Study on diversity of endophytic bacterial communities in seeds of hybrid maize and their parental lines

The seeds of plants are carriers of a variety of beneficial bacteria and pathogens. Using the non-culture methods of building 16S rDNA libraries, we investigated the endophytic bacterial communities of seeds of four hybrid maize offspring and their respective parents. The results of this study show that the hybrid offspring Yuyu 23, Zhengdan958, Jingdan 28 and Jingyu 11 had 3, 33, 38 and 2 OTUs of bacteria, respectively. The parents Ye 478, Chang 7-2, Zheng 58, Jing 24 and Jing 89 had 12, 36, 6, 12 and 2 OTUs, respectively. In the hybrid Yuyu 23, the dominant bacterium Pantoea (73.38?%) was detected in its female parent Ye 478, and the second dominant bacterium of Sphingomonas (26.62?%) was detected in both its female (Ye 478) and male (Chang 7-2) parent. In the hybrid Zhengdan 958, the first dominant bacterium Stenotrophomonas (41.67?%) was detected in both the female (Zheng 58) and male (Chang 7-2) parent. The second dominant bacterium Acinetobacter (9.26?%) was also the second dominant bacterium of its male parent. In the hybrid Jingdan 28, the second dominant bacterium Pseudomonas (12.78?%) was also the second dominant bacterium of its female parent, and its third dominant bacterium Sphingomonas (9.90?%) was the second dominant bacterium of its male parent and detected in its female parent. In the hybrid Jingyu 11, the first dominant bacterium Leclercia (73.85?%) was the third dominant bacterium of its male parent, and the second dominant bacterium Enterobacter (26.15?%) was detected in its male parent. As far as we know, this was the first research reported in China on the diversity of the endophytic bacterial communities of the seeds of various maize hybrids with different genotypes.     

Biotransformation of (RS)-tropic acid in suspension cultures of Coffea arabica,Datura innoxia,Eucalyptus perriniana and Nicotiana tabacum

Suspension cultures of Datura innoxia and Nicotiana tabacum are able to convert (RS)-tropic acid into its glucose esters (2RS)-3-hydroxy-2-phenylpropionyl β-d-glucopyranoside and (2RS)-2-O-(3-hydroxy-2-phenylpropionyl)-d-glucose whereas a cultures of Eucalyptus perriniana converts it into its glucoside (2RS)-3-O-β-d-glucopyranosyl-2-phenylpropionic acid in addition to glucose esters. Suspension cultures of Coffea arabica converts: (RS)-tropic acid into its glucose, sucrose and isotrehalose esters and a small amount of its glucoside; (RS)-2-(4-hydroxyphenyl)propionic acid into its glucose and sucrose esters and a small amount of its glucoside; and (RS)-ethyl 2-(4-hydroxyphenyl)propionate into its gentiobioside. The formation of sucrose esters and linkage of the aglycone to the C-6 position of glucose are characteristic of the biotransformation of carboxylic acids by suspension cultures of C. arabica. The suspension culture of C. arabica selectively converted (R)-tropic acid into its isotrehalose ester on administration of (RS)-tropic acid.     

Control of the dynamics and homeostasis of the Drosophila Hedgehog receptor Patched by two C2-WW-HECT-E3 Ubiquitin ligases

The conserved Hedgehog (HH) signals control animal development, adult stem cell maintenance and oncogenesis. In Drosophila, the HH co-receptor Patched (PTC) controls both HH gradient formation and signalling. PTC is post-translationally downregulated by HH, which promotes its endocytosis and destabilization, but the mechanisms of PTC trafficking and its importance in the control of PTC remain to be understood. PTC interacts with E3 Ubiquitin (UB)-ligases of the C2-WW-HECT family; two of them—SMURF and NEDD4—are known to regulate its levels. We demonstrate that mutation of the PTC PY motif, which mediates binding of C2-WW-HECT family members, inhibits its internalization but not its autonomous and non-autonomous signalling activities. In addition, we show that the two related UB-C2-WW-HECT ligases NEDD4 and SU(DX) regulate PTC trafficking and finely tune its accumulation through partially redundant but distinct functions. While both NEDD4 and SU(DX) promote PTC endocytosis, only SU(DX) is able to induce its lysosomal targeting and degradation. In conclusion, PTC trafficking and homeostasis are tightly regulated by a family of UB-ligases.     

