bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and application of a PCR‐based ‘molecular tool box’ for the identification of Phytophthora species damaging forests and natural ecosystems
Authors: Schena L. , Duncan J. M. , Cooke D. E. L.
Published: September 2007

A PCR‐based ‘molecular tool box’, based on a region of the ras‐related protein gene Ypt1, was developed for the identification of 15 Phytophthora species that damage forests and trees: P. cactorum, P. cambivora, P. cinnamomi, P. citricola, P. europaea, P. inundata, P. lateralis, P. megasperma, P. nemorosa, P. kernoviae, P. pseudosyringae, P. psychrophila, P. quercina, P. ramorum and P. ilicis. Most primers proved highly specific in blast analyses and in tests with DNA from 72 isolates of 35 species of Phytophthora and nine species representative of Pythium. Exceptions were primers designed for P. cactorum and P. ilicis, which cross‐reacted with P. idaei and P. nemorosa, respectively. Amplification with Phytophthora‐genus‐specific primers before amplification with the various species‐specific primers (nested PCR) increased the sensitivity of detection over amplification with species‐specific primers only: detection limits ranged between 100 and 10 pg target DNA µL−1 in the latter, compared with 100 fg µL−1 in nested PCR. Using existing methods for rapid extraction and purification of DNA, single‐round amplification was appropriate for detection of target Phytophthora species in leaves, but nested PCR was required for soil and water samples. The quarantine pathogens P. ramorum and P. kernoviae were detected in a number of naturally infected leaves collected in England and Wales, whereas P. citricola was commonest in water and soil samples from natural Scottish ecosystems.
Branch cankers on citrus trees in Spain caused by Phytophthora citrophthora
Authors: Alvarez L. A. , Vicent A. , De la Roca E. , Bascón J. , Abad‐Campos P. , Armengol J. , García‐Jiménez J.
Published: September 2007

Considerable losses of citrus trees have been observed in the major citrus‐growing areas of Spain. Samples were collected from 132 orchards, and isolations and pathogencity tests were conducted to determine the aetiology of a serious canker disease. Affected trees showed cankers on the scion that frequently began on the branches. Three Phytophthora species were identified based on their morphological, cultural, physiological and molecular profiles. Phytophthora citrophthora was the main species associated with this new syndrome in 114 orchards. Phytophthora nicotianae (syn. P. parasitica) was isolated from nine orchards as the sole Phytophthora species and in coinfection with P. citrophthora from another nine orchards. Phytophthora citricola was isolated only from one orchard. In stem‐inoculation studies conducted under greenhouse conditions, clementine mandarin cv. Hernandina and sweet orange cv. Navel Late were more susceptible to P. citrophthora than sour orange and Carrizo citrange rootstocks. Clementine cv. Hernandina was also highly susceptible in field inoculation experiments. In agreement with field surveys, clementine mandarin cultivars were the most affected, their rootstocks remaining healthy. Phytophthora citrophthora was found to be the predominant species in orchard soils; however, P. nicotianae was also isolated. This information changes the scenario of diseases caused by Phytophthora spp. in Spain and consequently, the present knowledge of epidemiology and the effectiveness of the current control measures should be reassessed.
Dynamics of soilborne Rhizoctonia solani in the presence of Trichoderma harzianum: effects on stem canker, black scurf and progeny tubers of potato
Authors: Wilson P. S. , Ketola E. O. , Ahvenniemi P. M. , Lehtonen M. J. , Valkonen J. P. T.
Published: September 2007

Stem canker and black scurf are diseases of potato caused by the fungus Rhizoctonia solani. Spatiotemporal experimentation and empirical modelling were applied for the first time to investigate the effect of antagonistic Trichoderma harzianum on the dynamics of soilborne R. solani on individual potato plants. Trichoderma harzianum reduced the severity of symptoms, expressed as ‘rhizoctonia stem lesion index’ (RSI), during the first 7 days post‐inoculation when the inoculum of R. solani was placed at certain distances (30–60 mm) from the host. For example, with inoculum at 40 mm from the host, RSI was 6 and 40 with and without T. harzianum, respectively. At later observation times, the antagonistic effect was overcome. Trichoderma harzianum reduced the severity of black scurf on progeny tubers. Furthermore, the mean number of progeny tubers per potato plant was reduced by the biocontrol treatment (means of 6·5 ± 1·1 and 9·9 ± 2·7 tubers per plant with and without T. harzianum, respectively), as was the proportion of small (0·1–20·0 g) tubers (48% and 66% with and without T. harzianum, respectively). Additionally, there were fewer malformed and green‐coloured tubers in pots treated with T. harzianum than in those without T. harzianum.
Modulation of primary and secondary infections in epidemics of carrot cavity spot through agronomic management practices
Authors: Suffert F. , Delalande D. , Prunier M. , Andrivon D.
Published: September 2007

