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As an important seedling source, monospores closely associate with yields in nori farming. However, the molecular mechanism underlying differences in monospore production for different strains remains unknown. Comparative transcriptome analysis was performed to examine gene expression differences between the spore abundant wild-type strain (WT) and spore deficient mutant (Y1) of Pyropia chauhanii. The WT strain that produces monospores in abundance exhibited more differentially expressed genes (DEGs) in both number and higher fold-changes than the Y1 strain incapable of producing monospores, indicating that the specific regulation of genes is involved in monospore production. Three lists of DEGs were obtained between the two strains using intersection and displayed in Venn diagram: one expressed only in WT strain, another expressed only in Y1 strain, and the third shared in both strains. DEGs annotated as homologous genes of Arabidopsis thaliana in these 3 lists were curated for online functional enrichment analysis on Metascape website. Gene regulatory networks of WT were functionally enriched in the processing, proteolysis, and transport of proteins, especially within the small GTPase protein family, which might be account for the monospore production ability, whereas Y1 were functionally enriched in the metabolism of essential substance and utilization of indispensable energy, which might be account for the rapid growth of blades. We found the differentially enriched gene regulatory networks between strains might be the intrinsic mechanisms of the different monospore production traits. These findings provide novel insights into the genes and regulatory networks associated with monospore production abilities, which are essential for developing accurate breeding technologies for optimal release of monospores and increase of total nori production.

Intrinsic self-healing polymers via dynamic covalent bonds have been attracting extensive attention because of their repeatable self-healing property. Herein, a novel self-healing epoxy resin was synthesized with disulfide-containing curing agent via the condensation of dimethyl 3,3′-dithiodipropionate (DTPA) and polyether amine (PEA). Therefore, in the structure of cured resin, flexible molecular chains and disulfide bonds were imported into the cross-linked polymer networks for triggering self-healing performance. The self-healing reaction of cracked samples was realized under a mild condition (60 °C for 6 h). The distribution of flexible polymer segments, disulfide bonds and hydrogen bonds in cross-linked networks plays a great role in the self-healing process of prepared resins. The molar ratio of PEA and DTPA strongly affects the mechanical performance and self-healing property. Especially when that molar ratio of PEA to DTPA is 2, the cured self-healing resin sample showed great ultimate elongation (795%) and excellent healing efficiency (98%). The products can be used as an organic coating, in which the crack could self-repair during a limited time. The corrosion resistance of a typical cure coating sample has been testified by an immersion experiment and electrochemistry impedance spectrum (EIS). This work provided a simple and low-cost route to prepare a self-healing coating for prolonging the service life of conventional epoxy coatings.

Nori is the cultivated seaweed with the highest market value in the world. Monospores from the thalli reseed the cultivating nets and provide useful secondary seedlings in nori farming, but the underlying molecular basis remains unclear. To explore crucial genes and pathways related to monospore-producing process in Phycocalida chauhanii (Pyropia chauhanii), transcriptomic analysis over the time-course of key developmental stages was carried out. According to comparative analysis, a total of 19,490 differentially expressed genes (DEGs) were identified. Based on time series trend clustering analysis, 7294 DEGs were enriched in a predominant profile 45, in good accordance with the actual temporal monospore-producing processes, exhibiting an expression trend of first upregulated and then downregulated. Gene Ontology (GO) analysis revealed that the function of these DEGs were top three enriched in GO biological processes of positive regulation of GTPase activity, signal transduction, and protein phosphorylation. KEGG pathway analysis indicated that these DEGs were top three enriched in the “mitogen-activated protein kinase (MAPK) signaling pathway, regulation of autophagy, and endocytosis”. Besides, the expression levels of 12 selected DEGs were validated by real-time quantitative PCR and proved the accuracy of RNA-seq results. Collectively, these findings provide a comprehensive landscape of the molecular mechanism underlying the formation and release of monospores, which might serve as essential basis for the identification of key genes that contribute to monospore formation.

Calmodulin (CaM) plays an important regulatory role in plant growth and development. In this study, on the basis of previous transcriptomic annotation a homolog of CaM gene (Pc-CaM7) was identified from the red alga Phycocalida chauhanii (previously known as Porphyra chauhanii). It encoded a 151 amino acids protein with 4 EF-hand regions, which was the typical structure of calmodulin family proteins. Evolutionary analysis showed that Pc-CaM7 shared conserved orthologous relationships with CaMs from Neoporphyra haitanensis (formerly Pyropia haitanensis), Porphyra umbilicalis, and Gracilariopsis chorda. During the developmental period of P. chauhanii gametophytic germlings from 25- to 50-day-old, the asexual archeospores were continuedly released from the marginal region of blades, followed by the emergence of spermatangia from 40-day-old germlings. Based on quantitative real-time PCR analysis, it showed that expression trend of Pc-CaM7 was correlated with the rule of archeospores’ formation and release, whereas in N. haitanensis without archeospore characteristic, the expression pattern of the orthologous gene (Pha_00404) was different, which increased and reached a plateau during the same developmental period. These findings suggested that Pc-CaM7 may be involved in the process of archeospores formation and release, which may provide a foundation for understanding the molecular mechanisms of asexual reproduction in Bangiales.

