bluuebunny/crossref_metadata_2025 huggingface dataset:
Phosphorylated α(1→4)Glucans as Substrate for Potato Starch-Branching Enzyme I1
Authors: Viksø-Nielsen Anders , Blennow Andreas , Hamborg Nielsen Tom , Lindberg Møller Birger
Published: July 2002

The possible involvement of potato (Solanum tuberosum L.) starch-branching enzyme I (PSBE-I) in the in vivo synthesis of phosphorylated amylopectin was investigated in in vitro experiments with isolated PSBE-I using33P-labeled phosphorylated and 3H end-labeled nonphosphorylated α(1→4)glucans as the substrates. From these radiolabeled substrates PSBE-I was shown to catalyze the formation of dual-labeled (3H/33P) phosphorylated branched polysaccharides with an average degree of polymerization of 80 to 85. The relatively high molecular mass indicated that the product was the result of multiple chain-transfer reactions. The presence of α(1→6) branch points was documented by isoamylase treatment and anion-exchange chromatography. Although the initial steps of the in vivo mechanism responsible for phosphorylation of potato starch remains elusive, the present study demonstrates that the enzyme machinery available in potato has the ability to incorporate phosphorylated α(1→4)glucans into neutral polysaccharides in an interchain catalytic reaction. Potato mini tubers synthesized phosphorylated starch from exogenously supplied 33PO43− and [U-14C]Glc at rates 4 times higher than those previously obtained using tubers from fully grown potato plants. This system was more reproducible compared with soil-grown tubers and was therefore used for preparation of 33P-labeled phosphorylated α(1→4)glucan chains.
Changes in Salicylic Acid and Antioxidants during Induced Thermotolerance in Mustard Seedlings
Authors: Dat James F. , Foyer Christine H. , Scott Ian M.
Published: July 2002

Heat-acclimation or salicylic acid (SA) treatments were previously shown to induce thermotolerance in mustard (Sinapis alba L.) seedlings from 1.5 to 4 h after treatment. In the present study we investigated changes in endogenous SA and antioxidants in relation to induced thermotolerance. Thirty minutes into a 1-h heat-acclimation treatment glucosylated SA had increased 5.5-fold and then declined during the next 6 h. Increases in free SA were smaller (2-fold) but significant. Changes in antioxidants showed the following similarities after either heat-acclimation or SA treatment. The reduced-to-oxidized ascorbate ratio was 5-fold lower than the controls 1 h after treatment but recovered by 2 h. The glutathione pool became slightly more oxidized from 2 h after treatment. Glutathione reductase activity was more than 50% higher during the first 2 h. Activities of dehydroascorbate reductase and monodehydroascorbate reductase decreased by at least 25% during the first 2 h but were 20% to 60% higher than the control levels after 3 to 6 h. One hour after heat acclimation ascorbate peroxidase activity was increased by 30%. Young leaves appeared to be better protected by antioxidant enzymes following heat acclimation than the cotyledons or stem. Changes in endogenous SA and antioxidants may be involved in heat acclimation.
The Xanthophyll Cycle Modulates the Kinetics of Nonphotochemical Energy Dissipation in Isolated Light-Harvesting Complexes, Intact Chloroplasts, and Leaves of Spinach1
Authors: Ruban Alexander V. , Horton Peter
Published: July 2002

We analyzed the kinetics of nonphotochemical quenching of chlorophyll fluorescence (qN) in spinach (Spinacia oleracea) leaves, chloroplasts, and purified light-harvesting complexes. The characteristic biphasic pattern of fluorescence quenching in dark-adapted leaves, which was removed by preillumination, was evidence of light activation of qN, a process correlated with the de-epoxidation state of the xanthophyll cycle carotenoids. Chloroplasts isolated from dark-adapted and light-activated leaves confirmed the nature of light activation: faster and greater quenching at a subsaturating transthylakoid pH gradient. The light-harvesting chlorophylla/b-binding complexes of photosystem II were isolated from dark-adapted and light-activated leaves. When isolated from light-activated leaves, these complexes showed an increase in the rate of quenching in vitro compared with samples prepared from dark-adapted leaves. In all cases, the quenching kinetics were fitted to a single component hyperbolic function. For leaves, chloroplasts, and light-harvesting complexes, the presence of zeaxanthin was associated with an increased rate constant for the induction of quenching. We discuss the significance of these observations in terms of the mechanism and control of qN.
A Photoperiod-Insensitive Barley Line Contains a Light-Labile Phytochrome B1
Authors: Hanumappa Mamatha , Pratt Lee H. , Cordonnier-Pratt Marie-Michele , Deitzer Gerald F.
Published: July 2002

