bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biolistic delivery of Ca2+ dyes into plant and algal cells
Authors: Bothwell John H.F. , Brownlee Colin , Hetherington Alistair M. , Ng Carl K.‐Y. , Wheeler Glen L. , McAinsh Martin R. 
Published: March 2006

SummaryIn eukaryotes, changes in cytosolic Ca2+ concentrations ([Ca2+]cyt) are associated with a number of environmental and developmental stimuli. However, measuring [Ca2+]cyt changes in single plant or algal cells is often problematic. Although a wide range of Ca2+‐sensitive fluorescent dyes is available, they are often difficult to introduce into plant cells. Micro‐injection is the most robust method for dye loading, but is time‐consuming, technically demanding, and unsuitable in many cell types. To overcome these problems, we have adapted biolistic techniques to load Ca2+‐sensitive dyes into guard cells of the flowering plant, Commelina communis, cells of the green alga Chlamydomonas reinhardtii, and zygotes of the brown alga, Fucus serratus. Using this approach, we have been able to monitor [Ca2+]cyt changes in response to various stimuli, including a novel [Ca2+]cyt response in C. reinhardtii. The method allows the use of free acid and dextran‐conjugated dyes. Biolistic loading of differentiated plant cells is easier, quicker, and more widely applicable than micro‐injection, and should broaden the study of plant signal transduction.
An Arabidopsis cell wall‐associated kinase required for invertase activity and cell growth
Authors: Kohorn Bruce D. , Kobayashi Masaru , Johansen Sue , Riese Jeff , Huang Li‐Fen , Koch Karen , Fu Sarita , Dotson Anjali , Byers Nicole 
Published: March 2006

SummaryThe wall‐associated kinases (WAK), a family of five proteins that contain extracellular domains that can be linked to pectin molecules of the cell wall, span the plasma membrane and have a cytoplasmic serine/threonine kinase domain. Previous work has shown that a reduction in WAK protein levels leads to a loss of cell expansion, indicating that these receptor‐like proteins have a role in cell shape formation. Here it is shown that a single wak2 mutation exhibits a dependence on sugars and salts for seedling growth. This mutation also reduces the expression and activity of vacuolar invertase, often a key factor in turgor and expansion. WAKs may thus provide a molecular mechanism linking cell wall sensing (via pectin attachment) to regulation of solute metabolism, which in turn is known to be involved in turgor maintenance in growing cells.
Use of the glucosyltransferase UGT71B6 to disturb abscisic acid homeostasis in Arabidopsis thaliana
Authors: Priest David M. , Ambrose Stephen J. , Vaistij Fabián E. , Elias Luisa , Higgins Gillian S. , Ross Andrew R. S. , Abrams Suzanne R. , Bowles Dianna J. 
Published: March 2006

SummaryA glucosyltransferase (GT) of Arabidopsis, UGT71B6, recognizing the naturally occurring enantiomer of abscisic acid (ABA) in vitro, has been used to disturb ABA homeostasis in planta. Transgenic plants constitutively overexpressing UGT71B6 (71B6‐OE) have been analysed for changes in ABA and the related ABA metabolites abscisic acid glucose ester (ABA‐GE), phaseic acid (PA), dihydrophaseic acid (DPA), 7′‐hydroxyABA and neo‐phaseic acid. Overexpression of the GT led to massive accumulation of ABA‐GE and reduced levels of the oxidative metabolites PA and DPA, but had marginal effect on levels of free ABA. The control of ABA homeostasis, as reflected in levels of the different metabolites, differed in the 71B6‐OEs whether the plants were grown under standard conditions or subjected to wilt stress. The impact of increased glucosylation of ABA on ABA‐related phenotypes has also been assessed. Increased glucosylation of ABA led to phenotypic changes in post‐germinative growth. The use of two structural analogues of ABA, known to have biological activity but to differ in their capacity to act as substrates for 71B6 in vitro, confirmed that the phenotypic changes arose specifically from the increased glucosylation caused by overexpression of 71B6. The phenotype and profile of ABA and related metabolites in a knockout line of 71B6, relative to wild type, has been assessed during Arabidopsis development and following stress treatments. The lack of major changes in these parameters is discussed in the context of functional redundancy of the multigene family of GTs in Arabidopsis.
Beta diversity of tropical marine benthic assemblages in the Spermonde Archipelago, Indonesia
Authors: Becking Leontine E. , Cleary Daniel F. R. , de Voogd Nicole J. , Renema Willem , de Beer Manon , van Soest Rob W. M. , Hoeksema Bert W. 
Published: March 2006

