Apoplastic glutathione degradation by gamma-glutamyl transferase isoforms GGT1 and GGT2 is important for generative and vegetative development in Arabidopsis thaliana

Gamma-glutamyl transferase (GGT) is the unique enzyme able to degrade glutathione (GSH) in extra cytosolic spaces. In plant cell GGT1 and GGT2 isoforms are located in the apoplast, bound to the cell wall and to the plasma membrane respectively. GGT1 is expressed in whole plants mainly in leaves and in the vascular system, whereas more specific expression concerns GGT2 that is found in seed, trichome, pollen and weakly in root. However their role in plant physiology is still waiting to be defined. Glutathione, the substrate of GGT, is one of the most multifunctional molecule in biology, being the most important redox buffer and in plants one of the major source of reduced sulfur. Glutathione is a constituent of the phloem sap, but the mechanisms of its phloem loading and unloading are largely unknown. Obtaining and characterizing the ggt1/ggt2 RNAi double mutant allows to add more clues than the relative single mutants and to shutdown possible compensatory expression between the two isoforms. In this work the selection and characterization of previously obtained ggt1/ggt2 RNAi lines has been performed. The silencing level of both GGT1 and GGT2 transcript was verified by qRT-PCR and the total GGT activity analyzed. Furthermore phenotypic characterization was carried out; firstly, the GGT contribution in cysteine delivery to the seed and in seed development and composition was investigated. The ggt1/ggt2 RNAi plants showed lower seed yield due to reduced silique number and silique length. However thiol content and 2S albumin storage proteins did not change in mutant seeds. It can be concluded that GGT silencing results in metabolic readjustments leading to allocation of resources to less, but fully viable seeds. The fact that GGT uses GSH as a substrate poses the question whether altered resource allocation results from impairment of cysteine delivery to sink tissues and cells, or from redox imbalances which may result in altered glutathione metabolism. The latter might correlate with the observed proline accumulation, which suggests the occurrence of oxidative stress affecting also the germination rate, which resulted delayed. The vegetative growth was also slightly slowed down with a reduced growth rate of rosette diameter and root length. Trichomes, the leaf hair characterized by high level of GSH, were also less in number than wild-type. Moreover the GSH depletion by roots in ggt mutants suggests cooperation between the two isoforms. In conclusion the simultaneous GGT1 and GGT2 silencing induces the decrease of number of organs with high GSH demand (seed and trichome), oxidative stress in seeds and slightly affects vegetative growth. Further information about GGT will be provided by the double mutants obtained in this thesis work through the crossing between ggt mutants with sir1-1, that has reduced sulfur flux, and with ggct2;1, that lacks cytosolic GSH degradation

Draft Genome Sequences of Three Virulent Streptococcus thermophilus Bacteriophages Isolated from the Dairy Environment in the Veneto Region of Italy

ABSTRACT Streptococcus thermophilus , a very important dairy species, is constantly threatened by phage infection. We report the genome sequences of three S. thermophilus bacteriophages isolated from a dairy environment in the Veneto region of Italy. These sequences will be used for the development of new strategies to detect and control phages in dairy environments. </jats:p

Proteome readjustments in the apoplastic space of Arabidopsis thaliana ggt1 mutant leaves exposed to UV-B radiation

Ultraviolet-B radiation acts as an environmental stimulus, but in high doses it has detrimental effects on plant metabolism. Plasma membranes represent a major target for ROS generated by this harmful radiation. Oxidative reactions occurring in the apoplastic space are counteracted by antioxidative systems mainly involving ascorbate and, to some extent, glutathione. The occurrence of the latter and its exact role in the extracellular space are not well documented, however. In Arabidopsis thaliana, the gamma-glutamyl transferase isoform GGT1 bound to the cell wall takes part in the so-called gamma-glutamyl cycle for extracellular glutathione degradation and recovery, and may be implicated in redox sensing and balance. In this work, oxidative conditions were imposed with UV-B and studied in redox altered ggt1 mutants. The response of ggt1 knockout Arabidopsis leaves to UV-B radiation was assessed by investigating changes in extracellular glutathione and ascorbate content and their redox state, and in apoplastic protein composition. Our results show that, on UV-B exposure, soluble antioxidants respond to the oxidative conditions in both genotypes. Rearrangements occur in their apoplastic protein composition, suggesting an involvement of H2O2, which may ultimately act as a signal. Other important changes relating to hormonal effects, cell wall remodeling, and redox activities are discussed. We argue that oxidative stress conditions imposed by UV-B and disruption of the gamma-glutamyl cycle result in similar stress-induced responses, to some degree at least. Data are available via ProteomeXchange with identifier PXD001807

X-SRAM: Enabling In-Memory Boolean Computations in CMOS Static Random Access Memories