Barley (Hordeum vulgare L.) is a long-day plant whose flowering is enhanced when the photoperiod is supplemented with far-red light, and this promotion is mediated by phytochrome. A chemically mutagenized dwarf cultivar of barley was selected for early flowering time (barley maturity daylength response [BMDR]-1) and was made isogenic with the cultivar Shabet (BMDR-8) by backcrossing. BMDR-1 was found to contain higher levels of both phytochrome A and phytochrome B in the dark on immunoblots with monoclonal antibodies from oat (Avena sativa L.) that are specific to different members of the phytochrome gene family. Phytochrome A was light labile in both BMDR-1 and BMDR-8, decreasing to very low levels after 4 d of growth in the light. Phytochrome B was light stable in BMDR-8, being equal in both light and darkness. However, phytochrome B became light labile in BMDR-1 and this destabilization of phytochrome B appeared to make BMDR-1 insensitive to photoperiod. In addition, both the mutant and the wild type lacked any significant promotion of flowering in response to a pulse of far-red light given at the end of day, and the end-of-day, far-red inhibition of tillering is normal in both, suggesting that phytochrome B is not involved with these responses in barley.
Molecular and Genetic Characterization of a Novel Pleiotropic Tomato-Ripening Mutant1
Authors: Thompson Andrew J. , Tor Mahmut , Barry Cornelius S. , Vrebalov Julia , Orfila Caroline , Jarvis Michael C. , Giovannoni James J. , Grierson Donald , Seymour Graham B.
Published: July 2002

In this paper we describe a novel, dominant pleiotropic tomato (Lycopersicon esculentum)-ripening mutation, Cnr(colorless nonripening). This mutant occurred spontaneously in a commercial population.Cnr has a phenotype that is quite distinct from that of the other pleiotropic tomato-ripening mutants and is characterized by fruit that show greatly reduced ethylene production, an inhibition of softening, a yellow skin, and a nonpigmented pericarp. The ripening-related biosynthesis of carotenoid pigments was abolished in the pericarp tissue. The pericarp also showed a significant reduction in cell-to-cell adhesion, with cell separation occurring when blocks of tissue were incubated in water alone. The mutant phenotype was not reversed by exposure to exogenous ethylene. Crosses with other mutant lines and the use of a restriction fragment length polymorphism marker demonstrated that Cnr was not allelic with the pleiotropic ripening mutants nor, alc, rin,Nr, Gr, andNr-2. The gene has been mapped to the top of chromosome 2, also indicating that it is distinct from the other pleiotropic ripening mutants. We undertook the molecular characterization of Cnr by examining the expression of a panel of ripening-related genes in the presence and absence of exogenous ethylene. The pattern of gene expression inCnr was related to, but differed from, that of several of the other well-characterized mutants. We discuss here the possible relationships among nor, Cnr, andrin in a putative ripening signal cascade.
Properties of Enhanced Tonoplast Zinc Transport in Naturally Selected Zinc-TolerantSilene vulgaris
Authors: Chardonnens Agnes N. , Koevoets Paul L.M. , van Zanten Alisa , Schat Henk , Verkleij Jos A.C.
Published: July 2002

It was demonstrated recently that isolated tonoplast vesicles derived from plants of a Zn-tolerant ecotype of Silene vulgaris accumulate more Zn than vesicles derived from a Zn-sensitive ecotype. We have now characterized the tonoplast-transport system that causes this uptake difference and demonstrated its genetic correlation to Zn tolerance using plant crosses. We conclude that the tonoplast Zn uptake system of the tolerant ecotype differs greatly in its characteristics from that of the sensitive one, with the most prominent differences being its insensitivity to protonophores and ortho-vanadate and its stimulation by Mg-GTP. These differences in characteristics are most likely due to the fact that Zn can be taken up by two or more parallel pathways, which are not present in the same proportions in both ecotypes. In both ecotypes, Zn is actively transported across the tonoplast (temperature coefficient > 1.6), most likely as a free ion, since citrate does not accumulate in vesicles. Most importantly, the uptake difference found using the ecotypes was also found between homozygous Zn-tolerant and Zn-sensitive F3 plants, proving the genetic correlation between increased tonoplast Zn transport and naturally selected Zn tolerance in S. vulgaris.
Purification of a Jojoba Embryo Wax Synthase, Cloning of its cDNA, and Production of High Levels of Wax in Seeds of Transgenic Arabidopsis
Authors: Lardizabal Kathryn D. , Metz James G. , Sakamoto Tetsuo , Hutton William C. , Pollard Michael R. , Lassner Michael W.
Published: July 2002

Wax synthase (WS, fatty acyl-coenzyme A [coA]: fatty alcohol acyltransferase) catalyzes the final step in the synthesis of linear esters (waxes) that accumulate in seeds of jojoba (Simmondsia chinensis). We have characterized and partially purified this enzyme from developing jojoba embryos. A protein whose presence correlated with WS activity during chromatographic fractionation was identified and a cDNA encoding that protein was cloned. Seed-specific expression of the cDNA in transgenic Arabidopsis conferred high levels of WS activity on developing embryos from those plants. The WS sequence has significant homology with several Arabidopsis open reading frames of unknown function. Wax production in jojoba requires, in addition to WS, a fatty acyl-CoA reductase (FAR) and an efficient fatty acid elongase system that forms the substrates preferred by the FAR. We have expressed the jojoba WS cDNA in Arabidopsis in combination with cDNAs encoding the jojoba FAR and a β-ketoacyl-CoA synthase (a component of fatty acid elongase) from Lunaria annua.13C-Nuclear magnetic resonance analysis of pooled whole seeds from transgenic plants indicated that as many as 49% of the oil molecules in the seeds were waxes. Gas chromatography analysis of transmethylated oil from individual seeds suggested that wax levels may represent up to 70% (by weight) of the oil present in those seeds.
A Novel Gibberellin-Induced Gene from Rice and Its Potential Regulatory Role in Stem Growth
Authors: van der Knaap Esther , Kim Jeong Hoe , Kende Hans
Published: July 2002

