bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid Repression of Maize Invertases by Low Oxygen. Invertase/Sucrose Synthase Balance, Sugar Signaling Potential, and Seedling Survival
Authors: Zeng Ying , Wu Yong , Avigne Wayne T. , Koch Karen E.
Published: July 2002

We show here that invertase gene expression and the invertase-sucrose (Suc) synthase ratio decrease abruptly in response to low oxygen in maize root tips. In addition to aiding in the conservation of carbon and possibly ATP, this response has the potential to directly affect sugar signaling relative to carbon flux. Experiments were motivated by the potential for a reduced invertase/Suc synthase balance to alter the impact of respiratory and/or membrane carbon flux on sugar signaling. Maize (Zea mays L.) seedlings with 5-cm primary roots were exposed to anoxic (0% [v/v] O2), hypoxic (3% [v/v] O2), and aerobic conditions. Rapid repression of theIvr1 and Ivr2 maize invertases by low oxygen was evident in root tips within 3 h at both the transcript and activity levels. The speed and extent of this response increased with the degree of oxygen deprivation and differed with genotypes. This decrease in expression also contrasted markedly to that of other genes for respiratory Suc metabolism, such as Suc synthases, which typically increased or remained constant. Although previous work showed that the contrasting effects of sugars on Suc synthase genes were reflected in their regulation by hypoxia and anoxia, the same was not observed for the differentially sugar-responsive invertases. Theoretically advantageous reductions in the invertase/Suc synthase balance thus resulted. However, where this response was extreme (an Oh43 inbred), total sucrolytic capacity dropped below an apparent minimum and root tip viability was reduced. Paradoxically, only Oh43 seedlings showed survival levels >80% (versus <50%) after extreme, long-term stress, suggesting a possible advantage for multiple means of reducing sink activity. Overall, our results demonstrate a rapid change in the regulation and balance of invertases and Suc synthases that could have an immediate impact on limiting the extent of Suc cleavage and reducing the extent of concomitant, hexose-based sugar signaling under low oxygen.
A Re-Evaluation of the Relative Roles of Two Invertases, INCW2 and IVR1, in Developing Maize Kernels and Other Tissues
Authors: Carlson Susan J. , Chourey Prem S.
Published: July 2002

We have examined the relative abundance and distribution of the transcripts and protein products of a cell wall gene (Incw2) and a soluble invertase gene (Ivr1) to better understand their relative roles during maize (Zea mays L.) kernel development. In developing kernels the steady-state levels of Incw2 transcript increased dramatically from 0 to 12 d after pollination, whileIvr1 transcript, in contrast to a previous report, was undetectable. Consistent with the RNA expression data, the IVR1 protein could not be detected in kernel extracts using antisera raised to a synthetic peptide. Fractionation of the soluble form of invertase from developing kernels by isoelectric focusing and protein blots suggested that the enzyme activity was due to contamination of the cell wall invertase protein. A similar observation was made in a maize cell suspension culture in which Ivr1 RNA, but not IVR1 protein, was significantly modulated by sugars in the medium. Protein-blot analyses of the soluble enzyme activity suggested that changes in the enzyme activity are attributable to a cell wall invertase protein in the soluble fraction. Based on the collective evidence, we propose that the cell wall, but not the soluble invertase, is critical to heterotrophic sinks such as cell suspension cultures and developing kernels.
The Redox State Regulates RNA Degradation in the Chloroplast ofChlamydomonas reinhardtii
Authors: Salvador Maria L. , Klein Uwe
Published: July 2002

A Chlamydomonas reinhardtii chloroplast transformant, designated MU7, carrying a chimeric (rbcL promoter: β-glucuronidase [GUS]:psaB 3′ end) gene whose transcripts have been found previously to be unstable in light (half-life of 20 min in light as opposed to a half-life of 5 h in the dark), was used to study the role of electron transport and of the redox state in the degradation of chloroplast transcripts in the light. Blocking photosynthetic electron transport with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) prevented the light-dependent breakdown of the pool of GUS transcripts in MU7 cells. Diamide, an oxidizing agent, caused a measurable delay in the degradation of GUS transcripts in the light. The addition of dithiothreitol (DTT), a dithiol reductant, to MU7 cells in which GUS transcript levels were stabilized by DCMU induced degradation of GUS transcripts. Similarly, DTT induced a decrease in the levels of GUS transcripts when added to MU7 cells in the dark period of the light/dark cycle, a period in which GUS transcript levels normally increase. The levels of transcripts of endogenous chloroplast genes were affected by DCMU and DTT in the same direction as levels of GUS transcripts. The results suggest a regulatory role of the redox state in the degradation of chloroplast transcripts in C. reinhardtii.
Cell Division and Subsequent Radicle Protrusion in Tomato Seeds Are Inhibited by Osmotic Stress But DNA Synthesis and Formation of Microtubular Cytoskeleton Are Not
Authors: de Castro Renato D. , van Lammeren André A.M. , Groot Steven P.C. , Bino Raoul J. , Hilhorst Henk W.M.
Published: July 2002