Silicon-based Static Random Access Memories (SRAM) and digital Boolean logic have been the workhorse of the state-of-art computing platforms. Despite tremendous strides in scaling the ubiquitous metal-oxide-semiconductor transistor, the underlying \textit{von-Neumann} computing architecture has remained unchanged. The limited throughput and energy-efficiency of the state-of-art computing systems, to a large extent, results from the well-known \textit{von-Neumann bottleneck}. The energy and throughput inefficiency of the von-Neumann machines have been accentuated in recent times due to the present emphasis on data-intensive applications like artificial intelligence, machine learning \textit{etc}. A possible approach towards mitigating the overhead associated with the von-Neumann bottleneck is to enable \textit{in-memory} Boolean computations. In this manuscript, we present an augmented version of the conventional SRAM bit-cells, called \textit{the X-SRAM}, with the ability to perform in-memory, vector Boolean computations, in addition to the usual memory storage operations. We propose at least six different schemes for enabling in-memory vector computations including NAND, NOR, IMP (implication), XOR logic gates with respect to different bit-cell topologies $-$ the 8T cell and the 8$^+$T Differential cell. In addition, we also present a novel \textit{`read-compute-store'} scheme, wherein the computed Boolean function can be directly stored in the memory without the need of latching the data and carrying out a subsequent write operation. The feasibility of the proposed schemes has been verified using predictive transistor models and Monte-Carlo variation analysis.Comment: This article has been accepted in a future issue of IEEE Transactions on Circuits and Systems-I: Regular Paper

Short communication: Comparison of growth kinetics at different temperatures of Streptococcus macedonicus and Streptococcus thermophilus strains of dairy origin

Within the genus Streptococcus, S. thermophilus and S. macedonicus are the 2 known species related to foods. Streptococci are widely used as starter cultures to rapidly lower milk pH. As S. macedonicus has been introduced quite recently, much less information is available on its technological potential. Because temperature is an important factor in fermented food production, we compared the growth kinetics over 24 h of 8 S. thermophilus and 7 S. macedonicus strains isolated from various dairy environments in Italy, at 4 temperatures, 30\ub0C, 34\ub0C, 37\ub0C and 42\ub0C. We used the Gompertz model to estimate the 3 main growth parameters; namely, lag phase duration (\u3bb), maximum growth rate (\ub5max), and maximum cell number at the stationary phase (Nmax). Our results showed significant differences in average growth kinetics between the 2 species. Among the strains tested, 37\ub0C appeared to be the optimal temperature for the growth of both species, particularly for S. macedonicus strains, which showed mean shorter lag phases and higher cell numbers compared with S. thermophilus. Overall, the growth curves of S. macedonicus strains were more similar to each other whereas S. thermophilus strains grew very differently. These results help to better define and compare technological characteristics of the 2 species, in view of the potential use of S. macedonicus in place of S. thermophilus in selected technological applications

CUSTOS ENVOLVIDOS NA FORMAÇÃO DO PREÇO DE VENDA NA CONSTRUÇÃO DE CASAS DE MADEIRA PRÉ-FABRICADAS

As informações oriundas da contabilidade gerencial e de custos, são instrumentos preponderantes para garantir a sobrevivência da organização e ainda, auxiliam no mapeamento dos dados necessários para a formação do preço de venda com vistas a alcançar um resultado eficaz na organização. A pesquisa teve por objetivo principal analisar os custos envolvidos na formação do preço de venda de casas de madeira pré-fabricas na Madeireira Cappelletto, localizada em Chapecó Santa Catarina. A pesquisa foi realizada em uma madeireira de pequeno porte com administração familiar com sede na cidade de Chapecó no estado de Santa Catarina. Na metodologia, o estudo de caso de caráter descritivo fez uso de uma abordagem quantitativa dos dados. Para coleta dos dados foram realizadas entrevistas abertas com o gestor da empresa durante o primeiro semestre de 2016, bem como coletados relatórios gerenciais para evidenciar as receitas, custos e as despesas da empresa. As informações foram coletadas e analisadas e posteriormente realizou-se o cálculo do Mark-up para aferir o preço de venda das casas pré-fabricadas. Os resultados demonstram que empresa apresenta gastos elevados que não foram mensurados anteriormente por seus gestores. Estes valores se refletem na formação do preço de venda que deve sofrer um aumento para absorver esses gastos e assim manter a sustentabilidade do negócio

Apoplastic glutathione degradation by gamma-glutamyl transferase isoforms GGT1 and GGT2 is important for generative and vegetative development in Arabidopsis thaliana

