Search results for "Calcium"
showing 10 items of 1740 documents
Seguimiento del fenómeno blanco de la laguna de la Cruz (Cuenca, España)
2020
[EN] In the present study, a five-year follow-up was performed by remote sensing of the calcium carbonate precipitation in La Gitana karstic lake also known as La Cruz (located on the province of Cuenca, Spain). The important role that calcium carbonate precipitation plays in the ecology of the lake is well known for its influence on the vertical migrations of phytoplankton, the concentration of bioavailable phosphorus and, therefore, the eutrophication and quality of the waters. Whiting take place between the months of July and August, and it can be studied at this time through its optical properties, with the main objective of offering updated data on a phenomenon traditionally studied an…
Ions channels/transporters and chloroplast regulation.
2015
International audience; Ions play fundamental roles in all living cells and their gradients are often essential to fuel transports, to regulate enzyme activities and to transduce energy within and between cells. Their homeostasis is therefore an essential component of the cell metabolism. Ions must be imported from the extracellular matrix to their final subcellular compartments. Among them, the chloroplast is a particularly interesting example because there, ions not only modulate enzyme activities, but also mediate ATP synthesis and actively participate in the building of the photosynthetic structures by promoting membrane-membrane interaction. In this review, we first provide a comprehen…
Effectiveness of sodium bicarbonate combined with hydrogen peroxide and CPP-ACPF in whitening and microhardness of enamel
2017
Background: This study investigated the effects of sodium bicarbonate (NaHCO3) combined with 1.5 hydrogen peroxide (H2O2) and casein phosphopeptide amorphous calcium phosphate fluoride (CPP-ACPF) on color and microhardness of enamel. Material and Methods: Seventy-five bovine incisors were immersed in a tea solution for 7.5 days. The specimens were randomly divided into five groups according to the whitening agent applied: 1) 94 NaHCO3, 2) a blend of 94 NaHCO3 and CPP-ACPF, 3) a blend of 94 NaHCO3 and 1.5 H2O2, 4) a blend of 94 NaHCO3, 1.5 H2O2 and CPP-ACPF, 5) control. The whitening procedure was performed for 10 times over 10 days. At each day, the buccal surfaces were covered with whiteni…
An Appraisal of Calcium Cyanamide as Alternative N Source for Spring-Summer and Fall Season Curly Endive Crops: Effects on Crop Performance, NUE and …
2020
A two-year study was conducted in both spring-summer and fall seasons to evaluate calcium cyanamide (CaCN2) as an alternative nitrogen (N) source for curly endive (Cichorium endivia L. var. crispum) grown in a Mediterranean environment. Four types of N applications were administered: (i) pre-transplanting base application of 100 kg N ha&minus
Colonization of flax roots and early physiological responses of flax cells inoculated with pathogenic and nonpathogenic strains of Fusarium oxysporum
2003
ABSTRACT Fusarium oxysporum includes nonpathogenic strains and pathogenic strains that can induce necrosis or tracheomycosis in plants. The objective of this study was to compare the abilities of a pathogenic strain (Foln3) and a nonpathogenic strain (Fo47) to colonize flax roots and to induce early physiological responses in flax cell culture suspensions. Both strains colonized the outer cortex of the root; however, plant defense reactions, i.e., the presence of wall appositions, osmiophilic material, and collapsed cells, were less frequent and less intense in a root colonized by Foln3 than by Fo47. Early physiological responses were measured in flax cell suspensions confronted with germin…
Involvement of putative glutamate receptors in plant defence signaling and NO production
2011
International audience; Ionotropic glutamate receptors (iGluRs) are non-selective cation channels permeable to calcium, present in animals and plants. In mammals, glutamate is a well-known neurotransmitter and recently has been recognized as an immunomodulator. As animals and plants share common mechanisms that govern innate immunity with calcium playing a key role in plant defence activation, we have checked the involvement of putative iGluRs in plant defence signaling. Using tobacco cells, we first provide evidence supporting the activity of iGluRs as calcium channels and their involvement in NO production as reported in animals. Thereafter, iGluRs were shown to be activated in response t…
Nitric Oxide in Plants: Production and Cross-talk with Ca2+ Signaling
2008
International audience; Nitric oxide (NO) is a diatomic gas that performs crucial functions in a wide array of physiological processes in animals. The past several years have revealed much about its roles in plants. It is well established that NO is synthesized from nitrite by nitrate reductase (NR) and via chemical pathways. There is increasing evidence for the occurrence of an alternative pathway in which NO production is catalysed from L-arginine by a so far non-identified enzyme. Contradictory results have been reported regarding the respective involvement of these enzymes in specific physiological conditions. Although much remains to be proved, we assume that these inconsistencies can …
AM fungal exudates activate MAP kinases in plant cells in dependence from cytosolic Ca2+ increase
2011
International audience; The molecular dialogue occurring prior to direct contact between the fungal and plant partners of arbuscular-mycorrhizal (AM) symbioses begins with the release of fungal elicitors, so far only partially identified chemically, which can activate specific signaling pathways in the host plant. We show here that the activation of MAPK is also induced by exudates of germinating spores of Gigaspora margarita in cultured cells of the non-leguminous species tobacco (Nicotiana tabacum), as well as in those of the model legume Lotus japonicus. MAPK activity peaked about 15 min after the exposure of the host cells to the fungal exudates (FE). FE were also responsible for a rapi…
Integrated signaling network involving calcium, nitric oxide, active oxygen species but not mitogen-activated protein kinases in BcPG1-elicited grape…
2006
We have already reported the identification of the endopolygalacturonase 1 (BcPG1) from Botrytis cinerea as a potent elicitor of defense responses in grapevine, independently of its enzymatic activity. The aim of the present study is the analysis of the signaling pathways triggered by BcPG1 in grapevine cells. Our data indicate that BcPG1 induces a Ca2+ entry from the apoplasm, which triggers a phosphorylation-dependent nitric oxide (NO) production via an enzyme probably related to a NO synthase. Then NO is involved in i) cytosolic calcium homeostasis, by activating Ca2+ release from internal stores and regulating Ca2+ fluxes across the plasma membrane, ii) plasma membrane potential variat…
Encapsulation of black mulberry microcuttings: studies on capsules and synthetic seeds
2017
The encapsulation technology for plant tissue culture can be an efficient tool to optimize the plant management systems and to preserve valuable plant germplasm. In this paper, two experiments were carried out to evaluate the encapsulation efficiency in mulberry (Morus nigra L.). In the first experiment, gel capsules were stored at 4°C for different times (0, 30, 90, 180 and 360 days). The highest percentage of shoot viability (82.5%) and regrowth (72.5%) was scored after 180 days of storage, with an average development of 2.5 shoots/capsule. The second experiment was aimed to point out an efficient protocol to turn the capsules of black mulberry in synthetic seeds ready to develop into who…