bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flavone Glucoside Uptake into Barley Mesophyll and Arabidopsis Cell Culture Vacuoles. Energization Occurs by H+-Antiport and ATP-Binding Cassette-Type Mechanisms
Authors: Frangne Nathalie , Eggmann Thomas , Koblischke Carsten , Weissenböck Gottfried , Martinoia Enrico , Klein Markus 
Published: November 2008

Abstract
In many cases, secondary plant products accumulate in the large central vacuole of plant cells. However, the mechanisms involved in the transport of secondary compounds are only poorly understood. Here, we demonstrate that the transport mechanisms for the major barley (Hordeum vulgare) flavonoid saponarin (apigenin 6-C-glucosyl-7-O-glucoside) are different in various plant species: Uptake into barley vacuoles occurs via a proton antiport and is competitively inhibited by isovitexin (apigenin 6-C-glucoside), suggesting that both flavone glucosides are recognized by the same transporter. In contrast, the transport into vacuoles from Arabidopsis, which does not synthesize flavone glucosides, displays typical characteristics of ATP-binding cassette transporters. Transport of saponarin into vacuoles of both the species is saturable with a K m of 50 to 100 μm. Furthermore, the uptake of saponarin into vacuoles from a barley mutant exhibiting a strongly reduced flavone glucoside biosynthesis is drastically decreased when compared with the parent variety. Thus, the barley vacuolar flavone glucoside/H+antiporter could be modulated by the availability of the substrate. We propose that different vacuolar transporters may be responsible for the sequestration of species-specific/endogenous and nonspecific/xenobiotic secondary compounds in planta.
Characterization of a Family of Arabidopsis Genes Related to Xyloglucan Fucosyltransferase1
Authors: Sarria Rodrigo , Wagner Tanya A. , O'Neill Malcolm A. , Faik Ahmed , Wilkerson Curtis G. , Keegstra Kenneth , Raikhel Natasha V. 
Published: November 2008

Abstract
To understand primary cell wall assembly in Arabidopsis, we have focused on identifying and characterizing enzymes involved in xyloglucan biosynthesis. Nine genes (AtFUT2–10) were identified that share between 47% and 62% amino acid similarity with the xyloglucan-specific fucosyltransferase AtFUT1. Reverse transcriptase-PCR analysis indicates that all these genes are expressed. Bioinformatic analysis predicts that these family members are fucosyltransferases, and we first hypothesized that some may also be involved in xyloglucan biosynthesis. AtFUT3,AtFUT4, and AtFUT5 were expressed in tobacco (Nicotiana tabacum L. cv BY2) suspension culture cells, and the resulting proteins did not transfer fucose (Fuc) from GDP-Fuc to tamarind xyloglucan. AtFUT3, AtFUT4, and AtFUT5 were overexpressed in Arabidopsis plants. Leaves of plants overexpressing AtFUT4 or AtFUT5 contained more Fuc than wild-type plants. Stems of plants overexpressing AtFUT4 or AtFUT5 contained more xylose, less arabinose, and less galactose than wild-type plants. We suggest that the AtFUT family is likely to include fucosyltransferases important for the synthesis of wall carbohydrates. A targeted analysis of isolated cell wall matrix components from plants altered in expression of these proteins will help determine their specificity and biological function.
Identification, Purification, and Characterization of a Thermally Stable Lipase from Rice Bran. A New Member of the (Phospho) Lipase Family
Authors: Bhardwaj Kanchan , Raju Aruna , Rajasekharan Ram 
Published: November 2008

