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The trunk (core) muscles are involved in daily functions (i. e., stabilizing the body in everyday tasks) and force generation of the limbs during athletic tasks such as kicking, throwing, or running. Even though trunk training is a popular means for improving physical fitness and athletic performance, the direct relationship of improved trunk function (i.e., stability, strength, or endurance), fitness and sport-specific performance is not conclusive. The aim of this proposed review is to evaluate the effects of trunk training on physical fitness and sport-specific performance, and to examine potential subject-related (e.g., age, sex) and trunk training-related moderator variables (e.g., training period, training frequency) for performance changes. We will conduct a systematic literature search in Web of Science, MEDLINE (via EBSCO) and SportDiscus. Relevant papers will be screened independently by two reviewers in two stages: (1) title and abstracts and (2) the full text of the remaining papers. A third reviewer will resolve possible disagreements. Data extraction and risk of bias of the included studies will be performed in addition to the PEDro scoring to judge the quality of the studies. A meta-analysis will be conducted to determine the efficacy of trunk training to increase physical fitness and sport-specific performance measures. In addition, subgroup univariate analyses were computed for subject-related (i.e., age, sex, performance level) and training-related moderator variables (i.e., training period, training frequency, training sessions, session duration). The results of this proposed systematic review and meta-analysis will assess the effects of trunk training on physical fitness and sport-specific and identify which subject-related and training-related moderate variables of trunk training modality might be beneficial for performance gains. This knowledge has potential importance for athletes and coaches in sports.

In this demonstration, we present a full implementation of Tacita, a display personalisation system designed to address viewer privacy concerns whilst still capable of providing relevant content to viewers and therefore increasing the value of displays.

Although mixed-species associations of birds or primates have been well studied, primate–bird associations have received comparatively little attention. Additionally, benefits accruing with such associations have rarely been quantified. Over 13 months, 17 insectivorous bird species were observed associating with golden-backed uacaris. Detailed study of four found that feeding sally frequency significantly increased for sit-and-wait foragers (bronzy jacamar, Galbula leucogastra; black-fronted nunbird, Monasa nigrifrons), when uacaris were present within 14.9 m, but not when within 15–30 m. Contemporaneously, no significant differences were observed in peck bout frequency for two uacari-following bark- and leaf-gleaning antbirds (black-crested antshrike, Sakesphorus canadensis, black-winged antbird, Hypocnemoides melanopogon) when uacaris were present or absent. Antbird/uacari approximation is attributed to significant reductions in the presence of small bird-eating raptors when uacaris are present. Reasons for this are uncertain but may be because large raptors (e.g. harpy eagles) follow uacaris. So, while some bird species may gain foraging benefits from uacari presence, others may follow them because their proximity reduces predation risk. This appears foraging guild dependent. Except for work linking increased jacana peck rates with swamp-visiting gorilla presence, this study is the first to quantify benefits to birds of following primates, and the first such Neotropical study.

We directly recorded predation of Black-legged Kittiwake chicks (Rissa tridactyla) by a Peregrine Falcon (Falco peregrinus) using a remote time-lapse camera. Between 20 July 2013 and 23 July 2013, all four nests in the camera's field of view failed. A peregrine was recorded depredating chicks in two of these four nests. Periods of adult desertion at the other two nests strongly suggests chicks in these nests were depredated as well. Predation happened at night, a rarely documented behavior of the peregrine. Along with giving insights into peregrine hunting behavior, the use of remote cameras allows us to determine nest fate. Determining sources of chick mortality is invaluable for identifying causes of variability in productivity rates of colonial breeding birds.

The horse chestnut leaf miner Cameraria ohridella was discovered in the Balkans in 1986 and appeared in the UK in 2002. The aim of this study was to quantify and describe the parasitism rates and parasitoids of the moth in urban and rural stands of Aesculus hippocastanum in the UK and to compare the results with those from European studies. A maximum parasitism rate of 6.67% was obtained, and a significant difference in parasitism rate between urban and rural stands was noted. Two species Minotetrastichus frontalis and Pnigalio agraules alone were responsible for 37% of total parasitism. However, the results show no ideal candidate for use in the biological control of C. ohridella within the native UK parasitoids.

Here we describe methods for producing nuclei from Arabidopsis suspension cultures or root tips of Arabidopsis, wheat, or pea. These methods could be adapted for other species and cell types. The resulting nuclei can be further purified for use in biochemical or proteomic studies, or can be used for microscopy. We also describe how the nuclei can be used to obtain a preparation of nucleoli.

Small nucleolar RNAs (snoRNAs) and small Cajal body-specific RNAs (scaRNAs) are non-coding RNAs whose main function in eukaryotes is to guide the modification of nucleotides in ribosomal and spliceosomal small nuclear RNAs, respectively. Full-length sequences of Arabidopsis snoRNAs and scaRNAs have been obtained from cDNA libraries of capped and uncapped small RNAs using RNA from isolated nucleoli from Arabidopsis cell cultures. We have identified 31 novel snoRNA genes (9 box C/D and 22 box H/ACA) and 15 new variants of previously described snoRNAs. Three related capped snoRNAs with a distinct gene organization and structure were identified as orthologues of animal U13snoRNAs. In addition, eight of the novel genes had no complementarity to rRNAs or snRNAs and are therefore putative orphan snoRNAs potentially reflecting wider functions for these RNAs. The nucleolar localization of a number of the snoRNAs and the localization to nuclear bodies of two putative scaRNAs was confirmed by in situ hybridization. The majority of the novel snoRNA genes were found in new gene clusters or as part of previously described clusters. These results expand the repertoire of Arabidopsis snoRNAs to 188 snoRNA genes with 294 gene variants.