In this work, we prepared the epoxy-based adhesives with a binary filler system, which was composed of organosilicon modified hexagonal BN (h-BN) and α-Al2O3. H-BN platelets and α-Al2O3 nanoparticles were decorated by aminopropyltrimethoxysilane (APTMS) and glycidylpropyltrimethoxysilane (GPTMS), respectively, to form covalent links to the filler/polymer matrix interface. The surface chemical composition was investigated by Fourrier transform infrared spectroscopy (FTIR) and thermogravimetry analysis (TGA), which demonstrated that the modifiers were successfully grafted onto the surface of fillers. This modification has been confirmed beneficial to thermal conductivity so that the thermal conductivity of adhesives incorporated with modified binary fillers could reach 0.85 w/m k, which is 10% more than specimen filled with unmodified fillers, because covalent links strengthened the interface and prohibited heat diffusion. Modified Hashin–Shtrikman model was utilized to analyze thermal resistance of the binary filler system, indicating that adhesives filled with modified fillers displayed lower thermal resistance. The enhancement of interface also brought about some other positive effect, especially in the decreasing of dielectric constant ( 1014). Furthermore, the mechanical strength is significantly improved when the modified binary fillers were used.

As an economically important marine seaweed, Pyropia yezoensis can be asexually reproduced via archeospores. However, the molecular mechanism of archeospore formation remains unclear. In this study, we characterized the transcriptomes of two strains of Py. yezoensis, which are strain W′ with abundant archeospores and strain W with scarce archeospores. The 25- and 35-day-old gametophytic blades of both strains were sampled for RNA sequencing. Based on comparative transcriptomic analysis, a large number of differential expressed genes (DEGs) of four pairwise groups between samples were generated. In an effort to identify the genes related to archeospore formation, 415 consensus DEGs reflecting the difference between two strains were investigated. Gene ontology and KEGG analysis revealed that the function for these DEGs was enriched in various processes, such as translation, ribosome assembly, RNA methylation, vesicles assembly, intracellular localization of organelles, and endocytosis. According to functional analysis on 80 selected DEGs, it indicated that genes involved in calcium and MAPK signaling pathway, cytoskeletal movement, and cell wall degradation were related to the formation of archeospores. The accuracy of RNA-seq results was validated by quantitative real-time PCR of 8 selected DEGs. These findings suggest that the molecular mechanism of archeospore formation in Py. yezoensis is sophisticated and our results will serve as an essential foundation for further studies.

An edible green algal species Caulerpa lentillifera J. Agardh is reported from China for the first time. The species was collected from the southwest of Hainan Island and morphologically identified...

Owing to the development of modern micro-electronic devices, polymer composites with high thermal conductivity and low dielectric constant have become increasingly important. Herein, a combination of covalent and non-covalent modification was used to functionalize boron nitride (BN) platelets via first deposition with poly(dopamine) (PDA) followed by grafting with γ-methacryloxypropyl trimethoxy silane (KH570) (denoted as BN-PDA-KH570). The as-prepared BN-PDA-KH570 platelets were incorporated into the natural rubber (NR) matrix to prepare thermal conductive composites. After modification with PDA-KH570, the BN platelets were uniformly dispersed into the NR matrix, which is beneficial for improving the thermal conductivity of NR. The interfacial thermal resistance of the composites was also reduced due to the stronger interfacial interaction via vulcanization of NR with double bonds in KH570. Thus, the NR composites filled with 30 vol% BN-PDA-KH570 platelets exhibited a relatively high thermal conductivity of 0.39 W/mK, which is about 1.5 times and 4 times of 30 vol% BN/NR composite (0.26 W/mK) and pure NR (0.10 W/mK), respectively. In addition, the BN-PDA-KH570/NR composites exhibited a low dielectric constant (3.51 at 100 Hz) and a low dielectric loss tangent (0.25 at 100 Hz), which holds promising applications as thermal management materials for electronic devices.

Dictyopteris divaricata is a kind of important brown algae with many biological activities. It has been receiving more and more attention, yet there are rarely studies done on its polysaccharides. In this study, the optimum extraction and biological activity of seaweed polysaccharides from Dictyopteris divaricata (DDSP) were investigated. Response surface methodology (RSM), based on a three-level, three-variable Box-Behnken design (BBD), was employed to obtain the best possible combinations for maximum polysaccharides yield. The optimum extraction conditions were as follows: liquid-solid ratio of 110 mL/g, extraction time of 6 h and extraction temperature of 100 °C. Under these conditions, the experimental yield was 3.05%, which was in close agreement with the predicted value of 3.15%. The average molecular weight of DDSP was 58.05 kDa. Gas chromatograph (GC) results showed that DDSP was composed of fucose, xylose, mannose, glucose and galactose with the corresponding molar ratio of 4.45:2.74:1.00:2.94:1.35. Biological activity showed that DDSP exhibited strong antioxidant activity in vitro and possessed the potential on stimulating immune response of RAW264.7 cells. So DDSP can be used as a natural ingredient in functional foods.

Caulerpa cupressoides (Vahl) C. Agardh is a widely distributed tropical green algae. The circular chloroplast genome was 130,895 bp in length, with a GC content of 34%. In total, 99 genes were identified and they were consisted of 63 coding genes, 30 tRNA genes, and 6 rRNA genes. This chloroplast genome did not show an obvious quadripartite structure. Phylogenetic analysis revealed that C. cupressoides, C. racemosa, and Tydemania expeditionis were close relatives, with high bootstrap values. The characterized complete chloroplast genome of C. cupressoides will provide essential date for further studies of Bryopsidales.