Biotransformation of paeonol by Panax ginseng root and cell cultures

Panax ginseng root and cell cultures were shown to biotransform paeonol (1) into its 2-O-β-d-glucopyranoside (2). P. ginseng root cultures were also able to biotransform paeonol (1) into its 2-O-β-d-xylopyranoside (3), 2-O-β-d-glucopyranosyl(1 → 6)-β-d-glucopyranoside (4) and 2-O-β-d-xylopyranosyl(1 → 6)-β-d-glucopyranoside (5), and its demethylated derivate, 2′,4′-dihydroxyacetophenone (6). Compounds 3 and 4 are new glycosides. It is the first example that the administrated compound was converted into its xylopyranoside by plant biotransformation.     

A lignan from Lonicera hypoleuca

A new lignan characterised as (-)-4-hydroxy-2,6-di-(4′-hydroxy-3′-methoxy)phenyl-3,7-dioxabicyclo-(3.3.0)octane along with n-10-nonacosanol, scopoletin, syringic acid, β-sitosterol and its glucoside, has been isolated from the aerial parts of Lonicera hypoleuca. The stereochemistry of the lignan has been established by its spectroscopic analysis and those of its derivatives, and by its conversion to (+)-pinoresinol. β-Sitosterol-β-D-glucoside displayed good spasmolytic activity.     

Biological and physicochemical evaluation of the conformational stability of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)

Tumor necrosis factor (TNF)-related, apoptosis-inducing ligand (Apo2L/TRAIL) has a unique homotrimeric structure, and its conformational stability is essential for its apoptotic activity. The conformational stability of a modified version of TRAIL(114–281) with two additional domains of histidine tag and isoleucine zipper [His-ILZ-TRAIL(114–281)] was evaluated in various pH environments according to three different biological or physicochemical considerations: cytotoxicity, antibody-binding affinity, and tertiary structure. The biological properties of His-ILZ-TRAIL(114–281) were the most stably maintained at pH 6.0. The physicochemical analyses (circular dichroism and fluorescence spectroscopy) demonstrate that its bioactivity loss by pH challenge was originated from its structural collapse as a homotrimer.     

Biotransformation of progesterone by suspension cultures of Digitalis purpurea cultured cells

It has been shown that the cultured cells of Digitalis purpruea are capable of transforming progesterone (I) to 5α-pregnane-3,20-dione (II), 5α-pregnan-3β-ol-20-one (III), its glucoside (IV), 5α-pregnane-3β,20α-diol (V), its glucoside (VI), 5α-pregnane-3β,20β-diol (VII), its glucoside (VIII), Δ⁴-pregnen-20α-ol-3-one (IX), its glucoside (X), Δ-pregnen-20β-ol-3-one (XI) and its glucoside (XII). 5α-Pregnan-3β-ol-20-one glucoside (IV), 5α-pregnane-3β,20α-diol glucoside (VI), 5α-pregnane-3β,20β-diol glucoside (VIII), Δ⁴-pregnen-20α-ol-3-one glucoside (X) and Δ⁴-pregnen-20β-ol-3-one glucoside (XII) have been found for the first time as new metabolises by plant tissue cultures. A scheme for the biotransformation of progesterone (I) has been proposed, and the reduction and glucosidation activities distinctly have been observed in these cultured cells.     

菜缢管蚜、棉铃虫对杀虫混剂及其单剂的抗性遗传力分析

采用阈性状分析法,估算了菜缢管蚜Lipaphis erysimi(Kaltenbach)和棉铃虫Helicoverpa armigera(Hubuer)对菊马混剂及其单剂、棉铃虫对灭铃威混剂及其单剂的抗性现实遗传力,并对抗性风险和混剂延缓抗性的作用进行了评估。结果表明,菜缢管蚜和棉铃虫对混剂的现实抗性遗传力均明显小于各单剂,依次为：拟除虫菊酯>氨基甲酸酯>有机磷>混剂。混剂的使用寿命大于组成其各个单剂的使用寿命之和,抗性风险依次为：拟除虫菊脂>氨基甲酸酯>有机磷>混剂。菊马混剂对菜缢管蚜和棉铃虫,灭铃威混剂对棉铃虫均有延缓抗性发展的作用。灭铃威对棉铃虫抗性发展的延缓作用最显著。     

Microsporogenesis,microgametogenesis, and pollen morphology of <Emphasis Type="Italic">Ambrosia artemisiifolia</Emphasis> L. in China