Os-GRF1(Oryza sativa-GROWTH-REGULATING FACTOR1) was identified in a search for genes that are differentially expressed in the intercalary meristem of deepwater rice (Oryza sativa L.) internodes in response to gibberellin (GA). Os-GRF1 displays general features of transcription factors, contains a functional nuclear localization signal, and has three regions with similarities to sequences in the database. One of these regions is similar to a protein interaction domain of SWI2/SNF2, which is a subunit of a chromatin-remodeling complex in yeast. The two other domains are novel and found only in plant proteins of unknown function. To study its role in plant growth, Os-GRF1 was expressed in Arabidopsis. Stem elongation of transformed plants was severely inhibited, and normal growth could not be recovered by the application of GA. Our results indicate that Os-GRF1 belongs to a novel class of plant proteins and may play a regulatory role in GA-induced stem elongation.
The Role of Pyruvate Dehydrogenase and Acetyl-Coenzyme A Synthetase in Fatty Acid Synthesis in Developing Arabidopsis Seeds
Authors: Ke Jinshan , Behal Robert H. , Back Stephanie L. , Nikolau Basil J. , Wurtele Eve Syrkin , Oliver David J.
Published: July 2002

Acetyl-coenzyme A (acetyl-CoA) formed within the plastid is the precursor for the biosynthesis of fatty acids and, through them, a range of important biomolecules. The source of acetyl-CoA in the plastid is not known, but two enzymes are thought to be involved: acetyl-CoA synthetase and plastidic pyruvate dehydrogenase. To determine the importance of these two enzymes in synthesizing acetyl-CoA during lipid accumulation in developing Arabidopsis seeds, we isolated cDNA clones for acetyl-CoA synthetase and for the ptE1α- and ptE1β-subunits of plastidic pyruvate dehydrogenase. To our knowledge, this is the first reported acetyl-CoA synthetase sequence from a plant source. The Arabidopsis acetyl-CoA synthetase preprotein has a calculated mass of 76,678 D, an apparent plastid targeting sequence, and the mature protein is a monomer of 70 to 72 kD. During silique development, the spatial and temporal patterns of the ptE1β mRNA level are very similar to those of the mRNAs for the plastidic heteromeric acetyl-CoA carboxylase subunits. The pattern of ptE1β mRNA accumulation strongly correlates with the formation of lipid within the developing embryo. In contrast, the level of mRNA for acetyl-CoA synthetase does not correlate in time and space with lipid accumulation. The highest level of accumulation of the mRNA for acetyl-CoA synthetase during silique development is within the funiculus. These mRNA data suggest a predominant role for plastidic pyruvate dehydrogenase in acetyl-CoA formation during lipid synthesis in seeds.
At-ACA8 Encodes a Plasma Membrane-Localized Calcium-ATPase of Arabidopsis with a Calmodulin-Binding Domain at the N Terminus
Authors: Bonza Maria Cristina , Morandini Piero , Luoni Laura , Geisler Markus , Palmgren Michael Gjedde , De Michelis Maria Ida
Published: July 2002

A Ca2+-ATPase was purified from plasma membranes (PM) isolated from Arabidopsis cultured cells by calmodulin (CaM)-affinity chromatography. Three tryptic fragments from the protein were microsequenced and the corresponding cDNA was amplified by polymerase chain reaction using primers designed from the microsequences of the tryptic fragments. At-ACA8 (Arabidopsis-autoinhibited Ca2+-ATPase, isoform 8, accession no. AJ249352) encodes a 1,074 amino acid protein with 10 putative transmembrane domains, which contains all of the characteristic motifs of Ca2+-transporting P-type Ca2+-ATPases. The identity of At-ACA8p as the PM Ca2+-ATPase was confirmed by immunodetection with an antiserum raised against a sequence (valine-17 through threonine-31) that is not found in other plant CaM-stimulated Ca2+-ATPases. Confocal fluorescence microscopy of protoplasts immunodecorated with the same antiserum confirmed the PM localization of At-ACA8.At-ACA8 is the first plant PM localized Ca2+-ATPase to be cloned and is clearly distinct from animal PM Ca2+-ATPases due to the localization of its CaM-binding domain. CaM overlay assays localized the CaM-binding domain of At-ACA8p to a region of the N terminus of the enzyme around tryptophan-47, in contrast to a C-terminal localization for its animal counterparts. Comparison between the sequence ofAt-ACA8p and those of endomembrane-localized type IIB Ca2+-ATPases of plants suggests that At-ACA8 is a representative of a new subfamily of plant type IIB Ca2+-ATPases.
A Maize Vacuolar Invertase, IVR2, Is Induced by Water Stress. Organ/Tissue Specificity and Diurnal Modulation of Expression
Authors: Kim Jae-Yean , Mahé Aline , Brangeon Judy , Prioul Jean-Louis
Published: July 2002

