Lactobacillus sakei CRL1862 improves safety and protein hydrolysis in meat systems

Aims The capacity of Lactobacillus sakei CRL1862 to prevent the growth of pathogens and its ability to degrade sarcoplasmic and myofibrillar proteins in pork meat systems was evaluated. In addition, basic safety aspects of Lact. sakei CRL1862 such as production of biogenic amines and antibiotic susceptibility were addressed. Methods and Results The bacteriocin-producing Lact. sakei CRL1862 showed respectively bactericide and bacteriostatic effect against Listeria monocytogenes and Staphylococcus aureus in beaker sausage assay during 9 days of storage at 22°C. The hydrolytic effect of Lact. sakei CRL1862 on protein extracts was evaluated by SDS-PAGE and reverse phase HPLC. A more pronounced proteolysis was evidenced in inoculated sarcoplasmic proteins compared with myofibrillar extracts with the generation of predominantly hydrophilic peptides and increase of total free amino acids concentration. Lactobacillus sakei CRL1862 produced neither histamine nor tyrosine and exhibited no resistance to the antibiotics assayed. Conclusions Lactobacillus sakei CRL1862 effectively controlled the growth of L. monocytogenes and Staph. aureus; moreover, it was able to hydrolyse pork meat extracts generating peptides and amino acids, which may improve hygienic and sensorial attributes of fermented meat products. Significance and Impact of the Study The use of an integrated approach to evaluate the major traits of Lact. sakei CRL1862 showed it can be applied as an autochthonous functional starter in meat fermentation.Fil: Castellano, Patricia Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Aristoy, Maria Concepción. Consejo Superior de Investigaciones Científicas. Instituto de Agroquímica y Tecnología de Alimentos; EspañaFil: Sentandreu, Miguel Angel. Consejo Superior de Investigaciones Científicas. Instituto de Agroquímica y Tecnología de Alimentos; EspañaFil: Vignolo, Graciela Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Toldrá, Fidel. Consejo Superior de Investigaciones Científicas. Instituto de Agroquímica y Tecnología de Alimentos; Españ

Molecular convergence of clock and photosensory pathways through PIF3–TOC1 interaction and co-occupancy of target promoters

This study defines a molecular mechanism for how clock- and light-signaling pathways converge in Arabidopsis. The data reveal that TOC1, an essential core component of the central oscillator, binds to and represses PIF transcriptional activators, which are also the direct molecular signaling partners of the phytochrome photosensory receptors. This finding shows that TOC1 functions as a clock output-transducer, directly linking the core oscillator to a pleiotopically-acting transcriptional network, through repression of target genes. Collectively, in the plant, these components comprise a transcriptionallycentered signaling hub that provides clock-imposed gating of PIF-mediated, photosensory-regulated diurnal growth patterns. These results provide a framework for future research aimed at understanding how circadian dynamics are integrated with other plant physiological processes important for optimal plant fitness.Fil: Soy, Judit. Universitat Autònoma de Barcelona; EspañaFil: Leivar, Pablo. Universitat Autònoma de Barcelona; EspañaFil: Gonzalez Schain, Nahuel Damian. Universitat Autònoma de Barcelona; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Martín, Guiomar. Universitat Autònoma de Barcelona; EspañaFil: Diaz, Céline. Universitat Autònoma de Barcelona; EspañaFil: Sentandreu, Maria. Universitat Autònoma de Barcelona; EspañaFil: Al-Sady, Bassem. University of California at Berkeley; Estados Unidos. United States Department of Agriculture; Estados UnidosFil: Quail, Peter H.. University of California at Berkeley; Estados Unidos. United States Department of Agriculture; Estados UnidosFil: Monte, Elena. Universitat Autònoma de Barcelona; Españ

Functional and Clinical Characteristics for Predicting Sarcopenia in Institutionalised Older Adults: Identifying Tools for Clinical Screening