Bacterial disease has caused high mortality of breeding molluscs from 2009 to 2011 in the Changhai area (Dalian, China). Vibrio spp. and Pseudomonas spp. have been detected as major pathogenic agents for aquatic animals in this area. In the present study, four virulence genes including vsm, toxR, aprX and carA were targeted to develop a real-time PCR assay for the quantitative detection of Vibrio splendidus, V. parahaemolyticus, Pseudomonas fluorescens and P. putida, respectively. The sensitivity and specificity of the assays were verified by experimental samples, and the variation tendencies of pathogenic V. splendidus, V. parahaemolyticus, P. fluorescens and P. putida strains from June to September were also detected in mollusc farming waters during 2011-2014. The concentration of V. splendidus increased from June to July, reduced in August, and then increased again in September. The highest count of V. parahaemolyticus appeared in July, and then dramatically decreased from August to September. Conversely, the counts of P. fluorescens and P. putida remained at lower levels from June to August, and then dramatically peaked in September. All four pathogenic bacteria displayed similar fluctuation tendencies of count variation in each year, and their concentrations were found to have a correlation with the average annual temperature. The variation tendency of pathogenic bacteria with temperature suggested that temperature was one of the most important factors to regulate the bacterial growth in a farming area, which could further provide information for the early warning of disease outbreak by using a convenient real-time PCR assay.

Animals living at high altitudes have evolved distinct phenotypic and genotypic adaptations against stressful environments. We studied the adaptive patterns of altitudinal stresses on transcriptome turnover in subterranean plateau zokors (Myospalax baileyi) in the high-altitude Qinghai-Tibetan Plateau. Transcriptomes of zokors from three populations with distinct altitudes and ecologies (Low: 2846 m, Middle: 3282 m, High: 3,714 m) were sequenced and compared. Phylogenetic and principal component analyses classified them into three divergent altitudinal population clusters. Genetic polymorphisms showed that the population at H, approaching the uppermost species boundary, harbors the highest genetic polymorphism. Moreover, 1056 highly up-regulated UniGenes were identified from M to H. Gene ontologies reveal genes like EPAS1 and COX1 were overexpressed under hypoxia conditions. EPAS1, EGLN1, and COX1 were convergent in high-altitude adaptation against stresses in other species. The fixation indices (F ST and G ST )-based outlier analysis identified 191 and 211 genes, highly differentiated among L, M, and H. We observed adaptive transcriptome changes in Myospalax baileyi, across a few hundred meters, near the uppermost species boundary, regardless of their relatively stable underground burrows’ microclimate. The highly variant genes identified in Myospalax were involved in hypoxia tolerance, hypercapnia tolerance, ATP-pathway energetics, and temperature changes.

Superhydrophobic surfaces arranged by hierarchical porous particles were prepared using modified hydrothermal routes under the effect of sodium citrate. Two particle samples were generated in the medium of hexamethylenetetramine (P1) and urea (P2), respectively. X-ray diffraction, scanning electron microscope, and transmission electron microscope were adopted for the investigation, and results revealed that the P1 and P2 particles are porous microspheres with crosslinked extremely thin (10–30 nm) sheet crystals composed of Zn 5 (OH) 8 Ac 2 ·2H 2 O and Zn 5 (CO 3 ) 2 (OH) 6 , respectively. The prepared particles were treated with a fluoroethylene vinyl ether derivative and studied using Fourier transform infrared spectroscopy and energy-dispersive X-ray spectrometer. Results showed that the hierarchical surfaces of these particles were combined with low-wettable fluorocarbon layers. Moreover, the fabricated surface composed of the prepared hierarchical particles displayed considerably high contact angles, indicating great superhydrophobicity for the products. The wetting behavior of the particles was analyzed with a theoretical wetting model in comparison with that of chestnut-like ZnO products obtained through a conventional hydrothermal route. Correspondingly, this study provided evidence that high roughness surface plays a great role in superhydrophobic behavior.

Tumor necrosis factor superfamily (TNFSF) members represent a group of cytokines participating in diverse immunological, pathological and developmental pathways. However, compared with deuterostomia and cnidaia, the composition and evolution of TNF homologous in protostomia are still not well understood. In the present study, a total of 81 TNF superfamily (TNFSF) genes from 15 mollusk species, including 23 TNFSF genes from Crassostrea gigas, were surveyed by genome-wide bioinformatics analysis. The phylogenetic analysis showed that 14 out of 23 C. gigas TNFSF genes in five clades exhibited orthologous relationships with Pinctada fucata TNFSF genes. Moreover, there were 15 C. gigas TNFSF genes located in oyster-specific clusters, which were contributed by small-scaled tandem and/or segmental duplication events in oyster. By comparing the sequences of duplicated TNFSF pairs, exon loss and variant in exon/intron length were revealed as the major modes of divergence in gene structure. Most of the duplicated C. gigas TNFSF pairs were evolved under purifying selection with consistent tissue expression patterns, implying functional constraint shaped diversification. This study demonstrated the expansion and early divergence of TNF superfamily in C. gigas, which provides potential insight into revealing the evolution and function of this superfamily in mollusk. (C) 2015 Elsevier Ltd. All rights reserved.

