bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of XET-Related Genes of Rice
Authors: Uozu Sakurako , Tanaka-Ueguchi Miyako , Kitano Hidemi , Hattori Kazumi , Matsuoka Makoto
Published: July 2002

To elucidate the mechanism of internodal elongation in rice (Oryza sativa L.), we analyzed genes encoding xyloglucan endotransglycosylase (XET), a cell wall-loosening enzyme essential for cell elongation. Four riceXET-related (XTR) genes,OsXTR1, OsXTR2,OsXTR3, and OsXTR4, were isolated and their expression patterns in rice plants determined. The expression of the four XTR genes showed different patterns of organ specificity and responses to several plant hormones.OsXTR1 and OsXTR3 were up-regulated by gibberellin and brassinosteroids, whereas OsXTR2 andOsXTR4 showed no clear response to these hormones. Expression of the four XTR genes was also investigated in elongating internodes at different developmental stages.OsXTR1 and OsXTR3 were preferentially expressed in the elongating zone of internodes, whileOsXTR2 and OsXTR4 were expressed in nodes and in the divisional and elongating zones of internodes. In three genetic mutants with abnormal heights, the expression ofOsXTR1 and OsXTR3 correlated with the height of the mutants, whereas no such correlation was observed forOsXTR2 and OsXTR4. Based on these observations, we discuss the roles that OsXTR1 andOsXTR3 may play in internodal elongation in rice.
Inactivation of Photosystems I and II in Response to Osmotic Stress in Synechococcus. Contribution of Water Channels
Authors: Allakhverdiev Suleyman I. , Sakamoto Atsushi , Nishiyama Yoshitaka , Murata Norio
Published: July 2002

The effects of osmotic stress due to sorbitol on the photosynthetic machinery were investigated in the cyanobacterium Synechococcus R-2. Incubation of cells in 1.0 m sorbitol inactivated photosystems I and II and decreased the intracellular solute space by 50%. These effects of sorbitol were reversible: Photosynthetic activity and cytoplasmic volume returned to the original values after removal of the osmotic stress. A blocker of water channels prevented the osmotic-stress-induced inactivation and shrinkage of the intracellular space. It also prevented the recovery of photosynthetic activity and cytoplasmic volume when applied just before release from osmotic stress. Inhibition of protein synthesis by lincomycin had no significant effects on the inactivation and recovery processes, an observation that suggests that protein synthesis was not involved in these processes. Our results suggest that osmotic stress decreased the amount of water in the cytoplasm via the efflux of water through water channels (aquaporins), with resultant increases in intracellular concentrations of ions and a decrease in photosynthetic activity.
Effects of Acetate on Facultative Autotrophy inChlamydomonas reinhardtii Assessed by Photosynthetic Measurements and Stable Isotope Analyses
Authors: Heifetz Peter B. , Förster Britta , Osmond C. Barry , Giles Lawrence J. , Boynton John E.
Published: July 2002

The green alga Chlamydomonas reinhardtii can grow photoautotrophically utilizing CO2, heterotrophically utilizing acetate, and mixotrophically utilizing both carbon sources. Growth of cells in increasing concentrations of acetate plus 5% CO2 in liquid culture progressively reduced photosynthetic CO2 fixation and net O2 evolution without effects on respiration, photosystem II efficiency (as measured by chlorophyll fluorescence), or growth. Using the technique of on-line oxygen isotope ratio mass spectrometry, we found that mixotrophic growth in acetate is not associated with activation of the cyanide-insensitive alternative oxidase pathway. The fraction of carbon biomass resulting from photosynthesis, determined by stable carbon isotope ratio mass spectrometry, declined dramatically (about 50%) in cells grown in acetate with saturating light and CO2. Under these conditions, photosynthetic CO2 fixation and O2 evolution were also reduced by about 50%. Some growth conditions (e.g. limiting light, high acetate, solid medium in air) virtually abolished photosynthetic carbon gain. These effects of acetate were exacerbated in mutants with slowed electron transfer through the D1 reaction center protein of photosystem II or impaired chloroplast protein synthesis. Therefore, in mixotrophically grown cells of C. reinhardtii, interpretations of the effects of environmental or genetic manipulations of photosynthesis are likely to be confounded by acetate in the medium.
Use of Recombinant Aequorin to Study Calcium Homeostasis and Monitor Calcium Transients in Response to Heat and Cold Shock in Cyanobacteria
Authors: Torrecilla Ignacio , Leganés Francisco , Bonilla Ildefonso , Fernández-Piñas Francisca
Published: July 2002

We investigated the possibility of Ca2+ signaling in cyanobacteria (blue-green algae) by measuring intracellular free Ca2+ levels ([Ca2+]i) in a recombinant strain of the nitrogen fixing cyanobacteriumAnabaena strain sp. PCC7120, which constitutively expresses the Ca2+-binding photoprotein apoaequorin. The homeostasis of intracellular Ca2+ in response to increasing external Ca2+ has been studied in this strain. The resting level of free Ca2+ in Anabaena was found to be between 100 and 200 nm. Additions of increasing concentrations of external Ca2+ gave a transient burst of [Ca2+]i followed by a very quick decline, reaching a plateau within seconds that brought the level of [Ca2+]i back to the resting value. These results indicate that Anabaena strain sp. PCC7120 is able to regulate its internal Ca2+ levels. We also monitored Ca2+ transients in our recombinant strain in response to heat and cold shock. The cell's response to both stresses was dependent on the way they were induced. The use of inhibitors suggests that heat shock mobilizes cytosolic Ca2+ from both intracellular and extracellular sources, while the Ca2+source for cold shock signaling is mostly extracellular.
The YeastHAL1Gene Improves Salt Tolerance of Transgenic Tomato
Authors: Gisbert Carmina , Rus Ana M. , Boları́n M. Carmen , López-Coronado J. Miguel , Arrillaga Isabel , Montesinos Consuelo , Caro Manuel , Serrano Ramon , Moreno Vicente
Published: July 2002