The relative importance of primary and secondary infections (auto‐ and alloinfections) in the development of a carrot cavity spot (CCS) epidemic caused by Pythium spp. were investigated. Three cropping factors: fungicide application, soil moisture and planting density, were selected as the key variables affecting the disease tetrahedron. Their effects on: (i) disease measurements at a specific time, (ii) the areas under the disease progress curves (AUDPCs) and (iii) a time‐dependent parameter in a pathometric incidence‐severity relationship, were studied. Mefenoxam applications 5 and 9 weeks after sowing reduced the intensity of a field CCS epidemic that involved both primary and secondary infections. In microcosm experiments, mefenoxam reduced secondary infections by Pythium violae obtained by transplanting infected carrot roots and slowed disease progress (1·6 lesions per root in treated versus 5·8 lesions in non‐treated microcosms). A deficit of soil moisture limited the movement of Pythium propagules to host tissue, and thus reduced primary infections in the field; it also promoted the healing of lesions, limiting lesion expansion and the potential for alloinfections (6·8–7·5 lesions per root in irrigated plots compared with 2·4 lesions in non‐irrigated plots). A negative relationship between the mean root‐to‐root distance and the rate of alloinfections was established in microcosms; a reduction in mean planting density was also effective in limiting CCS development (0·5, 1·6 and 2·0 lesions per root in microcosms containing 8, 16 and 31 roots, respectively). An integrated disease management system based on a combination of cultural methods, such as optimized fungicide application, date of harvest versus soil moisture content, and host density versus planting pattern, may make a useful contribute to the control of CCS.
Geographic distribution and genetic diversity of Fusarium graminearum and F. asiaticum on wheat spikes throughout China
Authors: Qu B. , Li H. P. , Zhang J. B. , Xu Y. B. , Huang T. , Wu A. B. , Zhao C. S. , Carter J. , Nicholson P. , Liao Y. C.
Published: September 2007

A large number of Fusarium graminearum and F. asiaticum isolates were collected from wheat spikes from all regions in China with a history of fusarium head blight (FHB) epidemics. Isolates were analysed to investigate their genetic diversity and geographic distribution. Sequence characterized amplified region (SCAR) analyses of 437 isolates resolved both species, with 21% being F. graminearum (SCAR type 1) and 79% being F. asiaticum (SCAR type 5). AFLP profiles clearly resolved two groups, A and B, that were completely congruent with both species. However, more diversity was detected by AFLP, revealing several subgroups within each group. In many cases, even for isolates from the same district, AFLP haplotypes differed markedly. Phylogenetic analyses of multilocus DNA sequence data indicated that all isolates of SCAR type 1, AFLP group A were F. graminearum, whilst isolates of SCAR type 5, AFLP group B were F. asiaticum, demonstrating that it is an efficient method for differentiating these two species. Both species seem to have different geographic distributions within China. Fusarium graminearum was mainly obtained from wheat growing in the cooler regions where the annual average temperature was 15°C or lower. In contrast, the vast majority of F. asiaticum isolates were collected from wheat growing in the warmer regions where the annual average temperature is above 15°C and where FHB epidemics occur most frequently. This is the first report of the distribution of, and genetic diversity within, F. graminearum and F. asiaticum on wheat spikes throughout China.
Mechanisms of Regulatory T‐cell Induction by Antigen‐IgG‐transduced Splenocytes
Authors: Wang R. , Song L. , Han G. , Wang J. , Chen G. , Xu R. , Yu M. , Qian J. , Shen B. , Li Y.
Published: September 2007

Our previous studies have demonstrated that splenocytes, transduced with glutamate decarboxylate 65 (GAD) and IgG fusion construct, protect non‐obese diabetes (NOD) mice from diabetes. However, the mechanism by which this strategy prevents diabetes is not well understood. Here, we found that CD4+Foxp3+Treg cells, in vitro induced by GAD‐IgG‐transduced splenocytes, after transfer, were responsible for prevention of diabetes in NOD mice. Further studies suggested that GAD‐IgG‐transduced B cells could secrete high level of TGF‐β and stimulated CD4+T cells to secrete high level of IFN‐γ. Finally, we found that when TGF‐β and/or IFN‐γ were blocked, CD4+Foxp3−T cells were not converted into CD4+Foxp3+Treg cells. The results suggest that GAD‐IgG‐transduced B cells via TGF‐β and IFN‐γin vitro induce the CD4+Foxp3+Treg cells which are responsible for prevention of diabetes in NOD mice by GAD‐IgG‐gene transfer.
A hydraulic signal in root‐to‐shoot signalling of water shortage
Authors: Christmann Alexander , Weiler Elmar W. , Steudle Ernst , Grill Erwin
Published: September 2007

Photosynthesis and biomass production of plants are controlled by the water status of the soil. Upon soil drying, plants can reduce water consumption by minimizing transpiration through stomata, the closable pores of the leaf. The phytohormone abscisic acid (ABA) mediates stomatal closure, and is the assigned signal for communicating water deficit from the root to the shoot. However, our study does not support ABA as the proposed long‐distance signal. The shoot response to limited soil water supply is not affected by the capacity to generate ABA in the root; however, the response does require ABA biosynthesis and signalling in the shoot. Soil water stress elicits a hydraulic response in the shoot, which precedes ABA signalling and stomatal closure. Attenuation of the hydraulic response in various plants prevented long‐distance signalling of water stress, consistent with root‐to‐shoot communication by a hydraulic signal.
The identification of a gene (Cwp1), silenced during Solanum evolution, which causes cuticle microfissuring and dehydration when expressed in tomato fruit
Authors: Hovav Ran , Chehanovsky Noam , Moy Michal , Jetter Reinhard , Schaffer Arthur A.
Published: September 2007