Here, we identify the Arabidopsis thaliana ortholog of the mammalian DEAD box helicase, eIF4A-III, the putative anchor protein of exon junction complex (EJC) on mRNA. Arabidopsis eIF4A-III interacts with an ortholog of the core EJC component, ALY/Ref, and colocalizes with other EJC components, such as Mago, Y14, and RNPS1, suggesting a similar function in EJC assembly to animal eIF4A-III. A green fluorescent protein (GFP)-eIF4A-III fusion protein showed localization to several subnuclear domains: to the nucleoplasm during normal growth and to the nucleolus and splicing speckles in response to hypoxia. Treatment with the respiratory inhibitor sodium azide produced an identical response to the hypoxia stress. Treatment with the proteasome inhibitor MG132 led to accumulation of GFP-eIF4A-III mainly in the nucleolus, suggesting that transition of eIF4A-III between subnuclear domains and/or accumulation in nuclear speckles is controlled by proteolysis-labile factors. As revealed by fluorescence recovery after photobleaching analysis, the nucleoplasmic fraction was highly mobile, while the speckles were the least mobile fractions, and the nucleolar fraction had an intermediate mobility. Sequestration of eIF4A-III into nuclear pools with different mobility is likely to reflect the transcriptional and mRNA processing state of the cell.

Plots of fresh pulverized fuel ash (PFA, an industrial waste) were inoculated with soils from existing PFA sites and fertilizers in a factorial design, then left unmanaged for 12 years during which time the floral development and soil chemistry were monitored annually. For the first 3 years, the site supported a sparse mix of chenopods (including the scarce Chenopodium glaucum) and halophytes. As salinity declined, ruderals, legumes, and grasses plus the fire-site moss Funaria hygrometrica colonized, followed by Festuca arundinacea grassland (NVC community MG12) and Hippophae rhamnoides scrub. Dactylorhiza incarnata (orchidacea) appeared after 7 years, but only in plots that had received soil from existing orchid colonies. Four years later, a larger second generation of Dactylorhiza appeared, but only in the central zone of the site where vegetation was thinnest. By year 12, the site was dominated by coarse grasses and scrub, with early successional species persisting only in the sparsely vegetated center, where nitrate levels were lowest. This edge effect is interpreted as centripetal encroachment, a process of potentially wider concern for the conservation of low-fertility habitat patches. Overall, seed bank inoculation seems to have introduced few but desirable species (D. incarnata, Pyrola rotundifolia, some halophytes, and annuals), whereasmore » initial application of organic fertilizer had long-lasting ({ge} 10 years) effects on cover and soil composition.« less

Cyclin-dependent kinases (CDKs) play key regulatory roles in diverse cellular functions, including cell-cycle progression, transcription and translation. In plants, CDKs have been classified into several groups, named A through to G, but the functions of most are poorly characterized. CDKCs are known to phosphorylate the C-terminal domain (CTD) of RNA polymerase II (RNAP II), and therefore the CDKC-cyclinT (CycT) complex may have a role similar to the animal CDK9-CycT complex of the positive transcription elongation factor b (P-TEFb). However, we found that the predicted structure of the Arabidopsis CDKC2 protein is more similar to the mammalian cdc2-related kinase, CRK7, than to CDK9. CRK7 is proposed to link transcription with splicing, and CDKC2 contains all the structural features of CRK7 that make the latter distinct from CDK9. Consistent with this, we show that GFP-CDKC2 fusion proteins co-localize with spliceosomal components, that the expression of CDKC2 modifies the location of these components, and that co-localization was dependent on the transcriptional status of the cells and on CDKC2-kinase activity. We propose, therefore, that the Arabidopsis CDKC2 combines the functions of both CRK7 and CDK9, and could also couple splicing with transcription.

The expression pattern of genes can identify the cells in which the respective proteins are active during development. As a step towards defining the genetic network that controls the development of roots, a high-throughput method of whole-mount in situ hybridization has been developed that does not require expensive equipment and allows the definition of the expression patterns of 137 transcription factor genes in young developing roots. Of the 137 transcription factors, 81.8% were expressed in the root while 18.2% showed no detectable expression. In all three proximal distal zones (meristem, elongation, and differentiation) of the root, 52.6% were expressed whereas 21.2% were expressed in only two zones. Eight percent of the genes were expressed in a single proximal distal zone. Cell-specific gene expression patterns were also detected. This rapid approach identified potential key regulators of cell differentiation and provides important spatial information for the expression patterns of a large number of transcriptional regulators that function during root development.

We studied the influence of a car park on soil and vegetation within Richmond Park, UK, before and after imposition of fenced boundaries restricted public access. Soil and vegetation samples were taken before (once) and after (twice) access restrictions were enforced. The over-riding trend in all the data was for soil adjacent to the car park to be less acidic and more fertile than pristine local soils, accompanied by a more eutrophic grassland community (Lolium perenne/Trifolium repens, compared with Agrostis/Festuca grassland away from the car park). The chemical influence of the car park extended at least 50 m from its boundary. A common acidophilic collembole Folsomia quadrioculata was replaced by Cryptopygus thermophilus adjacent to the car park. There was little evidence from the vegetation data that car park closure benefitted the ecosystem, but chemical data showed signs of progressive recovery in the 2 years following restrictions. Possible explanations for the car park's influence on the local landscape are suggested to include calcareous chippings and canine faecal deposits.

