Sedentary behavior : a key component in the interaction between an integrated lifestyle approach and cardiac autonomic function in active young men

This study aimed to verify the association between autonomic cardiac function (CAF) and the integration of caloric expenditure by physical activity (PA) intensity, sedentary behavior (SB), and sleep quality (PSQI) in active young men. Thirty-five subjects were included, and caloric expenditure in moderate-to-vigorous and light-intensity PA, SB, and PSQI were assessed using questionnaires. Heart rate variability (HRV) was recorded for short periods of time in the supine and orthostatic positions. Multiple linear regression was realized unadjusted and adjusted for covariables, such as age, body mass index, and fat mass. No adjusted analysis indicated that, in the supine position, there were negative associations between the SB and the TP, HF, and NorHF indices, and positive associations between SB and NorLF and LF/HF. In the orthostatic position, an interaction between SB and NorLF was found. Significance of proportion with the TP, HF, and LF/HF indices was confirmed. When adjusted, for the supine position, negative interactions were documented between SB and the TP as well as the HF indices, and between PSQI and the LF/HF index, with interference under the HF and LF/HF indices. Finally, our findings indicate that the proposed approach interacts with CAF, and SB is significantly related to CAF in young active men

The eINTACT system dissects bacterial exploitation of plant osmosignalling to enhance virulence

Bacteria inject effector proteins into host cells to manipulate cellular processes that promote disease. Since bacteria deliver minuscule amounts of effectors only into targeted host cells, it is technically challenging to capture effector-dependent cellular changes from bulk-infected host tissues. Here, we report a new technique called effector-inducible isolation of nuclei tagged in specific cell types (eINTACT), which facilitates affinity-based purification of nuclei from Arabidopsis plant cells that have received Xanthomonas bacterial effectors. Analysis of purified nuclei reveals that the Xanthomonas effector XopD manipulates the expression of Arabidopsis abscisic acid signalling-related genes and activates OSCA1.1, a gene encoding a calcium-permeable channel required for stomatal closure in response to osmotic stress. The loss of OSCA1.1 causes leaf wilting and reduced bacterial growth in infected leaves, suggesting that OSCA1.1 promotes host susceptibility. eINTACT allows us to uncover that XopD exploits host OSCA1.1/abscisic acid osmosignalling-mediated stomatal closure to create a humid habitat that favours bacterial growth and opens up a new avenue for accurately elucidating functions of effectors from numerous gram-negative plant bacteria in native infection contexts.Fil: You, Yuan. Eberhard Karls Universität Tübingen; AlemaniaFil: Koczyk, Grzegorz. Polish Academy of Sciences; ArgentinaFil: Nuc, Maria. Polish Academy of Sciences; ArgentinaFil: Morbitzer, Robert. Eberhard Karls Universität Tübingen; AlemaniaFil: Holmes, Danalyn R.. Eberhard Karls Universität Tübingen; AlemaniaFil: von Roepenack Lahaye, Edda. Eberhard Karls Universität Tübingen; AlemaniaFil: Hou, Shiji. Huazhong Agricultural University; ChinaFil: Giudicatti, Axel Joel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Gris, Carine. Université de Toulouse; FranciaFil: Manavella, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Noël, Laurent D.. Université de Toulouse; FranciaFil: Krajewski, Paweł. Polish Academy of Sciences; ArgentinaFil: Lahaye, Thomas. Eberhard Karls Universität Tübingen; Alemani

Recruitment of a lineage-specific virulence regulatory pathway promotes intracellular infection by a plant pathogen experimentally evolved into a legume symbiont