One of the most intriguing phenomena of fleshy fruit is the ability to maintain high water content at maturity, even following harvest. This is accomplished by a fruit cuticle that is highly impermeable to water diffusion. In this paper, we report on a novel genotype of tomato, developed via introgression from the wild species Solanum habrochaites, which is characterized by microfissuring of the fruit cuticle and dehydration of the mature fruit. The microfissure/dehydration phenotype is inherited as a single gene, termed Cwp1 (cuticular water permeability). The gene was fine mapped, and its identity was determined by map‐based cloning and differential expression analysis in near‐isogenic lines. Causality of the Cwp1 gene was shown by the heterologous transgenic expression of the gene in the cultivated tomato, which caused a microfissured fruit cuticle leading to dehydrated fruit. Cwp1 encodes for a protein of unidentified function in the DUF833 domain family. The gene is expressed in the fruit epidermis of the dehydrating genotype harbouring the wild‐species introgression, but not in the cultivated tomato. It is expressed only in the primitive green‐fruited wild tomato species, but is not expressed in the cultivated Solanum lycopersicum and the closely related Solanum cheesmaniae and Solanum pimpinellifolium, indicating a pre‐adaptive role for Cwp1 silencing in the evolution and domestication of the cultivated tomato.
Nuclear–mitochondrial cross‐talk during heat shock in Arabidopsis cell culture
Authors: Rikhvanov Eugene G. , Gamburg Kim Z. , Varakina Nina N. , Rusaleva Tatyana M. , Fedoseeva Irina V. , Tauson Elena L. , Stupnikova Irina V. , Stepanov Alexey V. , Borovskii Genadii B. , Voinikov Victor K.
Published: September 2007

Apart from energy generation, mitochondria perform a signalling function determining the life and death of a cell under stress exposure. In the present study we have explored patterns of heat‐induced synthesis of Hsp101, Hsp70, Hsp17.6 (class I), Hsp17.6 (class II) and Hsp60, and the development of induced thermotolerance in Arabidopsis thaliana cell culture under conditions of mitochondrial dysfunction. It was shown that treatment by mitochondrial inhibitors and uncouplers at the time of mild heat shock downregulates HSP synthesis, which is important for induced thermotolerance in plants. The exposure to elevated temperature induced an increase in cell oxygen consumption and hyperpolarization of the inner mitochondrial membrane. Taken together, these facts suggest that mitochondrial functions are essential for heat‐induced HSP synthesis and development of induced thermotolerance in A. thaliana cell culture, suggesting that mitochondrial–nuclear cross‐talk is activated under stress conditions. Treatment of Arabidopsis cell culture at 50°C initiates a programmed cell death determined by the time course of viability decrease, DNA fragmentation and cytochrome c release from mitochondria. As treatment at 37°C protected Arabidopsis cells from heat‐induced cell death, it may be suggested that Hsp101, Hsp70 and small heat‐shock proteins, the synthesis of which is induced under these conditions, are playing an anti‐apoptotic role in the plant cell. On the other hand, drastic heat shock upregulated mitochondrial Hsp60 synthesis and induced its release from mitochondria to the cytosol, indicating a pro‐apoptotic role of plant Hsp60.
Mitochondrial type‐I prohibitins of Arabidopsis thaliana are required for supporting proficient meristem development
Authors: Van Aken Olivier , Pečenková Tamara , Van De Cotte Brigitte , De Rycke Riet , Eeckhout Dominique , Fromm Hillel , De Jaeger Geert , Witters Erwin , Beemster Gerrit T. S. , Inzé Dirk , Van Breusegem Frank
Published: September 2007

The Arabidopsis thaliana genome expresses five evolutionarily conserved prohibitin (PHB) genes that are divided into type‐I (AtPHB3 and AtPHB4) and type‐II (AtPHB1, AtPHB2 and AtPHB6) classes, based on their phylogenetic relationships with yeast PHB1 and PHB2, respectively. Yeast and animal PHBs are reported to have diverse roles in the cell cycle, mitochondrial electron transport, aging and apoptosis. All transcribed Arabidopsis PHB genes are primarily expressed in both shoot and root proliferative tissues, where they are present in mitochondrial multimeric complexes. Loss of function of the type‐I AtPHB4 had no phenotypic effects, while loss of function of the homologous AtPHB3 caused mitochondrial swelling, decreased meristematic cell production, increased cell division time and reduced cell expansion rates, leading to severe growth retardation. Double knockout atphb3 atphb4 plants were not viable, but transgenic lines overexpressing AtPHB3 or AtPHB4 showed leaf shape aberrations and an increased shoot branching phenotype. Genome‐wide microarray analysis revealed that both knockout and overexpression perturbations of AtPHB3 and AtPHB4 provoked an altered abundance of mitochondrial and stress‐related transcripts. We propose that plant type‐I PHBs take part in protein complexes that are necessary for proficient mitochondrial function or biogenesis, thereby supporting cell division and differentiation in apical tissues.
Phosphatidylinositol 4,5‐bisphosphate is important for stomatal opening
Authors: Lee Yuree , Kim Yong‐Woo , Jeon Byeon Wook , Park Ki‐Youb , Suh Su Jeoung , Seo Jiyoung , Kwak June M. , Martinoia Enrico , Hwang Inhwan , Lee Youngsook
Published: September 2007