It has long intrigued researchers why some but not all organisms can regenerate missing body parts. Plants are remarkable in that they can regenerate the entire organism from a small piece of tissue, or even a single cell. Epigenetic mechanisms that control chromatin organization are now known to regulate the cellular plasticity and reprogramming necessary for regeneration. Interestingly, although animals and plants have evolved different strategies and mechanisms to control developmental processes, they have maintained many similarities in the way they regulate chromatin organization. Given that plants can rapidly switch fate, we propose that an understanding of the mechanisms regulating this process in plant cells could provide a new perspective on cellular dedifferentiation in animals.

Cajal bodies (CBs) are subnuclear bodies that are widespread in eukaryotes, being found in mammals, many other vertebrates and in all plant species so far examined. They are mobile structures, moving, fusing, and budding within the nucleus. Here we describe a screen for Arabidopsis mutants with altered CBs and describe mutants that have smaller Cajal bodies (ncb-2, ncb-3), lack them altogether (ncb-1), have increased numbers of CBs (pcb) or have flattened CBs (ccb). We have identified the gene affected in the ncb mutants as a distant homolog of the vertebrate gene that encodes coilin (At1g13030) and have termed the resulting protein Atcoilin. A T-DNA insertional mutant in this gene (ncb-4) also lacks Cajal bodies. Overexpression of Atcoilin cDNA in ncb-1 restores Cajal bodies, which recruit U2B″ as in the wild type, but which are, however, much larger than in the wild type. Thus we have shown that At1g13030 is required for Cajal body formation in Arabidopsis, and we hypothesize that the level of its expression is correlated with Cajal body size. The Atcoilin gene is unaffected in pcb and ccb, suggesting that other genes can also affect CBs.

SUMMARY As part of a long-term open-air fumigation experiment, Scots pine was exposed continuously to SO2 pollution following a predetermined pattern of hourly mean values based upon monitoring data from a site in central England. Although annual mean concentrations did not exceed 22 ppb, up to 200% of trees developed foliar necrosis in three consecutive growing seasons similar to published descriptions of acute SO2 damage. The number of trees affected increased with S02 concentration, and there was a significant tendency for the same trees to be affected in consecutive years, implying that sensitivity to these levels was genetically based. As a group, trees showing necrotic symptoms were not significantly retarded in their growth, although their 1990 budburst was significantly delayed and the few trees which lost over 50 % of their foliage were visibly stunted. Fumigation of potted trees for short periods in chambers with up to 1000 ppb SO2 failed to produce any comparable effects. Regression analyses between the number of plants affected each year and a range of gas concentration parameters showed mean concentrations during a critical period in May to be most closely related to the development of symptoms, although no effects became visible until approximately 5 wk later. The start date for the critical period differed between years, and for the two years for which budburst data were available it coincided with the start of needle elongation. The duration of the critical period lay in the range 6-14 d. Linear extrapolation from the data suggested the threshold mean S02 concentration for visible injury to be in the range 6-8 ppb (measured during the critical period during needle expansion) although this could underestimate the true value.

The Arabidopsis Nucleolar Protein Database (http://bioinf.scri.sari.ac.uk/cgi-bin/atnopdb/home) provides information on 217 proteins identified in a proteomic analysis of nucleoli isolated from Arabidopsis cell culture. The database is organized on the basis of the Arabidopsis gene identifier number. The information provided includes protein description, protein class, whether or not the plant protein has a homologue in the most recent human nucleolar proteome and the results of reciprocal BLAST analysis of the human proteome. In addition, for one-third of the 217 Arabidopsis nucleolar proteins, localization images are available from analysis of full-length cDNA–green fluorescent protein (GFP) fusions and the strength of signal in different parts of the cell—nucleolus, nucleolus-associated structures, nucleoplasm, nuclear bodies and extra-nuclear—is provided. For each protein, the most likely human and yeast orthologues, where identifiable through BLASTX analysis, are given with links to relevant information sources.

We describe a streamlined and systematic method for cloning green fluorescent protein (GFP)-open reading frame (ORF) fusions and assessing their subcellular localization in Arabidopsis thaliana cells. The sequencing of the Arabidopsis genome has made it feasible to undertake genome-based approaches to determine the function of each protein and define its subcellular localization. This is an essential step towards full functional analysis. The approach described here allows the economical handling of hundreds of expressed plant proteins in a timely fashion. We have integrated recombinational cloning of full-length trimmed ORF clones (available from the SSP consortium) with high-efficiency transient transformation of Arabidopsis cell cultures by a hypervirulent strain of Agrobacterium. To demonstrate its utility, we have used a selection of trimmed ORFs, representing a variety of key cellular processes and have defined the localization patterns of 155 fusion proteins. These patterns have been classified into five main categories, including cytoplasmic, nuclear, nucleolar, organellar and endomembrane compartments. Several genes annotated in GenBank as unknown have been ascribed a protein localization pattern. We also demonstrate the application of flow cytometry to estimate the transformation efficiency and cell cycle phase of the GFP-positive cells. This approach can be extended to functional studies, including the precise cellular localization and the prediction of the role of unknown proteins, the confirmation of bioinformatic predictions and proteomic experiments, such as the determination of protein interactions in vivo, and therefore has numerous applications in the post-genomic analysis of protein function.

We report a two year survey of saprotrophic fungi colonising woodchip mulch at two contrasting sites in Surrey, a formal garden and a roadside planting scheme. Two alien species ( Stropharia aurantiaca and Psilocybe cyanescens ) occurred at both sites, along with other notable species including Psilocybe percevalii, Agrocybe putaminum and Collybia biformis . Very little fruiting occurred on areas mulched with bark chippings. In the formal garden there was virtually no repeat fruiting in successive years. At the roadside site most species fruited profusely in the first season after deposition, then decreased greatly in numbers in the second year. It is concluded that ornamental woodchips, but not bark chippings, can support diverse fungal communities including unusual species, although these assemblages are short-lived.