Overexpression of the HAL1 gene in yeast has a positive effect on salt tolerance by maintaining a high internal K+ concentration and decreasing intracellular Na+ during salt stress. In the present work, the yeast geneHAL1 was introduced into tomato (Lycopersicon esculentum Mill.) by Agrobacterium tumefaciens-mediated transformation. A sample of primary transformants was self-pollinated, and progeny from both transformed and non-transformed plants (controls) were evaluated for salt tolerance in vitro and in vivo. Results from different tests indicated a higher level of salt tolerance in the progeny of two different transgenic plants bearing four copies or one copy of the HAL1 gene. In addition, measurement of the intracellular K+ to Na+ ratios showed that transgenic lines were able to retain more K+ than the control under salt stress. Although plants and yeast cannot be compared in an absolute sense, these results indicate that the mechanism controlling the positive effect of theHAL1 gene on salt tolerance may be similar in transgenic plants and yeast.
A DEFICIENS Homolog from the Dioecious Tree Black Cottonwood Is Expressed in Female and Male Floral Meristems of the Two-Whorled, Unisexual Flowers
Authors: Sheppard Lorraine A. , Brunner Amy M. , Krutovskii Konstantin V. , Rottmann William H. , Skinner Jeffrey S. , Vollmer Sheila S. , Strauss Steven H.
Published: July 2002

We isolated PTD, a member of theDEFICIENS (DEF) family of MADS box transcription factors, from the dioecious tree, black cottonwood (Populus trichocarpa). In females, in situ hybridization experiments showed that PTD mRNA was first detectable in cells on the flanks of the inflorescence meristem, before differentiation of individual flowers was visually detectable. In males, the onset of PTD expression was delayed until after individual flower differentiation had begun and floral meristems were developing. Although PTD was initially expressed throughout the inner whorl meristem in female and male flowers, its spatial expression pattern became sex-specific as reproductive primordia began to form. PTD expression was maintained in stamen primordia, but excluded from carpel primordia, as well as vegetative tissues. Although PTD is phylogenetically most closely related to the largely uncharacterized TM6subfamily of theDEF/APETELA3(AP3)/TM6group, its spatio-temporal expression patterns are more similar to that of DEF and AP3 than to other members of the TM6 subfamily.
A Leaf Lipoxygenase of Potato Induced Specifically by Pathogen Infection
Authors: Kolomiets Michael V. , Chen Hao , Gladon Richard J. , Braun E.J. , Hannapel David J.
Published: July 2002

Lipoxygenase (LOX) activity has been identified consistently during pathogen-induced defense responses. Here we report the involvement of a specific leaf LOX gene of potato (Solanum tuberosum), designated POTLX-3 (GenBank/EMBL accession no. U60202), in defense responses against pathogens. The sequence ofPOTLX-3 does not match any other LOX genes of potato and has the greatest match to a tobacco LOX gene that contributes to a resistance mechanism against Phytophthora parasitica varnicotianae. POTLX-3 transcript accumulation was not detected in untreated, healthy potato organs or in wounded mature leaves. POTLX-3 mRNA accumulation was induced in potato leaves treated with ethylene or methyl jasmonate or infected with either virulent or avirulent strains of Phytophthora infestans, the causal agent of late blight. During the resistance response, POTLX-3 was induced within 6 hours, increased steadily through 24 hours, and its mRNA continued to accumulate for a week after inoculation. In contrast, when a plant was susceptible to P. infestans, induction of mRNA accumulation in response to inoculation was inconsistent and delayed. LOX activity assayed during an incompatible interaction in leaves peaked 3 days earlier than during a compatible interaction.POTLX-3 mRNA accumulation also was induced during hypersensitive response development caused by the incompatible pathogenPseudomonas syringae pv phaseolicola. Our results show that POTLX-3 may be involved specifically in defense responses against pathogen infection.
Complex I Impairment, Respiratory Compensations, and Photosynthetic Decrease in Nuclear and Mitochondrial Male Sterile Mutants of Nicotiana sylvestris
Authors: Sabar Mohammed , De Paepe Rosine , de Kouchkovsky Yaroslav
Published: July 2002