Previously, we demonstrated that a protein that binds phosphatidylinositol 4,5‐bisphosphate [PtdIns(4,5)P2] inhibits both light‐induced stomatal opening and ABA‐induced stomatal closing. The latter effect is due to a reduction in free PtdIns(4,5)P2, decreasing production of inositol 1,4,5‐trisphosphate and phosphatidic acid by phospholipases C and D. However, it is less clear how PtdIns(4,5)P2 modulates stomatal opening. We found that in response to white light irradiation, the PtdIns(4,5)P2‐binding domain GFP:PLCδ1PH translocated from the cytosol into the plasma membrane. This suggests that the level of PtdIns(4,5)P2 increases at the plasma membrane upon illumination. Exogenously administered PtdIns(4,5)P2 substituted for light stimuli, inducing stomatal opening and swelling of guard cell protoplasts. To identify PtdIns(4,5)P2 targets we performed patch‐clamp experiments, and found that anion channel activity was inhibited by PtdIns(4,5)P2. Genetic analyses using an Arabidopsis PIP5K4 mutant further supported the role of PtdIns(4,5)P2 in stomatal opening. The reduced stomatal opening movements exhibited by a mutant of Arabidopsis PIP5K4 (At3g56960) was countered by exogenous application of PtdIns(4,5)P2. The phenotype of reduced stomatal opening in the pip5k4 mutant was recovered in lines complemented with the full‐length PIP5K4. Together, these data suggest that PIP5K4 produces PtdIns(4,5)P2 in irradiated guard cells, inhibiting anion channels to allow full stomatal opening.
A novel serine/proline‐rich domain in combination with a transmembrane domain is required for the insertion of AtTic40 into the inner envelope membrane of chloroplasts
Authors: Tripp Joanna , Inoue Kentaro , Keegstra Kenneth , Froehlich John E.
Published: September 2007

AtTic40 is part of the chloroplastic protein import apparatus that is anchored in the inner envelope membrane by a single N‐terminal transmembrane domain, and has a topology in which the bulk of the C‐terminal domain is oriented toward the stroma. The targeting of AtTic40 to the inner envelope membrane involves two steps. Using an in vitro import assay, we showed that the sorting of AtTic40 requires a bipartite transit peptide, which was first cleaved by the stromal processing peptidase (SPP), thus generating a soluble AtTic40 stromal intermediate (iAtTic40). iAtTic40 was further processed by a second unknown peptidase, which generates its mature form (mAtTic40). Using deletion mutants, we identified a sequence motif N‐terminal of the transmembrane domain that was essential for reinsertion of iAtTic40 into the inner envelope membrane. We have designated this region a serine/proline‐rich (S/P‐rich) domain and present a model describing its role in the targeting of AtTic40 to the inner envelope membrane.
Silencing of DELLA induces facultative parthenocarpy in tomato fruits
Authors: Martí Cristina , Orzáez Diego , Ellul Philippe , Moreno Vicente , Carbonell Juan , Granell Antonio
Published: September 2007

DELLA proteins are plant nuclear factors that restrain growth and proliferation in response to hormonal signals. The effects of the manipulation of the DELLA pathway in the making of a berry‐like fruit were investigated. The expression of the Arabidopsis thaliana gain‐of‐function DELLA allele Atgai del in tomato (Solanum lycopersicum L.) produced partially sterile dwarf plants and compacted influorescences, as expected for a constitutively activated growth repressor. In contrast, antisense silencing of the single endogenous tomato DELLA gene homologue (SlDELLA) produced slender‐like plants with elongated flower trusses. Interestingly, the depletion of SlDELLA in tomato was sufficient to overcome the growth arrest normally imposed on the ovary at anthesis, resulting in parthenocarpic fruits in the absence of pollination. Antisense SlDELLA‐engineered fruits were smaller in size and elongated in shape compared with wild type. Cell number estimations showed that fruit set, resulting from reduced SlDELLA expression, arose from activated cell elongation at the longitudinal and lateral axes of the fruit pericarp, bypassing phase‐II (post‐pollination) cell divisions. Parthenocarpy caused by SlDELLA depletion is facultative, as hand pollination restored wild‐type fruit phenotype. This indicates that fertilization‐associated SlDELLA‐independent signals are operational in ovary–fruit transitions. SlDELLA was also found to restrain growth in other reproductive structures, affecting style elongation, stylar hair primordial growth and stigma development.
Overexpression of a chromatin architecture‐controlling AT‐hook protein extends leaf longevity and increases the post‐harvest storage life of plants
Authors: Lim Pyung Ok , Kim Yumi , Breeze Emily , Koo Ja Choon , Woo Hye Ryun , Ryu Jong Sang , Park Don Ha , Beynon Jim , Tabrett Alex , Buchanan‐Wollaston Vicky , Nam Hong Gil
Published: September 2007

Leaf senescence is the final stage of leaf development and is finely regulated via a complex genetic regulatory network incorporating both developmental and environmental factors. In an effort to identify negative regulators of leaf senescence, we screened activation‐tagged Arabidopsis lines for mutants that exhibit a delayed leaf senescence phenotype. One of the mutants (ore7‐1D) showed a highly significant delay of leaf senescence in the heterozygous state, leading to at least a twofold increase in leaf longevity. The activated gene (ORE7/ESC) encoded a protein with an AT‐hook DNA‐binding motif; such proteins are known to co‐regulate transcription of genes through modification of chromatin architecture. We showed that ORE7/ESC, in addition to binding to a plant AT‐rich DNA fragment, could also modify the chromatin architecture, as illustrated by an altered distribution of a histone–GFP fusion protein in the nucleus of the mutant. Globally altered gene expression, shown by microarray analysis, also indicated that activation of ORE7/ESC results in a younger condition in the mutant leaves. We propose that ectopically expressed ORE7/ESC is negatively regulating leaf senescence and suggest that the resulting chromatin alteration may have a role in controlling leaf longevity. Interestingly, activation of ORE7/ESC also led to a highly extended post‐harvest storage life.
Duplicated P5CS genes of Arabidopsis play distinct roles in stress regulation and developmental control of proline biosynthesis
Authors: Székely Gyöngyi , Ábrahám Edit , Cséplő Ágnes , Rigó Gábor , Zsigmond Laura , Csiszár Jolán , Ayaydin Ferhan , Strizhov Nicolai , Jásik Jan , Schmelzer Elmon , Koncz Csaba , Szabados László
Published: September 2007