Superhydrophobic surfaces on the basis of hierarchical ZnO particles grafted by fluoroethylene-vinylether (FEVE) polymer derivative were prepared using a facile, mild and low-cost method. X-ray diffraction (XRD) and scanning electron microscope (SEM) revealed that the resulting ZnO particles via hydrothermal process exhibit micro–nano dual-scale morphology with high purity under a suitable surfactant amount and alkali concentration. The grafting of FEVE derivative was confirmed by Fourier transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectrometer (EDS), suggesting that hierarchical surface of ZnO particles was an imported monomolecular layer of fluorocarbon polymer. The obtained surface fabricated by drop-casting shows considerably high contact angle and good resistance to water immersion. The wetting behavior in this work was furthermore analyzed by theoretical wetting model. This work demonstrates that the sufficient low-wettable surface and high roughness both take a vital role in the superhydrophobic behavior.

Splicing of plant organellar group II introns is under accurate nuclear control that employs many nucleus-encoded protein cofactors from various families. For mitochondrial introns, only a few splicing factors have been characterized because disruption of their functions often causes embryo lethality. Here, we report the function of Empty Pericarp8 (Emp8) in the splicing of three group II introns in mitochondria, complex I biogenesis, and seed development in maize. Emp8 encodes a P subfamily pentatricopeptide repeat protein that localizes in mitochondria. The loss-of-function mutants of Emp8 are embryo lethal, showing severely arrested embryo and endosperm development in maize. The respiration rate in the emp8 mutants is reduced with substantially enhanced expression of alternative oxidases. Transcript analysis indicated that the trans-splicing of nad1 intron 4 and cis-splicing of nad4 intron 1 are abolished, and the cis-splicing of nad2 intron 1 is severely impaired in the emp8 mutants. These defects consequently lead to the disassembly of mitochondrial complex I and a dramatic reduction in its activity. Together, these results suggest that Emp8 is required for the trans-splicing of nad1 intron 4 and cis-splicing of nad4 intron 1 and nad2 intron 1, which is essential to mitochondrial complex I assembly and hence to embryogenesis and endosperm development in maize.

Most cellulolytic enzyme blends, either procured from a commercial vendor or isolated from a single cellulolytic microbial secretome, do not efficiently hydrolyze ammonia-pretreated (e.g., ammonia fiber expansion or AFEX) lignocellulosic agricultural crop residues like corn stover to fermentable sugars. Typically reported commercial enzyme loading (30-100 mg protein/g glucan) necessary to achieve >90% total hydrolysis yield (to monosaccharides) for AFEX treated biomass, within a short saccharification time frame (24-48 h), is economically unviable. Unlike acid based pretreatments, AFEX retains most of the hemicelluloses in the biomass and therefore requires a more complex suite of enzymes for efficient hydrolysis of cellulose and hemicellulose at industrially relevant high solids loadings. One strategy to reduce enzyme dosage while improving cocktail effectiveness for AFEX treated biomass has been to use individually purified enzymes to determine optimal enzyme combinations to maximize hydrolysis yields. However, this approach is limited by the selection of heterologous enzymes available or the labor required for isolating low abundance enzymes directly from the microbial secretomes. Here, we show that directly blending crude cellulolytic and hemicellulolytic enzymes-rich microbial secretomes can maximize specific activity on AFEX treated biomass without having to isolate individual enzymes. Fourteen commercially available cellulolytic and hemicellulolytic enzymes were procured from leading enzyme companies (Novozymes®, Genencor®, and Biocatalysts®) and were mixed together to generate several hundred unique cocktail combinations. The mixtures were assayed for activity on AFEX treated corn stover (AFEX-CS) using a previously established high-throughput methodology. The optimal enzyme blend combinations identified from these screening assays were enriched in various low abundance hemicellulases and accessory enzymes typically absent in most commercial cellulases cocktails. Our simple approach of blending crude commercially available enzyme cocktails allowed a drastic four-fold reduction in total enzyme requirements (from 30 to 7.5 mg enzyme/g glucan loading) to achieve near-theoretical cellulose and hemicellulose saccharification yields for AFEX treated corn stover.

The whole chloroplast genome (cp DNA) sequence of Caulerpa lentillifera J. Agardh has been characterized from Illumina pair-end sequencing. The circular cpDNA was 119,402 bp in length, containing 122 genes, which included 91 protein-coding genes, 28 tRNA genes, and 3 ribosomal RNA genes (four rRNA species). The overall AT content of C. lentillifera cpDNA is 67.4%. The 48 genes phylogenetic analysis suggested that C. lentillifera formed a monophyletic clade with congeneric C. racemosa.

Nitrile-butadiene rubber (NBR) composites filled with functionalized BN platelets were successfully prepared to yield materials with high thermal conductivities and dielectric constants. To enhance the interfacial interactions between BN platelets and NBR matrix, non-covalent functionalization of poly(dopamine) (PDA) followed by covalent functionalization of γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560) were employed for BN platelets surface modification to yield BN-PDA-KH560. This route led to good filler dispersion of BN-PDA-KH560 plateltes with decreased interfacial thermal resistances. Large thermal conductivity (0.409 W/mK) was achieved with 30 vol% BN-PDA-KH560/NBR composite. This value was 2.6 folds higher than that of pure NBR (0.157 W/mK). The 30 vol% BN-PDA-KH560/NBR composite not only exhibited relatively high dielectric constant (9 at 100 Hz) but also remained low dielectric loss tangent (0.12 at 100 Hz). Overall, these findings provide a simple and effective route for preparing high-performance NBR composites with large thermal conductivities and dielectric constants for potential application in electronic devices.