The expression of invertases was analyzed in vegetative organs of well-watered and water-stressed maize (Zea mays) plants. Early changes in sucrose metabolism and in acid soluble invertase expression were observed in vegetative sink and source organs under mild water stress. The organ-specific induction of acid invertase activity was correlated with an increase in theIvr2 gene transcripts and in the vacuolar invertase proteins. In addition diurnal changes in activity andIvr2 transcripts for vacuolar invertase were noted in shoots. Hexoses (glucose and fructose) accumulated in all organs examined from water-stressed plants. In situ localization studies showed that glucose accumulation, vacuolar invertase activity, invertase protein, and the Ivr2 transcripts colocalized specifically in bundle sheath and vascular tissue cells of mature stressed leaf; in primary roots the stress-induced increase ofIvr2 transcripts was detected only in root tips. Based on these results different regulatory roles are proposed in sink and source organs for the stress induced Ivr2 vacuolar invertase.
Strategies for the Allocation of Resources under Sulfur Limitation in the Green Alga Dunaliella salina
Authors: Giordano Mario , Pezzoni Valerio , Hell Rüdiger
Published: July 2002

The effect of sulfur limitation on the partitioning of carbon, nitrogen, and sulfur was investigated in Dunaliella salina. D. salina was able to adapt to 6 μm sulfate; under these conditions, the cells showed reduced growth and photosynthetic rates. Whereas intracellular sulfate was depleted, phosphate, nitrate, and ammonium increased. Amino acids showed a general increase, and alanine became the most abundant amino acid. The activities of four key enzymes of carbon, sulfur, and nitrogen metabolism were differentially regulated: Adenosine 5′ triphosphate sulfurylase activity increased 4-fold, nitrate reductase and phosphoenolpyruvate (PEP) carboxylase activities decreased 4- and 11-fold, respectively, whereas carbonic anhydrase activity remained unchanged. Sulfur limitation elicited specific increase or decrease of the abundance of several proteins, such us Rubisco, PEP carboxylase, and a light harvesting complex protein. The accumulation of potentially toxic ammonium indicates an insufficient availability of carbon skeletons. Sulfur deficiency thus induces an imbalance between carbon and nitrogen. The dramatic reduction in PEP carboxylase activity suggests that carbon was diverted away from anaplerosis and possibly channeled into C3 metabolism. These results indicate that it is the coordination of key steps and components of carbon, nitrogen, and sulfur metabolism that allows D. salina to adapt to prolonged sulfur limitation.
Expression of an Expansin Is Associated with Endosperm Weakening during Tomato Seed Germination
Authors: Chen Feng , Bradford Kent J.
Published: July 2002

Expansins are extracellular proteins that facilitate cell wall extension, possibly by disrupting hydrogen bonding between hemicellulosic wall components and cellulose microfibrils. In addition, some expansins are expressed in non-growing tissues such as ripening fruits, where they may contribute to cell wall disassembly associated with tissue softening. We have identified at least three expansin genes that are expressed in tomato (Lycopersicon esculentumMill.) seeds during germination. Among these, LeEXP4mRNA is specifically localized to the micropylar endosperm cap region, suggesting that the protein might contribute to tissue weakening that is required for radicle emergence. In gibberellin (GA)-deficient (gib-1) mutant seeds, which germinate only in the presence of exogenous GA, GA induces the expression ofLeEXP4 within 12 hours of imbibition. Whengib-1 seeds were imbibed in GA solution combined with 100 μm abscisic acid, the expression ofLeEXP4 was not reduced, although radicle emergence was inhibited. In wild-type seeds, LeEXP4 mRNA accumulation was blocked by far-red light and decreased by low water potential but was not affected by abscisic acid. The presence ofLeEXP4 mRNA during seed germination parallels endosperm cap weakening determined by puncture force analysis. We hypothesize that LeEXP4 is involved in the regulation of seed germination by contributing to cell wall disassembly associated with endosperm cap weakening.
Specific Binding of vf14-3-3a Isoform to the Plasma Membrane H+-ATPase in Response to Blue Light and Fusicoccin in Guard Cells of Broad Bean
Authors: Emi Takashi , Kinoshita Toshinori , Shimazaki Ken-ichiro
Published: July 2002

The plasma membrane H+-ATPase is activated by blue light with concomitant binding of the 14-3-3 protein to the C terminus in guard cells. Because several isoforms of the 14-3-3 protein are expressed in plants, we determined which isoform(s) bound to the H+-ATPase in vivo. Four cDNA clones (vf14-3-3a, vf14-3-3b,vf14-3-3c, and vf14-3-3d) encoding 14-3-3 proteins were isolated from broad bean (Vicia faba) guard cells. Northern analysis revealed that mRNAs encoding vf14-3-3a and vf14-3-3b proteins were expressed predominantly in guard cells. The 14-3-3 protein that bound to the H+-ATPase in guard cells had the same molecular mass as the recombinant vf14-3-3a protein. The H+-ATPase immunoprecipitated from mesophyll cell protoplasts, which had been stimulated by fusicoccin, coprecipitated with the 32.5-kD 14-3-3 protein, although three 14-3-3 isoproteins were found in mesophyll cell protoplasts. Digestions of the bound 14-3-3 protein and recombinant vf14-3-3a with cyanogen bromide gave the identical migration profiles on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but that of vf14-3-3b gave a different profile. Mass profiling of trypsin-digested 14-3-3 protein bound to the H+-ATPase gave the predicted peptide masses of vf14-3-3a. Far western analysis revealed that the H+-ATPase had a higher affinity for vf14-3-3a than for vf14-3-3b. These results suggest that the 14-3-3 protein that bound to the plasma membrane H+-ATPase in vivo is vf14-3-3a and that it may play a key role in the activation of H+-ATPase in guard cells.
Mapping Maize Sequences to Chromosomes Using Oat-Maize Chromosome Addition Materials,
Authors: Okagaki Ron J. , Kynast Ralf G. , Livingston Suzanne M. , Russell Charles D. , Rines Howard W. , Phillips Ronald L.
Published: July 2002