We studied cell cycle events in embryos of tomato (Lycopersicon esculentum Mill. cv Moneymaker) seeds during imbibition in water and during osmoconditioning (“priming”) using both quantitative and cytological analysis of DNA synthesis and β-tubulin accumulation. Most embryonic nuclei of dry, untreated control seeds were arrested in the G1 phase of the cell cycle. This indicated the absence of DNA synthesis (the S-phase), as confirmed by the absence of bromodeoxyuridine incorporation. In addition, β-tubulin was not detected on western blots and microtubules were not present. During imbibition in water, DNA synthesis was activated in the radicle tip and then spread toward the cotyledons, resulting in an increase in the number of nuclei in G2. Concomitantly, β-tubulin accumulated and was assembled into microtubular cytoskeleton networks. Both of these cell cycle events preceded cell expansion and division and subsequent growth of the radicle through the seed coat. The activation of DNA synthesis and the formation of microtubular cytoskeleton networks were also observed throughout the embryo when seeds were osmoconditioned. However, this pre-activation of the cell cycle appeared to become arrested in the G2 phase since no mitosis was observed. The pre-activation of cell cycle events in osmoconditioned seeds appeared to be correlated with enhanced germination performance during re-imbibition in water.
Purification and Characterization of Barley Dipeptidyl Peptidase IV
Authors: Davy Anne , Thomsen Karl Kristian , Juliano Maria A. , Alves Lira C. , Svendsen Ib , Simpson David J.
Published: July 2002

Barley (Hordeum vulgare L.) storage proteins, which have a high content of proline (Pro) and glutamine, are cleaved by cysteine endoproteases to yield peptides with a Pro next to the N-terminal and/or C-terminal amino acid residues. A peptidase cleaving after Xaa-Pro- at the N terminus of peptides was purified from green barley malt. It was identified as a serine-type dipeptidyl peptidase (DPP), based on inhibitor studies, and the nature of the cleavage product. It is a monomeric glycoprotein with an apparent molecular mass of 105 kD (85 kD after deglycosylation), with a pI of 3.55 and a pH optimum at 7.2. Substrate specificity was determined with a series of fluorogenic peptide substrates with the general formula Xaa-Pro-AMC, where Xaa is an unspecified amino acid and AMC is 7-amino-4-methylcoumarin. The best substrates were Xaa = lysine and arginine, while the poorest were Xaa = aspartic acid, phenylalanine, and glutamic acid. TheK  m values ranged from 0.071 to 8.9 μm, compared with values of 9 to 130 μmreported for mammalian DPP IVs. We discuss the possible role of DPP IV in the degradation of small Pro-containing peptides transported from the endosperm to the embryo of the germinating barley grain.
Hormone Autotrophic Growth and Differentiation Identifies Mutant Lines of Arabidopsis with Altered Cytokinin and Auxin Content or Signaling
Authors: Frank Markus , Rupp Hans-Michael , Prinsen Els , Motyka Václav , Van Onckelen Harry , Schmülling Thomas
Published: July 2002

We describe mutant tissue lines of Arabidopsis that are able to grow in vitro as callus on hormone-free medium. The 14 lines presented here show different hormone autotrophic differentiation behaviors that can be classified into three categories: (a) forming roots (rooty callus), (b) forming shoots or shoot-like structures (shooty callus), or (c) growing without organ formation (callus). Three fast-growing lines showed altered steady-state mRNA levels of the Cdc2 andCycD3 cell cycle genes. Three of the six rooty callus lines contained about 20- to 30-fold higher levels of auxins than wild-type callus. These and two other lines with normal auxin content showed an increased steady-state level ofIAA1 and IAA2 transcripts in the absence of exogenous auxin. Five of the six shooty callus lines had increased steady-state mRNA levels of the CKI1 gene and/or of the homeobox genes KNAT1 andSTM, suggesting that the phenotype is linked to altered cytokinin signaling. Also, one cytokinin-overproducing line with only 5% of wild-type cytokinin oxidase activity was identified. These results indicate that screening for hormone-autonomous growth identifies mutants with altered hormone content or signaling.
Coordinate Regulation of the Nuclear and Plastidic Genes Coding for the Subunits of the Heteromeric Acetyl-Coenzyme A Carboxylase
Authors: Ke Jinshan , Wen Tuan-Nan , Nikolau Basil J. , Wurtele Eve Syrkin
Published: July 2002

Plastidic acetyl-coenzyme A (CoA) carboxylase (ACCase) catalyzes the first committed reaction of de novo fatty acid biosynthesis. This heteromeric enzyme is composed of one plastid-coded subunit (β-carboxyltransferase) and three nuclear-coded subunits (biotin carboxy-carrier, biotin carboxylase, and α-carboxyltransferase). We report the primary structure of the Arabidopsis α-carboxyltransferase and β-carboxyltransferase subunits deduced from nucleotide sequences of the respective genes and/or cDNA. Co-immunoprecipitation experiments confirm that the α-carboxyltransferase and β-carboxyltransferase subunits are physically associated. The plant α-carboxyltransferases have gained a C-terminal domain relative to eubacteria, possibly via the evolutionary acquisition of a single exon. This C-terminal domain is divergent among plants and may have a structural function rather than being essential for catalysis. The four ACCase subunit mRNAs accumulate to the highest levels in tissues and cells that are actively synthesizing fatty acids, which are used either for membrane biogenesis in rapidly growing tissues or for oil accumulation in developing embryos. Development coordinately affects changes in the accumulation of the ACCase subunit mRNAs so that these four mRNAs maintain a constant molar stoichiometric ratio. These data indicate that the long-term, developmentally regulated expression of the heteromeric ACCase is in part controlled by a mechanism(s) that coordinately affects the steady-state concentrations of each subunit mRNA.
The Photoreduction of H2O2 bySynechococcus sp. PCC 7942 and UTEX 625
Authors: Miller Anthony G. , Hunter Kristopher J. , O'Leary Stephen J.B. , Hart Leslie J.
Published: July 2002