Micro ribonucleic acids (miRNAs) represent a class of small noncoding RNAs that play important roles in multiple biological processes by degrading targeted mRNAs or by repressing mRNA translation. In the case of algal lineages, especially dinoflagellates, knowledge regarding the miRNA system is still limited and its regulatory role remains unclear. In the present study, a computational approach was employed to screen miRNAs from the expressed sequence tags (ESTs) of Alexandrium tamarense. A total of 18 potential miRNAs were identified according to a range of filtering criteria. In addition, unique evolutionary features, such as miRNA gene duplication and sequence similarity to metazoan miRNAs, implied that the miRNA system in dinoflagellates is complex. Moreover, based on these 18 miRNA sequences, 42 potential target genes showing diverse functions in regulating growth and development were predicted in Thalassiosira pseudonana and Phaeodactylum tricornutum. Taken together, our data suggest the existence of miRNAs in dinoflagellates and provide clues for further functional studies on these predicted miRNAs.

Substrate binding is typically one of the rate-limiting steps preceding enzyme catalytic action during homogeneous reactions. However, interfacial-based enzyme catalysis on insoluble crystalline substrates, like cellulose, has additional bottlenecks of individual biopolymer chain decrystallization from the substrate interface followed by its processive depolymerization to soluble sugars. This additional decrystallization step has ramifications on the role of enzyme–substrate binding and its relationship to overall catalytic efficiency. We found that altering the crystalline structure of cellulose from its native allomorph I β to III I results in 40–50% lower binding partition coefficient for fungal cellulases, but surprisingly, it enhanced hydrolytic activity on the latter allomorph. We developed a comprehensive kinetic model for processive cellulases acting on insoluble substrates to explain this anomalous finding. Our model predicts that a reduction in the effective binding affinity to the substrate coupled with an increase in the decrystallization procession rate of individual cellulose chains from the substrate surface into the enzyme active site can reproduce our anomalous experimental findings.

This report describes the draft genome sequences of two strains, Pseudoalteromonas telluritireducens DSM 16098 and P. spiralis DSM 16099, which were isolated from hydrothermal vents of the Juan de Fuca Ridge. The reads generated by an Ion Torrent PGM were assembled into contigs with total sizes of 4.4 Mb and 4.1 Mb for DSM 16098 and DSM 16099, respectively.

This report describes the draft genome sequence of Alcanivorax sp. strain KX64203, isolated from deep-sea sediment samples. The reads generated by an Ion Torrent PGM were assembled into contigs, with a total size of 4.76 Mb. The data will improve our understanding of the strain's function in alkane degradation.

The neuroendocrine-immune (NEI) regulatory network is a complex system, which plays an indispensable role in the immunity of the host. In the present study, the bioinformatical analysis of the transcriptomic data from oyster Crassostrea gigas and further biological validation revealed that oyster TNF (CgTNF-1 CGI_10018786) could activate the transcription factors NF-κB and HSF (heat shock transcription factor) through MAPK signaling pathway, and then regulate apoptosis, redox reaction, neuro-regulation and protein folding in oyster haemocytes. The activated immune cells then released neurotransmitters including acetylcholine, norepinephrine and [Met5]-enkephalin to regulate the immune response by arising the expression of three TNF (CGI_10005109, CGI_10005110 and CGI_10006440) and translocating two NF-κB (Cgp65, CGI_10018142 and CgRel, CGI_10021567) between the cytoplasm and nuclei of haemocytes. Neurotransmitters exhibited the immunomodulation effects by influencing apoptosis and phagocytosis of oyster haemocytes. Acetylcholine and norepinephrine could down-regulate the immune response, while [Met5]-enkephalin up-regulate the immune response. These results suggested that the simple neuroendocrine-immune regulatory network in oyster might be activated by oyster TNF and then regulate the immune response by virtue of neurotransmitters, cytokines and transcription factors.