This investigation assessed whether prior heavy resistance exercise would improve the repeated sprint performance of 16 trained youth soccer players (Age 17.05 ± 0.65 years; height 182.6 ± 8.9 cm; body mass 77.8 ± 8.2 kg). In session 1, individual 1 repetition max was measured utilising a squat movement. In sessions 2 and 3, participants performed a running-based repeated anaerobic sprint test with and without prior heavy resistance exercise of 91% of their 1 repetition max. Times were recorded for each of the 6 sprints performed in the repeated sprint test and summed to provide total time. T-tests compared the two exercise conditions via differences in corresponding sprint times and total time. Analysis revealed significantly reduced total time with use of heavy resistance exercise (33.48 (±1.27) vs. 33.59 (±1.27); P = 0.01). Sprints 1 (P = 0.05) and 2 (P = 0.02) were also faster in the heavy resistance exercise condition (5.09 (±0.16) vs. 5.11 (±0.16) and 5.36 (±0.24) vs. 5.45 (±0.26) seconds respectively) although no other differences were shown. Findings demonstrate improved sprint times of trained adolescent soccer players after heavy resistance exercise although benefits appear not as sustained as in adult participants.

Genomes are organized as chromatin into complex 3D structures in interphase nuclei, and the relation of these structures to gene function is the subject of much current debate and research. In this chapter, we describe key landmarks that have led to our present understanding of interphase nuclear architecture, with particular emphasis on model and crop plants, such as wheat, rice and Arabidopsis. We discuss the significance of the plasticity of interphase chromosome organization in relation to transcriptional state, epigenetic regulation and environmental influences. We describe our current understanding of in vivo chromatin dynamics down to molecular resolution. Finally, we consider the prospects for using an understanding of chromatin organization and behaviour to improve plant performance in challenging environmental conditions.

Many species exhibit polyploidy. The presence of more than one diploid set of similar chromosomes in polyploids can affect the assortment of homologous chromosomes, resulting in unbalanced gametes. Therefore, a mechanism is required to ensure the correct assortment and segregation of chromosomes for gamete formation. Ploidy has been shown to affect gene expression. We present in this study an example of a major effect on a phenotype induced by ploidy within the Triticeae. We demonstrate that centromeres associate early during anther development in polyploid species. In contrast, centromeres in diploid species only associate at the onset of meiotic prophase. We propose that this mechanism provides a potential route by which chromosomes can start to be sorted before meiosis in polyploids. This explains previous reports indicating that meiotic prophase is shorter in polyploids than in their diploid progenitors. Even artificial polyploids exhibit this phenotype, suggesting that the mechanism must be present in diploids, but only expressed in the presence of more than one diploid set of chromosomes.

We have used whole mount immunofluorescence labelling with the antibody 4G3, raised against the human snRNP-specific protein U2B″, and whole mount in situ hybridization with an anti-sense probe to a conserved region of U2 snRNA, in combination with confocal microscopy, to examine the organization of spliceosomal components throughout the development of the Arabidopsis thaliana root epidermis. We show that the number of coiled bodies, nuclear organelles in which splicing snRNPs and snRNAs concentrate, is developmentally regulated in the Arabidopsis root epidermis. Firstly, there is a progression from a small number of coiled bodies in the quiescent centre and initial cells, to a larger number in the cell division zone, returning to a lower number in the cell elongation and differentiation zone. Secondly, trichoblasts (root-hair forming epidermal cells) have on average 1.5 times more and often smaller coiled bodies than atrichoblasts (hairless epidermal cells). Moreover, we have shown that these differences in coiled body numbers are related to differences in cell cycle stage, cell type and developmental stage, but are not due to differences in nucleolar or general metabolic activity per se. We discuss possible explanations, including a model in which coiled bodies coalesce during interphase, for the developmental dynamics of coiled bodies.

Morphometric data were collected from Dactylorhiza growing on two types of industrial waste (pulverized fuel ash or PFA, and Leblanc process waste) during the summer of 1997. Three species grew on PFA ( D. fuchsii , D. incarnata , D. praetermissa ). The same species plus D. purpurella grew on the Leblanc site, although on both substrates the majority of plants failed to correspond precisely with published descriptions, introducing an element of subjectivity into the field identifications. Principal Components Analysis and Detrended Correspondence Analysis ordinations confirmed that textbook species descriptions corresponded to extremes of multivariate space. Cluster Analysis failed to produce a useful resolution of the data. Discriminant Functions Analysis initially gave the misleading result that any plant with spotted leaves was D. fuchsii , but produced useful results after leaf spotting was removed from the analysis. On PFA sites hybrids appeared to be mainly D. praetermissa×D. fuchsii (= D. grandis ) or D. praetermissa×D. incarnata (= D. wintoni ). The identity of hybrids on the Leblanc site was unclear, perhaps reflecting the greater age of this site which may have allowed extensive introgression.