It has been claimed that the sole H2O2-scavenging system in the cyanobacteriumSynechococcus sp. PCC 7942 is a cytosolic catalase-peroxidase. We have measured in vivo activity of a light-dependent peroxidase in Synechococcus sp. PCC 7942 and UTEX 625. The addition of small amounts of H2O2 (2.5 μm) to illuminated cells caused photochemical quenching (qP) of chlorophyll fluorescence that was relieved as the H2O2 was consumed. The qP was maximal at about 50 μmH2O2 with a Michaelis constant of about 7 μm. The H2O2-dependent qP strongly indicates that photoreduction can be involved in H2O2 decomposition. Catalase-peroxidase activity was found to be almost completely inhibited by 10 μm NH2OH with no inhibition of the H2O2-dependent qP, which actually increased, presumably due to the light-dependent reaction now being the only route for H2O2-decomposition. When18O-labeled H2O2 was presented to cells in the light there was an evolution of16O2, indicative of H2  16O oxidation by PS 2 and formation of photoreductant. In the dark 18O2 was evolved from added H2  18O2 as expected for decomposition by the catalase-peroxidase. This evolution was completely blocked by NH2OH, whereas the light-dependent evolution of16O2 during H2  18O2 decomposition was unaffected.
A Matrix Metalloproteinase Gene Is Expressed at the Boundary of Senescence and Programmed Cell Death in Cucumber
Authors: Delorme Valérie G.R. , McCabe Paul F. , Kim Dae-Jae , Leaver Christopher J.
Published: July 2002

Cell-cell and extracellular cell matrix (ECM) interactions provide cells with information essential for controlling morphogenesis, cell-fate specification, and cell death. In animals, one of the major groups of enzymes that degrade the ECM is the matrix metalloproteinases (MMPs). Here, we report the characterization of the cucumber (Cucumis sativus L. cv Marketmore)Cs1-MMP gene encoding such an enzyme likely to play a role in plant ECM degradation. Cs1-MMP has all the hallmark motif characteristics of animal MMPs and is a pre-pro-enzyme having a signal peptide, propeptide, and zinc-binding catalytic domains. Cs1-MMP also displays functional similarities with animal MMPs. For example, it has a collagenase-like activity that can cleave synthetic peptides and type-I collagen, a major component of animal ECM. Cs1-MMP activity is completely inhibited by a hydroxamate-based inhibitor that binds at the active site of MMPs in a stereospecific manner. TheCs1-MMP gene is expressed de novo at the end stage of developmental senescence, prior to the appearance of DNA laddering in cucumber cotyledons leaf discs and male flowers. As the steady-state level of Cs1-MMP mRNA peaks late in senescence and the pro-enzyme must undergo maturation and activation, the protease is probably not involved in nutrient remobilization during senescence but may have another function. The physiological substrates for Cs1-MMP remain to be determined, but the enzyme represents a good candidate for plant ECM degradation and may be involved in programmed cell death (PCD). Our results suggest that PCD occurs only at the culmination of the senescence program or that the processes are distinct with PCD being triggered at the end of senescence.
Compression Wood-Responsive Proteins in Developing Xylem of Maritime Pine (Pinus pinasterAit.),
Authors: Plomion Christophe , Pionneau Cédric , Brach Jean , Costa Paulo , Baillères Henri
Published: July 2002

When a conifer shoot is displaced from its vertical position, compression wood (CW) is formed on the under side and can eventually return the shoot to its original position. Changes in cell wall structure and chemistry associated with CW are likely to result from differential gene/protein expression. Two-dimensional polyacrylamide gel electrophoresis of differentiating xylem proteins was combined with the physical characterization of wooden samples to identify and characterize CW-responsive proteins. Differentiating xylem was harvested from a 22-year-old crooked maritime pine (Pinus pinaster Ait.) tree. Protein extracted from different samples were revealed by high-resolution silver stained two-dimensional polyacrylamide gel electrophoresis and analyzed with a computer-assisted system for single spot quantification. Growth strain (GS) measurements allowed xylem samples to be classified quantitatively from normal wood to CW. Regression of lignin and cellulose content on GS showed that an increase in the percentage of lignin and a decrease of the percentage of cellulose corresponded to increasing GS values, i.e. CW. Of the 137 studied spots, 19% were significantly associated with GS effect. Up-regulated proteins included 1-aminocyclopropane-1-carboxylate oxidase (an ethylene forming enzyme), a putative transcription factor, two lignification genes (caffeicO-methyltransferase and caffeoyl CoA-O-methyltransferase), members of theS-adenosyl-l-methionine-synthase gene family, and enzymes involved in nitrogen and carbon assimilation (glutamine synthetase and fructokinase). A clustered correlation analysis was performed to study simultaneously protein expression along a gradient of gravistimulated stressed xylem tissue. Proteins were found to form “expression clusters” that could identify: (a) Gene product under similar control mechanisms, (b) partner proteins, or (c) functional groups corresponding to specialized pathways. The possibility of obtaining regulatory correlations and anticorrelations between proteins provide us with a new category of homology (regulatory homology) in tracing functional relationships.
Origin and Seed Phenotype of Maize low phytic acid 1-1 and low phytic acid 2-1
Authors: Raboy Victor , Gerbasi Paola F. , Young Kevin A. , Stoneberg Sierra D. , Pickett Suewiya G. , Bauman Andrew T. , Murthy Pushpalatha P.N. , Sheridan William F. , Ertl David S.
Published: July 2002

