observed, and after that the fungal growth and the mycot…
An early Ca2+ influx is a prerequisite to thaxtomin A-induced cell death in Arabidopsis thaliana cells
2008
International audience; The pathogenicity of various Streptomyces scabies isolates involved in potato scab disease was correlated with the production of thaxtomin A. Since calcium is known as an essential second messenger associated with pathogen-induced plant responses and cell death, it was investigated whether thaxtomin A could induce a Ca 2+ influx related to cell death and to other putative plant responses using Arabidopsis thaliana suspension cells, which is a convenient model to study plant–microbe interactions. A. thaliana cells were treated with micromolar concentrations of thaxto-min A. Cell death was quantified and ion flux variations were analysed from electrophysiological measu…
Artificial Oral Processing of Extruded Pea Flour Snacks
2021
International audience; The structure of extruded pea flour can affect chewing performances. Our objective was to relate the bolus properties (fragmentation, moisture content and viscosity) of chewed extruded pea snacks to their structure. In order to have control over oral physiological parameters, we opted for an in vitro approach using a chewing simulator, the variables of which were the flow rate of artificial salivary fluid and chewing time. The structure of the extruded pea snacks was characterized by its density and protein solubility in dithioerythritol (DTE), which reflected the amount of protein aggregates cross-linked by disulphide bonds. The particle size distribution and median…
Plant proteome analysis
2004
Proteome analysis is becoming a powerful tool in the functional characterization of plants. Due to the availability of vast nucleotide sequence information and based on the progress achieved in sensitive and rapid protein identification by mass spectrometry, proteome approaches open up new perspectives to analyze the complex functions of model plants and crop species at different levels. In this review, an overview is given on proteome studies performed to analyze whole plants or specific tissues with particular emphasis on important physiological processes such as germination. The chapter on subcellular proteome analysis of plants focuses on the progress achieved for plastids and mitochond…
Comparative Respiratory Physiology in Cetaceans.
2019
In the current study, we used breath-by-breath respirometry to evaluate respiratory physiology under voluntary control in a male beluga calf [Delphinapterus leucas, body mass range (M b): 151-175 kg], an adult female (estimated M b = 500-550 kg) and a juvenile male (M b = 279 kg) false killer whale (Pseudorca crassidens) housed in managed care. Our results suggest that the measured breathing frequency (f R) is lower, while tidal volume (V T) is significantly greater as compared with allometric predictions from terrestrial mammals. Including previously published data from adult bottlenose dolphin (Tursiops truncatus) beluga, harbor porpoise (Phocoena phocoena), killer whale (Orcinus orca), p…