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1.
The influence of nodal rooting on branching was studied in three evolutionarily and morphologically diverse species of prostrate
clonal herbs: Tradescantia fluminensis (a monocotyledonous extreme ‘phalanx’ species), Calystegia silvatica (a dicotyledonous extreme ‘guerrilla’ species) and Trifolium repens (a dicotyledonous intermediate species). In all three, branch development from axillary buds is regulated by a positive signal
produced by roots together with inhibitory influences from both pre-existing branches and shoot apical buds (apical dominance).
Responses to nodal roots are cumulative and increased root activity leads to more vigorous bud outgrowth. In the absence of
nodal roots, a single basal root system is unable to maintain continued extension growth of the shoot. We suggest that as
individual nodal roots and stem internodes are both short-lived in these nodally-rooting clonal species, the plants’ investment
in them is minimal. Thus, in contrast to perennial species lacking nodal roots, individual root systems in prostrate clonal
herbs are small and stems have little secondary thickening and development of long-distance transport tissues. Hence the decline
in extension growth of the shoot in the absence of nodal roots could be linked to the weak development of long-distance transport
tissues in their relatively thin horizontal stems and to resource sharing between primary stems and lateral branches (as suggested
by the greater retardation of primary stem growth in the more profusely branched ‘phalanx’ species (Trifolium and Tradescantia) than in the weakly branched ‘guerrilla’ species, Calystegia). These findings are consistent with the view that the long-term persistence of genotypes of nodally-rooting prostrate species
is dependent upon them encountering the moist conditions required to facilitate the continual development of new young nodal
root systems. 相似文献
2.
The ‘mustard oil bomb’: not so easy to assemble?! Localization, expression and distribution of the components of the myrosinase enzyme system 总被引:2,自引:0,他引:2
Glucosinolates are plant secondary metabolites that are hydrolysed by the action of myrosinases into various products (isothiocyanates,
thiocyanates, epithionitriles, nitriles, oxazolidines). Massive hydrolysis of glucosinolates occurs only upon tissue damage
but there is also evidence indicating metabolism of glucosinolates in intact plant tissues. It was originally believed that
the glucosinolate–myrosinase system in intact plants was stable due to a spatial separation of the components. This has been
coined as the ‘mustard oil bomb’ theory. Proteins that form complexes with myrosinases have been described: myrosinase-binding
proteins (MBPs) and myrosinase-associated proteins (MyAPs/ESM). The roles of these proteins and their biological relevance
are not yet completely known. Other proteins of the myrosinase enzyme system are the epithiospecifier protein (ESP) and the
thiocyanate-forming protein (TFP) that divert the glucosinolate hydrolysis from isothiocyanate production to nitrile/epithionitrile
or thiocyanate production. Some glucosinolate hydrolysis products act as plant defence compounds against insects and pathogens
or have beneficial health effects on humans. In this review, we survey and critically assess the available information concerning
the localization, both at the tissular/cellular and subcellular level, of the different components of the myrosinase enzyme
system. Data from the model plant Arabidopsis thaliana is compared to that from other glucosinolate-producing Brassicaceae in order to show common as well as divergent features
of the ‘mustard oil bomb’ among these species. 相似文献
3.
Doreen Jia Yi Ng Kishore Kumar Pasikanti Eric Chun Yong Chan 《Metabolomics : Official journal of the Metabolomic Society》2011,7(2):155-178
In this paper, trend analyses were performed to compare the different ‘omic’ technologies and the different analytical platforms
and biological matrices exploited in metabonomic studies. While common and differential marker metabolites had been identified
using various analytical platforms in metabonomics, little research was directed to review and consolidate marker metabolites
in each disease state. A systematic review of metabonomics-derived marker metabolites in different cancers was performed to
understand the significance of metabonomics in elucidating cancer biochemistry. The biological pathways associated with the
cancer marker metabolites were further correlated to the pathology of cancers. Our trend analyses indicated that metabonomic
publications increased exponentially in recent years, with nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography/mass
spectrometry (LC/MS) being the most popular analytical platforms while blood, urine and tissue are the most commonly profiled
biological matrices. Based on the consolidated cancer marker metabolites, it is reinforced that different cancers possess
some common and yet distinct metabolic phenotypes, exhibiting numerous perturbed biochemical pathways related to their needs
to support cell growth and proliferation and facilitate cancer cell survival. 相似文献
4.