Phytic acid (myo-inositol-1, 2, 3, 4, 5, 6-hexakisphosphate or Ins P6) typically represents approximately 75% to 80% of maize (Zea mays) seed total P. Here we describe the origin, inheritance, and seed phenotype of two non-lethal maize low phytic acid mutants, lpa1-1 and lpa2-1. The loci map to two sites on chromosome 1S. Seed phytic acid P is reduced in these mutants by 50% to 66% but seed total P is unaltered. The decrease in phytic acid P in mature lpa1-1 seeds is accompanied by a corresponding increase in inorganic phosphate (Pi). In mature lpa2-1 seed it is accompanied by increases in Pi and at least three othermyo-inositol (Ins) phosphates (and/or their respective enantiomers): d-Ins(1,2,4,5,6) P5;d-Ins (1,4,5,6) P4; andd-Ins(1,2,6) P3. In both cases the sum of seed Pi and Ins phosphates (including phytic acid) is constant and similar to that observed in normal seeds. In both mutants P chemistry appears to be perturbed throughout seed development. Homozygosity for either mutant results in a seed dry weight loss, ranging from 4% to 23%. These results indicate that phytic acid metabolism during seed development is not solely responsible for P homeostasis and indicate that the phytic acid concentration typical of a normal maize seed is not essential to seed function.
Differential Effects of Methyl Jasmonate on the Expression of the Early Light-Inducible Proteins and Other Light-Regulated Genes in Barley
Authors: Wierstra Inken , Kloppstech Klaus
Published: July 2002

The effects of methyl jasmonate (JA-Me) on early light-inducible protein (ELIP) expression in barley (Hordeum vulgare L. cv Apex) have been studied. Treatment of leaf segments with JA-Me induces the same symptoms as those exhibited by norflurazon bleaching, including a loss of pigments and enhanced light stress that results in increased ELIP expression under both high- and low-light conditions. The expression of both low- and high-molecular-mass ELIP families is considerably down-regulated by JA-Me at the transcript and protein levels. This repression occurs despite increased photoinhibition measurable as a massive degradation of D1 protein and a delayed recovery of photosystem II activity. In JA-Me-treated leaf segments, the decrease of the photochemical efficiency of photosystem II under high light is substantially more pronounced as compared to controls in water. The repression of ELIP expression by JA-Me is superimposed on the effect of the increased light stress that leads to enhanced ELIP expression. The fact that the reduction of ELIP transcript levels is less pronounced than those of light-harvesting complex II and small subunit of Rubisco transcripts indicates that light stress is still affecting gene expression in the presence of JA-Me. The jasmonate-induced protein transcript levels that are induced by JA-Me decline under light stress conditions.
Nodal Endoplasmic Reticulum, a Specialized Form of Endoplasmic Reticulum Found in Gravity-Sensing Root Tip Columella Cells
Authors: Zheng Hui Qiong , Staehelin L. Andrew
Published: July 2002

The endoplasmic reticulum (ER) of columella root cap cells has been postulated to play a role in gravity sensing. We have re-examined the ultrastructure of columella cells in tobacco (Nicotiana tabacum) root tips preserved by high-pressure freezing/freeze-substitution techniques to gain more precise information about the organization of the ER in such cells. The most notable findings are: the identification of a specialized form of ER, termed “nodal ER,” which is found exclusively in columella cells; the demonstration that the bulk of the ER is organized in the form of a tubular network that is confined to a peripheral layer under the plasma membrane; and the discovery that this ER-rich peripheral region excludes Golgi stacks, vacuoles, and amyloplasts but not mitochondria. Nodal ER domains consist of an approximately 100-nm-diameter central rod composed of oblong subunits to which usually seven sheets of rough ER are attached along their margins. These domains form patches at the interface between the peripheral ER network and the ER-free central region of the cells, and they occupy defined positions within central and flanking columella cells. Over one-half of the nodal ER domains are located along the outer tangential walls of the flanking cells. Cytochalasin D and latrunculin A cause an increase in size and a decrease in numbers of nodal ER domains. We postulate that the nodal ER membranes locally modulate the gravisensing signals produced by the sedimenting amyloplasts, and that the confinement of all ER membranes to the cell periphery serves to enhance the sedimentability of the amyloplasts in the central region of columella cells.
A Comparison of the Effects of DNA-Damaging Agents and Biotic Elicitors on the Induction of Plant Defense Genes, Nuclear Distortion, and Cell Death
Authors: Choi Jane Junghae , Klosterman Steven J. , Hadwiger Lee A.
Published: July 2002