We have previously shown that in Nicotiana sylvestris cytoplasmic male-sterile (CMS) mutants where the mtDNA lacks the nad7 gene coding for a subunit of respiratory Complex I (NADH:ubiquinone oxidoreductase, EC 1.6.5.3), glycine (Gly) oxidation was lower than in the wild type and insensitive to rotenone, suggesting Complex I dysfunction. In contrast, the oxidation rate of exogenous NADH and the capacity of the cyanide-resistant respiration (AOX) were enhanced. Here we report that, in contrast to Gly, the rate of malate oxidation was not affected, but proceeded totally in a rotenone-insensitive pathway, strongly suggesting that survival of CMS plants depends on the activation of internal and external alternative NAD(P) H dehydrogenases and that Gly decarboxylase activity depends on Complex I functioning. A similar defect in Complex I activity and Gly oxidation was found in the NMS1 nuclear mutant, defective in the processing of the nad4transcript, but alternative NAD(P) H dehydrogenases were less activated. In CMS and NMS1, the fraction of the AOX pathway was increased, as compared to wild type, associated with higher amounts ofaox transcripts, AOX protein, and plant resistance to cyanide. Non-phosphorylating respiratory enzymes maintained normal in vivo respiration levels in both mutants, but photosynthesis was decreased, in correlation with lower leaf conductance, emphasizing mitochondrial control on photosynthesis.
New Techniques Enable Comparative Analysis of Microtubule Orientation, Wall Texture, and Growth Rate in Intact Roots of Arabidopsis
Authors: Sugimoto Keiko , Williamson Richard E. , Wasteneys Geoffrey O.
Published: July 2002

This article explores root epidermal cell elongation and its dependence on two structural elements of cells, cortical microtubules and cellulose microfibrils. The recent identification of Arabidopsis morphology mutants with putative cell wall or cytoskeletal defects demands a procedure for examining and comparing wall architecture and microtubule organization patterns in this species. We developed methods to examine cellulose microfibrils by field emission scanning electron microscopy and microtubules by immunofluorescence in essentially intact roots. We were able to compare cellulose microfibril and microtubule alignment patterns at equivalent stages of cell expansion. Field emission scanning electron microscopy revealed that Arabidopsis root epidermal cells have typical dicot primary cell wall structure with prominent transverse cellulose microfibrils embedded in pectic substances. Our analysis showed that microtubules and microfibrils have similar orientation only during the initial phase of elongation growth. Microtubule patterns deviate from a predominantly transverse orientation while cells are still expanding, whereas cellulose microfibrils remain transverse until well after expansion finishes. We also observed microtubule-microfibril alignment discord before cells enter their elongation phase. This study and the new technology it presents provide a starting point for further investigations on the physical properties of cell walls and their mechanisms of assembly.
The Arabidopsis Genome. An Abundance of Soluble N-Ethylmaleimide-Sensitive Factor Adaptor Protein Receptors
Authors: Sanderfoot Anton A. , Assaad Farhah F. , Raikhel Natasha V.
Published: July 2002

Many factors have been characterized as essential for vesicle trafficking, including a number of proteins commonly referred to as soluble N-ethylmaleimide-sensitive factor adaptor protein receptor (SNARE) components. The Arabidopsis genome contains a remarkable number of SNAREs. In general, the vesicle fusion machinery appears highly conserved. However, whereas some classes of yeast and mammalian genes appear to be lacking in Arabidopsis, this small plant genome has gene families not found in other eukaryotes. Very little is known about the precise function of plant SNAREs. By contrast, the intracellular localization of and interactions between a large number of plant SNAREs have been determined, and these data are discussed in light of the phylogenetic analysis.
The Ubiquitin-Specific Protease Family from Arabidopsis.AtUBP1 and 2 Are Required for the Resistance to the Amino Acid Analog Canavanine
Authors: Yan Ning , Doelling Jed H. , Falbel Tanya G. , Durski Adam M. , Vierstra Richard D.
Published: July 2002

Ubiquitin-specific proteases (UBPs) are a family of unique hydrolases that specifically remove polypeptides covalently linked via peptide or isopeptide bonds to the C-terminal glycine of ubiquitin. UBPs help regulate the ubiquitin/26S proteolytic pathway by generating free ubiquitin monomers from their initial translational products, recycling ubiquitins during the breakdown of ubiquitin-protein conjugates, and/or by removing ubiquitin from specific targets and thus presumably preventing target degradation. Here, we describe a family of 27 UBP genes from Arabidopsis that contain both the conserved cysteine (Cys) and histidine boxes essential for catalysis. They can be clustered into 14 subfamilies based on sequence similarity, genomic organization, and alignments with their closest relatives from other organisms, with seven subfamilies having two or more members. Recombinant AtUBP2 functions as a bona fide UBP: It can release polypeptides attached to ubiquitins via either α- or ε-amino linkages by an activity that requires the predicted active-site Cys within the Cys box. From the analysis of T-DNA insertion mutants, we demonstrate that the AtUBP1 and2 subfamily helps confer resistance to the arginine analog canavanine. This phenotype suggests that theAtUBP1 and 2 enzymes are needed for abnormal protein turnover in Arabidopsis.
Gibberellin Biosynthesis Mutations and Root Development in Pea
Authors: Yaxley Julian R. , Ross John J. , Sherriff Leanne J. , Reid James B.
Published: July 2002