AbstractIn order to preserve diversity it is essential to understand how assemblages change across space. Despite this fact, we still know very little about how marine diversity is spatially distributed, especially among lesser‐studied invertebrate taxa. In the present study beta‐diversity patterns of sea urchins, sponges, mushroom corals and larger foraminifera were assessed in the Spermonde Archipelago (Indonesia). Using ordinations we showed that the inshore zone (<5 km offshore), midshore zone (5 < x < 30 km offshore) and distance offshore zone (>30 km offshore) all contained distinct assemblages of sponges and corals, while only foraminifera assemblages from the inshore (<5 km offshore) zone were distinct. There was a significant spatial pattern of community similarity for all taxa surveyed, but this pattern proved to be wholly related to environmental variables for sponges and foraminifera, and primarily for mushroom corals and sea urchins. The lack of a pure spatial component suggests that these taxa may not be dispersal limited within the spatial scales of this study (c. 1600 km2). The analyses of the corals and foraminifera were additionally tested at two spatial scales of sampling. Both taxa were primarily associated with local‐scale environmental variables at the local scale and larger‐scale variables at the larger scale. Mean inter‐plot similarity was also higher and variation lower at the larger scale. The results suggest that substantial variation in similarity can be predicted using simple locally assessed environmental variables combined with remotely sensed parameters.
Sharksucker–shark interaction in two carcharhinid species
Authors: Brunnschweiler Juerg M. 
Published: March 2006

AbstractIt is not known whether sharksuckers have positive or negative effects on their hosts, partly because this association is difficult to study in free‐ranging fish. I observed the behaviour of sharks with and without sharksuckers, to determine whether the hosts actively avoid sharksuckers. Wild blacktip sharks, Carcharhinus limbatus, took evasive actions when sharksuckers, Echeneis naucrates, attached to them, presumably to escape from skin irritation or hydrodynamical drag caused by the sharksuckers. Sharksuckers were most often attached to the belly or back of the shark, and sharks reacted most strongly to sharksuckers on their heads, sides, and dorsal fins. Observations of two captive bull sharks, Carcharhinus leucas, indicated that swimming speed increased when sharksuckers were attached. This paper supports the hypothesis that sharksucker attachment irritates sharks, and that the relationship between the two is best viewed as a subtle host–parasite interaction.
ENSO as a natural experiment to understand environmental control of meiofaunal community structure
Authors: Sellanes Javier , Neira Carlos 
Published: March 2006

AbstractThe sediments of the Bay of Concepción and the adjacent shelf underlie one of the most productive upwelling areas in the SE Pacific margin. Reports on factors controlling meiofaunal community structure in these kinds of organic‐rich and oxygen‐deficient habitats are scarce in the literature. In this study, five sites along a transect from the mid‐Bay of Concepción (27 m) to the outer shelf (120 m) were studied on fives dates (May, August, November 1997, and March and May 1998) in order to assess the dynamic relationships between sedimentary organic matter and metazoan meiofauna. The sampling period coincided with the 1997–1998 El Niño event. Sediment parameters investigated were the redox potential discontinuity depth, photosynthetic pigment concentrations (chlorophyll a and phaeopigments), organic carbon, nitrogen, total lipids, carbohydrates, and proteins. In general, lowest values of meiofauna abundance and biomass were found within the naturally eutrophic Bay of Concepción and towards the shelf break, while maximum values occurred at intermediate depths. During the whole period, the meiofaunal abundance was negatively correlated with the concentration of most of the biochemical components of organic matter, as well as with the sediment phaeopigment content. However, positive correlations were found with chlorophyll a derived indices and with bottom‐water oxygen content. Most of the sediment parameters displayed a seasonal cycle, but towards the beginning of 1998, an effect of the 1997–1998 El Niño was evident. Typical austral‐summer (i.e. oxygen‐deficient) conditions did not develop, and sedimentary parameters reflected a decreased input of phytodetritus. Along the transect, the magnitude of this effect on meiofauna varied among sites. An overall positive response, in terms of meiofaunal abundance was observed, probably due to the amelioration of low oxygen conditions in the sediment.
Distribution of macrobenthic assemblages along a marine gradient in Mediterranean eutrophic coastal lagoons
Authors: Rossi Francesco , Castelli Alberto , Lardicci Claudio 
Published: March 2006