Δ‐1‐pyrroline‐5‐carboxylate synthetase enzymes, which catalyse the rate‐limiting step of proline biosynthesis, are encoded by two closely related P5CS genes in Arabidopsis. Transcription of the P5CS genes is differentially regulated by drought, salinity and abscisic acid, suggesting that these genes play specific roles in the control of proline biosynthesis. Here we describe the genetic characterization of p5cs insertion mutants, which indicates that P5CS1 is required for proline accumulation under osmotic stress. Knockout mutations of P5CS1 result in the reduction of stress‐induced proline synthesis, hypersensitivity to salt stress, and accumulation of reactive oxygen species. By contrast, p5cs2 mutations cause embryo abortion during late stages of seed development. The desiccation sensitivity of p5cs2 embryos does not reflect differential control of transcription, as both P5CS mRNAs are detectable throughout embryonic development. Cellular localization studies with P5CS–GFP gene fusions indicate that P5CS1 is sequestered into subcellular bodies in embryonic cells, where P5CS2 is dominantly cytoplasmic. Although proline feeding rescues the viability of mutant embryos, p5cs2 seedlings undergo aberrant development and fail to produce fertile plants even when grown on proline. In seedlings, specific expression of P5CS2–GFP is seen in leaf primordia where P5CS1–GFP levels are very low, and P5CS2–GFP also shows a distinct cell‐type‐specific and subcellular localization pattern compared to P5CS1–GFP in root tips, leaves and flower organs. These data demonstrate that the Arabidopsis P5CS enzymes perform non‐redundant functions, and that P5CS1 is insufficient for compensation of developmental defects caused by inactivation of P5CS2.
Antagonistic selection between adult thorax and wing size in field released Drosophila melanogaster independent of thermal conditions
Authors: HOFFMANN A. A. , RATNA E. , SGRÒ C. M. , BARTON M. , BLACKET M. , HALLAS R. , DE GARIS S. , WEEKS A. R.
Published: September 2007

Attempts to explain size variation in Drosophila and other small insects often focus on the larval stage and association between development time and size, but patterns are also influenced by direct selection on size‐related traits in the adults. Here we use multiple field releases of Drosophila melanogaster to test the association between size and one component of field fitness, the ability of Drosophila to locate resources for feeding and breeding. We find antagonistic selection between wing length and thorax length in both males and females, such that capture at baits is higher for flies with relatively larger thorax lengths and smaller wings. However flies with large wings relative to thoraces disperse further as reflected in the longer distances moved to baits. These patterns did not depend strongly on weather conditions, suggesting that selection on adult size is at least partly independent of temperature. Antagonistic selection between size traits can generate changes in size along gradients if the distribution of resources in the environment varies and selects for different dispersal patterns, particularly as dispersal is relatively higher under warmer conditions.
Out‐of‐Africa origin and dispersal‐mediated diversification of the butterfly genus Junonia (Nymphalidae: Nymphalinae)
Authors: KODANDARAMAIAH U. , WAHLBERG N.
Published: September 2007

The relative importance of dispersal and vicariance in the diversification of taxa has been much debated. Within butterflies, a few studies published so far have demonstrated vicariant patterns at the global level. We studied the historical biogeography of the genus Junonia (Nymphalidae: Nymphalinae) at the intercontinental level based on a molecular phylogeny. The genus is distributed over all major biogeographical regions of the world except the Palaearctic. We found dispersal to be the dominant process in the diversification of the genus. The genus originated and started diversifying in Africa about 20 Ma and soon after dispersed into Asia possibly through the Arabian Peninsula. From Asia, there were dispersals into Africa and Australasia, all around 5 Ma. The origin of the New World species is ambiguous; the ancestral may have dispersed from Asia via the Beringian Strait or from Africa over the Atlantic, about 3 Ma. We found no evidence for vicariance at the intercontinental scale. We argue that dispersal is as important as vicariance, if not more, in the global diversification of butterflies.
Ecological selection against hybrids in natural populations of sympatric threespine sticklebacks
Authors: GOW J. L. , PEICHEL C. L. , TAYLOR E. B.
Published: September 2007

Experimental work has provided evidence for extrinsic post‐zygotic isolation, a phenomenon unique to ecological speciation. The role that ecological components to reduced hybrid fitness play in promoting speciation and maintaining species integrity in the wild, however, is not as well understood. We addressed this problem by testing for selection against naturally occurring hybrids in two sympatric species pairs of benthic and limnetic threespine sticklebacks (Gasterosteus aculeatus). If post‐zygotic isolation is a significant reproductive barrier, the relative frequency of hybrids within a population should decline significantly across the life‐cycle. Such a trend in a natural population would give independent support to experimental evidence for extrinsic, rather than intrinsic, post‐zygotic isolation in this system. Indeed, tracing mean individual hybridity (genetic intermediateness) across three life‐history stages spanning four generations revealed just such a decline. This provides compelling evidence that extrinsic selection plays an important role in maintaining species divergence and supports a role for ecological speciation in sticklebacks.
The dynamics of sexual conflict over mating rate with endosymbiont infection that affects reproductive phenotypes
Authors: HAYASHI T. I. , MARSHALL J. L. , GAVRILETS S.
Published: September 2007