A total of 53 dipterocarp species belonging to ten genera were studied to examine phylogenetic relationships using the sequences of two non-coding regions in chloroplast DNA. Phylogenetic analysis showed the Selangan Batu, Yellow Meranti and White Meranti of the genus Shorea were monophyletic, while the Red Meranti was divided into three natural clades. The relationships in the Red Meranti could not be ascertained because of an insufficient number of nucleotide substitutions. The White Meranti was clustered with sect. Pelltacme and situated in an outer position of the genus Hopea, Neobalallocarpus and Parashorea although the bootstrap probability was not high. Two of the three deciduous Shorea species collected in Thailand, one belonging to White Meranti and the other to sect. Pelltacme based on morphological and anatomical evidence, were found to constitute a monophyletic group clustering with the other White Meranties. The third species in the Selangan Batu was clustered with the other Selangan Batus. This suggests that the deciduous character in the genus Shorea has evolved independently in different lineages. The divergence within sections of the genus Shorea was largest in sect. Mutica and smallest in sect. Richetioides. The genera Shorea and Hopea were more divergent than the other genera. These results suggest that they are the groups of phylogenetically more diversified species.

Reduction in chromosome number and genetic recombination during meiosis require the prior association of homologous chromosomes, and this has been assumed to be a central event in meiosis. Various studies have suggested, however, that while the reduction division of meiosis is a universally conserved process, the pre-meiotic association of homologues differs among organisms. In the fruit fly Drosophila melanogaster, some somatic tissues also show association of homologues [1,2]. In the budding yeast Saccharomyces cerevisiae, there is some evidence for homologue association during the interphase before meiotic division [3,4], and it has been argued that such associations lead directly to meiotic homologue pairing during prophase I [5]. The available evidence for mammals suggests that homologous chromosomes do not associate in germ cells prior to meiotic prophase [6]. To study the occurrence of homologue pairing in wheat, we have used vibratome tissue sections of wheat florets to determine the location of homologous chromosomes, centromeres and telomeres in different cell types of developing anthers. Fluorescence in situ hybridization followed by confocal microscopy demonstrated that homologous chromosomes associate pre-meiotically in meiocytes (germ-line cells). Surprisingly, association of homologues was observed simultaneously in all the surrounding somatic tapetum cells. Homologues failed to associate at equivalent stages in a homologue recognition mutant. These results demonstrate that the factors responsible for the recognition and association of homologues in wheat act before the onset of meiotic prophase. The observation of homologue association in somatic tapetum cells demonstrates that this process and meiotic division are separable.

Progression through anaphase requires high levels of type 1 protein phosphatase (PP1) activity in a variety of eukaryotes, including Aspergillus nidulans. A conditional lethal, temperature-sensitive mutant in one of the Aspergillus PP1 genes, bimG, prevents the normal completion of anaphase when cells are grown at restrictive temperature and this has been shown to be due to a reduction in type 1 phosphatase activity. We show that the bimG11 allele is recessive to the wild-type allele in heterozygous diploids, implying that the mutation is due to loss of function at restrictive temperature, but molecular disruption of the wild-type bimG gene shows that the gene is not essential and has no discernable phenotype under laboratory conditions. Sequence comparison of wild-type and mutant alleles reveals a single base pair difference between the two genes, within the 5' splicing site of the second intron. We demonstrate that the conditional lethal phenotype of bimG11 strains is due to impaired splicing of the mutant mRNA and that this leads to the production of a truncated protein comprising an intact N-subdomain and a modified C-terminus. Over-expression of this truncated form of PP1 in a wild-type haploid produces a lethal phenotype and reduced PP1 activity, supporting the idea that a toxic interfering protein is produced. PP1, therefore, may have at least two spatially separated sites, both of which are required for function. Temperature-sensitive splicing mutations may provide a novel means of engineering conditional versions of other proteins, particularly other phosphatases.

Experimental plots of pulverized fuel ash (PFA), alone or mixed with flue gas desulphurization (FGD) gypsum, were seeded with topsoil from areas where PFA had been revegetated naturally, or with estuarine soil. Plots containing fresh PFA became more saline during the first three years due to formation of a salt crust, and these plots experienced colonization by halophytic species. Plots initially containing 2-year-old PFA declined in salinity throughout the experiment and were colonized by a richer plant community dominated by legumes. A total of 57 plant species was recorded in the two experiments. Of these, Melilotus officinalis (ribbed melilot), Medicago lupulina (black medick), Vulpia myuros (rat's tail fescue), and Puccinellia maritima (common saltmarsh grass) showed commercial potential for stabilizing these wastes, and by implication other saline or high-boron materials.

A cDNA encoding a dihydrolipoamide acetyltransferase (E2) subunit of the pyruvate dehydrogenase complex has been isolated from Arabidopsis thaliana. A cell culture cDNA expression library was screened with a monoclonal antibody (JIM 63) raised against nuclear matrix proteins, and four clones were isolated. One of these was 2175 base pairs in length, and it contained an open reading frame with an amino acid sequence and domain structure with strong similarity to the E2s of other eukaryotic and prokaryotic organisms. The organization and number of functional domains within the Arabidopsis protein are identical to those of the human E2, although the amino acid sequences within these domains are equally similar to those of the yeast and human proteins. The predicted amino acid sequence reveals the presence of a putative amino-terminal leader sequence with characteristics similar to those of other proteins, which are targeted to the plant mitochondrial matrix. The cross-reactivities of plant mitochondrial matrix proteins with JIM 63 and antibodies raised against the E2 and protein X components of eukaryotic pyruvate dehydrogenase complexes are consistent with the clone encoding a mitochondrial form of E2 and not the smaller protein X. The E2 mRNA of 2.2 kilobases was expressed in a range of Arabidopsis and Brassica napus tissues.