Abstract
A thermally stable lipase (EC 3.1.1.3.) was first identified in rice (Oryza sativa) bran, and the enzyme was purified to homogeneity using octyl-Sepharose chromatography. The enzyme was purified to 7.6-fold with the final specific activity of 0.38 μmol min−1 mg−1 at 80°C using [9,10-3H]triolein as a substrate. The purified enzyme was found to be a glycoprotein of 9.4 kD. Enzyme showed a maximum activity at 80°C and at pH 11.0. The protein was biologically active and retained most of its secondary structure even at 90°C as judged by the enzymatic assays and far-ultraviolet circular dichroism spectroscopy, respectively. Differential scanning calorimetric studies indicated that the transition temperature was 76°C and enthalpy 1.3 × 105 Calorie mol−1 at this temperature. The purified lipase also exhibited phospholipase A2 activity. Colocalization of both the hydrolytic activities in reverse-phase high-performance liquid chromatography and isoelectric focusing showed that the dual activity was associated with a single protein. Further, a direct interaction between both the substrates and the purified protein was demonstrated by photoaffinity labeling, using chemically synthesized analogs of triolein and phosphatidylcholine (PC). Apparent K m for triolein (6.71 mm) was higher than that for PC (1.02 mm). The enzyme preferentially hydrolyzed thesn-2 position of PC, whereas it apparently exhibited no positional specificity toward triacylglycerol. Diisopropyl fluorophosphate inhibited both lipase and phospholipase activities of the purified enzyme. This enzyme is a new member from plants in the family of lipases capable of hydrolyzing phospholipids.
Efficient Down-Regulation of the Major Vegetative Storage Protein Genes in Transgenic Soybean Does Not Compromise Plant Productivity
Authors: Staswick Paul E. , Zhang Zhanyuan , Clemente Thomas E. , Specht James E. 
Published: November 2008

Abstract
Soybean (Glycine max L. Merr.) contains two related and abundant proteins, VSPα and VSPβ, that have been called vegetative storage proteins (VSP) based on their pattern of accumulation, degradation, tissue localization, and other characteristics. To determine whether these proteins play a critical role in sequestering N and other nutrients during early plant development, a VspA antisense gene construct was used to create transgenic plants in which VSP expression was suppressed in leaves, flowers, and seed pods. Total VSP was reduced at least 50-fold due to a 100-fold reduction in VSPα and a 10-fold reduction in VSPβ. Transgenic lines were grown in replicated yield trials in the field in Nebraska during the summer of 1999 and seed harvested from the lines was analyzed for yield, protein, oil, and amino acid composition. No significant difference (α = 0.05) was found between down-regulated lines and controls for any of the traits tested. Young leaves of antisense plants grown in the greenhouse contained around 3% less soluble leaf protein than controls at the time of flowering. However, total leaf N did not vary. Withdrawing N from plants during seed fill did not alter final seed protein content of antisense lines compared with controls. These results indicate that the VSPs play little if any direct role in overall plant productivity under typical growth conditions. The lack of VSPs in antisense plants might be partially compensated for by increases in other proteins and/or non-protein N. The results also suggest that the VSPs could be genetically engineered or replaced without deleterious effects.
Oxygen Deficiency Responsive Gene Expression inChlamydomonas reinhardtii through a Copper-Sensing Signal Transduction Pathway
Authors: Quinn Jeanette M. , Eriksson Mats , Moseley Jeffrey L. , Merchant Sabeeha 
Published: November 2008

Abstract
Chlamydomonas reinhardtii activatesCpx1, Cyc6, and Crd1, encoding, respectively, coproporphyrinogen oxidase, cytochromec 6, and a novel di-iron enzyme when transferred to oxygen-deficient growth conditions. This response is physiologically relevant because C. reinhardtiiexperiences these growth conditions routinely, and furthermore, one of the target genes, Crd1, is functionally required for normal growth under oxygen-depleted conditions. The same genes are activated also in response to copper-deficiency through copper-response elements that function as target sites for a transcriptional activator. The core of the copper-response element, GTAC, is required also for the hypoxic response, as is a trans-acting locus, CRR1. Mercuric ions, which antagonize the copper-deficiency response, also antagonize the oxygen-deficiency response of these target genes. Taken together, these observations suggest that the oxygen- and copper-deficiency responses share signal transduction components. Nevertheless, whereas the copper-response element is sufficient for the nutritional copper response, the oxygen-deficiency response requires, in addition, a second cis-element, indicating that the response to oxygen depletion is not identical to the nutritional copper response. The distinction between the two responses is also supported by comparative analysis of the response of the target genes,Cyc6, Cpx1, and Crd1, to copper versus oxygen deficiency. A Crr1-independent pathway forHyd1 expression in oxygen-depleted C. reinhardtii demonstrates the existence of multiple oxygen/redox-responsive circuits in this model organism.
Antisense RNA-Mediated Suppression of Benzophenanthridine Alkaloid Biosynthesis in Transgenic Cell Cultures of California Poppy
Authors: Park Sang-Un , Yu Min , Facchini Peter J. 
Published: November 2008