The comprehension of living organisms in all their complexity poses a major challenge to the biological sciences. Recently,
systems biology has been proposed as a new candidate in the development of such a comprehension. The main objective of this
paper is to address what systems biology is and how it is practised. To this end, the basic tools of a systems biological
approach are explored and illustrated. In addition, it is questioned whether systems biology ‘revolutionizes’ molecular biology
and ‘transcends’ its assumed reductionism. The strength of this claim appears to depend on how molecular and systems biology
are characterised and on how reductionism is interpreted. Doing credit to molecular biology and to methodological reductionism,
it is argued that the distinction between molecular and systems biology is gradual rather than sharp. As such, the classical
challenge in biology to manage, interpret and integrate biological data into functional wholes is further intensified by systems
biology’s use of modelling and bioinformatics, and by its scale enlargement. 相似文献
5.
Marielle Merlino Philippe Leroy Christophe Chambon Gérard Branlard 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(7):1321-1337
Albumins and globulins of wheat endosperm represent 20% of total kernel protein. They are soluble proteins, mainly enzymes
and proteins involved in cell functions. Two-dimensional gel immobiline electrophoresis (2DE) (pH 4-7) × SDS-Page revealed
around 2,250 spots. Ninety percent of the spots were common between the very distantly related cultivars ‘Opata 85’ and ‘Synthetic
W7984’, the two parents of the International Triticeae Mapping Initiative (ITMI) progeny. ‘Opata’ had 130 specific spots while
‘Synthetic’ had 96. 2DE and image analysis of the soluble proteins present in 112 recombinant inbred lines of the F9-mapped
ITMI progeny enabled 120 unbiased segregating spots to be mapped on 21 wheat (Triticum aestivum L. em. Thell) chromosomes. After trypsic digestion, mapped spots were subjected to MALDI-Tof or tandem mass spectrometry for
protein identification by database mining. Among the ‘Opata’ and ‘Synthetic’ spots identified, many enzymes have already been
mapped in the barley and rice genomes. Multigene families of Heat Shock Proteins, beta-amylases, UDP-glucose pyrophosphorylases,
peroxydases and thioredoxins were successfully identified. Although other proteins remain to be identified, some differences
were found in the number of segregating proteins involved in response to stress: 11 proteins found in the modern selected
cultivar ‘Opata 85’ as compared to 4 in the new hexaploid `Synthetic W7984’. In addition, ‘Opata’ and ‘Synthetic’ differed
in the number of proteins involved in protein folding (2 and 10, respectively). The usefulness of the mapped enzymes for future
research on seed composition and characteristics is discussed.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
6.
Tinga Ouédraogo Jérémy St-Pierre Claude-André Collin Jean Rioux Sylvie Comeau André 《Plant Cell, Tissue and Organ Culture》1998,53(1):59-66
The effects of an amino acid mixture and of plant growth regulators added to the FHG barley anther culture medium were examined
using three barley cultivars (Cadette, Léger, and Igri) grown in two environments (growth cabinet and glasshouse). ‘Léger’
and ‘Igri’ were known as responsive, and ‘Cadette’ as recalcitrant to androgenesis. Our first experiment showed that the amino
acid-supplemented medium was best for embryogenesis and regeneration of ‘Cadette’ and ‘Igri’ in both environments, and if
‘Léger’ in the growth cabinet. The addition of ABA and TDZ did not improve embryogenesis and plant regeneration, and PAA decreased
them in the growth cabinet. The addition of the amino acid mixture in the FHG medium also reduced the percentage of albino
plants in the growth cabinet, but growth regulators did not improve the percentage of albino plants, and in some cases increased
it. In the growth cabinet, disregarding media, ‘Léger’ produced more embryos than ‘Cadette’ and ‘Igri’, and Léger' and ‘Igri’
produced more green plants than ‘Cadette‘. Percentages of albino plants were higher or ‘Cadette’ than for ‘Igri’ or ‘Léger’.
In a second experiment, we compared seven hybrids with their parents for androgenic responsiveness. Hybrids had a higher ability
to generate green plants than expected based upon the weighted average reflecting the contribution of each parent.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
7.
K. Sorkheh B. Shiran M. Khodambshi V. Rouhi S. Ercisli 《Plant Cell, Tissue and Organ Culture》2011,105(3):395-404
Eight native Iranian almond species from three sections, ‘Euamygdalus’ (Prunus communis; Prunus eleagnifolia and Prunus orientalis); ‘Lycioides’ (Prunus lycioides and Prunus reuteri) and ‘Spartioides’ (Prunus arabica, Prunus glauca and Prunus scoparia) were in vitro screened for drought tolerance using sorbitol and polyethylene glycol (PEG) as an osmoticum. Different levels
of water stress were induced using five concentrations of either sorbitol or polyethylene glycol in Woody Plant Medium (WPM).