Oat- (Avena sativa) maize (Zea mays) chromosome additions are produced by crossing maize and oat. During early embryo development maize chromosomes are preferentially eliminated, and oat plants are often recovered that retain a single maize chromosome. Each of the 10 maize chromosomes recently has been isolated as a separate oat-maize addition. We describe here the mapping of 400 maize sequences to chromosomes using polymerase chain reaction and DNA from the oat-maize addition material. Fifty of the sequences were from cloned markers that had been previously mapped by linkage analysis, and our results were consistent with those obtained using Southern-blot analysis. Previously unmapped expressed sequence tags and sequence tagged sites (350) were mapped to chromosomes. Maize gene sequences and expression data are rapidly being accumulated. Coupling this information with positional information from high throughput mapping programs provides plant biologists powerful tools for identifying candidate genes of interest.
Xylem Cavitation in the Leaf of Prunus laurocerasusand Its Impact on Leaf Hydraulics
Authors: Nardini Andrea , Tyree Melvin T. , Salleo Sebastiano
Published: July 2002

This paper reports how water stress correlates with changes in hydraulic conductivity of stems, leaf midrib, and whole leaves ofPrunus laurocerasus. Water stress caused cavitation-induced dysfunction in vessels of P. laurocerasus. Cavitation was detected acoustically by counts of ultrasonic acoustic emissions and by the loss of hydraulic conductivity measured by a vacuum chamber method. Stems and midribs were approximately equally vulnerable to cavitations. Although midribs suffered a 70% loss of hydraulic conductance at leaf water potentials of −1.5 MPa, there was less than a 10% loss of hydraulic conductance in whole leaves. Cutting and sealing the midrib 20 mm from the leaf base caused only a 30% loss of conduction of the whole leaf. A high-pressure flow meter was used to measure conductance of whole leaves and as the leaf was progressively cut back from tip to base. These data were fitted to a model of hydraulic conductance of leaves that explained the above results, i.e. redundancy in hydraulic pathways whereby water can flow around embolized regions in the leaf, makes whole leaves relatively insensitive to significant changes in conductance of the midrib. The onset of cavitation events in P. laurocerasus leaves correlated with the onset of stomatal closure as found recently in studies of other species in our laboratory.
Brassicaceae Express Multiple Isoforms of Biotin Carboxyl Carrier Protein in a Tissue-Specific Manner
Authors: Thelen Jay J. , Mekhedov Sergei , Ohlrogge John B.
Published: July 2002

Plastidial acetyl-coenzyme A carboxylase from most plants is a multi-enzyme complex comprised of four different subunits. One of these subunits, the biotin carboxyl carrier protein (BCCP), was previously proposed to be encoded by a single gene in Arabidopsis. We report and characterize here a second Arabidopsis BCCP (AtBCCP2) cDNA with 42% amino acid identity to AtBCCP1 and 75% identity to a class of oilseed rape (Brassica napus) BCCPs. Both Arabidopsis BCCP isoforms were expressed in Escherichia coli and found to be biotinylated and supported carboxylation activity when reconstituted with purified, recombinant Arabidopsis biotin carboxylase. In vitro translated AtBCCP2 was competent for import into pea (Pisum sativum) chloroplasts and processed to a 25-kD polypeptide. Extracts of Arabidopsis seeds contained biotinylated polypeptides of 35 and 25 kD, in agreement with the masses of recombinant AtBCCP1 and 2, respectively. AtBCCP1 protein was present in developing tissues from roots, leaves, flowers, siliques, and seeds, whereas AtBCCP2 protein was primarily expressed in 7 to 10 d-after-flowering seeds at levels approximately 2-fold less abundant than AtBCCP1. AtBCCP1 transcript reflected these protein expression profiles present in all developing organs and highest in 14-d leaves and siliques, whereas AtBCCP2 transcript was present in flowers and siliques. In protein blots, four different BCCP isoforms were detected in developing seeds from oilseed rape. Of these, a 35-kD BCCP was detected in immature leaves and developing seeds, whereas developing seeds also contained 22-, 25-, and 37-kD isoforms highly expressed 21 d after flowering. These data indicate that oilseed plants in the familyBrassicaceae contain at least one to three seed-up-regulated BCCP isoforms, depending upon genome complexity.
Differential Expression of 1-Aminocyclopropane-1-Carboxylate Synthase Genes during Orchid Flower Senescence Induced by the Protein Phosphatase Inhibitor Okadaic Acid
Authors: Wang Ning Ning , Yang Shang Fa , Charng Yee-yung
Published: July 2002

