Complete Genome Sequence of the N2-Fixing Broad Host Range Endophyte Klebsiella pneumoniae 342 and Virulence Predictions Verified in Mice

We report here the sequencing and analysis of the genome of the nitrogen-fixing endophyte, Klebsiella pneumoniae 342. Although K. pneumoniae 342 is a member of the enteric bacteria, it serves as a model for studies of endophytic, plant-bacterial associations due to its efficient colonization of plant tissues (including maize and wheat, two of the most important crops in the world), while maintaining a mutualistic relationship that encompasses supplying organic nitrogen to the host plant. Genomic analysis examined K. pneumoniae 342 for the presence of previously identified genes from other bacteria involved in colonization of, or growth in, plants. From this set, approximately one-third were identified in K. pneumoniae 342, suggesting additional factors most likely contribute to its endophytic lifestyle. Comparative genome analyses were used to provide new insights into this question. Results included the identification of metabolic pathways and other features devoted to processing plant-derived cellulosic and aromatic compounds, and a robust complement of transport genes (15.4%), one of the highest percentages in bacterial genomes sequenced. Although virulence and antibiotic resistance genes were predicted, experiments conducted using mouse models showed pathogenicity to be attenuated in this strain. Comparative genomic analyses with the presumed human pathogen K. pneumoniae MGH78578 revealed that MGH78578 apparently cannot fix nitrogen, and the distribution of genes essential to surface attachment, secretion, transport, and regulation and signaling varied between each genome, which may indicate critical divergences between the strains that influence their preferred host ranges and lifestyles (endophytic plant associations for K. pneumoniae 342 and presumably human pathogenesis for MGH78578). Little genome information is available concerning endophytic bacteria. The K. pneumoniae 342 genome will drive new research into this less-understood, but important category of bacterial-plant host relationships, which could ultimately enhance growth and nutrition of important agricultural crops and development of plant-derived products and biofuels

Genome-wide analysis of phylogeny, expression profile andsub-cellular localization of SKP1-Like genes in wild tomato

SKP1 is a core component of SCF complex, a major type of E3 ubiquitin ligase catalyzing the last step in ubiquitin-mediated protein degradation pathway. In present study, SKP1 gene family in Solanum pimpinellifolium (SSK), a wild species of tomato, was investigated. A total of 19 SSK genes were identified through homologous search. Their chromosomal locations, gene structures, phylogeny, expression profiles, sub-cellular localizations and protein-protein interaction patterns with putative F-box proteins were analyzed in detail. The high homology and similar expression patterns among clustered SSK genes in chromosome suggested that they may have evolved from duplication events and are functionally redundant. Sub-cellular localization indicated that most of the SSK proteins are distributed in both cytosol and nucleus, except for SSK8, which is detected in cytosol only. Tissue-specific expression patterns suggested that many SSK genes may be involved in tomato fruit development. Furthermore, several SSK genes were found to be responsive to heat stress and salicylic acid treatment. Based on phylogenetic analysis, expression profiles and protein interaction property, we proposed that tomato SSK1 and SSK2 might have similar function to ASK1 and ASK2 in Arabidopsis. (C) 2015 Elsevier Ireland Ltd. All rights reserved

Genome-wide analysis of phylogeny, expression profile and sub-cellular localization of SKP1-Like genes in wild tomato

SKP1 is a core component of SCF complex, a major type of E3 ubiquitin ligase catalyzing the last step in ubiquitin-mediated protein degradation pathway. In present study, SKP1 gene family in Solanum pimpinellifolium (SSK), a wild species of tomato, was investigated. A total of 19 SSK genes were identified through homologous search. Their chromosomal locations, gene structures, phylogeny, expression profiles, sub-cellular localizations and protein-protein interaction patterns with putative F-box proteins were analyzed in detail. The high homology and similar expression patterns among clustered SSK genes in chromosome suggested that they may have evolved from duplication events and are functionally redundant. Sub-cellular localization indicated that most of the SSK proteins are distributed in both cytosol and nucleus, except for SSK8, which is detected in cytosol only. Tissue-specific expression patterns suggested that many SSK genes may be involved in tomato fruit development. Furthermore, several SSK genes were found to be responsive to heat stress and salicylic acid treatment. Based on phylogenetic analysis, expression profiles and protein interaction property, we proposed that tomato SSK1 and SSK2 might have similar function to ASK1 and ASK2 in Arabidopsis. (C) 2015 Elsevier Ireland Ltd. All rights reserved

Process development and characterization of BCB-based redistribution layer (RDL) for silicon interposer application

Redistribution layer (RDL) is necessary for electric interconnection of TSV-based 3D stacking applications. Fabrication process and electrical measurement of RDL using benzocyclobutene(BCB) as interlayer dielectric is investigated in this paper. Photosensitive BCB and electroplating copper are applied in this process featured with low temperature below 250 square. Multilayered RDL has been fabricated by repeating BCB spin-coating and Cu electroplating. Both DC and high frequency test of RDL are carried out. Furthermore, SPICE-compatible distributed RLCG parameter model of RDL is derived to be applied in silicon interposer design.Engineering, Electrical & ElectronicMaterials Science, MultidisciplinaryEICPCI-S(ISTP)

Investigation into the Perforation Optimization in Conglomerate Reservoir Based on a Field Test

The Mahu conglomerate reservoir is characterized by strong heterogeneity and the uneven stimulation of the horizontal lateral during hydraulic fracturing. The optimization of the perforation number per cluster is of great value for horizontal well multi-stage fracturing (HWMF) because the suitable perforation number not only promotes the uniform propagation of multiple fractures but also prevents excessive perforation erosion. In this work, a typical well in the Mahu conglomerate reservoir was selected, and a field test of optimizing the perforation number was carried out. The perforation schemes of three, five, and eight perforations per cluster were designed in nine fracturing stages, respectively. The wellhead pressure under different perforation schemes was compared and analyzed with the step-down flow rate test, and the optimal perforation number per cluster in the Mahu conglomerate reservoir was selected as eight. The theoretical calculation results show that eight perforations per cluster can generate the perforation friction of 5 MPa, sufficient to overcome the mechanical property differences among multiple clusters within one stage. The downhole video technology shows that the perforation erosion area is the most uniform with the case of eight perforations per cluster. Moreover, the optical fiber monitoring results show that the perforation number of eight per cluster can realize the simultaneous initiation and uniform propagation of six fractures or five fractures within one stage. This work is of great significance for the efficient development of the Mahu conglomerate reservoir through HWMF

A TSV last integration approach with wafer level pre-patterned adhesive bonding

In this paper, a TSV last wafer level 3D integration scheme using pre-patterned benzocyclobutene (BCB) adhesive bonding was proposed. With pre-patterned BCB adhesive bonding, a one-time bottom-up TSV filling features as the last step, which eliminates the traditional solder bumping and underfill filling. Preliminary results show that this process is promising for integration of similar chips such as memory chips.Engineering, Electrical & ElectronicMaterials Science, MultidisciplinaryEICPCI-S(ISTP)

The MFS efflux proteins of gram-positive and gram-negative bacteria

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