In this study, poly(methylphenylsiloxane) (PMPS) and phenylene-silica based hybrid material with interpenetrating networks was prepared by a two-step sol–gel process. Firstly, in the presence of H2SO4, the phenylene-silica was formed as sol particles with high branching degree by cohydrolysis and condensation of phenylene-bridged monomer, tetraethoxysilane (TEOS), and hexamethyldisiloxane (MM). Then, the intermediate transformed into gel framework in polymer matrix using alkali catalyst, in order to produce a homogenous hybrid material with interpenetrating networks. The structure of prepared hybrid material was characterized by FTIR and NMR, suggesting that phenylene-silica framework was imported into polymer matrix and the hybrid products have a much higher network chain density than neat PMPS. The thermogravimetric analysis (TGA) shows that the prepared materials start to degrade at around 490°C. The results of tensile test indicate that the typical PMPS/phenylene-silica hybrid material has a tensile strength up to 26 MPa and demonstrate a certain degree of flexibility. An increase of phenylene content in phenylene-silica particles tends to produce hybrid materials with improved thermal stability and tensile strength. The hybrid coating films after calcinating at 350 and 400°C for 2 h exhibit a good mechanical performance on adhesion, impact strength and flexibility. Electrochemical impedance spectroscopy (EIS) measurements show that the investigated films have an extremely high electric resistance (1010 Ohm·cm2) and a satisfied impermeability to 3.5 wt % sodium chloride solution. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Poly(methylphenylsiloxane) (PMPS)/phenylene-silica hybrid material was prepared by a two-step sol-gel process. In the structure of the hybrid system, the phenylene-silica framework was imported into the crosslinked PMPS matrix to obtain interpenetrating networks. The results of thermogravimetric analysis (TGA) and mechanical tests show that the products exhibit excellent thermal stability at ~400ºC in an inert atmosphere and a tensile strength up to 25.9 ± 1.7 MPa. The investigation of thermal degradation mechanism by TGA coupled with Fourier transform infrared (FTIR) spectroscopy (TGA-FTIR) reflects the linear segments unzipping (430–580ºC), the elimination of benzene (450–680ºC) and the rupture of Si-CH3 and Si-OH (620–850ºC), within which the first degradation step can be retarded by the steric effect of the phenylene-silica framework. In order to study Co60 gamma-irradiation induced effects, the hybrid products after irradiation were also studied by the same characterization, showing slightly increased crosslinking degree of PMPS and unchangeable initial degradation temperature at an irradiation dose of 1.6 × 105 Gy. The mechanical behavior for hybrid products, including tensile strength and coating film properties, was well maintained under the effect of irradiation. An increase of phenylene groups inserted in the phenylene-silica framework was confirmed to induce more significant steric interactions to polymer backbones. This effect permits the hybrid products to enhance thermal and irradiation resistance, as well as mechanical strength.

Efficient deconstruction of cellulosic biomass to fermentable sugars for fuel and chemical production is accomplished by a complex mixture of cellulases, hemicellulases, and accessory enzymes (e.g., >50 extracellular proteins). Cellulolytic enzyme mixtures, produced industrially mostly using fungi like Trichoderma reesei, are poorly characterized in terms of their protein composition and its correlation to hydrolytic activity on cellulosic biomass. The secretomes of commercial glycosyl hydrolase-producing microbes was explored using a proteomics approach with high-throughput quantification using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Here, we show that proteomics-based spectral counting approach is a reasonably accurate and rapid analytical technique that can be used to determine protein composition of complex glycosyl hydrolase mixtures that also correlates with the specific activity of individual enzymes present within the mixture. For example, a strong linear correlation was seen between Avicelase activity and total cellobiohydrolase content. Reliable, quantitative and cheaper analytical methods that provide insight into the cellulosic biomass degrading fungal and bacterial secretomes would lead to further improvements toward commercialization of plant biomass-derived fuels and chemicals.

Studying the binding properties of cellulases to lignocellulosic substrates is critical to achieving a fundamental understanding of plant cell wall saccharification. Lignin auto-fluorescence and degradation products formed during pretreatment impede accurate quantification of individual glycosyl hydrolases (GH) binding to pretreated cell walls. A high-throughput fast protein liquid chromatography (HT-FPLC)-based method has been developed to quantify cellobiohydrolase I (CBH I or Cel7A), cellobiohydrolase II (CBH II or Cel6A), and endoglucanase I (EG I or Cel7B) present in hydrolyzates of untreated, ammonia fiber expansion (AFEX), and dilute-acid pretreated corn stover (CS). This method can accurately quantify individual enzymes present in complex binary and ternary protein mixtures without interference from plant cell wall-derived components. The binding isotherms for CBH I, CBH II, and EG I were obtained after incubation for 2 h at 4 °C. Both AFEX and dilute acid pretreatment resulted in increased cellulase binding compared with untreated CS. Cooperative binding of CBH I and/or CBH II in the presence of EG I was observed only for AFEX treated CS. Competitive binding between enzymes was found for certain other enzyme-substrate combinations over the protein loading range tested (i.e., 25-450 mg/g glucan). Langmuir single-site adsorption model was fitted to the binding isotherm data to estimate total available binding sites E(bm) (mg/g glucan) and association constant K(a) (L/mg). Our results clearly demonstrate that the characteristics of cellulase binding depend not only on the enzyme GH family but also on the type of pretreatment method employed.

A silicone resin with silphenylene units in Si—O—Si backbones was prepared through hydrolysis-polycondensation of self-synthesized 1,4-bis(diethoxymethylsilyl)benzene (BDSB) and other alkoxysilanes. The structure and properties of this novel silicone resin were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), thermogravimetric analysis (TG), scanning electron microscope (SEM) and electrochemical impedance spectrum (EIS). The results of GPC, IR and NMR showed that silphenylene units had been successfully incorporated into the backbones of silicone resin. TG analyses reveal that silicone resin with silphenylene units in its backbones had a higher heat resistance than the usual methyl phenyl silicone resin. SEM results demonstrated that this silicone resin could form a full and uniform film, and its clear paints were able to stand temperatures below 350 °C. EIS analysis revealed that clear paints of this silicone resin have good resistance to corrosion.