Ambrosia artemisiifolia L. from Ambrosia of the Heliantheae of the Asteraceae family is a recognized harmful weed worldwide and one of the major invasive foreign plants in China. In this study, we investigated its reproductive features, focusing on its microsporogenesis, microgametogenesis, and pollen morphology. The results show that (1) Ambrosia artemisiifolia L. is a dicotyledonous plant and has spherical, tricolpate pollen grains with spiny outer wall; (2) its anther wall comprises four layers, namely epidermis, endothecium, middle layers, and amoeboid tapetum; (3) cytokinesis of microspore mother cells is successive; (4) most of tetrads are tetrahedral; and (5) mature pollen grains are three-celled. In conclusion, although Ambrosia artemisiifolia L. is a dicotyledonous plant with tricolpate pollen, its microsporogenesis is successive, which is different from typical dicots.     

Taxonomic and nomenclatural revision of Sládeček's list of ciliates (Protozoa: Ciliophora) as indicators of water quality

A taxonomic and nomenclatural revision of Sládeek's et al. (1981) and Wegl's (1983) lists of ciliates (Protozoa: Ciliophora) as indicators of water quality has been performed. The original reference, important synonyms, and modern taxonomic literature are provided for each of the 378 taxa recognized. The results of this revision are summarized in a table which shows the correct (modern) name, author, and date of publication of each species as well as its saprobity, its saprobic valency, its indicative weight, and its saprobic index.     

Male‐female differences in family size preferences among college students

Abstract

Three dimensions of isolated spousal separation largely determine its fertility impact: (1) length, (2) “completeness” (degree to which it is eliminating fecundability during fecundable months), and (3) its timing as defined by the reproductive state of the wife at its start. While it is obvious that by starting when the wife is in the fecundable state its net delaying of next conception is maximized, it is much less clear with which reproductive state its start should coincide in order to minimize its fertility impact. By means of a simple model, it is shown that for minimum impact a separation should start later in a pregnancy the longer is post‐partum anovulation, the higher is the level of intrauterine mortality, and the shorter is the period of separation. Conditions of natural fertility are assumed.     

Possible role of a taurine transporter in the deep-sea mussel Bathymodiolus septemdierum in adaptation to hydrothermal vents

Various invertebrates inhabiting hydrothermal vents possess sulfur-oxidizing bacteria in their tissues; however, the mechanisms by which toxic sulfides are delivered to these endosymbionts remain unknown. Recently, detoxification of sulfides using thiotaurine, a sulfur-containing amino acid, has been suggested. In this study, we propose the involvement of a taurine transporter in sulfide detoxification in the deep-sea mussel Bathymodiolus septemdierum by demonstrating: (i) the abundance of its mRNA in the gill; (ii) its activity under a wide range of salinities; (iii) its low Michaelis constant value in taurine transportation; and (iv) its affinity for thiotaurine and the thiotaurine precursor, hypotaurine.     

Recent advances in understanding the structure,function, and biotechnological usefulness of the hemoglobin from the bacterium <Emphasis Type="Italic">Vitreoscilla</Emphasis>

The hemoglobin from the bacterium Vitreoscilla (VHb) is the first microbial hemoglobin that was conclusively identified as such (in 1986). It has been extensively studied with respect to its ligand binding properties and mechanisms, structure, biochemical functions, and the mechanisms by which its expression is controlled. In addition, cloning of its gene (vgb) into a variety of heterologous hosts has proved that its expression results substantial increases in production of a variety of useful products and ability to degrade potentially harmful compounds. Recent studies (since 2005) have added significant knowledge to all of these areas and shown the broad range of biotechnological applications in which VHb can have a positive effect.     

Glutamicin CBII,a bacteriocin-like substance produced by

Corynebacterium glutamicum CBII, in the stationary phase of growth, was found to produce spontaneously a substance resembling bacteriocins by its bactericidal properties. This substance designated glutamicin CBII was observed to exhibit bactericidal activity against coryneform bacteria (12 species tested) but not against unrelated gram-positive (3) and gram-negative (3) bacteria, while its action on bacteria with no quite known relatedness to the coryneform group (14) was found to be variable. Glutamicin CBII was partially purified by precipitation with ammonium sulphate (70% saturation), selective heat precipitation and gel chromatography on Sepadex G-50. The antibacterial substance diffused through cellophane membrane with an approximate cut-off of 10000 dalton and its sedimentation coefficient was determined to be 1.1. S by ultracentrifugation. Heating at 100°C for 30 min had no effect on its activity. Glutamicin CBII was proved to be resistant to chloroform, trypsin, chymotrypsin, pronase, and subtilisin. According to its staining behaviour and ¹H NMR spectra it probably represents a glycoprotein containing only a minor protein component.