Water potential of various media ranged from −0.80 to −2.05 MPa and water stress in culture medium adversely affected plantlet
growth. Wild species from ‘Spartioides’ were less affected than ‘Lycioides’ and ‘Euamygdalus’. At the same level of water
potential, sorbitol had lower adverse effects than PEG; the latter being severe. Prunus × sorbitol and Prunus × PEG interactions were significant. At 0.2 M sorbitol and 0.003 M PEG, ‘Spartioides’ produced significantly more roots with
higher total root length and root volume, as well as root-dry weight than those of ‘Lycioides’ and ‘Euamygdalus.’ It is concluded
that in vitro screening of native Iranian almond species under specific and limited water-stress conditions may provide a
system for effectively differentiating the wild species of almond for their expected root mass production under field conditions. 相似文献
8.
A study was conducted to determine which bud (terminal or lateral) breaks first, and thereby exerts primigenic dominance,
on ‘Granny Smith’ and ‘Golden Delicious’, 1-year-old apple (Malus × domestica Borkh.) shoots grown in two locations in the Western Cape, South Africa, with differing degrees of chilling. Primigenic dominance
of laterals was more common in a warm area than a cool area, and more common in ‘Granny Smith’ than ‘Golden Delicious’. Laterals
rarely broke before the terminal in ‘Golden Delicious’, and so differences in lateral development due to position of first
bud to break were only analyzed in ‘Granny Smith’ shoots from this point on in the study. In ‘Granny Smith’, lateral budbreak
and growth was influenced by the position of the first bud to break on the shoot, but did not differ between locations. On
‘Granny Smith’ shoots with primigenic dominance of the terminal, lateral budbreak and growth was suppressed, in accordance
with the typical ‘delayed foliation’ commonly observed in warm winter climates. However, when at least one lateral broke before
the terminal, lateral budbreak and growth were similar to previous observations in cold winter areas. 相似文献
9.
Common names (CN) add to linguistic richness and ultimately derive from how a majority of people refer to a species. CN have
a biological and–above all—practical importance given that they are essential for connecting specialists and lay people. To
illustrate the diversity of CN between and within species, we made an overview of common name in Caprinae species—flagship
species in mountain ecosystems. Then, using Capra pyrenaica as a study case, we highlighted that the choice of CN is inextricably linked to current debates and trends in wildlife management
that should never be ignored, given their importance in the fields of ethics, zoology, systematics, conservation and current
management. We underline the need to investigate further the probable relationships linking common names, human perception
and wildlife management. Researchers, citizens and policy-makers will have to be watchful that clumsy common names, such as
‘wild-to-domestic’ transformed ones, will not hamper the conservation of wild species as a ‘Common Heritage’. 相似文献
10.
Microcuttings of three strains of ‘McIntosh’ apple that varied in their growth habit under field conditions were tested for
their tolerance to three cytokinins (BA, kinetin, and 2iP) and one cytokinin-like compound (TDZ) in vitro. The three strains
were ‘McIntosh’ (standard), ‘Macspur’ (intermediate) and ‘Wijcik’ (dwarf). For each cytokinin ‘Wijcik’ was more tolerant of
high cytokinin levels than either ‘Macspur‘, which showed an intermediate tolerance, or ‘McIntosh’ which did not tolerate
(died) high levels of cytokinins. These results show that ‘Wijcik’ exhibits multiple cytokinin tolerance in vitro. The relationship
between growth habit and BA tolerance has been reported earlier. The present study demonstrates that cytokinins can be used
to differentiate among growth types in apple.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
11.
12.