Background: Recently, the European Working Group on Sarcopenia in Older People (EWGSOP2) has updated the sarcopenia definition based on objective evaluation of muscle strength, mass and physical performance. The aim of this study was to analyse the relationship between sarcopenia and clinical aspects such as functionality, comorbidity, polypharmacy, hospitalisations and falls in order to support sarcopenia screening in institutionalised older adults, as well as to estimate the prevalence of sarcopenia in this population using the EWGSOP2 new algorithm. Methods: A multicentre cross-sectional study was conducted on institutionalised older adults (n = 132, 77.7% female, mean age 82 years). Application of the EWGSOP2 algorithm consisted of the SARC-F questionnaire, handgrip strength (HG), appendicular skeletal muscle mass index (ASMI) and Short Physical Performance Battery (SPPB). Clinical study variables were: Barthel Index (BI), Abbreviated Charlson's Comorbidity Index (ACCI), number of medications, hospital stays and falls. Results: Age, BI and ACCI were shown to be predictors of the EWGSOP2 sarcopenia definition (Nagelkerke's R-square = 0.34), highlighting the ACCI. Sarcopenia was more prevalent in older adults aged over 85 (p = 0.005), but no differences were found according to gender (p = 0.512). Conclusion: BI and the ACCI can be considered predictors that guide healthcare professionals in early sarcopenia identification and therapeutic approach

Using the Updated EWGSOP2 Definition in Diagnosing Sarcopenia in Spanish Older Adults : Clinical Approach

Recently the European Working Group on Sarcopenia in Older People (EWGSOP2) has updated diagnostic criteria for sarcopenia, which consist of one or more measures of muscle strength, muscle mass, and physical performance, plus an initial screening test called SARC-F. The main objective was to compare the number of cases of sarcopenia, using the different measurements and screening options. A cross-sectional study was conducted on Spanish older adults (n = 272, 72% women). Combining the different measures proposed by the steps described in the EWGSOP2 algorithm, 12 options were obtained (A-L). These options were studied in each of the three models: (1) using SARC-F as initial screening; (2) not using SARC-F; and (3) using SARC-CalF instead of SARC-F. A χ2 independence test was statistically significant (χ2(6) = 88.41, p < 0.001), and the association between the algorithm used and the classification of sarcopenia was moderate (Cramer's V = 0.226). We conclude that the different EWGSOP2 measurement options imply case-finding differences in the studied population. Moreover, when applying the SARC-F, the number of people classified as sarcopenic decreases. Finally, when SARC-CalF is used as screening, case finding of sarcopenic people decreases. Thus, clinical settings should consider these outcomes, since these steps can make preventive and therapeutic interventions on sarcopenia vary widely

Functional Profiling of PIF3 Regulated Genes in the Dark / Análisis funcional de los genes regulados por PIF3 en oscuridad