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AMID: new insights on its intracellular localization and expression at apoptosis

AMID (apoptosis-inducing factor (AIF)-like mitochondrion-associated inducer of death) is a poorly studied member of the AIF family; despite the given name AMID, predicting its association with mitochondria, its real cellular localization, as well as its role and changes during apoptosis are currently unclear. By means of MALDI-TOF mass spectrometry, we have identified as AMID (accession number AAH38129, sequence coverage 31%) the protein isolated by Pisum sativum lectin-affinity chromatography from the plasma membrane fraction of apoptotic murine leukemia L1210 cells, lacking in the intact cells. The obtained results suggest its possible glycosylation that was further suggested by finding N-glycosylation sequon in the signal peptide of AMID protein (in silica), and by predicting transmembrane localization of its N-terminal part. Using monoclonal antibodies to AMID, we demonstrated an increased expression of AMID in human leukemia Jurkat T-cells after apoptosis induction. Immunocytochemical study suggested its association to the plasma membrane.     

Biological Boundaries and Biological Age

The chronologic age classically used in demography is often unable to give useful information about which exact stage in development or aging processes has reached an organism. Hence, we propose here to explain in some applications for what reason the chronologic age fails in explaining totally the observed state of an organism, which leads to propose a new notion, the biological age. This biological age is essentially determined by the number of divisions before the Hayflick’s limit the tissue or mitochondrion in a critical organ (in the sense where its loss causes the death of the whole organism) has already used for its development and adult phases. We give a precise definition of the biological age of an organ based on the Hayflick’s limit of its cells and we introduce a desynchronization index (the cell entropy) for some critical tissues or membranes, which are mainly skin, intestinal endothelium, alveoli epithelium and mitochondrial inner membrane. In these actively metabolising interface tissues or membranes, there is a rapid turnover of cells, of their cytoplasmic constituents such as proteins, and of membrane lipids. The boundaries corresponding to these tissues, cells or membranes have vital functions of interface with the environment (protection, homeothermy, nutrition and respiration) and have a rapid turnover (the total cell renewal time is in mice equal to 3 weeks for the skin, 1.5 day for the intestine, 4 months for the alveolae and 11 days for mitochondrial inner membrane) conditioning their biological age. The biological age of a tissue is made of two major components: (1) first, its embryonic age based on the distance (in number of divisions) between the birth date of its first differentiated cell and the time until it reaches its final boundary at the end of its development and (2) second, its adult age whose complement until its death is just the lapse of time made of the sum of remaining cell cycle durations authorized by its Hayflick’s limit. From this definition, we calculate the global biological lifespan of an organism and revisit notions like demographic survival curves, duration and synchrony of cell cycles, living boundaries from proto-cells to organs, and embryonic and adult phases duration.     

Copper(II) import and reduction are dependent on His-Met clusters in the extracellular amino terminus of human copper transporter-1

Copper(I) is an essential metal for all life forms. Though Cu(II) is the most abundant and stable state, its reduction to Cu(I) via an unclear mechanism is prerequisite for its bioutilization. In eukaryotes, the copper transporter-1 (CTR1) is the primary high-affinity copper importer, although its mechanism and role in Cu(II) reduction remain uncharacterized. Here we show that extracellular amino-terminus of human CTR1 contains two methionine-histidine clusters and neighboring aspartates that distinctly bind Cu(I) and Cu(II) preceding its import. We determined that hCTR1 localizes at the basolateral membrane of polarized MDCK-II cells and that its endocytosis to Common-Recycling-Endosomes is regulated by reduction of Cu(II) to Cu(I) and subsequent Cu(I) coordination by the methionine cluster. We demonstrate the transient binding of both Cu(II) and Cu(I) during the reduction process is facilitated by aspartates that also act as another crucial determinant of hCTR1 endocytosis. Mutating the first Methionine cluster (⁷Met-Gly-Met⁹) and Asp¹³ abrogated copper uptake and endocytosis upon copper treatment. This phenotype could be reverted by treating the cells with reduced and nonreoxidizable Cu(I). We show that histidine clusters, on other hand, bind Cu(II) and are crucial for hCTR1 functioning at limiting copper. Finally, we show that two N-terminal His-Met-Asp clusters exhibit functional complementarity, as the second cluster is sufficient to preserve copper-induced CTR1 endocytosis upon complete deletion of the first cluster. We propose a novel and detailed mechanism by which the two His-Met-Asp residues of hCTR1 amino-terminus not only bind copper, but also maintain its reduced state, crucial for intracellular uptake.     