Foliar elements were analysed in Scots pine, Sitka spruce and Norway spruce over a 6 year period before and during continuous exposure to SO 2 and O 3 in an open-air fumigation experiment. Sulphur dioxide treatment elevated foliar sulphur concentration in all species, and there were increases in foliar nitrogen in the two spruce species but not in pine. The concentrations of cations were frequently increased by SO 2 treatment, but there was no correlation between the sulphur concentration of needles and their total cation charge. SO 2 -related elevations of foliar magnesium were correlated with the concentration of this element in soil solution, but the mechanism by which other cations were enhanced remains unclear. The only consistent effects on nutrient ratios were for SO 2 treatments to increase sulphur/cation ratios

In most eukaryotes that have been studied, the telomeres cluster into a bouquet early in meiosis, and in wheat and its relatives and in Arabidopsis the centromeres pair at the same time. In Arabidopsis, the telomeres do not cluster as a typical telomere bouquet on the nuclear membrane but are associated with the nucleolus both somatically and at the onset of meiosis. We therefore assessed whether Brachypodium distachyon, a monocot species related to cereals and whose genome is approximately twice the size of Arabidopsis thaliana, also exhibited an atypical telomere bouquet and centromere pairing. In order to investigate the occurrence of a bouquet and centromere pairing in B distachyon, we first had to establish protocols for studying meiosis in this species. This enabled us to visualize chromosome behaviour in meiocytes derived from young B distachyon spikelets in three-dimensions by fluorescent in situ hybridization (FISH), and accurately to stage meiosis based on chromatin morphology in relation to spikelet size and the timing of sample collection. Surprisingly, this study revealed that the centromeres clustered as a single site at the same time as the telomeres also formed a bouquet or single cluster.

The mycorrhizal community in a long-term outdoor fumigation experiment was studied by counting both fruitbodies and below-ground mycorrhizas. The fruitbody populations under Scots pine showed annual successional changes which were not paralleled below ground. The trend below ground was for a continuing increase in species number with stand age. No clear effects above or below ground were attributable to fumigation treatments, but the fruitbodies of Paxillus involutus tended to occur in greater numbers in SO2 treated plots. By contrast, below ground the mycorrhizas of this species were slightly adversely affected by SO2 fumigation.

We have investigated the position of the 5 S gene clusters in the nuclei of Pisum sativum root tip cells, and of their transcripts in the nucleolus, using in situ hybridization and confocal microscopy. Single-stranded RNA probes were produced by in vitro transcription, incorporating fluorescein or digoxygenin label. There are known to be 3 pairs of 5 S gene clusters in this species, which would be expected to give 6 sites of hybridization in G1 cells and 12 sites in G2 cells. In presumed G2 cells, many of the sites appeared as paired spots very close together, which we interpret as the sites on sister chromatids. A clear association of one or more clusters with the nucleolar periphery was observed, and it is possible that this has a functional significance. The transcript labelling within the nucleolus showed a reproducible and highly ordered pattern, consisting of cavities devoid of transcript labelling surrounded by sheets of bright labelling, making a characteristic and often very symmetrical cage-work structure. This labelling pattern may represent an underlying organization of transcript processing within the nucleolus, and is highly reminiscent of the distribution of a previously described nucleolar matrix protein.

We have used in situ hybridization with probes to rDNA, labelled either with digoxygenin or directly with fluorescein, to determine the arrangement of these genes within the nucleoli of Pisum sativum L. root cells. Confocal laser scanning microscopy was used to image the three-dimensional structures revealed, but we have also compared this technique with deconvolution of conventional (wide-field) fluorescence images measured with a cooled CCD camera, and have shown that the results are remarkably similar. When the deconvolution technique was applied to the confocal data it gave clearer images than could be achieved by confocal microscopy alone. We have analysed the distribution of rDNA in the different cell types observable in root tips: the quiescent centre; active meristematic cells; and relatively differentiated root cap, epidermal and cortical cells. In addition to four perinucleolar knobs of condensed, inactive rDNA genes, corresponding to the four nucleolar organizers in P. sativum, which were the most brightly labelled structures, several characteristic patterns of intranucleolar labelling were apparent, including bright foci, large central chromatin masses, and fine, decondensed interconnecting fibres. The larger and more active the nucleolus, the smaller the proportion of condensed perinucleolar rDNA. In some large and active meristematic nucleoli, all the internal rDNA is decondensed, showing that transcription cannot be restricted to the bright foci, and is most likely to occur on the decondensed fibres.

In Amazonian seasonally flooded forest (igapo), golden-backed uacaris, Cacajao melanocephalus ouakary, show high selectivity for sleeping trees. Of 89 tree species in igapo, only 16 were used for sleeping (18%). Hydrochorea marginata (Fabaceae) and Ormosia paraensis (Fabaceae) were used most frequently (41% of records) despite being uncommon (Ivlev electivity ratios were 0.76, and 0.84, respectively), though the third most commonly used species (11%), Amanoa oblongifolia (Euphorbiaceae), was selected at near parity. All three species have broad, open canopies with large horizontal limbs and uncluttered interiors. Compared with random trees, sleeping trees had above average diameter at breast height (DBH) and height, lacked lianas and wasp nests, and were more frequently within 5 m of open water. Uacaris generally slept one adult per tree or widely separated in the same canopy and on the outer third of the branch. These behaviours are interpreted as maximising detection of both aerial and arboreal predators.

The work described below was performed in an open air fumigation experiment in which young conifers were exposed to controlled levels of the pollutant gases sulphur dioxide (SO 2 ) and ozone (O 3 ). The mycorrhizal community was analysed both by fruitbody counts and root harvests for morphotype analysis throughout the 6 yr of the experiment. Above ground there was a classical fruit-body succession from nursery species to a mixed community dominated by Suillus spp. under Scots pine and Cortinarius spp. under Norway spruce. Below ground there were changes in the morphotype community structure with time, but no similarity between the morphotype and fruit-body data. There were no effects attributable to SO 2 or O 3 on the mycorrhizal community above or below ground, but multivariate analyses suggested that the fruit-body succession was more advanced in plots with low levels of available phosphate.