[spa] Los reguladores transcripcionales PIF, factores de interacción con fitocromos de tipo bHLH, aseguran de manera constitutiva el estado etiolado de las plántulas germinadas en oscuridad mediante la represión activa del proceso de desetiolación. Tras la exposición a luz, los fitocromos revierten rápidamente esta acción induciendo la degradación proteolítica de los PIFs. Un análisis reciente del transcriptoma de un cuádruple mutante deficiente en PIF1, PIF3, PIF4 y PIF5 demuestra que los PIFs, en condiciones de oscuridad, regulan transcripcionalmente un grupo de genes que coincide ampliamente con genes regulados por luz en las líneas salvajes. Tales resultados establecen que la inducción de la desetiolación mediada por los fitocromos, implica la reversión del perfil transcripcional mantenido por los PIFs en oscuridad. En este trabajo, elucidamos, como los PIFs implementan la desetiolación de la planta combinando una aproximación basada en el análisis de expresión génica con una estrategia de descripción funcional. Como resultado identificamos también cuatro genes regulados por PIF3 como nuevos reguladores del desarrollo en oscuridad, los genes MIDA de “MISREGULATED IN DARK” (DESREGULADOS EN OSCURIDAD) y proporcionamos evidencia de que cada uno de estos cuatro MIDA, regula un aspecto diferente de la etiolación ( mantenimiento del gancho apical, cierre de los cotiledones o elongación del hipocotilo), sugiriendo así, una ramificación de la señal que PIF3 ejerce sobre estos genes. Además, tras los estudios con mutantes, combinamos la función inferida para los genes MIDA con sus perfiles de expresión en respuesta a la degradación por luz de PIF3 y evidenciamos consistentemente con un modelo, que la acción de la red reguladora PIF3/MIDAS posibilita, tras la exposición a luz, una primera respuesta que induciría rápidamente el proceso de desetiolación y una segunda que modularía los efectos de la primera optimizando el proceso de desetiolación de la plántula en función de las condiciones ambientales que la rodean. Los datos presentados sugieren colectivamente que al menos parte del sistema phy/PIF actúa a través de estos cuatro MIDAs para iniciar y optimizar la desetiolación de la plántula , y que éste mecanismo podría permitir la implementación de respuestas espaciales (específicas de órgano) y temporales durante el programa fotomorfogénico.[eng] After germination in darkness, Arabidopsis seedlings follow a dark specific developmental pattern called skotomorphogenesis or etiolation, characterized because the plant develops long hypocotyls together with a closed apical hook and cotiledons in order to protect the apical meristem while passing through the soil. The phytochrome (phy)-interacting basic helix-loop-helix transcription factors (PIFs) constitutively sustain the etiolated state of dark-germinated seedlings by actively repressing deetiolation in darkness. This action is rapidly reversed upon light exposure by phy-induced proteolytic degradation of the PIFs. Here, we combined a microarray-based approach with a functional profiling strategy and identified four PIF3-regulated genes misexpressed in the dark (MIDAs) that are novel regulators of seedling deetiolation. We provide evidence that each one of these four MIDA genes regulates a specific facet of etiolation (hook maintenance, cotyledon appression, or hypocotyl elongation), indicating that there is branching in the signaling that PIF3 relays. Furthermore, combining inferred MIDA gene function from mutant analyses with their expression profiles in response to light-induced degradation of PIF3 provides evidence consistent with a model where the action of the PIF3/MIDA regulatory network enables an initial fast response to the light and subsequently prevents an overresponse to the initial light trigger, thus optimizing the seedling deetiolation process. Collectively, the data suggest that at least part of the phy/PIF system acts through these four MIDAs to initiate and optimize seedling deetiolation, and that this mechanism might allow the implementation of spatial (i.e., organ-specific) and temporal responses during the photomorphogenic program. After deetiolation plants will develop depending on the surrounding environmental conditions ans short-day, long-day, or shade. Arabidopsis seedlings display rhythmic growth when grown under diurnal conditions, with maximal elongation rates occurring at the end of the night under short-day photoperiods. Current evidence indicates that this behavior involves the action of the growth-promoting bHLH factors PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) and PHYTOCHROME-INTERACTING FACTOR 5 (PIF5) at the end of the night, through a coincidence mechanism that combines their transcriptional regulation by the circadian clock with control of protein accumulation by light. To assess the possible role of PIF3 in this process, we have analyzed hypocotyl responses and marker gene expression in pif single- and higher-order mutants. The data show that PIF3 plays a prominent role as a promoter of seedling growth under diurnal light/dark conditions, in conjunction with PIF4 and PIF5

Branching of the PIF3 regulatory network in Arabidopsis

Plants need to accurately adjust their development after germination in the underground darkness to ensure survival of the seedling, both in the dark and in the light upon reaching the soil surface. Recent studies have established that the photoreceptors phytochromes and the bHLH phytochrome interacting factors PIFs regulate seedling development to adjust it to the prevailing light environment during post-germinative growth. However, complete understanding of the downstream regulatory network implementing these developmental responses is still lacking. In a recent work, published in The Plant Cell, we report a subset of PIF3-regulated genes in dark-grown seedlings that we have named MIDAs (MISREGULATED IN DARK). Analysis of their functional relevance using mutants showed that four of them present phenotypic alterations in the dark, and that each affected a particular facet of seedling development, suggesting organ-specific branching in the signal that PIF3 relays downstream. Furthermore, our results also showed an altered response to light in seedlings with an impaired PIF3/MIDA regulatory network, indicating that these factors might also be essential to initiate and optimize the developmental adjustment of the seedling to the light environment.This work was supported by a Beatriu de Pinós fellowship from the “Comissionat per a Universitats i Recerca del Departament d’Innovació, Universitats i Empresa de la Generalitat de Catalunya” and by Marie Curie IRG PIRG06-GA-2009-256420 grant to P.L., and by grants Marie Curie IRG-046568, Spanish “Ministerio de Ciencia e Innovación” BIO2006-09254 and BIO2009-07675 and Generalitat de Catalunya 2009-SGR-206 to E.M.Peer reviewe