AbstractCalifornia poppy (Eschscholzia californicaCham.) cell cultures produce several benzophenanthridine alkaloids, such as sanguinarine, chelirubine, and macarpine, with potent pharmacological activity. Antisense constructs of genes encoding two enzymes involved in benzophenanthridine alkaloid biosynthesis, the berberine bridge enzyme (BBE) and N-methylcoclaurine 3′-hydroxylase (CYP80B1), were introduced separately into California poppy cell cultures. Transformed cell lines expressing antisenseBBE or antisense CYP80B1 constructs and displaying low levels of BBE or CYP80B1 mRNAs, respectively, showed reduced accumulation of benzophenanthridine alkaloids compared with control cultures transformed with a β-glucuronidase gene. Pathway intermediates were not detected in any of the transformed cell lines. The suppression of benzophenanthridine alkaloid biosynthesis using BBE or CYP80B1 antisense RNA constructs also reduced the growth rate of the cultures. Two-dimensional 1H-nuclear magnetic resonance and in vivo 15N-nuclear magnetic resonance spectroscopy showed no difference in the abundance of carbohydrate metabolites in the various transgenic cell lines. However, transformed cells with reduced benzophenanthridine alkaloid levels contained larger cellular pools of several amino acids including alanine, leucine, phenylalanine, threonine, and valine compared with controls. The relative abundance of tyrosine, from which benzophenanthridine alkaloids are derived, was less than 2-fold higher in antisense-suppressed cells relative to controls. These results show that alterations in the metabolic flux through benzophenanthridine alkaloid biosynthesis can affect the regulation of amino acid pools. These data provide new insight into the metabolic engineering of benzophenanthridine alkaloid pathways.
Electrophysiological Analysis of Cloned Cyclic Nucleotide-Gated Ion Channels
Authors: Leng Qiang , Mercier Richard W. , Hua Bao-Guang , Fromm Hillel , Berkowitz Gerald A. 
Published: November 2008

Abstract
Electrophysiological studies were conducted on the cloned plant cyclic nucleotide-gated ion channels AtCNGC2 and AtCNGC1 from Arabidopsis, and NtCBP4 from tobacco (Nicotiana tobacum). The nucleotide coding sequences for these proteins were expressed in Xenopus laevis oocytes or HEK 293 cells. Channel characteristics were evaluated using voltage clamp analysis of currents in the presence of cAMP. AtCNGC2 was demonstrated to conduct K+ and other monovalent cations, but exclude Na+; this conductivity profile is unique for any ion channel not possessing the amino acid sequence found in the selectivity filter of K+-selective ion channels. Application of cAMP evoked currents in membrane patches of oocytes injected with AtCNGC2 cRNA. Direct activation of the channel by cyclic nucleotide, demonstrated by application of cyclic nucleotide to patches of membranes expressing such channels, is a hallmark characteristic of this ion channel family. Voltage clamp studies (two-electrode configuration) demonstrated that AtCNGC1 and NtCBP4 are also cyclic nucleotide-gated channels. Addition of a lipophilic analog of cAMP to the perfusion bath of oocytes injected with NtCBP4 and AtCNGC1 cRNAs induced inward rectified, noninactivating K+currents.
Negative Regulation of Phosphate Starvation-Induced Genes
Authors: Mukatira Uthappa T. , Liu Chunming , Varadarajan Deepa K. , Raghothama Kashchandra G. 
Published: November 2008

Abstract
Phosphate (Pi) deficiency is a major nutritional problem faced by plants in many agro-ecosystems. This deficiency results in altered gene expression leading to physiological and morphological changes in plants. Altered gene expression is presumed to be due to interaction of regulatory sequences (cis-elements) present in the promoters with DNA binding factors (trans-factors). In this study, we analyzed the expression and DNA-protein interaction of promoter regions of Pi starvation-induced genes AtPT2 and TPSI1. AtPT2 encodes the high-affinity Pi transporter in Arabidopsis, whereas TPSI1 codes for a novel gene induced in the Pi-starved tomato (Lycopersicon esculentum). Expression of AtPT2 was induced rapidly under Pi deficiency and increased with decreasing concentrations of Pi. Abiotic stresses except Pi starvation had no affect on the expression of TPSI1. DNA mobility-shift assays indicated that specific sequences ofAtPT2 and TPSI1 promoter interact with nuclear protein factors. Two regions of AtPT2 andTPSI1 promoters specifically bound nuclear protein factors from Pi-sufficient plants. Interestingly, the DNA binding activity disappeared during Pi starvation, leading to the hypothesis that Pi starvation-induced genes may be under negative regulation.
A pilot study to evaluate gene expression profiles in peripheral blood mononuclear cells (PBMCs) from children with GH deficiency and Turner syndrome in response to GH treatment
Authors: Whatmore Andrew J. , Patel Leena , Clayton Peter E. 
Published: November 2008