Maternally inherited endosymbionts have been implicated as significant drivers of sexual conflict within their hosts, typically through sex‐ratio manipulation. Empirical studies show that some of these endosymbionts have the potential to influence sexual conflict not by sex‐ratio distortion, but by altering reproductive traits within their hosts. Research has already shown that reproductive traits involved in mating/fertilization process are integral ‘players’ in sexual conflict, thus suggesting the novel hypothesis that endosymbiont‐induced changes in reproductive phenotypes can impact the dynamics of sexual conflict. Here, we use a standard quantitative genetic approach to model the effects of endosymbiont‐induced changes in a female reproductive trait on the dynamics of sexual conflict over mating/fertilization rate. Our model shows that an endosymbiont‐induced alteration of a host female reproductive trait that affects mating rate can maintain the endosymbiont infection within the host population, and does so in the absence of sex‐ratio distortion and cytoplasmic incompatibility.
Growth and Anti‐Oxidative Systems Changes in Elymus dahuricus is Affected by Neotyphodium Endophyte Under Contrasting Water Availability
Authors: Zhang Y. P. , Nan Z. B.
Published: September 2007

Although the relationship between fungal endophyte and agronomic grass (Lolium perenne and Festuca arundinacea) in drought tolerance are well documented, the mechanisms responsible for wild grass are not well understood. In this study, we determined the biomass production and growth parameters endophyte infected (E+) and endophyte uninfected (E−) Elymus dahuricus plants under high water (HW) and low water (LW) treatment for 8 weeks in a controlled‐environment condition experiment. We also determined the changes in the activities of the anti‐oxidative enzymes superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX) and content of H2O2, as well as levels of proline and chlorophyll a + b were examined in the leaves of E+ and E− plants. Under low water treatment, E+ plants produced more biomass and had higher values in plant height and tiller numbers, but no influence by the fungus were observed in high water treatment. Anti‐oxidative enzyme (include SOD, POD, CAT and APX) activities and contents of proline and chlorophyll a + b increased and H2O2 concentration declined in the E+ plants compared with E− plants under low water treatment. Therefore, endophyte infection was a benefit to growth and anti‐oxidative affection E. dahuricus under low water treatment.
Effect of Prohexadione Calcium on Growth Components and Endogenous Gibberellins Contents of Rice (Oryza sativa L.)
Authors: Kim H.Y. , Lee I.J. , Hamayun M. , Kim J.T. , Won J.G. , Hwang I.C. , Kim K.U.
Published: September 2007

Prohexadione calcium (Pro‐Ca) is a novel plant growth regulator that inhibits the late stages of gibberellins (GAs) biosynthesis in plants, thus reducing the vegetative growth of the plant. Pro‐Ca was applied to field‐grown rice cultivar Ilpumbyeo to evaluate its effect on growth and yield components and endogenous GAs, when applied at different rates and timings. This study illustrated that Pro‐Ca application decreased the internode length, stem length, panicle length, shoots fresh weight and stem lodging index, while stem breaking force was increased in all treatments. The effect of Pro‐Ca was more pronounced in 20 ppm concentration than 10 ppm. The number of panicles m−2, ripened grain ratio and 1000 grain weight and milled rice yield parameters, increased with the application of Pro‐Ca, though the number of grains per panicle decreased insignificantly. The endogenous bioactive GA1 contents significantly decreased with the application of Pro‐Ca, as the GA biosynthesis was interrupted at later stages, when GA20 conversion to GA1 was blocked, thus drastically reducing GA1 and GA8 levels, but only insignificant changes were observed for intermediates from GA12 to GA20. The levels of the endogenous GAs in rice shoots were measured by GC‐MS‐SIM using 2H2‐labelled GAs as internal standards. Present results also illustrated that early application of Pro‐Ca was more effective than its late application for effective control of different growth parameters and thus reducing lodging in rice plants.
Relationship between Carbon Isotope Discrimination and Grain Yield in Spring Wheat under Different Water Regimes and under Saline Conditions in the Ningxia Province (North‐west China)
Authors: Xu X. , Yuan H. , Li S. , Monneveux P.
Published: September 2007

The relationship between grain yield and carbon isotope discrimination (Δ) was analysed in wheat grown under different water regimes in the Ningxia Province (north‐west of China). When the association was significant, the relationships between grain yield, Δ and other drought tolerance related traits, such as leaf ash content (ma), chlorophyll concentration (Chl), relative water content (RWC), stomatal conductance (gS) and the ratio of internal CO2 leaf concentration to ambient CO2 concentration (Ci/Ca), were also examined. Using correlation analysis, the relationships were determined during two consecutive years in a set of 20 spring wheat cultivars (landraces, improved varieties and advanced lines) under rainfed and irrigated conditions, including saline conditions. The relationship between Δ and yield within environments highly depended on the quantity of water stored in the soil at sowing, the quantity and distribution of rainfall during the growth cycle, and the irrigation before anthesis. Δ predicted grain yield under limited irrigation (post‐anthesis water stress) but not under pre‐anthesis water stress (rainfed conditions), fully irrigated and saline conditions. Under limited irrigation, grain Δ correlated significantly to grain yield leaf ma at heading and maturity. It also significantly positively correlated to Chl, RWC, gS and Ci/Ca assessed at anthesis. A precise characterization of the timing and intensity of the abiotic constraints experienced by the crop is consequently needed before implementing the use of Δ in wheat breeding programmes.
The Effects of Bacillus pumilus, Isolated from Wheat Rhizosphere, on Resistance in Wheat Seedling Roots against the Take‐all Fungus, Gaeumannomyces graminis var. tritici
Authors: Sari E. , Etebarian H. R. , Aminian H.
Published: September 2007