We have applied a rational four-step strategy to identify novel bacterial glycosyl hydrolases (GH), in combination with various fungal enzymes, in order to define an efficient enzyme cocktail to hydrolyze pretreated lignocellulosic biomass. The fungal cellulases include cellobiohydrolase I (CBH I; GH family 7A), cellobiohydrolase II (CBH II; GH family 6A), endoglucanase I (EG I; GH family 7B) and ��-glucosidase (��G; GH family 3). Bacterial endocellulases (LC1 and LC2; GH family 5), ��-glucosidase (L��G; GH family 1), endoxylanases (LX1 and LX2; GH family 10) and ��-xylosidase (L��X; GH family 52) from multiple sources were cloned, expressed and purified as well. Enzymatic hydrolysis for various enzyme combinations was performed on Ammonia Fiber Expansion (AFEX) treated corn stover at various total protein loadings (30, 15 and 10 mg enzyme/g glucan). The optimal mass ratio of enzymes necessary for obtaining high glucan and xylan yields was determined using a suitable mixture design of experiments. The optimal hybrid enzyme mixtures contain fungal cellulases (78% of total protein loading), which include CBH I (loading ranging between 9-51% of total enzyme load), CBH II (9-51%), EG I (10-50%), and bacterial hemicellulases (22% of total protein loading) comprising of LXl (13%) and L��X (9%). The hybrid mixture works effectively at 50 ��C and pH 4.5 to efficiently saccharify AFEX treated corn stover giving as high as 95% glucan and 65% xylan conversion, respectively. This strategy of screening enzyme mixtures on pretreated lignocellulose will ultimately help develop enzyme cocktails that can hydrolyze plant cell walls efficiently and economically to produce cellulosic ethanol.

Resistance of silicone resin to heat and irradiation was studied. The chemical structure of silicone resin before and after being heated and irradiated was analyzed by Fourier Transform Infrared Spectroscopy (FT-IR). The thermal stability of silicone resin was investigated by thermogravimetric analysis (TG) and differential thermogravimetry analysis (DTG), and its improvement was indicated by TG and DTG analyses of silicone resin after being irradiated by 60Co γ-ray under different fluence. The surface morphology, mechanical properties, corrosion resistance and chemical resistance of silicone resin clear paints before and after being heated and irradiated were studied by SEM, EIS et al.

Pinus densata is a homoploid hybrid species, originating from P. tabuliformis × P. yunnanensis. The physiological fitness of this natural hybrid compared to its two parental species remains unknown. In this study, we investigated physiological responses of the three species by exposing artificially breed seedlings of each to drought stress lasting 28 days. Our results suggest that, in all three species, drought affected the contents of the plants’ chlorophyll, stomatal conductance, TBARS, hydrogen peroxide, and free proline and increased the activities of antioxidant enzymes, including superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6), and peroxidase (POD; EC 1.11.1.7). The drought stress also induced significant changes in the activity of ascorbate peroxidase (APX; EC 1.11.1.11), monodehydroascorbate reductase (MDHAR; EC 1.6.5.4), dehydroascorbate reductase (DHAR; EC 1.8.5.1), glutathione reductase (GR; EC 1.6.4.2), and levels of ascorbate and glutathione in the ascorbate–glutathione cycle. The hybrid species P. densata appeared to achieve greater drought tolerance and exhibit hybrid superiority in antioxidant processes and other related physiological traits compared to the two parental species, although a few of the hybrid’s measured variables were similar to those of P. tabuliformis. However, P. yunnanensis was more sensitive to drought and appeared to have the lowest resistance to such stress. These physiological differences are largely consistent with the species’ habitat preferences, which may reflect their early genetic divergences and niche differentiation. These findings provide important information for management and forest restoration efforts of these species in the future.

The sfr6-1 mutant of Arabidopsis thaliana was identified previously on the basis of its failure to undergo acclimation to freezing temperatures following exposure to low positive temperatures. This failure is attributed to a defect in the pathway leading to cold on-regulated (COR) gene expression via CBF (C-box binding factor) transcription factors. We identified a region of chromosome 4 containing SFR6 by positional mapping. Fine mapping of the sfr6-1 mutation proved impossible as the locus resides very close to the centromere. Therefore, we screened 380 T-DNA lines with insertions in genes within the large region to which sfr6-1 mapped. This resulted in the identification of two further mutant alleles of SFR6 (sfr6-2 and sfr6-3); like the original sfr6-1 mutation, these disrupt freezing tolerance and COR gene expression. To determine the protein sequence, we cloned an SFR6 cDNA based on the predicted coding sequence, but this offered no indication as to the mechanism by which SFR6 acts. The SFR6 gene itself is not strongly regulated by cold, thus discounting regulation of SFR6 activity at the transcriptional level. We show that over-expression of CBF1 or CBF2 transcription factors, which constitutively activate COR genes in the wild-type, cannot do so in sfr6-1. We demonstrate that CBF protein accumulates to wild-type levels in response to cold in sfr6-1. These results indicate a role for the SFR6 protein in the CBF pathway -downstream of CBF translation. The fact that the SFR6 protein is targeted to the nucleus may suggest a direct role in modulating gene expression.