SummaryResponse to GH treatment is variable and dependent on diagnosis and dose. We used a pharmacogenomic approach to assess whether this variability is reflected in patterns of GH‐induced gene expression in peripheral blood mononuclear cells (PBMCs) taken from three children with GH deficiency (GHD) and three girls with Turner syndrome (TS).Analysis of the response to GH treatment revealed that in GHD, 15 probe sets (11 genes) showed a fold change > ± 1·4 at a P‐value < 0·0005 (and a false detection rate ≤ 15%). These genes included a suppressor of cytokine signalling (SOCS1) and a modulator of cAMP response elements (CREM). In marked contrast, in TS no genes fulfilled these criteria.ANOVA identified a subset of genes significantly affected by diagnosis, GH treatment or an interaction between diagnosis and treatment (P < 0·05, n = 2266). Cluster analysis indicated that genes up‐regulated in both GHD and TS were related to DNA metabolism and transcription. Genes up‐regulated in GHD but down‐regulated in TS were involved in RNA processing and metabolism, whereas those down‐regulated in GHD and up‐regulated in TS were related to immune function.This pilot study has shown that major changes in gene expression in PBMCs can only be seen with confidence in GHD inferring that the pattern of gene expression in response to GH in GHD vs. TS is distinct and disease‐specific. Further studies in larger cohorts will be required to evaluate whether GH‐induced PBMCs gene expression patterns can predict responses to GH in a clinical setting.
Ecosystem–atmosphere exchange of CH4 and N2O and ecosystem respiration in wetlands in the Sanjiang Plain, Northeastern China
Authors: SONG CHANGCHUN , XU XIAOFENG , TIAN HANQIN , WANG YIYONG 
Published: November 2008

AbstractNatural wetlands are critically important to global change because of their role in modulating atmospheric concentrations of CO2, CH4, and N2O. One 4‐year continuous observation was conducted to examine the exchanges of CH4 and N2O between three wetland ecosystems and the atmosphere as well as the ecosystem respiration in the Sanjiang Plain in Northeastern China. From 2002 to 2005, the mean annual budgets of CH4 and N2O, and ecosystem respiration were 39.40 ± 6.99 g C m−2 yr−1, 0.124 ± 0.05 g N m−2 yr−1, and 513.55 ± 8.58 g C m−2 yr−1 for permanently inundated wetland; 4.36 ± 1.79 g C m−2 yr−1, 0.11 ± 0.12 g N m−2 yr−1, and 880.50 ± 71.72 g C m−2 yr−1 for seasonally inundated wetland; and 0.21 ± 0.1 g C m−2 yr−1, 0.28 ± 0.11 g N m−2 yr−1, and 1212.83 ± 191.98 g C m−2 yr−1 for shrub swamp. The substantial interannual variation of gas fluxes was due to the significant climatic variability which underscores the importance of long‐term continuous observations. The apparent seasonal pattern of gas emissions associated with a significant relationship of gas fluxes to air temperature implied the potential effect of global warming on greenhouse gas emissions from natural wetlands. The budgets of CH4 and N2O fluxes and ecosystem respiration were highly variable among three wetland types, which suggest the uncertainties in previous studies in which all kinds of natural wetlands were treated as one or two functional types. New classification of global natural wetlands in more detailed level is highly expected.
Distribution Pattern of Neuropeptide Y in the Brain, Pituitary and Olfactory System during the Larval Development of the Toad Rhinella arenarum (Amphibia: Anura)
Authors: Heer T. , Pozzi A. G. , Yovanovich C. A , Paz D. A. 
Published: November 2008