Pea (Pisum sativum L. cv Alcan) endocarp tissue challenged with an incompatible fungal pathogen, Fusarium solani f. sp. phaseoli or fungal elicitors results in the induction of pathogenesis-related (PR) genes and the accumulation of pisatin, a phytoalexin. Essentially the same response occurs in pea tissue exposed to DNA-specific agents that crosslink or intercalate DNA. In this study, the effects of DNA-damaging agents were assessed relative to the inducible expression of several pea PR genes: phenylalanine ammonia lyase, chalcone synthase, and DRR206. Mitomycin C and actinomycin D mimicked the biotic elicitors in enhancing the expression of all three PR genes. The activities of these PR gene promoters, isolated from different plants, were evaluated heterologously in transgenic tobacco. It is remarkable that β-glucuronidase expression was induced when plants containing the heterologous phenylalanine ammonia lyase, chalcone synthase, and DRR206 promoter-β-glucuronidase chimeric reporter genes were treated by DNA-damaging agents. Finally, cytological analyses indicated that many of these agents caused nuclear distortion and collapse of the treated pea cells. Yet we observed that cell death is not necessary for the induction of the PR gene promoters assessed in this study. Based on these observations and previously published results, we propose that DNA damage or the associated alteration of chromatin can signal the transcriptional activation of plant defense genes.
Screening of the Rice Viviparous Mutants Generated by Endogenous Retrotransposon Tos17 Insertion. Tagging of a Zeaxanthin Epoxidase Gene and a Novel OsTATCGene
Authors: Agrawal Ganesh Kumar , Yamazaki Muneo , Kobayashi Masatomo , Hirochika Rei , Miyao Akio , Hirochika Hirohiko
Published: July 2002

The rice (Oryza sativa) retrotransposonTos17 is one of a few active retrotransposons in plants and its transposition is activated by tissue culture. Here, we present the characterization of viviparous mutants of rice induced by tissue culture to demonstrate the feasibility of the use of retrotransposonTos17 as an endogenous insertional mutagen and cloning of the tagged gene for forward genetics in unraveling the gene function. Two mutants were shown to be caused by the insertion ofTos17. Osaba1, a strong viviparous mutant with wilty phenotype, displayed low abscisic acid level and almost no further increase in its levels upon drought. The mutant is shown to be impaired in the epoxidation of zeaxanthin. On the other hand,Ostatc, a mutant with weak phenotype, exhibited the pale green phenotype and slight increase in abscisic acid levels upon drought. Deduced amino acids of the causative genes ofOsaba1 and Ostatc manifested a significantly high homology with zeaxanthin epoxidase isolated from other plant species and with bacterial Sec-independent translocase TATC protein, respectively. This is the first example of transposon tagging in rice.
Quantitative Trait Locus Mapping of Loci Influencing Elongation Factor 1α Content in Maize Endosperm
Authors: Wang Xuelu , Woo Young-min , Kim Cheol Soo , Larkins Brian A.
Published: July 2002

The nutritional value of maize (Zea mays) seed is most limited by its protein quality because its storage proteins are devoid of the essential amino acid lysine (Lys). The Lys content of the kernel can be significantly increased by the opaque-2 mutation, which reduces zein synthesis and increases accumulation of proteins that contain Lys. Elongation factor 1α (eEF1A) is one of these proteins, and its concentration is highly correlated with the Lys content of the endosperm. We investigated the genetic regulation of eEF1A and the basis for its relationship with other Lys-containing proteins by analyzing the progeny of a cross between a high (Oh51Ao2) and a low (Oh545o2) eEF1A maize inbred. We identified 83 simple sequence repeat loci that are polymorphic between these inbreds; the markers are broadly distributed over the genome (1,402 cM) with an average interval of 17 cM. Genotypic analysis of the F2 progeny revealed two significant quantitative trait loci that account for 25% of the variance for eEF1A content. One of these is on the short arm of chromosome 4 and is linked with a cluster of 22-kD α-zein coding sequences; the other quantitative trait locus is on the long arm of chromosome 7. The content of α-zein and γ-zein was measured in pools of high- and low-eEF1A individuals obtained from this cross, and a higher level of α-zein was found to cosegregate with high eEF1A content. Allelic variation at the 22-kD α-zein locus may contribute to the difference of eEF1A content between Oh51Ao2 and Oh545o2 by increasing the surface area of protein bodies in the endosperm and creating a more extensive network of cytoskeletal proteins.
Altered Expression of SPINDLY Affects Gibberellin Response and Plant Development
Authors: Swain Stephen M. , Tseng Tong-seung , Olszewski Neil E.
Published: July 2002

Gibberellins (GAs) are plant hormones with diverse roles in plant growth and development. SPINDLY (SPY) is one of several genes identified in Arabidopsis that are involved in GA response and it is thought to encode an O-GlcNAc transferase. Genetic analysis suggests that SPY negatively regulates GA response. To test the hypothesis that SPY acts specifically as a negatively acting component of GA signal transduction,spy mutants and plants containing a 35S:SPY construct have been examined. A detailed investigation of the spymutant phenotype suggests that SPY may play a role in plant development beyond its role in GA signaling. Consistent with this suggestion, the analysis of spy er plants suggests that theERECTA (ER) gene, which has not been implicated as having a role in GA signaling, appears to enhance the non-GA spy mutant phenotypes. Arabidopsis plants containing a 35S:SPY construct possess reduced GA response at seed germination, but also possess phenotypes consistent with increased GA response, although not identical to spy mutants, during later vegetative and reproductive development. Based on these results, the hypothesis that SPY is specific for GA signaling is rejected. Instead, it is proposed that SPY is a negative regulator of GA response that has additional roles in plant development.
Influence of Growth Conditions and Developmental Stage onN-Glycan Heterogeneity of Transgenic Immunoglobulin G and Endogenous Proteins in Tobacco Leaves
Authors: Elbers Ingrid J.W. , Stoopen Geert M. , Bakker Hans , Stevens Lucas H. , Bardor Muriel , Molthoff Jos W. , Jordi Wilco J.R.M. , Bosch Dirk , Lommen Arjen
Published: July 2002