Applying 10 pmol of okadaic acid (OA), a specific inhibitor of type 1 or type 2A serine/threonine protein phosphatases, to the orchid (Phalaenopsis species) stigma induced a dramatic increase in ethylene production and an accelerated senescence of the whole flower. Aminoethoxyvinylglycine or silver thiosulfate, inhibitors of ethylene biosynthesis or action, respectively, effectively inhibited the OA-induced ethylene production and retarded flower senescence, suggesting that the protein phosphatase inhibitor induced orchid flower senescence through an ethylene-mediated signaling pathway. OA treatment induced a differential expression pattern for the 1-aminocyclopropane-1-carboxylic acid synthase multigene family. Accumulation of Phal-ACS1 transcript in the stigma, labelum, and ovary induced by OA were higher than those induced by pollination as determined by “semiquantitative” reverse transcriptase-polymerase chain reaction. In contrast, the transcript levels of Phal-ACS2 and Phal-ACS3 induced by OA were much lower than those induced by pollination. Staurosporine, a protein kinase inhibitor, on the other hand, inhibited the OA-inducedPhal-ACS1 expression in the stigma and delayed flower senescence. Our results suggest that a hyper-phosphorylation status of an unidentified protein(s) is involved in up-regulating the expression of Phal-ACS1 gene resulting in increased ethylene production and accelerated the senescence process of orchid flower.
Rapid Accumulation of Phosphatidylinositol 4,5-Bisphosphate and Inositol 1,4,5-Trisphosphate Correlates with Calcium Mobilization in Salt-Stressed Arabidopsis
Authors: DeWald Daryll B. , Torabinejad Javad , Jones Christopher A. , Shope Joseph C. , Cangelosi Amanda R. , Thompson James E. , Prestwich Glenn D. , Hama Hiroko
Published: July 2002

The phosphoinositide phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] is a key signaling molecule in animal cells. It can be hydrolyzed to release 1,2-diacyglycerol and inositol 1,4,5-trisphosphate (IP3), which in animal cells lead to protein kinase C activation and cellular calcium mobilization, respectively. In addition to its critical roles in constitutive and regulated secretion of proteins, PtdIns(4,5)P2 binds to proteins that modify cytoskeletal architecture and phospholipid constituents. Herein, we report that Arabidopsis plants grown in liquid media rapidly increase PtdIns(4,5)P2 synthesis in response to treatment with sodium chloride, potassium chloride, and sorbitol. These results demonstrate that when challenged with salinity and osmotic stress, terrestrial plants respond differently than algae, yeasts, and animal cells that accumulate different species of phosphoinositides. We also show data demonstrating that whole-plant IP3 levels increase significantly within 1 min of stress initiation, and that IP3 levels continue to increase for more than 30 min during stress application. Furthermore, using the calcium indicators Fura-2 and Fluo-3 we show that root intracellular calcium concentrations increase in response to stress treatments. Taken together, these results suggest that in response to salt and osmotic stress, Arabidopsis uses a signaling pathway in which a small but significant portion of PtdIns(4,5)P2 is hydrolyzed to IP3. The accumulation of IP3 occurs during a time frame similar to that observed for stress-induced calcium mobilization. These data also suggest that the majority of the PtdIns(4,5)P2 synthesized in response to salt and osmotic stress may be utilized for cellular signaling events distinct from the canonical IP3 signaling pathway.
Do we really understand coaching? How can we make it work better?
Authors: Redshaw Bernard
Published: July 2002

Coaching has enormous benefits for both organisations and for the individuals they employ. When good coaching is widespread, the whole organisation can learn new things more quickly and therefore can adapt to change more effectively. Individuals not only learn the new skills they are coached in, they also become better and proactive learners. For coaching to be effective in an organisation, a supportive climate is required; one where coaching is regarded as a normal part of managing and where greater importance is placed on learning from mistakes than on blaming people for them. This is too often overlooked by many organisations which wish to introduce coaching. Effective coaching requires that both organisations and the learning establishments that support them adopt a more informed strategy to develop coaches and to build and maintain a climate where coaching can happen.
Whole‐brain Project Management for All
Authors: Webster Gordon
Published: July 2002

Examines project management and project work, and the tools and
techniques used. Claims these tools and techniques have largely failed
to deliver. Details Herrmann′s framework for testing individuals′
preferred ways and modes of thinking in order to forecast their likely
behaviours and attitudes. Argues that this projection can lead to a
better understanding between professionals and occupations.
Employability ‐ creating a contract of mutual investment
Authors: Bagshaw Michael
Published: July 2002

Employability can be a new form of job security. It involves a new mutual psychological contract where employers provide self‐development for vulnerable employees (i.e. all employees) and employees take advantage of those opportunities. It is important that the self‐enhancement is in tune with business goals. There needs to be an ongoing dialogue about the present and future needs of the individual and the business. Individuals need to prioritize and set goals, manage change, present themselves well, network strategically, invest in continuous learning and work well in teams. Management needs to adopt a coaching style, using listening and motivation skills to facilitate good decision making by employees. All this requires a high level of understanding, a healthy life balance, and change resilience. Congruence is a key concept. When employees are seeking the same goals as the organization, both are likely to succeed.
Repatriation – the toughest assignment of all
Authors: Hurn Brian J.
Published: July 2002