AbstractCoastal lagoons can be characterised by strong environmental changes along the outer marine‐inner brackish gradient, which are reflected in the patterns of distribution of organisms and composition of assemblages. Close to the sea the assemblages are dominated by marine animals, while in the innermost confined areas, there would be estuarine taxa and organisms typical of organically‐enriched areas. During the last decades, human impact has been severe in these habitats and has often profoundly altered the distribution of animals and plants along the gradient. In this study we have analysed the distribution of macrofauna along the outer marine‐inner brackish gradient in five Italian lagoons, affected by severe human disturbance on the Adriatic, Tyrrhenian and Sardinian coasts. We aimed to measure changes in the composition of assemblages according to the distance from the sea, consistent among lagoons and time, after the occurrence of eutrophication, repeated distrophic crisis and other human interventions. We considered existing data from campaigns done during 1994, 1995 and 1999. We arranged different datasets according to the available data, in order to measure the spatial distribution of macrofauna genera with distance from the sea and through time. Analyses showed differences among assemblages related to the gradient. Nevertheless, the species characterizing the assemblages were all typical of organically‐enriched areas, which testified to an impoverishment of diversity and functioning of all these systems.
Regional patterns of microsatellite diversity in Ethiopian tetraploid wheat accessions
Authors: Yifru T. , Hammer K. , Huang X. Q. , Röder M. S. 
Published: March 2006

AbstractThis study was conducted to assess regional patterns of diversity of Ethiopian tetraploid wheat accessions and to identify areas of diversity that can be used as source of new germplasm for developing high yielding and stable varieties. A collection of 133 Ethiopian tetraploid wheat accessions and eight introduced cultivars was analysed using 29 wheat microsatellite markers. A total of 383 alleles were detected with an average value of 13.14 alleles per locus. Relatively more alleles were observed in the B genome than in the A genome. Gene diversity indices ranged from 0.08 to 0.95, with a mean value of 0.72. Accessions collected from the same region were pooled and the number of alleles and gene diversity were calculated over the 29 simple sequence repeats for each region. Higher numbers of alleles were detected in the Shewa region (8.72), followed by Tigray (5.86) and Hararghe (5.76). The highest average gene diversity value was found in Shewa (0.65), followed by Gondar (0.64). No significant correlation was observed between geographic distance and genetic distance. Out of 383 different alleles detected, 93 (24.4%) were observed to be region‐specific. Region‐specific alleles were found across all chromosomes except for Xgwm752, Xgwm155 and Xgwm148. Genetic similarity coefficients were estimated for all the possible 55 pairs of regional comparisons and they ranged from 0.16 to 0.52, with a mean value of 0.50. All provinces were differentiated in the UPGMA cluster diagram.
Approaches for field assessment of resistance to leaf pathogens in spring barley varieties
Authors: Pinnschmidt H. O. , Hovmøller M. S. , ØStergård H. 
Published: March 2006

AbstractThe resistance of spring barley varieties to powdery mildew, leaf rust, leaf scald and net blotch was characterized by using results from inoculated small‐plot nurseries and larger survey plots subject to natural infection. The experiments were conducted in different environments. Both trial types often yielded complementary results with respect to the ranking of varieties suggesting that a recommended variety characterization should include both naturally infected survey‐type trials and nursery trials in which the most relevant pathogen isolates and/or isolate mixtures or populations are used for inoculation. Average and median values of the diseased leaf area of a variety were highly correlated with each other and with the ‘genotype main effect’ determined by joint regression analysis, whereas maximum diseased leaf area was poorly correlated with them. Statistics based on absolute disease severity values were highly correlated with the corresponding statistics derived from relative values. It is suggested that one should use at least two parameters to characterize the disease resistance of a variety, a parameter indicating the overall resistance level and a parameter indicating the potential susceptibility and/or resistance instability of a variety. For practical purposes, the genotype median and maximum, respectively, may represent these, although statistically more appropriate parameters do exist.
Identification of wheat–Thinopyrum intermedium 2Ai‐2 ditelosomic addition and substitution lines with resistance to barley yellow dwarf virus
Authors: Lin Z. S. , Huang D. H. , Du L. P. , Ye X. G. , Xin Z. Y. 
Published: March 2006