Plants are regarded as a promising system for the production of heterologous proteins. However, little is known about the influence of plant development and growth conditions on N-linked glycosylation. To investigate this, transgenic tobacco (Nicotiana tabacum cv Samsun NN) plants expressing a mouse immunoglobulin G antibody (MGR48) were grown in climate rooms under four different climate conditions, i.e. at 15°C and 25°C and at either low or high light conditions. N-glycans on plantibodies and soluble endogenous proteins were analyzed with matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS). Antibodies isolated from young leaves have a relatively high amount of high- mannose glycans compared with antibodies from older leaves, which contain more terminal N-acetylglucosamine. Senescence was shown to affect the glycosylation profile of endogenous proteins. The relative amount of N-glycans without terminalN-acetylglucosamine increased with leaf age. Major differences were observed between glycan structures on endogenous proteins versus those on antibodies, probably to be attributed to their subcellular localization. The relatively high percentage of antibodyN-glycan lacking both xylose and fucose is interesting.
Net Intensities: Accuracy Improvement Through a Bayesian Perspective on the Measuring Strategy and Their Persistent Lack of Precision. An Illustration
Authors: Lenstra A. T. H. , Bracke B. , van Dijk B. , Maes S. , Vanhulle C. , Desseyn H. O.
Published: July 2002

2,3-Diketopiperazine (2,3-piperazinedione), C4H6N2O2, crystallizes in the monoclinic space group P21/c with a = 5.941 (3), b = 10.080 (3), c = 8.282 (2) Å, β = 95.87 (3)°, V = 493.4 (5) Å3, Z = 4, Dx
= 1.536 Mg m−3 and Mr
= 114.1. The six-membered ring adopts a skew-boat conformation with Q = 0.467 (3) Å, θ = 64.6 (3)° and φ = 269.8 (4)°. The C
2 symmetry, which typifies the free molecule, is broken by the formation of two intermolecular N—H...O bonds involving only one of the C=O groups of the 2,3-diketopiperazine molecule. The intensity data typical for a time series are summarized in traditional statistics by B = σ2(B) = ΣBi
and R = σ2(R) = ΣRi
, where B is the background and R the raw intensity. Exploitation of the same data using Bayesian methodology leads to similar values for B and R, but the variances for these signals are significantly smaller. This reduction in variance is dictated by the length N of the time series. With 25 observations in each hkl time series we arrive at variances that are 25% of their classical values. So, a measuring strategy in which a single observation with a slow scan at speed 1/N is preferred above a series of N observations at speed 1 produces the worst possible benefit within a fixed time frame. In complete contrast to our expectation, structure refinements reveal that that the standard deviation of an observation of unit weight, S, will converge towards its ideal unit value only when we decrease the accuracy of the data set. This unpleasant behaviour points to a serious discrepancy between accuracy and precision. Our reflection intensities are systematically wrong, because we underestimate the wavelength dispersion. On our CAD-4 equipment a sealed Mo tube and the standard graphite monochromator produce an incident beam with Δλ/λ = 14%. As a consequence, the observed background intensities are not representative of the real background. The size of the background error depends on the nearby Bragg intensity. The magnitude of the signal pollution contaminating the local background is ∼2% of the maximum Bragg intensity found at λ = 0.71 Å.
Single crystal blades
Authors: Ford Terry
Published: July 2002

Describes the evolution in manufacture of jet engine turbine blades from wrought steel to directional solidification and single crystal growth. Reports on SCORPIO, the single crystal orientation rapid processing and interpretation operation, developed by Rolls‐Royce for blade inspection to ensure that each is formed from a single crystal grain with the correct orientation. Also reports the improvement in performance that has been achieved in blade performance.
Influence of a cationic surfactant on the inhibition efficiency of calcium gluconate – Zn2+ system
Authors: Rajendran S. , Apparao B.V. , Palaniswamy N.
Published: July 2002

The influence of a cationic surfactant, N‐cetyl‐N, N, N‐trimethyl ammonium bromide (CTAB) on the inhibition efficiency (IE) of calcium gluconate (CG) – Zn2+ system in controlling corrosion of mild steel in a neutral aqueous environment containing 60ppm Cl‐ has been evaluated by weight‐loss method. The formulation consisting of 200 ppm CG and 50ppm Zn2+ has 86 per cent IE (immersion period = three days). Addition of various concentrations of CTAB to the above system improves the IE to 99 per cent. Presence of CTAB facilitates the transport of CG and Zn2+ from the bulk of the solution to the metal surface. The nature of the protective film formed on the surface of mild steel has been analysed by FTIR and fluorescence spectra. The protective film is found to be fluorescent and to consist of iron‐CG complex, iron‐CTAB complex and Zn(OH)2.
High temperature corrosion‐resistant coating on steel for short‐term application
Authors: Singh M.N. , Singh Inder , Pandey J.L.
Published: July 2002