The possible roles of reduced glutathione(GSH) in chilling tolerance were studied in callus generated from a representative alpine plant, Chorispora bungeana Fisch. & C.A. Mey (C. bungeana). The callus grew well under low-temperature and chilling treatment led only to slight injury, as indicated by a low level of ion leakage (IL). Malondialdehyde measurements also were not elevated, however GSH was. Exogencrusly application of L-buthionine-(S R)-sulfoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase (gamma-ECS), arrested the GSH accumulation induced by chilling and resulted in a significant decrease in cell growth and an increase in IL and malondialdehyde. These results implied that C. bungeana is a plant with a strong low-temperature tolerance mechanism, and the tolerance of C, bungeana may be associated with GSH accumulation. Under chilling treatment, the proportion of unsaturated fatty acid in the plasma membrane (PM) increased significantly in callus of C. bungeana mainly due to increases in C18:2 and C18:3, the membrane fluidity (indicated by DPH fluorescent polarization) however was maintained. High PM H+-ATPase activities were also induced by chilling. Exogenously application of BSO blocked the effects of chilling treatments on the changes of fatty acids and PM H+-ATPase activities, reducing the PM membrane fluidity. On the other hand, simultaneous application of GSH and BSO to callus under chilling treatments reversed the effects of BSO on the changes of fatty acids, PM fluidity and PM H+-ATPase activities. These results Suggested that GSH induced by low-temperature treatments may confer chilling tolerance to C. bungeana, probably by increasing unsaturated fatty acid compositions and maintaining PM fluidity and high enzymatic activity. (C) 2008 Elsevier Inc. All rights reserved.

Gene duplication has been proposed to serve as the engine of evolutionary innovation. It is well recognized that eukaryotic genomes contain a large number of duplicated genes that evolve new functions or expression patterns. However, in mollusks, the evolutionary mechanisms underlying the divergence and the functional maintenance of duplicate genes remain little understood. In the present study, we performed a comprehensive analysis of duplicate genes in the protein kinase superfamily using whole genome and transcriptome data for the Pacific oyster. A total of 64 duplicated gene pairs were identified based on a phylogenetic approach and the reciprocal best BLAST method. By analyzing gene expression from RNA-seq data from 69 different developmental and stimuli-induced conditions (nine tissues, 38 developmental stages, eight dry treatments, seven heat treatments, and seven salty treatments), we found that expression patterns were significantly correlated for a number of duplicate gene pairs, suggesting the conservation of regulatory mechanisms following divergence. Our analysis also identified a subset of duplicate gene pairs with very high expression divergence, indicating that these gene pairs may have been subjected to transcriptional subfunctionalization or neofunctionalization after the initial duplication events. Further analysis revealed a significant correlation between expression and sequence divergence (as revealed by synonymous or nonsynonymous substitution rates) under certain conditions. Taken together, these results provide evidence for duplicate gene sequence and expression divergence in the Pacific oyster, accompanying its adaptation to harsh environments. Our results provide new insights into the evolution of duplicate genes and their expression levels in the Pacific oyster.

RNA editing, converting cytidines (C) to uridines (U) at specific sites in the transcripts of mitochondria and plastids, plays a critical role in organelle gene expression in land plants. Recently pentatricopeptide repeat (PPR) proteins were identified as site-specific recognition factors for RNA editing. In this study, we characterized an empty pericarp7 mutant (emp7) in Zea mays (maize), which confers an embryo-lethal phenotype. In emp7 mutants, mitochondrial functions are seriously perturbed, resulting in a strikingly reduced respiration rate. Emp7 encodes an E-subgroup PPR protein that is localized exclusively in the mitochondrion. Null mutation of Emp7 abolishes the C → U editing of ccmF(N) transcript solely at position 1553. CcmF(N) is coding for a subunit of heme lyase complex in the cytochrome c maturation pathway. The resulting Phe → Ser substitution in CcmF(N) leads to the loss of CcmF(N) protein and a strikingly reduced c-type cytochrome. Consequently, the mitochondrial cytochrome-linked respiratory chain is impaired as a result of the disassembly of complex III in the emp7 mutant. These results indicate that the PPR-E subgroup protein EMP7 is required for C → U editing of ccmF(N) -1553 at a position essential for cytochrome c maturation and mitochondrial oxidative phosphorylation, and hence is essential to embryo and endosperm development in maize.

Statistics for the filtered clean reads. (DOCX 13 kb)

Statistics for the distribution of reads filtered in order. (DOCX 15 kb)

Sequence length distribution of the libraries. X axis displays the reads length; Y axis shows the amount (by million reads). (PDF 177 kb)

The species-level taxonomy of the marine brown algal genus Sargassum is problematic. To resolve some of these systematic issues in the northern China seas, a molecular analysis of Sargassum species was carried out using ITS-2, cox3, and rbcL DNA sequences. Phylogenetic analyses confirmed eight species, including: S. confusum, S. fusiforme, S. hemiphyllum var. chinense, S. horneri, S. muticum, S. siliquastrum, S. thunbergii, and S. vachellianum. The previously described S. shandongense and S. qingdaoense, endemic to the Shandong Peninsula, are shown to be synonymous with S. vachellianum. Seven species previously described from the East China Sea were not observed, and require further investigation.

Thellungiella salsuginea (Brassiaceae) is a typical halophyte which can tolerate extreme cold, drought, and salinity. In order to understand the adaptive evolution of this species in the arid habitats, it is important to know its genetic structure. In this study, 17 polymorphic microsatellite loci were isolated and characterized from an enrichment genomic library of this species. We further assessed the polymorphisms of each locus in 18 individuals from nine geographically distant populations. The number of alleles per locus ranged from six to fourteen. The observed and expected heterozygosity ranged from 0.17 to 0.28 and 0.32 to 0.45, respectively. These markers have been crossly checked in another congeneric species, T. halophila. These microsatellite markers will be useful for investigating population genetics and adaptive evolution of this species and morphological divergence between and it and the closely related species.