Dwarf mutants of pea (Pisum sativum), with impaired gibberellin (GA) biosynthesis in the shoot, were studied to determine whether the roots of these genotypes had altered elongation and GA levels. Mutations na, lh-2, andls-1 reduced GA levels in root tips and taproot elongation, although in lh-2 and ls-1roots the reduction in elongation was small (less than 15%). Thena mutation reduced taproot length by about 50%. The roots of na plants elongated in response to applied GA1 and recombining na with mutationsln (which blocks GA catabolism) increased GA1 levels in root tips and completely restored normal root development. In shoots, Mendel's le-1 mutation impairs the 3β-hydroxylation of GA20 to the bioactive GA1, resulting in dwarfism. However, GA1 and GA20 levels were normal in le-1 roots, as was root development. The null mutation le-2 also did not reduce root GA levels or elongation. The results support the theory that GAs are important for normal root elongation in pea, and indicate that a 3β-hydroxylase gene other than LE operates in pea roots.
Molecular Interactions between the Specialist HerbivoreManduca sexta (Lepidoptera, Sphingidae) and Its Natural Host Nicotiana attenuata. III. Fatty Acid-Amino Acid Conjugates in Herbivore Oral Secretions Are Necessary and Sufficient for Herbivore-Specific Plant Responses
Authors: Halitschke Rayko , Schittko Ursula , Pohnert Georg , Boland Wilhelm , Baldwin Ian T.
Published: July 2002

Feeding by the tobacco specialist Manduca sexta(Lepidoptera, Sphingidae) and application of larval oral secretions and regurgitant (R) to mechanical wounds are known to elicit: (a) a systemic release of mono- and sesquiterpenes, (b) a jasmonate burst, and (c) R-specific changes in transcript accumulation of putatively growth- and defense-related mRNAs in Nicotiana attenuata Torr. ex Wats. We identified several fatty acid-amino acid conjugates (FACs) in the R of M. sexta and the closely related species Manduca quinquemaculata which, when synthesized and applied to mechanical wounds at concentrations comparable with those found in R, elicited all three R-specific responses. Ion-exchange treatment of R, which removed all detectable FACs and free fatty acids (FAs), also removed all detectable activity. The biological activity of ion-exchanged R could be completely restored by the addition of synthetic FACs at R-equivalent concentrations, whereas the addition of FAs did not restore the biological activity of R. We conclude that the biological activity of R is not related to the supply of FAs to the octadecanoid cascade for endogenous jasmonate biosynthesis, but that FACs elicit the herbivore-specific responses by another mechanism and that the insect-produced modification of plant-derived FAs is necessary for the plant's recognition of this specialized herbivore.
A Complete Set of Maize Individual Chromosome Additions to the Oat Genome
Authors: Kynast Ralf G. , Riera-Lizarazu Oscar , Vales M. Isabel , Okagaki Ron J. , Maquieira Silvia B. , Chen Gang , Ananiev Evgueni V. , Odland Wade E. , Russell Charles D. , Stec Adrian O. , Livingston Suzanne M. , Zaia Herika A. , Rines Howard W. , Phillips Ronald L.
Published: July 2002

All 10 chromosomes of maize (Zea mays, 2n = 2x = 20) were recovered as single additions to the haploid complement of oat (Avena sativa, 2n = 6x = 42) among F1 plants generated from crosses involving three different lines of maize to eight different lines of oat. In vitro rescue culture of more than 4,300 immature F1 embryos resulted in a germination frequency of 11% with recovery of 379 F1plantlets (8.7%) of moderately vigorous growth. Some F1plants were sectored with distinct chromosome constitutions among tillers of the same plant and also between root and shoot cells. Meiotic restitution facilitated development of un-reduced gametes in the F1. Self-pollination of these partially fertile F1 plants resulted in disomic additions (2n = 6x + 2 = 44) for maize chromosomes 1, 2, 3, 4, 6, 7, and 9. Maize chromosome 8 was recovered as a monosomic addition (2n = 6x + 1 = 43). Monosomic additions for maize chromosomes 5 and 10 to a haploid complement of oat (n = 3x + 1 = 22) were recovered several times among the F1 plants. Although partially fertile, these chromosome 5 and 10 addition plants have not yet transmitted the added maize chromosome to F2 offspring. We discuss the development and general utility of this set of oat-maize addition lines as a novel tool for maize genomics and genetics.
B-Bolivia, an Allele of the Maize b1 Gene with Variable Expression, Contains a High Copy Retrotransposon-Related Sequence Immediately Upstream
Authors: Selinger David A. , Chandler Vicki L.
Published: July 2002

The maize (Zea mays) b1 gene encodes a transcription factor that regulates the anthocyanin pigment pathway. Of the b1 alleles with distinct tissue-specific expression,B-Peru and B-Bolivia are the only alleles that confer seed pigmentation. B-Bolivia produces variable and weaker seed expression but darker, more regular plant expression relative to B-Peru. Our experiments demonstrated that B-Bolivia is not expressed in the seed when transmitted through the male. When transmitted through the female the proportion of kernels pigmented and the intensity of pigment varied. Molecular characterization of B-Boliviademonstrated that it shares the first 530 bp of the upstream region with B-Peru, a region sufficient for seed expression. Immediately upstream of 530 bp, B-Bolivia is completely divergent from B-Peru. These sequences share sequence similarity to retrotransposons. Transient expression assays of various promoter constructs identified a 33-bp region inB-Bolivia that can account for the reduced aleurone pigment amounts (40%) observed with B-Bolivia relative to B-Peru. Transgenic plants carrying theB-Bolivia promoter proximal region produced pigmented seeds. Similar to native B-Bolivia, some transgene loci are variably expressed in seeds. In contrast to nativeB-Bolivia, the transgene loci are expressed in seeds when transmitted through both the male and female. Some transgenic lines produced pigment in vegetative tissues, but the tissue-specificity was different from B-Bolivia, suggesting the introduced sequences do not contain theB-Bolivia plant-specific regulatory sequences. We hypothesize that the chromatin context of the B-Boliviaallele controls its epigenetic seed expression properties, which could be influenced by the adjacent highly repeated retrotransposon sequence.
Expression of bar in the Plastid Genome Confers Herbicide Resistance
Authors: Lutz Kerry A. , Knapp Jane E. , Maliga Pal
Published: July 2002