Ajuts: We are grateful to Lidwine Trouilh for helping in NimbleGen microarray hybridizations and Loic Escoriza for mutant construction. J.P.C. and C.C. were supported by the Initiative d'Excellence IDEX UNITI Actions Thématiques Stratégiques program (RHIZOWHEAT 2014) and by the French National Research Agency (ANR-12-ADAP-0014-01). This work was supported by funds from the French National Institute for Agricultural Research (Plant Health and the Environment Division), the French National Research Agency (ANR-12-ADAP-0014-01) and the French Laboratory of Excellence project TULIP (ANR-10-LABX-41). The complete collections of events generated for all the clones from this study are available on the Microscope platform (https://www.genoscope.cns.fr/agc/microscope/expdata/NGSProjectEvo.php, SYMPA tag).Ecological transitions between different lifestyles, such as pathogenicity, mutualism and saprophytism, have been very frequent in the course of microbial evolution, and often driven by horizontal gene transfer. Yet, how genomes achieve the ecological transition initiated by the transfer of complex biological traits remains poorly known. Here we used experimental evolution, genomics, transcriptomics and high-resolution phenotyping to analyze the evolution of the plant pathogen Ralstonia solanacearum into legume symbionts, following the transfer of a natural plasmid encoding the essential mutualistic genes. We show that a regulatory pathway of the recipient R. solanacearum genome involved in extracellular infection of natural hosts was reused to improve intracellular symbiosis with the Mimosa pudica legume. Optimization of intracellular infection capacity was gained through mutations affecting two components of a new regulatory pathway, the transcriptional regulator efpR and a region upstream from the RSc0965-0967 genes of unknown functions. Adaptive mutations caused the downregulation of efpR and the over-expression of a downstream regulatory module, the three unknown genes RSc3146-3148, two of which encoding proteins likely associated to the membrane. This over-expression led to important metabolic and transcriptomic changes and a drastic qualitative and quantitative improvement of nodule intracellular infection. In addition, these adaptive mutations decreased the virulence of the original pathogen. The complete efpR/RSc3146-3148 pathway could only be identified in the genomes of the pathogenic R. solanacearum species complex. Our findings illustrate how the rewiring of a genetic network regulating virulence allows a radically different type of symbiotic interaction and contributes to ecological transitions and trade-offs

Experimental Evolution of a Plant Pathogen into a Legume Symbiont

Following acquisition of a rhizobial symbiotic plasmid, adaptive mutations in the virulence pathway allowed pathogenic Ralstonia solanacearum to evolve into a legume symbiont under plant selection

Genome Sequences of 17 Strains from Eight Races of Xanthomonas campestris pv. campestris

International audienceXanthomonas campestris pv. campestris is a group of phytopathogenic bacteria causing black rot disease on Brassicaceae crops. Here, we report on draft genome sequences of 17 strains representing eight of nine known races of this pathogen, including the pathotype strain CFBP 6865

Détection et typage du gène à l'aide de biopuces à ADN : perspectives pour l'étude de la diversité et de l'écologie moléculaire des rhizobia

