Search results for "PROTEIN"
showing 10 items of 21431 documents
In vivoanalysis of the lumenal binding protein (BiP) reveals multiple functions of its ATPase domain
2007
International audience; The endoplasmic reticulum (ER) chaperone binding protein (BiP) binds exposed hydrophobic regions of misfolded proteins. Cycles of ATP hydrolysis and nucleotide exchange on the ATPase domain were shown to regulate the function of the ligand-binding domain in vitro. Here we show that ATPase mutants of BiP with defective ATP-hydrolysis (T46G) or ATP-binding (G235D) caused permanent association with a model ligand, but also interfered with the production of secretory, but not cytosolic, proteins in vivo. Furthermore, the negative effect of BiP(T46G) on secretory protein synthesis was rescued by increased levels of wild-type BiP, whereas the G235D mutation was dominant. U…
Assessment of genetically modified maize 1507 × 59122 × MON810 × NK603 and subcombinations, for food and feed uses, under Regulation (EC) No 1829/200…
2017
In this opinion, the GMO Panelassessed the four-event stack maize 1507 x 59122 x MON810 x NK603 and its ten subcombinations, independently of their origin. The GMO Panelpreviously assessed the four single events combined in this four-event stack maize and five of their combinations and did not identify safety concerns. No new data on the single events or their previously assessed combinations leading to modification of the original conclusions were identified. Based on the molecular, agronomic, phenotypic and compositional characteristics, the combination of the single maize events and of the newly expressed proteins in the four-event stack maize did not give rise to food and feed safety or…
Members of the WRKY gene family are upregulated in Canary palms attacked by Red Palm Weevil
2018
The Red Palm Weevil (RPW), Rhynchophorus ferrugineus, is one of the major pests affecting several palm species all around the world. The aim of this work was to identify palm genes that are responsive to RPW infestations as a valuable diagnostic tool to detect the insect attack. We have analysed a total of 15 genes that were divided in two subsets: (1) 7 genes previously linked with RPW attacks, but not involved in biotic stress responses, and (2) 8 genes encoding members of the WRKY family, a class of transcription factors well-known to be linked with both abiotic and biotic stress responses. The analysis was conducted on 4-year-old Canary palms comparing uninfested plants and infested pla…
Sterol and ecdysteroids profiles of Serratula tinctoria (L.) : plant and cell cultures producing steroids
1993
Abstract Cell suspension cultures have been obtained from Serratula tinctoria, a plant producing ecdysteroids. Sterol profiles and ecdysteroid contents have been analysed and compared in plants and cell cultures. In particular, the composition of free and esterified sterols was investigated using appropriate analytical techniques. In plants, esterified sterols were more abundant (50–70% of the total sterol) than in cell cultures (13–36%). A selectivity for sterol esterification was noted: in plants, the triterpenes (as amyrins) were esterified, whereas it was the 4-desmethylsterols (sitosterol and cholesterol) in cell cultures. Ecdysteroids were present in higher quantities in plant (0.1–1.…
Nitric oxide and glutathione impact the expression of iron uptake- and iron transport-related genes as well as the content of metals in A. thaliana p…
2012
International audience; Mounting evidence indicate that nitric oxide (NO) acts as a signaling molecule mediating iron deficiency responses through the upregulation of the expression of iron uptake-related genes. Accordingly, NO donors such as nitrosoglutathione (GSNO) were reported to improve the fitness of plants grown under iron deficiency. Here, we showed that glutathione, a by-product of GSNO, triggered the upregulation of the expression of iron uptake- and transport-related gene and an increase of iron concentration in Arabidopsis thaliana seedlings facing iron deficiency. Furthermore, we provided evidence that under iron deficiency, NO released by GSNO did not improve the root iron co…
Soybean and casein hydrolysates induce grapevine immune responses and resistance against Plasmopara viticola
2014
International audience; Plasmopara viticola, the causal agent of grapevine downy mildew, is one of the most devastating grape pathogen in Europe and North America. Although phytochemicals are used to control pathogen infections, the appearance of resistant strains and the concern for possible adverse effects on environment and human health are increasing the search for alternative strategies. In the present investigation, we successfully tested two protein hydrolysates from soybean (soy) and casein (cas) to trigger grapevine resistance against P. viticola. On Vitis vinifera cv. Marselan plants, the application of soy and cas reduced the infected leaf surface by 76 and 63%, as compared to th…
Plasma membrane protein trafficking in plant-microbe interactions: a plant cell point of view
2014
International audience; In order to ensure their physiological and cellular functions, plasma membrane (PM) proteins must be properly conveyed from their site of synthesis, i.e., the endoplasmic reticulum, to their final destination, the PM, through the secretory pathway. PM protein homeostasis also relies on recycling and/or degradation, two processes that are initiated by endocytosis. Vesicular membrane trafficking events to and from the PM have been shown to be altered when plant cells are exposed to mutualistic or pathogenic microbes. In this review, we will describe the fine-tune regulation of such alterations, and their consequence in PM protein activity. We will consider the formatio…
Early signaling events induced by elicitors of plant defenses
2006
International audience; Plant pathogen attacks are perceived through pathogenissued compounds or plant-derived molecules that elicit defense reactions. Despite the large variety of elicitors, general schemes for cellular elicitor signaling leading to plant resistance can be drawn. In this article, we review early signaling events that happen after elicitor perception, including reversible protein phosphorylations, changes in the activities of plasma membrane proteins, variations in free calcium concentrations in cytosol and nucleus, and production of nitric oxide and active oxygen species. These events occur within the first minutes to a few hours after elicitor perception. One specific eli…
Nitric oxide contributes to cadmium toxicity in Arabidopsis by promoting cadmium accumulation in roots and by up-regulating genes related to iron upt…
2009
Abstract Nitric oxide (NO) functions as a cell-signaling molecule in plants. In particular, a role for NO in the regulation of iron homeostasis and in the plant response to toxic metals has been proposed. Here, we investigated the synthesis and the role of NO in plants exposed to cadmium (Cd2+), a nonessential and toxic metal. We demonstrate that Cd2+ induces NO synthesis in roots and leaves of Arabidopsis (Arabidopsis thaliana) seedlings. This production, which is sensitive to NO synthase inhibitors, does not involve nitrate reductase and AtNOA1 but requires IRT1, encoding a major plasma membrane transporter for iron but also Cd2+. By analyzing the incidence of NO scavenging or inhibition …
Colorimetic biosensing dispositive based on reagentless hybrid biocomposite: Application to hydrogen peroxide determination
2016
Abstract An efficient approach to enhance the performance of colorimetric biosensors has been developed. The biosensor is based on the co-immobilization of the reagent 3,3′,5,5′-teramethylbencidine (TMB) and the enzyme horseradish peroxidase (HRP) in a PDMS-TEOS-SiO2NPs support. The HRP, in presence of H2O2, catalyzes the oxidation of TMB, producing a blue color. The generated biosensor, doped with the substrate (TMB) and the enzyme (HRP) (entrapped or adsorbed), has been used to determine H2O2 in real samples. Firstly, the immobilization of TMB and HRP in the composite has been studied in order to find the best suitable configuration. The kinetic parameters Vmax (maximum reaction rate) and…