The large unicellular flagellate,Gloeomonas kupfferi, has recently been used as an important tool in chlamydomonad cell biology research, especially in studies dealing with the structure and function of the endomembrane system. However, little is known about the main secretory product, the cell wall. This study presents structural, chemical and immunological information about this wall. This 850–900 nm thick matrix is highly elaborate and consists of three distinct layers: an inner stratum (325 nm thick) consisting of tightly interwoven fibers, a medial crystalline layer consisting of 22–23 nm subunits and an outer wall layer (500 nm thick) of outwardlyradiating fibrils. Rapid freeze-deep etch analysis reveals that the 35–40 nm fibers of the outer layer form a quasi-lattice of 160 nm subunits. The outer wall can be removed from whole pellets using the chelator, CDTA. The medial wall complex can be solubilized by perchlorate. SDS-gel electrophoresis reveals that the perchlorate soluble-material consists of five high molecular weight glycoproteins and five major low molecular weight glycoproteins. The electrophoretic profile is roughly similar to that ofChlamydomonas reinhardtii. Antibodies were successfully raised against the outer wall component and were shown to label the outer wall layer.

The Liphook Forest Fumigation Project is a long-term field study of the effects of sulphur dioxide (SO 2 ) and ozone (O 3 ) on the coniferous ecosystem including the growth and performance of three species of conifer: Picea sitchensis (Bong.) Carr, Picea abies (L.) Karsten and Pinus sylvestris L. Seven experimental plots (diameter 50 m) were planted with 200 2-year-old seedlings of each species in 1985. Five of the plots receive computer-controlled fumigation treatments with two levels of SO 2 fumigation (annual means 14 and 24 ppb; parts in 10 9 by volume), one level of O 3 fumigation (1.5 times ambient) and the combination of these treatments. SO 2 fumigation commenced in early 1987 and O 3 fumigation in early 1988. Over 35 studies are in progress at the site including work on tree growth, physiology, nutrient status, litter decomposition, soil chemistry, root growth, insects, micro-organisms, throughfall chemistry and lichens. This wide range of studies using a large number of trees under realistic environmental conditions demonstrates the potential of this method for investigating air-pollutant effects on forest ecology.

The unicellular green algal flagellate,Mesostigma viride, is characterized by an extracellular matrix of multiple layers of scales. These scales are processed within the Golgi apparatus (GA). The GA consists of 11–13 closely stacked cisternae. The cis cisternae are highly fenestrated and grow via vesicles from adjacent transition ER. Medial-trans cisternae are plate-like with swollen peripheries. The calcified basket scales are produced in the peripheries of GA cisternae, usually first observable in the medial zone of the cisternal stack. Cisternal membrane closely conforms to the precise architecture of the developing scale. Antimonate labeling reveals that a population of smooth cytoplasmic vacuoles situated near the GA contains a store of calcium, perhaps used for scale processing. Vesicles carry calcium from these vacuoles to the cisternal loci where basket scale ontogenesis is occurring. The smaller scale types are produced within the central areas of the GA. A discussion concerning membrane flow through the GA is provided.

The eukaryotic nucleolus is multifunctional and involved in the metabolism and assembly of many different RNAs and ribonucleoprotein particles as well as in cellular functions, such as cell division and transcriptional silencing in plants. We previously showed that Arabidopsis thaliana exon junction complex proteins associate with the nucleolus, suggesting a role for the nucleolus in mRNA production. Here, we report that the plant nucleolus contains mRNAs, including fully spliced, aberrantly spliced, and single exon gene transcripts. Aberrant mRNAs are much more abundant in nucleolar fractions, while fully spliced products are more abundant in nucleoplasmic fractions. The majority of the aberrant transcripts contain premature termination codons and have characteristics of nonsense-mediated decay (NMD) substrates. A direct link between NMD and the nucleolus is shown by increased levels of the same aberrant transcripts in both the nucleolus and in Up-frameshift (upf) mutants impaired in NMD. In addition, the NMD factors UPF3 and UPF2 localize to the nucleolus, suggesting that the Arabidopsis nucleolus is therefore involved in identifying aberrant mRNAs and NMD.

In the post-genomic era, it is necessary to adapt methods for gene expression and functional analyses to more high-throughput levels of processing. mRNA in situ hybridization (ISH) remains a powerful tool for obtaining information regarding a gene's temporal and spatial expression pattern and can therefore be used as a starting point to define the function of a gene or a whole set of genes. We have deconstructed 'traditional' ISH techniques described for a range of organisms and developed protocols for ISH that adapt and integrate a degree of automation to standardized and shortened protocols. We have adapted this technique as a high-throughput means of gene expression analysis on wax-embedded plant tissues and also on whole-mount tissues. We have used wax-embedded wheat grains and Arabidopsis floral meristems and whole-mount Arabidopsis roots as test systems and show that it is capable of highly parallel processing.