Examines the need for HR departments to have a clear policy on repatriation, especially at times of restructuring and redundancy and the need to retain valuable staff on return. Considers the physical, psychological and emotional effects of “reverse culture shock”, the often unrealistic expectations of returnees and their families and suggests coping strategies, including assistance to the accompanying spouse and children, that can be implemented by both employers and employees. Outlines the possible content of a repatriation programme, stressing the need to tailor it to the needs of employees and their families. Comments on the heightened circumstances of natural disasters and political unrest that can cause rapid repatriation.
Nutritional awareness and food preferences of young consumers
Authors: Brown Karen , McIlveen Heather , Strugnell Christopher
Published: July 2002

The need for effective nutritional education for young consumers has become increasingly apparent given their general food habits and behaviour, particularly during adolescence. Aims to analyse the interaction between young consumers’ food preferences and their nutritional awareness behaviour, within three environments (home, school and social). Preliminary findings in this study would indicate that the perceived dominance of this home, school and social interaction appears to be somewhat overshadowed by the young consumers, developing “independence” trait, particularly during adolescent years. This appears to be reflected in their food preferences within the associated three environments. Suggests that such food preferences are often of a “fast food”‐style and consequently the food habits of many young consumers may fuel the consumption of poor nutritionally balanced meals. While young consumers were aware of healthy eating, their food preference behaviour did not always appear to reflect such knowledge, particularly within the school and social environments.
Statistics for food science – VI: correlation and regression (Part A)
Authors: Bower John A.
Published: July 2002

Describes methods for examination of the relationship between two variables measured on a set of objects, using correlation coefficients and simple regression analysis.
Using a life‐story approach in researching entrepreneurial learning: the development of a conceptual model and its implications in the design of learning experiences
Authors: Rae David , Carswell Mary
Published: July 2002

Summarises the conclusions from research which explores how people learn to start and grow high performing businesses. Seeks to understand better the ways in which individuals learn to act entrepreneurially and also suggests how this understanding might influence the design of more effective learning experiences. Proposes a conceptual model of entrepreneurial learning, and assesses its implications for designing entrepreneurship education and development programmes. Findings indicate that there would be benefits from designing development programmes for current and aspirant business owners with a greater emphasis on personal development, based upon the entrepreneurial learning model proposed in the article.
The true value of failing
Authors: Baker Helen
Published: July 2002

Examines a Teaching Company Scheme between Leeds Metropolitan
University and the Weldrick Group in the search for a computerized
information system, illustrating the complexity of such a task.
Traditional methodologies including the information systems development
cycle are examined in the light of a real life business environment and
the impact of external pressures and factors are demonstrated.
Illustrates the difficulties experienced by an SME and seeks to
demonstrate the value of the learning that can result from what is
initially perceived as failure.
Inclusion, exclusion and ambiguity – The role of organisational culture
Authors: Wilson Elisabeth
Published: July 2002

Describes case studies of three organisations, exploring the role of organisational culture as a framework for the inclusion and exclusion of actual and potential organisational members. To explore common understandings of culture, methods included: repertory grid, group discussions, documentary evidence, discussion with informants, and observation and reflection by the author. Both the culture‐as‐variable and culture‐as‐metaphor perspectives are used respectively to analyse and interpret the data. A number of processes were found significant in the promotion or otherwise of diversity. Significant symbols in each organisation are explored, and theoretical and practical implications are discussed in relation to managing diversity.
Inclination to opt for teleworking
Authors: Baruch Yehuda , King Joan Yuen Yuk
Published: July 2002

Teleworking is a developing practice in an increasing trend towards more flexible forms of work. This study investigates the attitudes of employees who have no experience of teleworking and their willingness to opt for it. The 74 participants, from four United Kingdom and three Hong Kong matched small companies in the high technology industry, represent a 54 per cent response rate. The results were surprisingly similar (in means, but not in standard deviations) and showed that both groups, even though coming from different cultures, tend to have similar diversified distribution of tendency to opt for teleworking, with the Hong Kong people more coherent in their answers. Both populations were willing, to a certain extent, to opt for teleworking given a chance, and preferred to practise it on part‐time schemes. However, the reasons for the inclinations comprise different sets of antecedents for both populations.
Systemic leadership via core value deployment
Authors: Edgeman Rick L. , Scherer Franz
Published: July 2002

Systemic leadership deploys leadership responsibilities and privileges across an organisation’s human resource. Business and performance excellence models limit leadership to senior executives, regarding it as competence based. Leadership legacy across history, however, is chiseled with such core values as courage, wisdom, sacrifice, stewardship and servanthood. Supporting corporate nihilism, business and performance excellence models ignore such values. Presented herein is a balance restoring the leadership core value set. Deployment through the reward and recognition system and assessment of leadership pervasiveness are briefly discussed.
TQM and business performance in the service sector: a Singapore study
Authors: Brah Shaukat A. , Li Wong Jen , Madhu Rao B.
Published: July 2002

This paper focuses on gaining insight into the impact of TQM on the business performance of the service sector of the economy. The study yields clear evidence that TQM implementation improved business performance in the service sector of Singapore. Success of TQM implementations appears to be attributable more to the rigor of its implementation rather than the duration. The study finds that while accrued benefits can be attributed to some of the tools of TQM, such as, customer focus and quality improvement rewards, the key to the success of TQM lies in its intangible and behavioral features such as top management support, employee empowerment and employee involvement.
Position and orientation sensing in virtual environments
Authors: Stone Robert J.
Published: July 2002