Relates to the development of high temperature resistant coating applicable in the temperature range of 500°C to 700°C. A12O3, TiO2 and ZrO2 have been incorporated in aluminium phosphate and ivory‐400 used as binders. Aluminium phosphate as a binder has not performed well in comparison to ivory‐400. Aims mainly to study and to highlight the behaviour of the corrosion‐resistant coating at high temperature.
Fuel lubricity
Authors: Margaroni David
Published: July 2002

Problems associated with inadequate fuel lubricity were identified in the aeronautical industry in the 1960s, following a succession of in‐flight engine failures. The influence of fuel composition upon fuel lubricity was established, as was the effect of various lubricity additives. Problems associated with inadequate fuel lubricity were also subsequently identified in light‐duty diesel engines when low‐sulphur fuel was introduced. Again, the use of additives or modifications to the refining process overcame the problem at the time, but the continuing trend towards higher injection pressures may require further improvements in current fuel lubricity. The manufacture and use of biodiesel is described, together with the attendant benefits, including use as a lubricity additive in conventional diesel fuel, also disadvantages. The imminent introduction of direct‐injection gasoline passenger car engines has now focused attention on the lubricity of gasoline, which is again likely to become a key issue. Two standardised test procedures for the measurement of fuel lubricities are described.
Pay as you learn: student employment and academic progress
Authors: Watts Catherine , Pickering Angela
Published: July 2002

Increasing numbers of full‐time undergraduates are supplementing their income by seeking paid employment during term‐time. This article presents some preliminary findings from a research project which explores to what extent academic progress is affected by the part‐time, term‐time paid employment of full‐time undergraduates. It begins by considering changes made to the student funding mechanism over the past few decades and briefly contextualises the study in relation to other relevant studies. It then presents the initial findings of the study and discusses these in the light of the implications raised for: students; the institution; academic staff; employers.
Adding value to the work placement: working towards a professional qualification in an undergraduate degree programme
Authors: Morgan Arthur , Turner David
Published: July 2002

This article reviews the opportunity provided by the work placement year for human resource management students to gain professional membership of the Chartered Institute of Personnel Development (CIPD). A case study approach is used to reflect on findings related to the first two cohorts. It concludes that the benefits of the opportunity to gain a separate professional qualification are twofold. First, it ties in closely with what appears is a more strategic career decision‐making process on behalf of the student and, second, the CIPD qualification provides a robust framework for the placement period during this important stage of student studies.
NVQs in the small business sector: a critical overview
Authors: Matlay Harry , Hyland Terry
Published: July 2002

In spite of the central role accorded to small and medium‐sized enterprises (SMEs) in recent government White Papers on competitiveness and national vocational education and training (VET) policies, the involvement of small firms in national training efforts remains disappointingly marginal. Studies over 2,000 SMEs in the West Midlands region and indicates a worrying gap between interest and attitudes to training and actual take‐up of training opportunities, particularly in relation to programmes linked to national vocational qualifications(NVQs). Recommends that, given the low awareness of and low value assigned to NVQs by SME owner/managers, training policies for SMEs are distinguished sharply from national training efforts concerned with NVQs and the achievement of national targets.
The transfer of management knowledge to China: building learning communities rather than translating Western textbooks?
Authors: Newell Sue
Published: July 2002

The economic reforms in the People’s Republic of China have begun to open up this very large market. However, a major impediment to quicker or more substantive growth has been the paucity of experienced Chinese managers. In response, there has been a very rapid growth in business and management education in China, especially in MBA education. Given that management as a discipline was not previously taught in China, much of the knowledge base for this education has been imported from the West. However, it is argued that the linear attempt to transfer explicit management knowledge from the West to China is based on false assumptions about the nature of knowledge and so is unlikely to be effective. Instead a community model of knowledge is presented, which suggests that there needs to be an interaction between Chinese and Western ideas, which will benefit all parties.
“Managing diversity” meets Aotearoa/New Zealand
Authors: Jones Deborah , Pringle Judith , Shepherd Deborah
Published: July 2002

Argues that the discourse of “managing diversity”, emerging from the US management literature, cannot be simply mapped on to organisations in other cultural contexts. It uses the example of Aotearoa/New Zealand to show that a “diversity” based on the demographics and dominant cultural assumptions of the USA fails to address – and may in fact obscure – key local “diversity” issues. It argues that the dominant discourse of “managing diversity” has embedded in it cultural assumptions that are specific to the US management literature. It calls for a genuinely multi‐voiced “diversity” discourse that would focus attention on the local demographics, cultural and political differences that make the difference for specific organisations.
Disability and diversity – a difference too far?
Authors: Woodhams Carol , Danieli Ardha
Published: July 2002

It is currently fashionable to herald “managing diversity” as an approach which signals a new dawn for equal opportunities. Within the management of diversity is a new, more positive approach to employee “‘difference” which prescribes the valuation of individuality and the abandonment of group based equality initiatives. In principle the focus on individuals suggests this approach lends itself particularly well to disabled employees who constitute a more heterogeneous group than women and ethnic minorities. The article evaluates this in the light of debates traditionally located within gender literatures and applies them to survey data gathered from UK HRM managers which details the disability equality initiatives adopted by their organisations. It argues that differences between disabled groups and those constituted on the basis of gender or race, together with differences amongst disabled people renders the group based and the managing diversity approach to equality largely rhetorical.
Banking on people
Authors: Cowling Alan , Newman Karin
Published: July 2002