Phosphinothricin (PPT) is the active component of a family of environmentally safe, nonselective herbicides. Resistance to PPT in transgenic crops has been reported by nuclear expression of abar transgene encoding phosphinothricin acetyltransferase, a detoxifying enzyme. We report here expression of a bacterial bar gene (b-bar1) in tobacco (Nicotiana tabacum cv Petit Havana) plastids that confers field-level tolerance to Liberty, an herbicide containing PPT. We also describe a second bacterial bar gene (b-bar2) and a codon-optimized syntheticbar (s-bar) gene with significantly elevated levels of expression in plastids (>7% of total soluble cellular protein). Although these genes are expressed at a high level, direct selection thus far did not yield transplastomic clones, indicating that subcellular localization rather than the absolute amount of the enzyme is critical for direct selection of transgenic clones. The codon-modified s-bar gene is poorly expressed in Escherichia coli, a common enteric bacterium, due to differences in codon use. We propose to use codon usage differences as a precautionary measure to prevent expression of marker genes in the unlikely event of horizontal gene transfer from plastids to bacteria. Localization of the bar gene in the plastid genome is an attractive alternative to incorporation in the nuclear genome since there is no transmission of plastid-encoded genes via pollen.
Unsaturated Fatty Acids in Membrane Lipids Protect the Photosynthetic Machinery against Salt-Induced Damage inSynechococcus
Authors: Allakhverdiev Suleyman I. , Kinoshita Mikio , Inaba Masami , Suzuki Iwane , Murata Norio
Published: July 2002

In this study, the tolerance to salt stress of the photosynthetic machinery was examined in relation to the effects of the genetic enhancement of the unsaturation of fatty acids in membrane lipids in wild-type and desA  + cells ofSynechococcus sp. PCC 7942. Wild-type cells synthesized saturated and mono-unsaturated fatty acids, whereasdesA  + cells, which had been transformed with the desA gene for the Δ12 acyl-lipid desaturase ofSynechocystis sp. PCC 6803, also synthesized di-unsaturated fatty acids. Incubation of wild-type anddesA  + cells with 0.5 m NaCl resulted in the rapid loss of the activities of photosystem I, photosystem II, and the Na+/H+ antiport system both in light and in darkness. However,desA  + cells were more tolerant to salt stress and osmotic stress than the wild-type cells. The extent of the recovery of the various photosynthetic activities from the effects of 0.5 m NaCl was much greater indesA  + cells than in wild-type cells. The photosystem II activity of thylakoid membranes fromdesA  + cells was more resistant to 0.5m NaCl than that of membranes from wild-type cells. These results demonstrated that the genetically engineered increase in unsaturation of fatty acids in membrane lipids significantly enhanced the tolerance of the photosynthetic machinery to salt stress. The enhanced tolerance was due both to the increased resistance of the photosynthetic machinery to the salt-induced damage and to the increased ability of desA  + cells to repair the photosynthetic and Na+/H+ antiport systems.
Hydraulic Conductance and Mercury-Sensitive Water Transport for Roots of Opuntia acanthocarpa in Relation to Soil Drying and Rewetting
Authors: Martre Pierre , North Gretchen B. , Nobel Park S.
Published: July 2002

Drought-induced changes in root hydraulic conductance (L  P) and mercury-sensitive water transport were examined for distal (immature) and mid-root (mature) regions ofOpuntia acanthocarpa. During 45 d of soil drying,L  P decreased by about 67% for distal and mid-root regions. After 8 d in rewetted soil,L  P recovered to 60% of its initial value for both regions. Axial xylem hydraulic conductivity was only a minor limiter of L  P. Under wet conditions, HgCl2 (50 μm), which is known to block membrane water-transport channels (aquaporins), decreasedL  P and the radial hydraulic conductance for the stele (L  R, S) of the distal root region by 32% and 41%, respectively; both L  P andL  R, S recovered fully after transfer to 2-mercaptoethanol (10 mm). In contrast, HgCl2 did not inhibit L  P of the mid-root region under wet conditions, although it reducedL  R, S by 41%. Under dry conditions, neitherL  P nor L  R, S of the two root regions was inhibited by HgCl2. After 8 d of rewetting, HgCl2 decreased L  Pand L  R, S of the distal region by 23% and 32%, respectively, but L  P andL  R, S of the mid-root region were unaltered. Changes in putative aquaporin activity accounted for about 38% of the reduction in L  P in drying soil and for 61% of its recovery for the distal region 8 d after rewetting. In the stele, changes in aquaporin activity accounted for about 74% of the variable L  R, S during drought and after rewetting. Thus, aquaporins are important for regulating water movement for roots of O. acanthocarpa.
Mutational Analysis of Branching in Pea. Evidence ThatRms1 and Rms5 Regulate the Same Novel Signal
Authors: Morris Suzanne E. , Turnbull Colin G.N. , Murfet Ian C. , Beveridge Christine A.
Published: July 2002