AbstractAmong the regenerated plants derived from immature hybrid embryos of wheat–Thinopyrum intermedium disomic addition line Z6 × common wheat variety ‘Zhong8601’, a plant with a telocentric chromosome and barley yellow dwarf virus (BYDV) resistance was obtained. The telocentric chromosome paired with an entire Thinopyrum chromosome to form a heteromorphic bivalent at meiotic metaphase I. Genomic in situ hybridization showed that the telosome originated from Th. intermedium. Two ditelosomic additions and one disomic substitution were identified among the offspring of the plant. Two random amplified polymorphic DNA molecular markers were identified among 150 random primers used to detect the different arms of the alien chromosome. These might be useful for developing translocation lines with BYDV resistance.
Detection of HMW glutenin subunit variations among 205 cultivated emmer accessions (Triticum turgidum ssp. dicoccum)
Authors: Li Q. Y. , Yan Y. M. , Wang A. L. , An X. L. , Zhang Y. Z. , Hsam S. L. K. , Zeller F. J. 
Published: March 2006

AbstractThe high molecular weight glutenin subunits (HMW‐GS) encoded by Glu‐1 loci among 205 accessions of cultivated emmer wheat (Triticum turgidum ssp. dicoccum Schrank) collected from different regions of Europe and China were separated and characterized by SDS‐PAGE in combination with two‐dimensional gel electrophoresis (A‐PAGE × SDS‐PAGE) and acidic capillary electrophoresis. High genetic polymorphisms in HMW‐GS compositions were found. A total of 40 alleles (6 for Glu‐A1 and 34 for Glu‐B1) and 62 subunit combinations (genotypes) were detected, some of which were not previously described. At Glu‐A1 locus, two novel alleles, designated Glu‐A1x coding for the subunit 1A × 1.1 and Glu‐A1y coding for the subunit 1A × 2.1′ were found while seven new subunits (1B × 17*, 1B × 6′, 1B × 13′, 1B × 20*, 1By9*, 1By14.1 and 1By8.1) and 20 novel alleles at Glu‐B1 locus were detected. In particular, some additional protein components were detected, which probably were 1Ay subunits encoded by Glu‐A1 locus. The introduction of both Ax and Ay subunits from tetraploid wheats into hexaploid wheats may increase the genetic variability of gluten genes and consequently improve flour technological properties.
Strong heritability across years and sites for pod wall proportion and specific weight in Lupinus albus and genotypic correlation with other pod and seed attributes
Authors: Mera M. , Beltran L. , Miranda H. , Rouanet J. L. 
Published: March 2006

AbstractThinner pod walls might contribute to increased yield potential and adaptation of lupins. Fourteen autumn‐sown genotypes of Lupinus albus L. were evaluated over 2 years at four sites in southern Chile. Pod wall proportion (PWP), pod wall specific weight (WSW) and five other pod‐related characters were measured to estimate their genetic variation, heritability across years and sites, and genotypic and phenotypic correlations among the characters. Ranges for PWP and pod WSW were 22.9−43.1% and 16.4−37.4 mg/cm2, respectively. PWP in cultivated L. albus was similar to that reported in L. angustifolius; however, specific weight was substantially lower. Highly significant genotypic effects were found for both characters. Broad sense heritabilities were high for PWP (0.63) and moderate for pod WSW (0.46). These characters were significantly correlated, more so genotypically (rg = 0.67) than phenotypically (rph = 0.36). Selection for low PWP should lead to lower pod wall thickness or density, both of which contribute to pod WSW. Nevertheless, selection for pod WSW could achieve further reductions, particularly if practised among low PWP materials.
Identification of a SCAR marker associated with Bm, the beet mosaic virus resistance gene, on chromosome 1 of sugar beet
Authors: Friesen T. L. , Weiland J. J. , Aasheim M. L. , Hunger S. , Borchardt D. C. , Lewellen R. T. 
Published: March 2006