The Arabidopsis endosperm is a temperature-sensing tissue that implements seed thermoinhibition through phyB

Seed thermoinhibition, the repression of germination under high temperatures, prevents seedling establishment under potentially fatal conditions. Thermoinhibition is relevant for phenology and agriculture, particularly in a warming globe. The temperature sensing mechanisms and signaling pathways sustaining thermoinhibition are unknown. Here we show that thermoinhibition in Arabidopsis thaliana is not autonomously controlled by the embryo but is rather implemented by the endosperm. High temperature is sensed through endospermic phyB by accelerating its reversion from the active signaling Pfr form into the inactive Pr form, as previously described in seedlings. This leads to thermoinhibition mediated by PIFs, mainly PIF1, PIF3 and PIF5. Endospermic PIF3 represses the expression of the endospermic ABA catabolic gene CYP707A1 and promotes endospermic ABA accumulation and release towards the embryo to block its growth. Furthermore, endospermic ABA represses embryonic PIF3 accumulation that would otherwise promote embryonic growth. Hence, under high temperatures PIF3 exerts opposite growth responses in the endosperm and embryo

The sequential action of MIDA9/PP2C.D1, PP2C.D2, and PP2C.D5 is necessary to form and maintain the hook after germination in the dark

During seedling etiolation after germination in the dark, seedlings have closed cotyledons and form an apical hook to protect the meristem as they break through the soil to reach the surface. Once in contact with light, the hook opens and cotyledons are oriented upward and separate. Hook development in the dark after seedling emergence from the seed follows three distinctly timed and sequential phases: formation, maintenance, and eventual opening. We previously identified MISREGULATED IN DARK9 (MIDA9) as a phytochrome interacting factor (PIF)-repressed gene in the dark necessary for hook development during etiolated growth. MIDA9 encodes the type 2C phosphatase PP2C.D1, and pp2c-d1/mida9 mutants exhibit open hooks in the dark. Recent evidence has described that PP2C.D1 and other PP2C.D members negatively regulate SMALL AUXIN UP RNA (SAUR)-mediated cell elongation. However, the fundamental question of the timing of PP2C.D1 action (and possibly other members of the PP2C.D family) during hook development remains to be addressed. Here, we show that PP2C.D1 is required immediately after germination to form the hook. pp2c.d1/mida9 shows reduced cell expansion in the outer layer of the hook and, therefore, does not establish the differential cell growth necessary for hook formation, indicating that PP2C.D1 is necessary to promote cell elongation during this early stage. Additionally, genetic analyses of single and high order mutants in PP2C.D1, PP2C.D2, and PP2C.D5 demonstrate that the three PP2C.Ds act collectively and sequentially during etiolation: whereas PP2C.D1 dominates hook formation, PP2C.D2 is necessary during the maintenance phase, and PP2C.D5 acts to prevent opening during the third phase together with PP2C.D1 and PP2C.D2. Finally, we uncover a possible connection of PP2C.D1 levels with ethylene physiology, which could help optimize hook formation during post-germinative growth in the dark.This work was supported by a “Comissionat per a Universitats i Recerca del Departament d’Innovació, Universitats i Empresa” fellowship of the Generalitat de Catalunya (Beatriu de Pino’s program) and Marie Curie IRG PIRG06-GA-2009-256420 grant to PL, by grants from FEDER/Ministerio de Ciencia, Innovación y Universidades – Agencia Estatal de Investigación (project references BIO2009-07675, BIO2015-68460-P, and PGC2018-099987-B-I00) and from the CERCA Programme/Generalitat de Catalunya (project references 2009-SGR-206 and 2017SGR-718) to EM. MS was recipient of a travel fellowship from the “Comissionat per a Universitats i Recerca del Departament d’Innovacio, Universitats i Empresa” of the Generalitat de Catalunya. We acknowledge financial support from the Spanish Ministry of Economy and Competitiveness, through the “Severo Ochoa Programme for Centres of Excellence in R&D” 2016–2019 (SEV-2015-0533).Support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).Peer reviewe