Looks at changes in the human‐computer interface, particularly in the field of using computers for applications which require an accurate registration from an input device in “six degrees of freedom”, including robotics, CAD, anthropometric/biomechanic analysis, military, digital antique cataloguing and archaeological site surveys.
Photochromic ultraviolet light sensor and applications
Authors: Goudjil Kamal , Sandoval Ray
Published: July 2002

The need for a small, low cost, simple, personal UVR detector has been motivated by the growing concerns about adverse health effects induced by UV radiation. SolarTech Enterprises, LLC has developed several such photochromic detectors for UV radiation detection. Broadband detectors (290nm to 400nm) and wavelength specific detectors for UVB and UVA regions of the spectrum have all been developed by SolarTech.
Modern integrated silicon Hall sensors
Authors: Schott C. , Burger F. , Blanchard H. , Chiesi L.
Published: July 2002

The new developments in silicon Hall sensors are highlighted. First, basic components made by microelectronic technology are explained. They lead to the development of high accuracy vectorial magnetic probes. Then examples of new applications like angular position sensor and current measurements are illustrated. Finally, new concepts in order to increase the detectivity using magnetic chopping are demonstrated.
Finite element linear and nonlinear, static and dynamic analysis of structural elements: a bibliography (1992‐1995)
Authors: Mackerle Jaroslav
Published: July 2002

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.
Creative performance on anin‐basket exercise
Authors: Cooper Barrie L. , Clasen Pamela , Silva‐Jalonen Dora E. , Butler Mark C.
Published: July 2002

Subjects provided creative responses to memoranda from an in‐basket exercise. In a 262 design, contingent/noncontingent extrinsic reward conditions were crossed with intrinsic motivation/no intrinsic motivation conditions. Results indicated that intrinsic motivation was associated with improved creativity, while offering contingent, extrinsic rewards were not. Thus, the hypothesized inoculation effect associated with intrinsic motivation was not supported. Results are discussed in terms of specific work history and creativity outcomes, with particular attention focused on defining creativity in the business context (i.e. applied creativity) rather than in more artistic settings (i.e. pure creativity).
Polychronicity and temporal dimensions of work in learning organizations
Authors: Benabou Charles
Published: July 2002

States that today, the corporate environment is characterized by complexity, uncertainty, contingency and evolution. In these conditions, the design of a learning organization should be based upon Einstein’s conception of time, which represents a dramatic shift from our traditional organizations built upon Newton’s time. In this research, the author defined nine temporal dimensions of organizational culture (for instance schedules and deadlines) which could be managed in order to facilitate change and learning and examined them in relation to individuals’ polychronic behavior, a temporal orientation. Polychronic people do many things at once and experience time as a relatively intangible phenomenon that emerges from specific events. This empirical investigation shows that polychronic time use is related to several dimensions of temporal culture. These results can be used to make the development of learning organizations more effective, particularly when applied to human resource activities and programs.
Training entrepreneurship at universities: a Swedish case
Authors: Klofsten Magnus
Published: July 2002

In Sweden today there are many initiatives to stimulate individuals to act in an entrepreneurial manner, including professorships in entrepreneurialism at universities, new courses and training programmes, while firms such as Ericsson, Telia and Saab have established “innovation units” to stimulate new ideas and utilize the energy and ideas of their employees. The purpose of this article is to describe and analyse such an initiative: the Entrepreneurship and New Business Development Programme (the ENP‐programme) for the training of individuals in the start‐up of new technology‐based or knowledge‐intensive enterprises. The model has been developed by the Centre for Innovation and Entrepreneurship at Linköping University and a private network of enterprises. This article begins with a comprehensive discussion on what characterises entrepreneurs and what implications this has in the training of individuals. Subsequently, the ENP‐programme, feedback from the participants in the programme, and what characterises a successful entrepreneurship programme are presented.
The role and effectiveness of case studies: student performance in case study vs “theory” examinations
Authors: Cinneide Barra O
Published: July 2002

Attempts to assess the value of case study use in examination mode. In particular, it is concerned with an appraisal of the results of the examination performance of a large class of graduate students who had participated in a comparatively traditional “theory”/lecture course. Experience with the author’s “Riverdance” case study shows that if topics are sufficiently attention directing, a high participation rate can be achieved on case questions, even though “more conventional” questions are optional. Shows the advantages of researching student performances “by going back to basics”. Within classroom sessions, students can feel inhibited/intimidated by large class sizes. However, if a stimulatory environment and appropriate exam structure can be devised, a particular “one‐to‐one” rapport between lecturer and student can be established ‐ through the much maligned examination script.
New possibilities for the professionalization of UK VET professionals
Authors: Young Michael , Guile David
Published: July 2002

Analyses the present condition of, and future possibilities for, the professionalization of those who work in vocational education and training in the UK. Argues that for the UK, as for other European countries, a high quality system of vocational education and training (VET) is a precondition for both a competitive economy and democratic society. Begins with a description of the current state and status of VET in the UK, and charts the legacy of 18 years of neo‐liberal conservative government and its implications for the position of VET professionals. Identifies the new demands being made on VET professionals by changes in the global economy and develops a model of the VET professional as a connective specialist for responding to these demands. Explores two aspects of the model ‐ pedagogy and the role of new technologies (telematics in particular) ‐ in some detail. Finally, considers some of the political and economic policies needed for such a model to be implemented.