The unicellular green algal flagellate, Mesostigma viride, possesses an extracellular matrix consisting of three layers of highly distinct scales. This study focused upon the elaborate basket scales. The basket scale is approximately 450–500 nm in height and consists of a solid base, two distinct lattices, two upper rims and various struts and roots. Pure preparations of isolated basket scales were obtained and used for subsequent chemical and immunological analyses. X-ray microanalyses revealed the scale as being mineralized with both calcium and phosphorus. Fourier Transform Infrared Spectroscopic analyses revealed the presence of phosphate, suggesting in turn that the basket scale is complexed with calcium phosphate. SDS-gel electrophoresis of partially digested scales revealed the presence of two protein components, a high Mr, non-migrating form and a form with a Mr of approximately 48000. Further biochemical analyses of scales showed the presence of two major sugars: glucose and the unusual keto sugar acid, 3-deoxy-lyxo-2-heptulosaric acid, or DHA. Antibodies to scales were raised in rats and used in immunolabeling studies. It is estimated from immunofluorescence studies that a cell of 8 μm contains about 800 basket scales. The scales are in a close-packed arrangement resulting in quasi-crystalline arrays upon the cell surface.

During development cells transit through different states as they pass from stem cell to terminally differentiated cell. There is evidence that the transition from one state to another can be accompanied by changes in epigenetic state of genes, which is embodied in chromatin state. Here we give an overview of the changes in chromatin that accompany the regulation of expression and review the evidence for the involvement of such changes during epidermal root development and discuss the roles that these changes play in the differentiation of the cell types involved.

We describe a method for isolating nuclei from cultured Arabidopsis cells. The same method can be used to further isolate nucleoli. Cell walls are first digested to yield protoplasts, which are purified by flotation on a Percoll gradient. Mechanical homogenisation is used to release nuclei, or with more homogenisation, nucleoli. These fractions are most easily purified by gentle centrifugation. The method has been used for proteomic analysis of nucleoli, as well as for biochemical studies. We also describe a method for immunological labelling of isolated nuclei.

The cell wall glycoproteins of Chlamydomonas reinhardii have been fractionated by FPLC ion exchange chromatography. The purified 2BII glycoproteins have been visualized by the technique of pleated-sheet negative staining (Smith and Seegan, 1984) . The method has allowed us to map epitopes on the glycoproteins recognised by a variety of antibodies. Using the nomenclature of Goodenough et al. (1986) for the purified glycoproteins, we have found that GP1 shows a very similar morphology to that reported by Goodenough et al. using rapid-freeze, deep-etch methods. However we have found that GP2 and GP3 show rather different morphologies from those reported by Goodenough et al. The epitopes recognised by the antibodies studied were localised to the head regions of the various molecules. A study of the 2BI glycoprotein wall component shows a complex ‘fish-bone’ type of structure.

The cereal caryopsis is a complex tissue in which maternal and endosperm tissues follow distinct but coordinated developmental programs. Because of the hexaploid genome in wheat (Triticum aestivum), the identification of genes involved in key developmental processes by genetic approaches has been difficult. To bypass this limitation, we surveyed 888 genes that are expressed during caryopsis development using a novel high-throughput mRNA in situ hybridization method. This survey revealed novel distinct spatial expression patterns that either reflected the ontogeny of the developing caryopsis or indicated specialized cellular functions. We have identified both known and novel genes whose expression is cell cycle–dependent. We have identified the crease region as important in setting up the developmental patterning, because the transition from proliferation to differentiation spreads from this region to the rest of the endosperm. A comparison of this set of genes with the rice (Oryza sativa) genome shows that approximately two-thirds have rice counterparts but also suggests considerable divergence with regard to proteins involved in grain filling. We found that the wheat genes had significant homology with 350 Arabidopsis thaliana genes. At least 25 of these are already known to be essential for seed development in Arabidopsis, but many others remain to be characterized.

Many types of plant cell retain their developmental plasticity and have the capacity to switch fate when exposed to a new source of positional information. In the root epidermis of Arabidopsis, cells differentiate in alternating files of hair cells and non-hair cells, in response to positional information and the activity of the homoeodomain transcription factor GLABRA2 (GL2) in future non-hair cells. Here we show by three-dimensional fluorescence in situ hybridization on intact root epidermal tissue that alternative states of chromatin organization around the GL2 locus are required to control position-dependent cell-type specification. When, as a result of an atypical cell division, a cell is displaced from a hair file into a non-hair file, it switches fate. We show that during this event the chromatin state around the GL2 locus is not inherited, but is reorganized in the G1 phase of the cell cycle in response to local positional information. This ability to remodel chromatin organization may provide the basis for the plasticity in plant cell fate changes.

Udgivelsesdato: 2005-Jan The eukaryotic nucleolus is involved in ribosome biogenesis and a wide range of other RNA metabolism and cellular functions. An important step in the functional analysis of the nucleolus is to determine the complement of proteins of this nuclear compartment. Here, we describe the first proteomic analysis of plant (Arabidopsis thaliana) nucleoli, in which we have identified 217 proteins. This allows a direct comparison of the proteomes of an important nuclear structure between two widely divergent species: human and Arabidopsis. The comparison identified many common proteins, plant-specific proteins, proteins of unknown function found in both proteomes, and proteins that were nucleolar in plants but nonnucleolar in human. Seventy-two proteins were expressed as GFP fusions and 87% showed nucleolar or nucleolar-associated localization. In a striking and unexpected finding, we have identified six components of the postsplicing exon-junction complex (EJC) involved in mRNA export and nonsense-mediated decay (NMD)/mRNA surveillance. This association was confirmed by GFP-fusion protein localization. These results raise the possibility that in plants, nucleoli may have additional functions in mRNA export or surveillance.

Yields of Tuber melanosporum fruit bodies from a commercial truffle plantation are examined in relation to time, soil conditions and basal diameter of host tree. Fruiting started 10 yr after planting, and the number of trees producing truffles increased steadily for the following 8 yr. The best predictor of truffle production was tree basal diameter.