Statistical strategies for avoiding false discoveries in metabolomics and related experiments 总被引:9,自引:8,他引:1
David I. Broadhurst Douglas B. Kell 《Metabolomics : Official journal of the Metabolomic Society》2006,2(4):171-196
Many metabolomics, and other high-content or high-throughput, experiments are set up such that the primary aim is the discovery
of biomarker metabolites that can discriminate, with a certain level of certainty, between nominally matched ‘case’ and ‘control’
samples. However, it is unfortunately very easy to find markers that are apparently persuasive but that are in fact entirely
spurious, and there are well-known examples in the proteomics literature. The main types of danger are not entirely independent
of each other, but include bias, inadequate sample size (especially relative to the number of metabolite variables and to
the required statistical power to prove that a biomarker is discriminant), excessive false discovery rate due to multiple
hypothesis testing, inappropriate choice of particular numerical methods, and overfitting (generally caused by the failure
to perform adequate validation and cross-validation). Many studies fail to take these into account, and thereby fail to discover
anything of true significance (despite their claims). We summarise these problems, and provide pointers to a substantial existing
literature that should assist in the improved design and evaluation of metabolomics experiments, thereby allowing robust scientific
conclusions to be drawn from the available data. We provide a list of some of the simpler checks that might improve one’s
confidence that a candidate biomarker is not simply a statistical artefact, and suggest a series of preferred tests and visualisation
tools that can assist readers and authors in assessing papers. These tools can be applied to individual metabolites by using
multiple univariate tests performed in parallel across all metabolite peaks. They may also be applied to the validation of
multivariate models. We stress in particular that classical p-values such as “p < 0.05”, that are often used in biomedicine, are far too optimistic when multiple tests are done simultaneously (as in metabolomics).
Ultimately it is desirable that all data and metadata are available electronically, as this allows the entire community to
assess conclusions drawn from them. These analyses apply to all high-dimensional ‘omics’ datasets. 相似文献
13.
N. Friesen R. Fritsch K. Bachmann 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(8):1229-1238
Random amplified polymorphic DNA (RAPD) and genomic in situ hybridization (GISH) methods have been used to verify the hybridogenic
origin and to identify the parental species of some ornamental cultivars in the subgenus Melanocrommyum of the genus Allium. The cultivars had been selected from seed obtained after uncontrolled pollination in breeders’ fields. The combination of
GISH analysis with RAPD markers is very suitable for testing the hybridogenic origin of plants and to ascertain the parental
species of the hybrids in such cases. As suspected, A. macleanii and A. cristophii are the parental species of ‘Globemaster’. The parental species of cultivar ‘Globus’ are A. karataviense and A. stipitatum, and not A. cristophii and A. giganteum as has been assumed on morphological grounds. Cultivars ‘Lucy Ball’ and ‘Gladiator’ are of hybrid origin, though only one
of the parental species, A. hollandicum, could be confirmed. The cultivars ‘Purple Sensation’, ‘Mount Everest’, ‘White Giant’, ‘Michael H. Hoog’ and ‘Mars’ are not
hybrids since neither GISH nor RAPD suggest the presence of a second genome. ‘Purple Sensation’ belongs to A. hollandicum, ‘Mount Everest’, ‘White Giant’ and ‘Mars’ to A. stipitatum,‘Michael H. Hoog’ to A. rosenorum.
Received: 3 July 1997 / Accepted: 9 October 1997 相似文献
14.
Sophie Y. Dillen Véronique Storme Nicolas Marron Catherine Bastien Sabrina Neyrinck Marijke Steenackers Reinhart Ceulemans Wout Boerjan 《Tree Genetics & Genomes》2009,5(1):147-164
Interspecific hybrids of Populus species are known for their superior growth. In this study, we examined the effect of the genetic background and contrasting
environmental conditions on growth and searched for quantitative trait loci (QTL) affecting growth traits. To this end, two
hybrid poplar families resulting from controlled crosses, Populus deltoides ‘S9-2’ × P. nigra ‘Ghoy’ (D × N, 180 F1) and P. deltoides ‘S9-2’ × P. trichocarpa ‘V24’ (D × T, 182 F1), were grown at two contrasting sites, Northern Italy and Central France. At the end of the second growing season, tree dimensions
(stem height, circumference, and volume) were assessed. The performances of both families significantly differed within and
between sites. Tree volume was significantly larger at the Italian site as compared to the French site. Genotype by environment
interactions were significant but low for both families and for all growth traits. Tight correlations among the individual
growth traits indicated that there may be a common genetic mechanism with pleiotropic effects on these growth traits. In line
with previous studies, linkage groups I, VII, IX, X, XVI, XVII, and XIX appeared to have genomic regions with the largest
effects on growth traits. This study revealed that (1) both families have high potential for selection of superior poplar
hybrids due to the pronounced heterosis (hybrid vigor) and the large genetic variability in terms of growth and (2) the choice
of site is crucial for poplar cultivation.
Dillen and Storme contributed equally to the work.
An erratum to this article can be found at 相似文献
15.