The aim of this study was to verify that induced resistance was another mechanism through which Bacillus pumilus 7 km can suppress Gaeumannomyces graminis (Sacc.) Von Arx and Oliver var. tritici Walker (Ggt). Also, plant growth‐promotion activity of B. pumilus 7 km and its effect on disease severity of take‐all were evaluated. Soil was drenched with B. pumilus 7 km and disease severity, root and shoot fresh weights and root and shoot heights were evaluated. The activities of soluble peroxidase (SPOX), ionically cell wall‐bound peroxidase (CWPOX), β‐1,3‐glucanase, β‐1,4‐glucanase and the contents of total phenolic compounds were also determined. The results indicated that disease severity in the bacterized roots was significantly less than the pathogen control roots. Also this isolate promoted root height, root and shoot fresh weights, compared with the healthy control plants. Wheat plants treated with B. pumilus 7 km showed increased presence of SPOX, CWPOX, β‐1,3‐glucanase, β‐1,4‐glucanase and phenolic compounds in bacterized roots challenged with the pathogen. In this treatment, maximum SPOX, β‐1,3‐glucanase and β‐1,4‐glucanase activities on day 4 and CWPOX activity on day 8 were recorded. Also, maximum total phenolic concentration on day 6 was recorded. The results suggest that the inhibitory effect of B. pumilus 7 km on the take‐all may be related to its ability to enhance defense responses in the wheat roots.
Capacity building: A concept analysis of the term applied to research
Authors: Condell Sarah L , Begley Cecily
Published: September 2007

Recent policy developments in Ireland have led to a focus on research capacity building as a means of consolidating nurse and midwifery education in the Irish academic setting. This follows similar initiatives in the United Kingdom and Australia. However, sparse literature and a lack of clarity of the term ‘research capacity building’ leads to some confusion. A concept analysis using Rodgers' framework was conducted. The literature examined included ‘grey’ literature, policy documents and indexed papers across a range of disciplines, derived from CINAHL/PubMed searches. The concept of research capacity building was deemed to imply a funded, dynamic intervention operationalized through a range of foci and levels to augment ability to achieve objectives in the research field over the long‐term, with aspects of social change as an ultimate outcome. This is presented as an interim statement because of the evolutionary nature of the concept and the limitations of the exercise.
‘I think PCA is great, but . . .’—Surgical nurses' perceptions of patient‐controlled analgesia
Authors: King Sue , Walsh Kenneth
Published: September 2007

This qualitative study investigated surgical nurses' perceptions of patient‐controlled analgesia as a strategy for managing acute pain in a tertiary care hospital. Patient‐controlled analgesia is commonly used and nurses play an essential role in caring for patients prescribed it. The study was divided into two parts. First, audiotaped semistructured interviews were conducted with 10 nurses. The interviews were followed by a postal questionnaire to 336 nurses with 171 returned. Thematic analysis was the chosen methodology. The audiotaped transcripts and questionnaires surfaced five themes, with the dominant one being ‘I think PCA is great, but . . .’. The paper outlines and explores these themes and addresses the implications arising from the research for both clinical practice and education.
Effect of computer game intervention on the attention capacity of mentally retarded children
Authors: Rezaiyan Akram , Mohammadi Eesa , Fallah Parviz A
Published: September 2007

The low rate of understanding and the limited domain of attention are two important and distinctive characteristics of mental retardation. One of the important strategies to provide effective education for these subjects is to lessen the backgrounds and impacts of these affective factors. The aim of this research was to find the effect of computer games program on the amount of mentally retarded persons' attention. Sixty educable male mentally retarded subjects were selected from two 24‐h care centres in Tehran. The Toulouse–Pieron Scale was used to determinate the subjects' attention at pre–post test. Members of the experimental group were subjected to 35 sets of computer games. After use of the sets of computer games, the attention scores of the subjects were assessed immediately after the intervention and 5 weeks later. The results showed that exactly after the intervention the average attention scores of the experimental group were significantly higher than those of the control group. But, 5 weeks after the intervention, there was actually no significant difference.
Jordanian women's postpartum beliefs: An exploratory study
Authors: Jarrah Samiha , Bond A Elaine
Published: September 2007

This study was aimed to determine the beliefs among Jordanian women regarding 10 selected postpartum behaviours. Following Human Subjects approval, a descriptive quantitative questionnaire was administered to 40 postpartum women, 20 from two rural communities and 20 from two urban communities. The majority believed, incorrectly, in prolonged bed rest, that the baby's exhalation on the mother's breast can lead to infection, that kofaleyas (tightly secured wraps around the baby) do not harm newborns, that observation by others while nursing might ‘steal’ the mother's milk, and that a belt around the mother's abdomen will tighten muscles. The majority correctly believed that dieting affects breast‐feeding. Most postpartum women could benefit from increased education about postpartum practices. Educational programmes can help women differentiate between helpful postpartum practices and those which might have adverse effects on the health of a mother and her newborn.
Planning primary health‐care services for South Australian young offenders: A preliminary study
Authors: Wilson Anne
Published: September 2007