Total quality management (TQM) principles are now being applied in
service industries in the UK, following their perceived success in
manufacturing industries, with the particular aim of improving service
quality. In financial services the impetus behind the adoption of
quality programmes is increased competition and higher customer
expectations. Studies of the introduction of quality programmes into
service organizations in the UK are as yet few, but both these and the
large number of studies of TQM in manufacturing point to the need for
high levels of motivation and involvement by staff, and the significance
of job satisfaction and of employment policies. Reports on an
investigation into the introduction of TQM into two major banks in the
UK, with a special focus on the reactions of employees. Highlights their
success and limitations in two case studies, and draws out the lessons
to be learned by senior management and human resources departments.
Understandings of conflict: a cross‐cultural investigation
Authors: Lee Monica
Published: July 2002

Two understandings of “conflict” are derived from a multi‐cultural East‐West experience: as a fundamental threat in which conflict is normally avoided, and as competitive games in which conflict is associated with confrontation and negotiation, and is sought after. Suggests that it is the view of conflict as competitive games that is promoted through “managerialism” and that it is this view that is largely being transferred to post‐Iron‐Curtain countries, despite the fact that conflict as competitive games does not lend itself easily to HR and management practice in cross‐cultural situations. Questions the appropriateness of transporting models of HR that promulgate the free‐market myth to transitional economies.
The adaptation of expatriates in Europe
Authors: Suutari Vesa , Brewster Chris
Published: July 2002

Despite an expanding research interest in the topic of expatriation, there is still a significant gap in our understanding of the expatriation process. This article presents recently collected research data on the experiences of Finnish expatriates adjusting to living and working in other European countries. It is argued that the process of adaptation varies considerably between countries and, on that basis, argues that the existing models of adaptation are useful, but themselves need adaptation. The article also offers recommendations for expatriates and for the organisations that employ them.
Exploring “bullying” culture in the para‐military organisation
Authors: Archer David
Published: July 2002

This paper is drawn from a research project into the influences of power and culture on bullying and harassment within the Fire Service, conducted using fire brigades of similar background from the UK, the USA and Eire. It discovered bullying within the Fire Service in two contexts: inappropriate behaviour by managers, such as intimidation, threats and the intimidating use of discipline; and bullying within groups, which is the most influential, and potentially the most damaging to individuals. This occurs within the group that is heavily dependent on the socialisation processes of acceptance, normalisation, indoctrination and preservation of hierarchy. It is also argued that the bullying of individuals because of their sex or race remains an aspect of Fire Service culture and is perpetuated by some to ensure the continuation of the white male culture.
The transformational leadership questionnaire (TLQ‐LGV): a convergent and discriminant validation study
Authors: Alban‐Metcalfe Robert J. , Alimo‐Metcalfe Beverly
Published: July 2002

This paper sets out to provide evidence of the convergent and discriminant validity of a recently developed leadership questionnaire, the Transformational Leadership Questionnaire (Local Government Version) (TLQ‐LGV). Evidence is presented, from a random, stratified sample of 1,464 male and female managers, working in local government, that each of the scales was significantly correlated with each of five criterion variables, even when the sample was divided by level, sex, and level x sex. Multiple regression analyses suggested differential patterns of relationships between the scales and the criterion variables among different groups and sub‐groups of managers, divided by level, sex, and level x sex. These latter data were interpreted as evidence of the discriminant validity of the instrument.
Can emotional intelligence be measured and developed?
Authors: Dulewicz Victor , Higgs Malcolm
Published: July 2002

Emotional intelligence (EI) is a topic of growing interest. This article describes the design of a new tailored instrument to measure emotional intelligence, which was piloted on 201 managers. Data are presented showing its high reliability and validity. In particular, construct validity is demonstrated using the 16PF, Belbin team roles, Myers‐Briggs type inventory and Type A behaviour. Seven elements (sub‐scales) make up the total questionnaire – self‐awareness; influence; decisive; interpersonal sensitivity; motivation; integrity; and resilience. These are defined in detail, and guidance is given on administration, and reporting which is done through an expert system. Advice on how the results can be used for personal development is also given. Finally, suggestions are put forward for further work on appropriate organisational cultures to reinforce emotional intelligence, and the issue of emotional intelligence and leadership.
Mobile robots: big benefits for US military
Authors: Pransky Joanne
Published: July 2002

Describes two types of mobile robots designed for the US military. One is the mobile detection assessment response system (MDARS), which is an automated robotic security and inventory system capable of patrolling interior and exterior warehouses and storage sites for the Department of Defense. The other is the spiral track autonomous robot (STAR), a multi‐terrain military vehicle used to reduce risk to military personnel and equipment. Both autonomous robots allow the US military to decrease unsecured threats and to increase savings which arise from the prevention of expensive hardware loss.
The role of performance measurement in business process re‐engineering
Authors: Kuwaiti M.E. , Kay John M.
Published: July 2002

This paper argues that a performance measurement system (PMS) is a prerequisite to the introduction of business process re‐engineering (BPR) based on the role it plays in the phases of introducing change. This hypothesis was tested by examining the relationship between the congruence of PMS and the concepts of empowerment, integration and strategic alignment. Data were collected from 301 respondents in 19 manufacturing and 30 financial companies in Bahrain. Analysis indicated that PMS and strategic alignment are strongly related, empowerment is moderately related and integration showed a weak relationship.