SummaryThe first NPY‐immunoreactivity (ir) in the central nervous system of Rhinella arenarum was obtained just after hatching in the pre‐optic area, ventral thalamus and rostral rhombencephalon. During pre‐metamorphosis, new NPY‐ir cells were observed in other brain areas such as pallium, septum and striatum, infundibulum and pars intermedia of the pituitary. Further maturation continued through pro‐metamorphosis with the appearance of cell groups in the diagonal band, amygdala, pre‐optic nucleus, dorsal nucleus of the habenula, anterior ventral and dorsal thalamus, suprachiasmatic nucleus, tuberculum posterior, tectum, torus semicircularis, inter‐peduncular nucleus and median eminence. During the metamorphic climax and soon after, the relative abundance of NPY‐ir fibres decreased in all hypothalamic areas and the staining intensity and number of NPY‐ir cells in the pallium also decreased, whereas no cells were found in the striatum, dorsal nucleus of the habenula and tectum. In the olfactory epithelium, nerve or bulb, neither cells nor NPY‐ir fibres were found during the stages of development analysed. The ontogeny pattern of the NPY‐ir neuronal system in the brain of Rh. arenarum is more similar to the spatiotemporal appearance reported for Rana esculenta than to that reported for Xenopus laevis. Many NPY‐ir fibres were found in the median eminence and in the pars intermedia of the pituitary, supporting the idea that this neuropeptide may play a role in the modulation of hypophyseal secretion during development.
Expression of Leptin and Long‐form Leptin‐receptor Proteins in Porcine Hypothalamus during Oestrous Cycle and Pregnancy
Authors: Siawrys G , Kaminski T , Smolinska N , Przala J 
Published: November 2008

ContentsIn this study, we examined the levels of leptin and OB‐Rb protein expression in the discrete areas of the porcine hypothalamus (mediobasal hypothalamus – MBH, pre‐optic area – POA, stalk median eminence – SME) during mid‐ and late‐luteal phases of the oestrous cycle (days 10–12 and 14–16) as well as two stages of pregnancy (days 14–16 and 30–32). The analysis showed that during the cycle, leptin protein expression in MBH was higher in the mid‐luteal phase than late‐luteal phase. In the case of OB‐Rb protein expression, a higher level was observed in MBH during the late‐luteal phase in comparison to the mid‐luteal phase, whereas in POA and SME the opposite dependence was noticed. In turn, during pregnancy, leptin protein expression in MBH and POA, and OB‐Rb protein expression in POA were more pronounced on days 14–16 than on days 30–32. In contrast, leptin protein content in SME as well as OB‐Rb protein in MBH and SME was higher on days 30–32 than during the earlier stage of pregnancy. Comparison of leptin and OB‐Rb protein expression between the cycle (days 10–12) and pregnancy showed a higher level of leptin and OB‐Rb protein contents in POA as well as in SME during pregnancy (on days 14–16 and 30–32, respectively). Yet, OB‐Rb protein expression in POA on days 30–32 of pregnancy was lower in comparison to days 10–12 of the cycle. Furthermore, during pregnancy, leptin protein expression in MBH was lower (days 14–16 and 30–32), whereas OB‐Rb protein expression in that area of hypothalamus was higher (days 30–32) in comparison to the mid‐luteal phase. Our results indicate that both leptin and OB‐Rb are synthesized in the porcine hypothalamus and suggest the participation of leptin in auto/paracrine regulation of these brain areas functions, including control of reproduction during the oestrous cycle and early pregnancy.
Occupational Knowledge and Practice amongst UK University Research Administrators
Authors: Hockey John , Allen‐Collinson Jacquelyn 
Published: November 2008

AbstractWith the exception of lecturing staff, research on occupational groups and cultures within the UK higher education system is relatively sparse. This paper focuses upon one specialist group, to‐date under‐researched but which plays a central role in contemporary higher education administration: graduate research administrators. This occupational group is of particular interest as its members administer and manage an increasing complex and key area of university life, which in many cases appears to span the putative occupational divide between ‘academic’ and ‘administrative’ work. Based upon qualitative interviews with 27 research administrators, and using some of Bourdieu's conceptual devices, the paper analyses particular kinds of informal occupational knowledge and practice, necessary in order effectively to ‘do’ the complex task of research administration in the pressurized environment of contemporary British higher education.
Towards a Holistic Framework for Driving Performance in Externally‐Funded Academic Research
Authors: Hagermann Axel 
Published: November 2008

AbstractA gradual shift in United Kingdom research funding from blanket financing by government agencies towards more diversified income streams through activities funded by various customers is prompting academic research institutions to orient their research portfolios accordingly. Academic organisations such as university institutes are increasingly relying on the funding obtained through research projects paid for by other customers than national funding bodies, thus diversifying their operations. Wrong choices in this diversification process can, however, have serious financial or operational implications for the organisation. A framework is proposed that should help enable academic institutes to rationalise their decision‐making processes when seeking external funding for their operations through project grants or research contracts and learn from projects.