The fifth increased branching ramosus(rms) mutant, rms5, from pea (Pisum sativum), is described here for phenotype and grafting responses with four other rms mutants. Xylem sap zeatin riboside concentration and shoot auxin levels inrms5 plants have also been compared withrms1 and wild type (WT). Rms1 andRms5 appear to act closely at the biochemical or cellular level to control branching, because branching was inhibited in reciprocal epicotyl grafts between rms5 orrms1 and WT plants, but not inhibited in reciprocal grafts between rms5 and rms1 seedlings. The weakly transgressive or slightly additive phenotype of therms1 rms5 double mutant provides further evidence for this interaction. Like rms1, rms5rootstocks have reduced xylem sap cytokinin concentrations, andrms5 shoots do not appear deficient in indole-3-acetic acid or 4-chloroindole-3-acetic acid. Rms1 andRms5 are similar in their interaction with otherRms genes. Reciprocal grafting studies withrms1, rms2, and rms5, together with the fact that root xylem sap cytokinin concentrations are reduced in rms1 and rms5 and elevated inrms2 plants, indicates that Rms1 andRms5 may control a different pathway than that controlled by Rms2. Our studies indicate thatRms1 and Rms5 may regulate a novel graft-transmissible signal involved in the control of branching.
Chloroplast Protein Translocon Components atToc159 and atToc33 Are Not Essential for Chloroplast Biogenesis in Guard Cells and Root Cells
Authors: Yu Tien-Shin , Li Hsou-min
Published: July 2002

Protein import into chloroplasts is mediated by a protein import apparatus located in the chloroplast envelope. Previous results indicate that there may be multiple import complexes in Arabidopsis. To gain further insight into the nature of this multiplicity, we analyzed the Arabidopsis ppi1 and ppi2 mutants, which are null mutants of the atToc33 and atToc159 translocon proteins, respectively. In the ppi2 mutant, in contrast to the extremely defective plastids in mesophyll cells, chloroplasts in guard cells still contained starch granules and thylakoid membranes. The morphology of root plastids in both mutants was similar to that in wild type. After prolonged light treatments, root plastids of both mutants and the wild type differentiated into chloroplasts. Enzymatic assays indicated that the activity of a plastid enzyme was reduced only in leaves but not in roots. These results indicated that both theppi1 and ppi2 mutants had functional root and guard cell plastids. Therefore, we propose that import complexes are cell type specific rather than substrate or plastid specific.
Corrosion behaviour of metals in SO2 environment and its prevention by some volatile corrosion inhibitors
Authors: Subramanian A. , Rajendran P. , Natesan N. , Balakrishnan K. , Vasudevan T.
Published: July 2002

Atmospheric corrosion of mild steel, copper and zinc was studied in SO2 environment under dynamic flow conditions by weight loss measurements, and their corrosion prevention by the use of volatile corrosion inhibitors such as cyclohexylamine (CHA) and dicyclohexylamine (DCHA) is discussed. These studies assume importance as SO2 is one of the dominant pollutants in the atmosphere and more so in industrial belts affecting the stability of metal articles to a greater extent.
Focusing on customers
Authors: Rowley Jennifer
Published: July 2002

Reviews a range of concepts associated with the customer and consumer buying behaviour, with the objective of exploring their applicability in the management and marketing of library and information services. Stresses that an understanding of the customers and the benefits which they seek from an organization is central to the marketing concept and a marketing orientation. An analysis of customers in terms of benefits can inform effective segmentation, which in turn can lead to more efficient targeting of resources. However, customer benefits are only part of the picture. The consumer decision‐making process is important in determining purchase behaviour. Introduces some models of the consumer buying process and an analysis of the factors which determine consumer buying behaviour.
Self‐perception and library anxiety: an empirical study
Authors: Jiao Qun G. , Onwuegbuzie Anthony J.
Published: July 2002

The relationship between seven dimensions of self‐perception and five dimensions of library anxiety was studied using canonical correlation analyses. Participants were 148 students enrolled in graduate‐level research methodology courses. The first canonical function revealed that students with the lowest level of self‐perception associated with perceived scholastic competence, perceived intellectual ability, perceived creativity, and perceived social acceptance tended to have the highest level of library anxiety related to affective barriers and comfort with the library. A comparison of the standardized and structure coefficients suggested that perceived self‐worth, barriers with staff, and mechanical barriers served as suppressor variables that assisted in the prediction of library anxiety. Implications of the findings are discussed.
User education at the Main Library of the University of the West Indies, St Augustine: a historical chronicle
Authors: Clarke Reginald
Published: July 2002

Reviews the development of user education at the Library of the University of the West Indies, St Augustine within the context of arguments for and against user education. Library orientation tours and different approaches to them are described. The development of undergraduate and postgraduate programmes of user eduction is discussed and details of changes of approach over the years are examined. Methods and materials are considered and evaluation of programmes outlined.
Functional foods or nutraceuticals
Authors: Blades Mabel
Published: July 2002

Clarifies the definition of functional foods and outlines some of the better‐known ones now in the marketplace.
The nutritional implications of food wastage in hospital food service management
Authors: Edwards John S.A. , Nash Andrew H.M.
Published: July 2002