Gamma-glutamyl transferase (GGT) is the unique enzyme able to degrade glutathione (GSH) in extra cytosolic spaces. In plant cell GGT1 and GGT2 isoforms are located in the apoplast, bound to the cell wall and to the plasma membrane respectively. GGT1 is expressed in whole plants mainly in leaves and in the vascular system, whereas more specific expression concerns GGT2 that is found in seed, trichome, pollen and weakly in root. However their role in plant physiology is still waiting to be defined. Glutathione, the substrate of GGT, is one of the most multifunctional molecule in biology, being the most important redox buffer and in plants one of the major source of reduced sulfur. Glutathione is a constituent of the phloem sap, but the mechanisms of its phloem loading and unloading are largely unknown. Obtaining and characterizing the ggt1/ggt2 RNAi double mutant allows to add more clues than the relative single mutants and to shutdown possible compensatory expression between the two isoforms. In this work the selection and characterization of previously obtained ggt1/ggt2 RNAi lines has been performed. The silencing level of both GGT1 and GGT2 transcript was verified by qRT-PCR and the total GGT activity analyzed. Furthermore phenotypic characterization was carried out; firstly, the GGT contribution in cysteine delivery to the seed and in seed development and composition was investigated. The ggt1/ggt2 RNAi plants showed lower seed yield due to reduced silique number and silique length. However thiol content and 2S albumin storage proteins did not change in mutant seeds. It can be concluded that GGT silencing results in metabolic readjustments leading to allocation of resources to less, but fully viable seeds. The fact that GGT uses GSH as a substrate poses the question whether altered resource allocation results from impairment of cysteine delivery to sink tissues and cells, or from redox imbalances which may result in altered glutathione metabolism. The latter might correlate with the observed proline accumulation, which suggests the occurrence of oxidative stress affecting also the germination rate, which resulted delayed. The vegetative growth was also slightly slowed down with a reduced growth rate of rosette diameter and root length. Trichomes, the leaf hair characterized by high level of GSH, were also less in number than wild-type. Moreover the GSH depletion by roots in ggt mutants suggests cooperation between the two isoforms. In conclusion the simultaneous GGT1 and GGT2 silencing induces the decrease of number of organs with high GSH demand (seed and trichome), oxidative stress in seeds and slightly affects vegetative growth. Further information about GGT will be provided by the double mutants obtained in this thesis work through the crossing between ggt mutants with sir1-1, that has reduced sulfur flux, and with ggct2;1, that lacks cytosolic GSH degradation.La gamma-glutammil transferasi (GGT) è l’unico enzima in grado di degradare il glutatione (GSH) nelle regioni extra citosoliche. Le isoforme GGT1 e GGT2, nelle cellule vegetali, sono localizzate nell’apoplasto; ancorate rispettivamente alla parete cellulare e alla membrana plasmatica. La GGT1 è espressa in complesso in tutta la pianta, principalmente nelle foglie e nel sistema vascolare; mentre la GGT2 ha un’espressione più specifica e la si trova principalmente nei semi, nei tricomi, nel polline e in misura minore nelle radici. Tuttavia il loro ruolo nella fisiologia vegetale non è ancora stato chiarito. Il glutatione, substrato della GGT, è una delle molecole più versatili in biologia; infatti è tra i più importanti regolatori dello stato redox cellulare e nelle piante una delle principali fonti di zolfo ridotto. Il glutatione è un normale costituente della linfa nel floema, ma i meccanismi del suo caricamento e scaricamento floematico non sono ancora chiari. Ottenere e caratterizzare un doppio mutante ggt1/ggt2 RNAi permetterebbe di aggiungere più informazioni rispetto a quelle fornite dai singoli mutanti, evitando inoltre possibili meccanismi compensatori tra le due isoforme. In questo lavoro sono state selezionate e caratterizzate le linee ggt1/ggt2 RNAi, generate già in precedenza. Il livello di silenziamento di entrambi i trascritti GGT1 e GGT2 è stato verificato mediante qRT-PCR e l’attività totale della GGT è stata quantificata. Inoltre è stata condotta una caratterizzazione fenotipica; in primo luogo è stato studiato il contributo che potrebbe avere la GGT nel rilasciare cisteina al seme e in particolare la sua rilevanza nello sviluppo e nella composizione del seme. Le piante ggt1/ggt2 RNAi hanno mostrato una minore produzione di semi dovuta al ridotto numero di silique e della loro lunghezza. Tuttavia nessun cambiamento è stato riscontrato nel contenuto di tioli e nelle proteine di riserva albumina 2S dei semi mutanti. In conclusione il silenziamento della GGT induce un riaggiustamento metabolico che porta ad una redistribuzione delle risorse in un numero inferiore di semi, ma quanto meno vitali. Il fatto che la GGT usi il GSH come substrato solleva la questione sul fatto che l’alterata ridistribuzione delle risorse sia dovuto o a deficit nel rilasciare cisteina ai tessuti/cellule sink, o a scompensi redox che possono portare ad alterazioni nel metabolismo del glutatione. Quest’ultima possibilità potrebbe essere correlata con l’accumulo di prolina rilevato nei semi ggt1/ggt2 RNAi, suggerendo la presenza di uno stress ossidativo che va influenzare negativamente anche il tasso di germinazione, risultato ritardato. Anche la crescita vegetativa ggt1/ggt2 RNAi è risultata leggermente rallentata con una riduzione del diametro della rosetta e della lunghezza delle radici. I tricomi, i peli fogliari caratterizzati da alti livelli di GSH, erano anch’essi in numero minore rispetto al wild-type. Inoltre nei mutanti ggt il consumo di GSH da parte delle radici suggerisce una cooperazione tra le due isoforme. In conclusione il contemporaneo silenziamento di GGT1 e GGT2 induce una riduzione nel numero degli organi che hanno un’alta domanda di GSH (semi e tricomi), uno stress ossidativo nei semi e in misura minore influenza la crescita vegetativa. Nuove interessanti informazioni sulle GGT potranno essere estrapolate tramite lo studio dei doppi mutanti generati in questo lavoro, ottenuti incrociando i mutanti ggt con sir1-1, il quale ha un ridotto flusso di zolfo, o con ggct2;1, nel quale manca la degradazione citosolica del GSH