AbstractBeet mosaic virus (BtMV) is an aphid transmitted, viral disease of beet found worldwide. The Bm gene, a resistance gene effective against BtMV, was identified in the sugar beet line 8500 and backcrossed into a C37 background to produce line C719. Three populations were developed from the cross of line C719 with the susceptible line C37 with the intent of developing markers for use in marker‐assisted selection. The F2 progeny of three crosses were scored for resistance. Two of the three populations conformed to a 3 : 1 ratio, indicating a single gene trait. Sequence characterized amplified region (SCAR) markers were developed by using bulked segregant analysis combined with random amplified polymorphic DNA type markers. The markers showed close association to the Bm resistance gene and were effective in all three populations. The A1 allele for genetic male sterility also was found to be associated with Bm and the SCAR marker. Development of a single‐nucleotide polymorphism marker from the SCAR sequence was used to validate linkage to chromosome 1 using separate mapping populations. This marker will be useful for the introgression of the Bm gene into germplasm.
(GATA)4 DNA fingerprinting identifies morphologically characterized ‘San Marzano’ tomato plants
Authors: Rao R. , Corrado G. , Bianchi M. , Di Mauro A. 
Published: March 2006

AbstractCurrently, registration, protection and breeding of the ‘San Marzano’ tomato cultivar rely on a number of morphological descriptors. Its correct identification is essential in order to preserve this variety, which is highly valued and known worldwide, from an increasing number of similar cultivars with inferior organoleptic features. However, the identification of this cultivar on the exclusive basis of morpho‐agronomic traits has some intrinsic limits and therefore, molecular signatures are required to efficiently discriminate plants and their fruits, and to characterize and make profitable use of the traditional accessions. The phenotype and genotype of 25 ‘San Marzano’ tomato accessions cultivated in the traditional area are characterized, along with the most popular peeling tomato cultivars, using a combination of DNA molecular analysis and morphological descriptors. (GATA)4 DNA fingerprinting proved to be a powerful tool for the analysis of the ‘San Marzano’ cultivar and in the description of the genetic inconsistencies present in the locally cultivated traditional ‘San Marzano’ collections.
Inheritance of useful traits in cassava grown in subhumid conditions
Authors: Cach N. T. , Lenis J. I. , Perez J. C. , Morante N. , Calle F. , Ceballos H. 
Published: March 2006

AbstractA diallel study among nine parental clones of cassava was conducted in the subhumid environment on the northern coast of Colombia. Analysis of variance suggested significant effects for the six variables analysed: fresh‐root yield, harvest index, root dry matter content, height of first branching, reaction to thrips and plant‐type scores. General and specific combining ability effects and their interaction with the environment were significant for most of the variables as well. Results suggested that dominance plays a particularly important role in the cases of fresh‐root yield and harvest index but had relatively little importance in the reaction to thrips, dry matter content or height of first branching. Specific breeding approaches are suggested for these traits, depending on the relative importance of additive or non‐additive effects in their inheritance. The correlations among different traits were also analysed and in several cases their magnitude reached statistical and biological significance.
Simple sequence repeat markers linked to a major QTL controlling pod shattering in soybean
Authors: Funatsuki H. , Ishimoto M. , Tsuji H. , Kawaguchi K. , Hajika M. , Fujino K. 
Published: March 2006

AbstractShattering of soybean pods prior to harvest leads to a reduction in yield. In order to identify simple sequence repeat (SSR) markers linked to quantitative trait loci (QTLs) conditioning pod shattering, QTL analysis was conducted using an recombinant inbred line (RIL) population segregating for this trait. The degrees of pod‐shattering resistance were evaluated by heat treatment applied to pods harvested from plants in the field and in a growth chamber. Composite interval mapping identified one major QTL between SSR markers Sat_093 and Sat_366 on linkage group J for both environments. The position and the effect of this QTL were confirmed in an F2 population derived from a cross between the pod shattering‐susceptible parental cultivar and a pod shattering‐resistant RIL. The SSR markers linked to the major QTL will be useful for marker‐assisted selection in soybean‐breeding programmes.