While there is considerable anecdotal evidence and some research indicating poor nutritional intake and high levels of food wastage in hospitals, there have been no studies relating these issues to the catering system used. The overall purpose of this study was, therefore, to measure food wastage and nutritional intake in selected hospital catering systems. Data were collected from three types of ward (elderly, medical and surgical) in four hospitals (nine wards), two in London and two in Southern England. Three wards used food cooked mainly in the hospital kitchen, six used cook‐chill and cook‐freeze dishes bought in ready prepared. Five of the wards used a bulk system where food is transported to the ward and plated, in the others, food is plated in the hospital kitchen then transported to the ward. Food sent to the ward, served to patients, and that which remained uneaten or left on the service trolley was weighed for a minimum of 24 hours in each ward; 966 patient‐meal‐days. This data enabled food wastage and nutritional intake to be calculated. Results indicate that food wastage was lower at the breakfast meal, than the midday and evening meal, 23.10 per cent, 39.99 per cent and 42.35 per cent, respectively; female wastage was higher than male, 33.91 per cent and 27.26 per cent, respectively; wastage was higher where food was plated in wards rather than in the kitchen, 57.75 per cent and 35.28 per cent, respectively; and wastage was higher where food was purchased‐in ready prepared, rather than prime cooked in the hospital kitchen. Nutritional intake was calculated for five wards and in all, energy intake was below the recommendations, the highest deficit being 58 per cent. Deficiencies were also noted for other nutrients.
Training and ethnic minority firms: the case of the independent restaurant sector
Authors: Ram Monder , Sanghera Balihar , Abbas Tahir , Barlow Gerald
Published: July 2002

Through the medium of a case study of Birmingham’s ethnic minority‐owned independent restaurant sector, the nature of training in the firms, the reasons for informal training, and employees’ tolerance of harsh working conditions are examined. The reluctance of many small businesses to utilise formal programmes of training is confirmed. However, even in this sector, which is characterised by poor personnel practices, the importance of informal approaches to training and learning is noteworthy. Moreover, from the perspective of workers, employment in the ethnic minority business sector can be seen as a form of training in itself; it can constitute an “apprenticeship” for entrepreneurship rather than permanent entrapment in low‐paid work. However, the capacity to realise this goal is contingent upon the availability of class resources. Further research is needed to explore approaches to training in other sectors that ethnic minorities are engaged in.
Entrepreneurship – a learning process: the experiences of Asian female entrepreneurs and women in business
Authors: Dhaliwal Spinder
Published: July 2002

The growth of Asian enterprises has been a much commented on feature of the small business population. While academic research has sought to identify the key success factors for this entrepreneurial minority, little study has been undertaken of the role female Asian entrepreneurs and Asian women working in “family” businesses play. This article features interview evidence gathered from both Asian women entrepreneurs in their own right and Asian women working in family enterprises, and seeks to provide a clearer picture of the roles, responsibilities and relationships of these two groups. In addition, the study is methodologically novel in so far as the researcher (an Asian female from a “typical” family business background) has taken care to observe the cultural proprieties often noted within this particular group. Hence, the data are arguably more authentic than previous studies undertaken by “distant” researchers.
The critical maintenance issues of the ISO 9000 system: Hong Kong manufacturing industries’ perspective
Authors: Chin Kwai‐Sang , Poon Gary K.K. , Pun Kit‐Fai
Published: July 2002

ISO 9000 is now a widespread quality management practice in Hong Kong manufacturing industries. There is a pressing need to investigate the critical success factors that can help those ISO 9000 registered companies to plan for the continuous maintenance and improvement of their quality systems. With this in mind, the authors have recently conducted a study to identify the critical issues of ISO 9000 maintenance in the Hong Kong electronics manufacturing industry. This paper presents the critical maintenance issues identified during the course of this study, which could facilitate the manufacturers in maintaining their ISO 9000 quality systems. The findings will be of use to the Hong Kong electronics manufacturing industry and will provide a good reference to other industries and other countries as well.
Section 11 Funding
Authors: Matthews Nicola , Roper Vincent
Published: July 2002

Examines briefly provision for ethnic minority groups and the extent to
which they are catered for by the public library service. This includes
a look at the library′s role in creating a multicultural and multiracial
society, with examples of libraries which are currently attempting to
integrate ethnic minorities into the service. Legislation, policy
statements and surveys that have been carried out are examined for their
relevance to current provision. Also examines the contentious issue of
“Section 11” funding, both in the original form and with the new criteria,
why it was originally introduced and the problems that were created,
followed by a look at the new criteria and some of the effects on the
public library service. Problems encountered with the new criteria are
examined as are the reasons why some authorities were more successful
than others in bidding for funds. The conclusions drawn are to the mixed
reactions that the new “Section 11” criteria have provoked, and the great
challenges the library service faces to integrate ethnic minority
provision into the mainstream of public library services.
Emotional dissonance in organizations: conceptualizing the roles of self‐esteem and job‐induced tension
Authors: Abraham Rebecca
Published: July 2002

In the workplace, emotional dissonance is the conflict between emotions experienced by the employee and those required by the organization. Earlier studies have established that emotional dissonance reduces job satisfaction and exacerbates emotional exhaustion. Emotional dissonance typically occurs during interactions between employees and customers in service industries. As Western economies are dominated by service industries, emotional dissonance may result in rising numbers of dissatisfied and burned out employees. This study examined the process by which emotional dissonance operates, and the impact of self‐esteem on emotional dissonance. Emotional dissonance was found to induce job tension leading, in turn, to emotional exhaustion. Employees with innately low self‐esteem were more likely to experience emotional dissonance and suffer from emotional exhaustion. Other employees found that emotional dissonance reduced their self‐esteem leaving them dissatisfied.
Identifying key characteristics of technical project leadership
Authors: Thite Mohan
Published: July 2002

