75 research outputs found
Beneficial Bacteria Isolated from Grapevine Inner Tissues Shape Arabidopsis thaliana Roots
We investigated the potential plant growth-promoting traits of 377 culturable endophytic bacteria, isolated from Vitis vinifera cv. Glera, as good biofertilizer candidates in vineyard management. Endophyte ability in promoting plant growth was assessed in vitro by testing ammonia production, phosphate solubilization, indole-3-acetic acid (IAA) and IAA-like molecule biosynthesis, siderophore and lytic enzyme secretion. Many of the isolates were able to mobilize phosphate (33%), release ammonium (39%), secrete siderophores (38%) and a limited part of them synthetized IAA and IAA-like molecules (5%). Effects of each of the 377 grapevine beneficial bacteria on Arabidopsis thaliana root development were also analyzed to discern plant growth-promoting abilities (PGP) of the different strains, that often exhibit more than one PGP trait. A supervised model-based clustering analysis highlighted six different classes of PGP effects on root architecture. A. thaliana DR5::GUS plantlets, inoculated with IAA-producing endophytes, resulted in altered root growth and enhanced auxin response. Overall, the results indicate that the Glera PGP endospheric culturable microbiome could contribute, by structural root changes, to obtain water and nutrients increasing plant adaptation and survival. From the complete cultivable collection, twelve promising endophytes mainly belonging to the Bacillus but also to Micrococcus and Pantoea genera, were selected for further investigations in the grapevine host plants towards future application in sustainable management of vineyards
Managing Banking Risk with the Risk Appetite Framework: a Quantitative Model for the Italian Banking System.
We analyse the structural aspects of the banking Risk Appetite Framework (RAF), providing an operational application in the light of the detailed recommendations of the banking supervisors. We develop a quantitative approach that could be used to adapt to the requirements of these regulations and that might be useful for management purposes. This approach is empirically applied to the balance sheets of the Italian banking system. Our findings show that the Italian banks are generally underexposed in terms of credit risk and market risk, so there is room for shifting the risk profiles towards higher thresholds with a view to improving the credit institutionsâ profitability while keeping their RAF consistent with the regulatory bodiesâ requirements. The quantitative model can be applied effectively to all banks, for different types of risk, making the necessary adjustments according to the particular features of the profile being examined
Managing Banking Risk with the Risk Appetite Framework: a Quantitative Model for the Italian Banking System.
We analyse the structural aspects of the banking Risk Appetite Framework (RAF), providing an operational application in the light of the detailed recommendations of the banking supervisors. We develop a quantitative approach that could be used to adapt to the requirements of these regulations and that might be useful for management purposes. This approach is empirically applied to the balance sheets of the Italian banking system. Our findings show that the Italian banks are generally underexposed in terms of credit risk and market risk, so there is room for shifting the risk profiles towards higher thresholds with a view to improving the credit institutionsâ profitability while keeping their RAF consistent with the regulatory bodiesâ requirements. The quantitative model can be applied effectively to all banks, for different types of risk, making the necessary adjustments according to the particular features of the profile being examined
Bioraznolikost mikrobnih konzorcija izoliranih iz tradicionalnog svjeĆŸeg ovÄjeg sira KarakaÄanski skakutanac
The aim of this study was to assess the structure of indigenous microbial community associated with traditional fresh sheep cheese KarakaÄanski skakutanac and to preserve autochthonous
microbial consortia. Eleven cheeses were sampled during production season (April-September) and subjected to microbiological analysis. Bacterial DNA was isolated by MaxwellÂź16 DNA system from
99 microbial consortia harvested from three culture media (M17, Rogosa, CATC) on the 1st, 2nd and 3rd day of the cheese shelf life. The extracted bulk DNA (n = 99) was used as a template for
PCR-ARDRA and PCR-DGGE analysis. There were no dramatic shifts in the bacterial number and structure of the microbial consortia harvested on the 1st, 2nd or 3rd day of the cheese shelf life neither
during period of sampling. Lactococcus lactis subsp. lactis reached the number of 107-108 CFU g-1, while Leuconostoc pseudomesenteroides, Enterococcus faecalis, and Lactobacillus versmoldensis were identified only at lower dilutions (10-2 - 10-3). This first polyphasic microbiological-molecular study of the KarakaÄanski skakutanac indicated the main LAB representatives associated with the cheese. Obtained autochthonous microbial consortia present a valuable pool of strains for further genetic and functional characterizations.Cilj ovog rada bio je analizirati strukturu mikrobnih konzorcija tradicionalnog svjeĆŸeg ovÄjeg sira KarakaÄanski skakutanac. Jedanaest sireva sakupljeno je tijekom sezone proizvodnje od travnja do rujna. Mikrobni konzorciji sakupljeni su sa 3 hranjive podloge (M17, Rogosa, CATC) od 11 sireva nakon prvog, drugog, i treÄeg dana proizvodnje. Mikrobna DNA je izolirana iz 99 konzorcija, te koriĆĄtena u PCR-ARDRA i PCR-DGGE analizi. Nije bilo promjene u strukturi mikrobnih konzorcija sakupljenih prvog, drugog i treÄeg dana nakon proizvodnje, niti tijekom sezone. UtvrÄena je dominantnost populacije Lactococcus lactis subsp. lactis (107-108 CFU g-1), dok su ostale vrste bakterija mlijeÄne kiseline, Leuconostoc pseudomesenteroides, Enterococcus faecalis i Lactobacillus versmoldensis, identificirane samo na niĆŸim razrjeÄenjima (10-2-10-3). Ova prva mikrobioloĆĄko- molekularna analiza tradicionalnog sira KarakaÄanski skakutanac omoguÄila je uvid u strukturu njegove specifiÄne mikrobne populacije. Sakupljeni mikrobni konzorciji predstavljaju znaÄajan izvor sojeva za daljnju genetsku i funkcionalnu karakterizaciju
Monitoring calcium handling by the plant endoplasmic reticulum with a lowâCa 2+ âaffinity targeted aequorin reporter
Precise measurements of dynamic changes in free Ca2+ concentration in the lumen of the plant endoplasmic reticulum (ER) have been lacking so far, despite increasing evidence for the contribution of this intracellular compartment to Ca2+ homeostasis and signalling in the plant cell. In the present study, we targeted an aequorin chimera with reduced Ca2+ affinity to the ER membrane and facing the ER lumen. To this aim, the cDNA for a low-Ca2+-affinity aequorin variant (AEQmut) was fused to the nucleotide sequence encoding a non-cleavable N-terminal ER signal peptide (fl2). The correct targeting of fl2-AEQmut was confirmed by immunocytochemical analyses in transgenic Arabidopsis thaliana (Arabidopsis) seedlings. An experimental protocol well-established in animal cells â consisting of ER Ca2+ depletion during photoprotein reconstitution followed by ER Ca2+ refilling â was applied to carry out ER Ca2+ measurements in planta. Rapid and transient increases of the ER luminal Ca2+ concentration ([Ca2+]ER) were recorded in response to different environmental stresses, displaying stimulus-specific Ca2+ signatures. The comparative analysis of ER and chloroplast Ca2+ dynamics indicates a complex interplay of these organelles in shaping cytosolic Ca2+ signals during signal transduction events. Our data highlight significant differences in basal [Ca2+]ER and Ca2+ handling by plant ER compared to the animal counterpart. The set-up of an ER-targeted aequorin chimera extends and complements the currently available toolkit of organelle-targeted Ca2+ indicators by adding a reporter that improves our quantitative understanding of Ca2+ homeostasis in the plant endomembrane system
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