Unlocking the microbiome communities of Banana (Musa spp.) under disease stressed (Fusarium wilt) and non-stressed conditions

We assessed the diversity, structure, and assemblage of bacterial and fungal communities associated with banana plants with and without Fusarium oxysporum f. sp. cubense (Foc) symptoms. A total of 117,814 bacterial and 17,317 fungal operational taxonomy units (OTUs) were identified in the rhizosphere, roots, and corm of the host plant. Results revealed that bacterial and fungal microbiota present in roots and corm primarily emanated from the rhizosphere. The composition of bacterial communities in the rhizosphere, roots, and corm were different, with more diversity observed in the rhizosphere and less in the corm. However, distinct sample types i.e., without (asymptomatic) and with (symptomatic) Fusarium symptoms were the major drivers of the fungal community composition. Considering the high relative abundance among samples, we identified core microbiomes with bacterial and fungal OTUs classified into 20 families and colonizing distinct plant components of banana. Our core microbiome assigned 129 bacterial and 37 fungal genera to known taxa

Characterizing fruit ripening in plantain and Cavendish bananas: A proteomics approach

The fruit physiology of banana cultivars other than Cavendish is poorly understood. To study the ripening process, samples were taken daily from plantain and Cavendish bananas and the ripening stages were determined. We present data from the green to the fully mature stage. By analyzing the protein abundances during ripening we provide some new insights into the ripening process and how plantains fruits are different. Multivariate analysis of the proteins was performed correlated to the starch dynamics. A drop in sucrose synthase and a rise of acid invertase during ripening indicated a change in the balance of the sucrose fate. During ripening, sugars may no longer be available for respiration since they are stored in the vacuoles, making citrate the preferred respiratory substrate. We found significant cultivar specific differences in granule-bound starch synthase, alpha- and beta amylases and cell wall invertase when comparing the protein content at the same ripening stage. This corroborates the difference in starch content/structure between both banana types. Differences in small heat shock proteins and in the cell wall-modifying enzyme xyloglucan endotransglucosylase/hydrolase support respectively the presumed higher carotenoid content and the firmer fruit structure of plantains

Evaluation of four different strategies to characterize plasma membrane proteins from banana roots

Plasma membrane proteins constitute a very important class of proteins. They are involved in the transmission of external signals to the interior of the cell and selective transport of water, nutrients and ions across the plasma membrane. However, the study of plasma membrane proteins is challenging because of their poor solubility in aqueous media and low relative abundance. In this work, we evaluated four different strategies for the characterization of plasma membrane proteins from banana roots: (i) the aqueous-polymer two-phase system technique (ATPS) coupled to gelelectrophoresis (gel-based), and (ii) ATPS coupled to LC-MS/MS (gel free), (iii) a microsomal fraction and (iv) a full proteome, both coupled to LC-MS/ MS. Our results show that the gel-based strategy is useful for protein visualization but has major limitations in terms of time reproducibility and efficiency. From the gel-free strategies, the microsomal-based strategy allowed the highest number of plasma membrane proteins to be identified, followed by the full proteome strategy and by the ATPS based strategy. The high yield of plasma membrane proteins provided by the microsomal fraction can be explained by the enrichment of membrane proteins in this fraction and the high throughput of the gel-free approach combined with the usage of a fast high-resolution mass spectrometer for the identification of proteins

A multi-scale approach to determine the REV in complex carbonate rocks

Complex porous carbonates display heterogeneity at different scales, influencing their reservoir properties (e.g. porosity) especially since different porosity types may exist on different spatial scales. This requires a quantitative geometric description of the complex (micro)structure of the rocks. Modern computer tomography techniques permit acquiring detailed information concerning the porosity network at different scales. These datasets allow evolvement to a more objective pore classification based on mathematical parameters. However computational limitations in complex reservoir models do not allow incorporating heterogeneities on small scales (e.g. sub-meter scale) in full-field reservoir simulations [Nordahl and Ringrose, 2008]. The suggested workflow allows characterizing different porosity networks in travertine rocks as well as establishing confidence intervals regarding the Representative Elementary Volume (REV) of these samples. The results of this study prove that one has to be very critical when determining the REV of heterogeneous complex carbonate rocks, since they are influenced by both resolution and size of the dataset

Cryopreservation of Byrsonima intermedia embryos followed by room temperature thawing

Byrsonima intermedia is a shrub from the Brazilian Cerrado with medicinal properties. The storage of biological material at ultra-low temperatures (-196°C) is termed cryopreservation and represents a promising technique for preserving plant diversity. Thawing is a crucial step that follows cryopreservation. The aim of this work was to cryopreserve B. intermedia zygotic embryos and subsequently thaw them at room temperature in a solution rich in sucrose. The embryos were decontaminated and desiccated in a laminar airflow hood for 0-4 hours prior to plunging into liquid nitrogen. The embryo moisture content (% MC) during dehydration was assessed. Cryopreserved embryos were thawed in a solution rich in sucrose at room temperature, inoculated in a germination medium and maintained in a growth chamber. After 30 days, the embryo germination was evaluated. No significant differences were observed between the different embryo dehydration times, where they were dehydrated for at least one hour. Embryos with a MC between 34.3 and 20.3% were germinated after cryopreservation. In the absence of dehydration, all embryos died following cryopreservation. We conclude that B. intermedia zygotic embryos can be successfully cryopreserved and thawed at room temperature after at least one hour of dehydration in a laminar airflow bench

Les variables familiales associées au trouble oppositionnel avec provocation chez les enfants

La prévalence du trouble oppositionnel avec provocation (TOP) chez les enfants est particulièrement élevée dans la population générale québécoise. Les conséquences liées à ce trouble sont lourdes et tendent à persister dans le temps. Puisque le TOP réside plus spécifiquement dans la relation problématique que l'enfant entretient avec ses figures d'autorité, porter attention aux variables du fonctionnement familial qui y sont associées est une avenue prometteuse pour identifier les cibles d’intervention à préconiser. L'objectif poursuivi dans ce mémoire est donc de déterminer les variables du fonctionnement familial les plus fortement associées à la présence d’un TOP chez les enfants et de vérifier l’effet modérateur du sexe. L'utilisation du modèle de fonctionnement familial de Pauzé et Petitpas (2013) a permis d'identifier les variables familiales les plus proximales à l'enfant et plus susceptibles d'avoir une influence sur son fonctionnement quotidien. L'échantillon est composé d'un groupe de 197 enfants (141 garçons et 56 filles) ayant un TOP comparé à un groupe témoin composé de 185 enfants (93 garçons et 92 filles) sans TOP, ni autres troubles de comportement. Au plan univarié, les résultats montrent que le fonctionnement familial global plus faible, la relation détériorée entre le parent et l'enfant, le faible engagement parental, le manque de supervision et la discipline inconstante sont significativement associés au groupe d'enfants présentant un TOP, en comparaison au groupe témoin. Au plan multivarié, les résultats montrent que la structure familiale (le fait de vivre dans une famille monoparentale ou recomposée) ainsi qu'une relation détériorée entre le parent et l'enfant ressortent comme étant les variables les plus fortement associées au TOP chez les enfants. La qualité de la relation parent-enfant serait d’ailleurs particulièrement importante pour les filles. Il y a donc tout lieu de travailler l'engagement parental, la supervision, la discipline et enfin, le fonctionnement familial global, mais la relation entre le parent et l'enfant demeure une cible d'intervention à prioriser