Differences in Carbohydrates Utilization and Antibiotic Resistance Between Streptococcus macedonicus and Streptococcus thermophilus Strains Isolated from Dairy Products in Italy

none6noneTarrah, Armin; Treu, Laura; Giaretta, Sabrina; Duarte, Vinicius; Corich, Viviana*; Giacomini, AlessioTarrah, Armin; Treu, Laura; Giaretta, Sabrina; Duarte, Vinicius; Corich, Viviana; Giacomini, Alessi

CUSTOS ENVOLVIDOS NA FORMAÇÃO DO PREÇO DE VENDA NA CONSTRUÇÃO DE CASAS DE MADEIRA PRÉ-FABRICADAS

As informações oriundas da contabilidade gerencial e de custos, são instrumentos preponderantes para garantir a sobrevivência da organização e ainda, auxiliam no mapeamento dos dados necessários para a formação do preço de venda com vistas a alcançar um resultado eficaz na organização. A pesquisa teve por objetivo principal analisar os custos envolvidos na formação do preço de venda de casas de madeira pré-fabricas na Madeireira Cappelletto, localizada em Chapecó Santa Catarina. A pesquisa foi realizada em uma madeireira de pequeno porte com administração familiar com sede na cidade de Chapecó no estado de Santa Catarina. Na metodologia, o estudo de caso de caráter descritivo fez uso de uma abordagem quantitativa dos dados. Para coleta dos dados foram realizadas entrevistas abertas com o gestor da empresa durante o primeiro semestre de 2016, bem como coletados relatórios gerenciais para evidenciar as receitas, custos e as despesas da empresa. As informações foram coletadas e analisadas e posteriormente realizou-se o cálculo do Mark-up para aferir o preço de venda das casas pré-fabricadas. Os resultados demonstram que empresa apresenta gastos elevados que não foram mensurados anteriormente por seus gestores. Estes valores se refletem na formação do preço de venda que deve sofrer um aumento para absorver esses gastos e assim manter a sustentabilidade do negócio

A OPINIÃO PÚBLICA SOBRE CRIMES CORPORATIVOS: O QUE PENSAM OS ESTUDANTES DE CURSOS DE GRADUAÇÃO DA ÁREA DE NEGÓCIOS

Esta pesquisa aborda a opinião pública sobre os crimes e ilegalidades corporativas.  É possível que atuais estudantes da área de negócios, no exercício futuro da função de gestores, enfrentem situações que demandem decisões, muitas vezes, com consequências danosas, o que exige uma postura ética e reflexiva acerca das condutas a serem tomadas, bem como de suas consequências. O objetivo desta pesquisa é caracterizar a opinião dos estudantes de graduação na área de negócios a respeito dos crimes corporativos, buscando compreender o que impulsiona as atuais opiniões desse público sobre questões importantes associadas ao tema. Esta é uma pesquisa de natureza quantitativa, realizada por meio de um questionário estruturado. Os resultados apontam que, em geral, há um nível médio de conhecimento dos estudantes sobre esta temática e, em relação à gravidade dos crimes corporativos, os estudantes consideram o “uso de mão de obra infantil e trabalho escravo” como aquele de maior gravidade em relação aos outros crimes e ilegalidades corporativas. Ainda, evidenciou-se que os pesquisados consideram os crimes de rua mais graves do que os crimes corporativos