Although many young offenders receive health care during periods of detention, addressing their health needs after release from secure care is a key strategy for successful rehabilitation and reintegration into the community. The purpose of this preliminary study was to examine current discharge planning practices for young offenders in Youth Training Centres in South Australia with a view to improving offenders' connection with primary health‐care services on discharge. To determine the strengths and weaknesses of current discharge planning practices, this exploratory study involved in‐depth review of literature and a semistructured focus group of stakeholders. Findings were discussed with an expert advisory group before final recommendations were made. This study identified a service model approach to discharge planning that recommended a nurse located within the Divisions of General Practice as the coordinator. The study found that trusted staff in detention centres, with an awareness of services available in the location of release, influence young offenders' decision‐making in relation to health‐care services. Awareness and recognition of young offenders' health beyond periods of juvenile detention and into their adult lives is valuable in that it has the potential to establish lifelong healthy behaviours. Bonding with young offenders and gaining their trust increases their likelihood of attending primary health‐care services.
Cooperation with school nurses described by Finnish sixth graders
Authors: Mäenpää Tiina , Paavilainen Eija , Åstedt‐Kurki Päivi
Published: September 2007

This paper deals with research on cooperation with the school nurse described by sixth graders. The data were collected via six focus group interviews in 2003–2004. Twenty‐two sixth graders (aged 11–12 years) participated in the research. The data were analysed by the constant comparison method based on grounded theory. The analysis yielded a number of concepts that describe the basis of the cooperation: the trusted expertise of the school nurse, informative interaction with the family and knowing the family situation. The cooperation consisted of supporting the pupil's growth and development, need for individual counselling and supporting coping at school. The cooperation was characterized by an open atmosphere and friendliness, a low level of reciprocity, the school nurse's stereotyped activities and respect for the pupil's privacy. Pupils' experiences and perspectives can be used to develop more holistic strategies for the school health service.
Muslims in Australian hospitals: The clash of cultures
Authors: Mohammadi Nooredin , Evans David , Jones Tina
Published: September 2007

The objective of this paper is to review the multicultural nature of Australian society, with a specific focus on the Islamic culture. Islamic principles will be presented and the impact this has on the health‐care provision of Muslim people will be explored. This paper highlights issues that Muslim patients face when hospitalized in Australia. Australia has seen a major shift in its society, from English‐speaking European to one that boasts enormous cultural diversity. However, this cultural diversity poses a number of challenges for a Western‐based health‐care service based on differing needs and expectations. This challenge is perhaps most evident during times of illness, when the Muslim patient must attempt to adhere to the principles of their faith in the non‐Islamic environment of the Australian hospital. The differences discussed in this paper serve to highlight the importance of having strategies that identify the needs and expectations of culturally diverse consumers of the hospital system.
Enhancing nurses' capacity to facilitate learning in nursing students: Effective dissemination and uptake of best practice guidelines
Authors: Eaton Emma , Henderson Amanda , Winch Sarah
Published: September 2007

The preparation of nursing students for the real world of practice is a significant contemporary issue for health care and education institutions globally. Positive learning experiences are enabled through positive role models and attitudes which impact on ward culture. Although these best practices have been described, they have not been assimilated into the health‐care system as the uptake of evidence is fraught with difficulties. Using the problem‐solving approach of fitting evidence into practice––Read, Think, Do, this paper describes practical activities throughout the process to assimilate evidence. In particular, it details effective strategies that take into account the clinical context, such as displaying posters, demonstration of problem resolution in small group sessions and role modelling, and a presence in the clinical area. All of these contribute to the uptake of the guidelines to improve student experiences within the clinical setting.
Hypoxia‐inducible factor 1α may be a marker for vasculitic neuropathy
Authors: Oka Nobuyuki , Kawasaki Teruaki , Mizutani Kotaro , Sugiyama Hiroshi , Akiguchi Ichiro
Published: September 2007

Neuromuscular biopsy is still an essential method for diagnosing vasculitic neuropathy, although its diagnostic sensitivity is at most 60%. Our objective was to examine the expression of hypoxia‐inducible factor 1α (HIF‐1α) in peripheral nerves and to evaluate its usefulness in diagnosing vasculitic neuropathy, especially for discrimination from other axonal neuropathies. Forty‐one patients with vasculitic neuropathy consisting of 20 definite, 14 probable and seven possible diagnoses, 15 patients with metabolic neuropathy, five with motor neuron disease and six with chronic inflammatory demyelinating polyneuropathy were included. Nerve biopsy specimens were immunohistochemically examined for HIF‐1α and various cell markers. Distinct immunoreactivity (IR) was observed in nuclei of endoneurial cells in 54% (22/41) of vasculitic patients, while specimens from metabolic neuropathies showed less nuclear IR and the difference of mean density of HIF‐1α‐positive nuclei was significant. Two patients with possible vasculitis who showed HIF‐1α‐positive nuclei in endoneurium, were later confirmed to have vasculitis by skin biopsies. Most of the cells expressing HIF were demonstrated to be Schwann cells. There was a trend in the vasculitic patients with early phase nerve damage to display higher endoneurial HIF‐1α‐IR. HIF‐1α may be an immunohistochemical marker for vasculitic neuropathy, especially when the observed section contains no vasculitic lesions.