International audienceMicroarray-based detection and typing of : perspectives for studying the diversity and molecular ecology of rhizobia. Environmental screening of bacteria for the presence of genes of interest is a challenging problem due to the high variability of the nucleotide sequence of a given gene between species. Here we tackle this general issue using a particularly well-suited model system that consists of the nodulation gene nodC, which is shared by phylogenetically distant rhizobia. 41 mer and 50 mer oligonucleotides featuring the nucleotide diversity of two highly conserved regions of the NodC protein were spotted on glass slides and cross hybridized with the radioactive-labeled target genomic DNA under low stringency conditions. Statistical analysis of the hybridization patterns allowed the detection of known as well as new nodC sequences and classified the rhizobial strains accordingly. The microarray was successfully used to type the nodC gene directly from legume nodules thus eliminating the need of cultivation of the endosymbiont. This approach could be extended to a panel of diagnostic genes and constitute a powerful tool for studying the distribution of genes of interest in the environment, as well as for bacteria identification. Its potential for studying rhizobial diversity and molecular ecology is discussed. microarray/ rhizobium/ nodulation/ bacteria identification/ gene typing Résumé : Le screening environnemental de bactéries pour la présence de gènes d'intérêt reste difficile à réaliser en raison de la grande variabilité de la séquence d'un même gène présent chez des espèces différentes. Pour aborder ce problème, nous avons réalisé une puce prototype en utilisant comme modèle le gène de nodulation nodC des rhizobia, bactéries fixatrices d'azote symbiotiques des légumineuses, répar-ties dans différentes branches des-et-protéobactéries. Des oligonucléotides de 41 et 50 mers représentatifs de la diversité nucléotidique de deux régions conservées * Correspondance et tirés à part : [email protected] C. Bovin-Masson et al. 98 de la protéine NodC ont été déposés sur lame de verre et hybridés avec de l'ADN génomique marqué radio-activement en conditions faiblement stringentes. L'analyse statistique des patterns d'hybridation a permis la détection de séquences connues ainsi que de nouvelles séquences nodC et de classer les souches en fonction de la séquence nucléotidique de ce gène. La puce a permis également le typage du gène nodC des bactéries présentes dans une nodosité par hybridation avec de l'ADN extrait directement du matériel végétal, permettant ainsi de s'affranchir de la culture préalable de l'endosymbionte. Cette approche, qui peut être étendue à divers autres gènes d'intérêt, constitue un outil puissant pour l'étude de la distribution de gènes d'intérêt ainsi que pour le diagnostic bactérien. Son intérêt pour l'étude de la diver-sité et de l'écologie moléculaire des rhizobia est discutée. puce à ADN/ rhizobium/ nodulation/ identification bactérienne/ typage de gèn

Microarray-Based Detection and Typing of the Rhizobium Nodulation Gene nodC: Potential of DNA Arrays To Diagnose Biological Functions of Interest

Environmental screening of bacteria for the presence of genes of interest is a challenging problem, due to the high variability of the nucleotide sequence of a given gene between species. Here, we tackle this general issue using a particularly well-suited model system that consists of the nodulation gene nodC, which is shared by phylogenetically distant rhizobia. 41mer and 50mer oligonucleotides featuring the nucleotide diversity of two highly conserved regions of the NodC protein were spotted on glass slides and cross hybridized with the radioactive-labeled target genomic DNA under low-stringency conditions. Statistical analysis of the hybridization patterns allowed the detection of known, as well as new, nodC sequences and classified the rhizobial strains accordingly. The microarray was successfully used to type the nodC gene directly from legume nodules, thus eliminating the need of cultivation of the endosymbiont. This approach could be extended to a panel of diagnostic genes and constitute a powerful tool for studying the distribution of genes of interest in the environment, as well as for bacteria identification

Experimental evolution of rhizobia may lead to either extra- or intracellular symbiotic adaptation depending on the selection regime

Special Issue: Microbial Local AdaptationExperimental evolution is a powerful approach to study the process of adaptation to new environments, including the colonization of eukaryotic hosts. Facultative endosymbionts, including pathogens and mutualists, face changing and spatially structured environments during the symbiotic process, which impose diverse selection pressures. Here, we provide evidence that different selection regimes, involving different times spent in the plant environment, can result in either intra- or extracellular symbiotic adaptations. In previous work, we introduced the symbiotic plasmid of Cupriavidus taiwanensis, the rhizobial symbiont of Mimosa pudica, into the phytopathogen Ralstonia solanacearum and selected three variants able to form root nodules on M. pudica, two (CBM212 and CBM349) being able to rudimentarily infect nodule cells and the third one (CBM356) only capable of extracellular infection of nodules. Each nodulating ancestor was further challenged to evolve using serial ex planta-in planta cycles of either 21 (three short-cycle lineages) or 42 days (three long-cycle lineages). In this study, we compared the phenotype of the 18 final evolved clones. Evolution through short and long cycles resulted in similar adaptive paths on lineages deriving from the two intracellularly infectious ancestors, CBM212 and CBM349. In contrast, only short cycles allowed a stable acquisition of intracellular infection in lineages deriving from the extracellularly infecting ancestor, CBM356. Long cycles, instead, favoured improvement of extracellular infection. Our work highlights the importance of the selection regime in shaping desired traits during host-mediated selection experiments