This paper explores the nature and importance of leadership in technical projects. It argues that there is a need to develop a leadership model incorporating the distinguishing personality and occupational characteristics of technical professionals. It tested the applicability of Bass and Avolio’s transformational leadership model in an information systems project environment along with technical leadership scale derived from the technical leadership literature. The results indicated that a combination of transformational and technical leadership behaviours augments the effectiveness of transactional leadership leading to high project success. While recognising that there is no one leadership style that is effective in all project situations, the study recommends an underlying yet flexible style characterised by organisational catalyst, intellectual stimulation, behavioural charisma, and contingent reward behaviours for enhanced leadership effectiveness.
A multi‐agent architecture for intelligent building sensing and control
Authors: Sharples Sue , Callaghan Vic , Clarke Graham
Published: July 2002

We describe a new approach to intelligent building systems, that utilises an intelligent agent approach to autonomously governing the building environment. We discuss the role of learning in building control systems, and contrast this approach with existing IB solutions. We explain the importance of acquiring information from sensors, rather than relying on pre‐programmed models, to determine user needs. We describe how our architecture, consisting of distributed embedded agents, utilises sensory information to learn to perform tasks related to user comfort, energy conservation, safety and monitoring functions. We show how these agents, employing a behaviour‐based approach derived from robotics research, are able to continuously learn and adapt to individuals within a building, while always providing a fast, safe response to any situation. Finally, we show how such a system could be used to provide support for older people, or people with disabilities, allowing them greater independence and quality of life.
Whither FM? A Delphi study of the profession and the industry
Authors: Green Andrew , Price If
Published: July 2002

A project conceived as finding expert common ground on the future evolution of facilities management (FM) revealed, instead, differing perceptions of the FM role rooted in different backgrounds, mind‐sets, and cultures, and held by the business, property, and FM disciplines. We report it in the hope of starting the change process which will allow the changing facilities needs of businesses and clients to be met.
Teleworking – the perception‐reality gap
Authors: Lupton Paul , Haynes Barry
Published: July 2002

Data were collected, by questionnaires, from facilities managers who attended BIFM CPD events. The research compared two main sources, organisations that had introduced teleworking (TWO), and organisations that had not yet introduced teleworking or non‐teleworking organisations (NTWO). The two different data sets allowed comparisons to be made between the perceived issues that related to the introduction of teleworking, i.e. the data from the non‐teleworking organisations, and the actual issues encountered when teleworking was introduced, i.e. the data from the teleworking organisations. The data analysis of the perceived issues versus the actual issues allowed an assessment to be made of the teleworking perception‐reality gap between the non‐teleworking organisations and the teleworking organisations.
Design and facilities management in a time of change
Authors: Duffy Francis
Published: July 2002

The development of facilities management over the last 20 years is reviewed. A parallel and similarly retrospective view is taken of developments in office design. There is some reason to believe that both movements have been a failure for the same reason – an exaggerated notion of the importance of cost cutting leading to the predominance of supplying side values rather than serving the real interests of increasingly demanding views. More optimistically, it is agreed that, if both facilities managers and designers (including architects) were to give proper attention, in a period of particularly rapid change, to user interests, then considerable and beneficial innovation would become possible.
A new definition of intelligent buildings for Asia
Authors: So Albert T.P. , Wong Alvin C.W. , Wong K‐c.
Published: July 2002

Intelligent building (IB) is the future of our building industry. All new commercial buildings and probably luxurious domestic buildings are designed with a common goal – to become intelligent buildings. However, the official definition of IB has not yet been standardised around the world. In the USA, an IB is categorised by four basic elements, namely building structure, building systems, building services and building management. In Europe, the emphasis is on information technology and the genuine need of the user. In Singapore and China, it appears that the term “automation” has been dominating with a great emphasis on high technology. It is our view that a proper definition of IB should be based on users’ needs instead of the image of the building itself. We have therefore developed a new method for defining and specifying IBs. The requirements of users are categorised into eight key modules. All building systems and features are summarised in terms of tens of elements. Selected elements are assigned to a particular key area, i.e. module. Each type of building is then allocated certain key areas for detailed design. Once the areas have been chosen, the elements will automatically be assigned for the consultants to carry out detailed design works. This concept of definition has both advantages of comprehensiveness and flexibility, hoping that it will be useful for the developments of IBs not merely in Asia but also the whole world.
Model of steady rolling contact between layered rolls with thin media in the nip
Authors: Conlon Hinge Kathleen , Maniatty Antoinette M.
Published: July 2002

A finite element model of large deformation, plane strain rolling contact between rubber‐coated rolls with thin media in the nip is developed. The rubber layers on each roll are modeled as incompressible, hyperelastic materials using a Neo‐Hookean model. Steady rolling contact is analyzed using a standard Lagrangian finite element code with a modified friction algorithm which converts the code from a Lagrangian framework to an Eulerian framework. The case of a rigid roll against a layered roll is presented. It is shown how this analysis can be easily extended to the case of two layered rolls with thin media in the nip if the thin media has a much higher elastic modulus than the layers. Simple static indentation models are shown to provide useful information regarding the steady rolling case. Numerical results illustrate the effect of indentation, nominal speed ratio and paper velocity on the velocity and traction distributions in the nip.