Ethers and esters derived from apocynin avoid the interaction between p47phox and p22phox subunits of NADPH oxidase: evaluation in?vitro and in silico

NOX (NADPH oxidase) plays an important role during several pathologies because it produces the superoxide anion (O₂^•−), which reacts with NO (nitric oxide), diminishing its vasodilator effect. Although different isoforms of NOX are expressed in ECs (endothelial cells) of blood vessels, the NOX2 isoform has been considered the principal therapeutic target for vascular diseases because it can be up-regulated by inhibiting the interaction between its p47phox (cytosolic protein) and p22phox (transmembrane protein) subunits. In this research, two ethers, 4-(4-acetyl-2-methoxy-phenoxy)-acetic acid (1) and 4-(4-acetyl-2-methoxy-phenoxy)-butyric acid (2) and two esters, pentanedioic acid mono-(4-acetyl-2-methoxy-phenyl) ester (3) and heptanedioic acid mono-(4-acetyl-2-methoxy-phenyl) ester (4), which are apocynin derivatives were designed, synthesized and evaluated as NOX inhibitors by quantifying O₂^•− production using EPR (electron paramagnetic resonance) measurements. In addition, the antioxidant activity of apocynin and its derivatives were determined. A docking study was used to identify the interactions between the NOX2′s p47phox subunit and apocynin or its derivatives. The results showed that all of the compounds exhibit inhibitory activity on NOX, being 4 the best derivative. However, neither apocynin nor its derivatives were free radical scavengers. On the other hand, the in silico studies demonstrated that the apocynin and its derivatives were recognized by the polybasic SH3A and SH3B domains, which are regions of p47phox that interact with p22phox. Therefore this experimental and theoretical study suggests that compound 4 could prevent the formation of the complex between p47phox and p22phox without needing to be activated by MPO (myeloperoxidase), this being an advantage over apocynin.     

An optimized chemical synthesis of human relaxin‐2

Human gene 2 relaxin (RLX) is a member of the insulin superfamily and is a multi‐functional factor playing a vital role in pregnancy, aging, fibrosis, cardioprotection, vasodilation, inflammation, and angiogenesis. RLX is currently applied in clinical trials to cure among others acute heart failure, fibrosis, and preeclampsia. The synthesis of RLX by chemical methods is difficult because of the insolubility of its B‐chain and the required laborious and low yielding site‐directed combination of its A (RLXA) and B (RLXB) chains. We report here that oxidation of the Met²⁵ residue of RLXB improves its solubility, allowing its effective solid‐phase synthesis and application in random interchain combination reactions with RLXA. Linear Met(O)²⁵‐RLX B‐chain (RLXBO) reacts with a mixture of isomers of bicyclic A‐chain (bcRLXA) giving exclusively the native interchain combination. Applying this method Met(O)²⁵‐RLX (RLXO) was obtained in 62% yield and was easily converted to RLX in 78% yield, by reduction with ammonium iodide. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.     

A gallium complex with a new tripodal tris-hydroxypyridinone for potential nuclear diagnostic imaging: solution and in vivo studies of 67Ga-labeled species

The gallium(III) complex of a new tripodal 3-hydroxy-4-pyridinone (3,4-HP) chelator has been studied in terms of its physico-chemical and in vivo properties aimed at potential application as probe for nuclear imaging. In particular, based on spectrophotometric titrations, the hexa-coordinated (1:1) gallium complex appeared as the major species in a wide physiological acid-neutral pH range and its high stability (pGa = 27.5) should avoid drug-induced toxicity resulting from Ga(III) accumulation in tissues due to processes of transmetallation with endogenenous ligands or demetallation. A multinuclear (¹H and ⁷¹Ga) NMR study gave some insights into the structure and dynamics of the gallium(III) chelate in solution, which are consistent with the tris-(3,4-HP) coordination and an eventual pseudo-octahedral geometry. Biodistribution and scintigraphic studies of the ⁶⁷Ga(III) labelled chelate, performed in Wistar rats, confirmed the in vivo stability of the radiolabelled complex, its non interaction with blood proteins and its quick renal clearance. These results indicate good perspectives for potential application of extrafunctionalized analogues in radiodiagnostic techniques.