D. A. Lalli A. G. Abbott T. N. Zhebentyayeva M. L. Badenes V. Damsteegt J. Polák B. Krška J. Salava 《Tree Genetics & Genomes》2008,4(3):481-493
Plum pox virus (sharka; PPV) can cause severe crop loss in economically important Prunus species such as peach, plum, apricot, and cherry. Of these species, certain apricot cultivars (‘Stark Early Orange’, ‘Goldrich’,
‘Harlayne’) display significant levels of resistance to the disease and are the genetic substrate for studies of several xlaboratories
working cooperatively to genetically characterize and mark the resistance locus or loci for marker-assisted breeding. The
goals of the work presented in this communication are the characterization of the genetics of PPV resistance in ‘Stark Early
Orange’ and the development of co-dominant molecular markers for marker-assisted selection (MAS) in PPV resistance breeding.
We present the first genetic linkage map for an apricot backcross population of ‘Stark Early Orange’ and the susceptible cultivar
‘Vestar’ that segregates for resistance to PPV. This map is comprised of 357 loci (330 amplified fragment length polymorphisms
(AFLPs), 26 simple sequence repeats (SSRs), and 1 morphological marker for PPV resistance) assigned to eight linkage groups.
Twenty-two of the mapped SSRs are shared in common with genetic reference map for Prunus (T × E; Joobeur et al. 1998) and anchor our apricot map to the general Prunus map. A PPV resistance locus was mapped in linkage group 1 and four AFLP markers segregating with the PPV resistance trait,
identified through bulk segregant analysis, facilitated the development of SSRs in this region.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Lalli, D.A. and Salava, J. contributed equally to this work. 相似文献
16.
Beata Kułek Jolanta Floryszak-Wieczorek Hanna Jackowiak 《Acta Physiologiae Plantarum》2004,26(1):95-102
The involvement of β-D-glucosidase activity in grey mould was studied in two ornamental plant species attacked by Botrytis cinerea.
β-D-glucosidase activity in the susceptible pelargonium cultivar ‘Shiva’ gradually increased with the disease development
in the leaf spots and their surroundings. The endogenic level of the studied hydrolase in the resistant pelargonium ‘Cascade’
was several times higher than in the susceptible cultivar ‘Shiva’ and in principle underwent no changes after inoculation.
The postinfection increase in the activity of β-D-glucosidase noted in the leaves of the susceptible poinsettia cultivar ‘Malibu
Red’ was evidently weaker in the intensity, but its tendencies were similar to those of the susceptible pelargonium cultivar.
In the leaves of the medium-resistant poinsettia ‘Coco White’ the constitutional level of β-D-glucosidase was 2-3-fold higher
in that cultivar than in the susceptible cv. ‘Malibu Red’. In attacked leaves of ‘Coco White’, the enzyme activity continued
to increase temporarily until the 3rd h after inoculation.
The process of healthy leaf senescence in both species had no significant influence on the change of the studied enzyme activity
which was generally low. A high activity of β-D-glucosidase was also observed in the homogenate prepared from mycelium and
in the fungal spores. 相似文献
17.
This paper studies a class of dynamical systems that model multi-species ecosystems. These systems are ‘resource bounded’
in the sense that species compete to utilize an underlying limiting resource or substrate. This boundedness means that the
relevant state space can be reduced to a simplex, with coordinates representing the proportions of substrate utilized by the
various species. If the vector field is inward pointing on the boundary of the simplex, the state space is forward invariant
under the system flow, a requirement that can be interpreted as the presence of non-zero exogenous recruitment. We consider
conditions under which these model systems have a unique interior equilibrium that is globally asymptotically stable. The
systems we consider generalize classical multi-species Lotka–Volterra systems, the behaviour of which is characterized by
properties of the community (or interaction) matrix. However, the more general systems considered here are not characterized
by a single matrix, but rather a family of matrices. We develop a set of ‘explicit conditions’ on the basis of a notion of
‘uniform diagonal dominance’ for such a family of matrices, that allows us to extract a set of sufficient conditions for global
asymptotic stability based on properties of a single, derived matrix. Examples of these explicit conditions are discussed. 相似文献
18.
Matthew R. Gilligan 《Environmental Biology of Fishes》1980,5(2):109-116
Synopsis Reef fish community composition in three segments of a peninsular rocky shoreline in the Gulf of California was estimated
over four periods by visual observation. ‘Point’ and ‘bay’ segments had regular and distinct species compositions over most
periods while a ‘middle’ segment was least distinct but consistently had the greatest number of species. Compositional change
along the peninsula was least regular during the coldest sea temperature period (April). Mean species turnover between segments
was highest between point and bay. Within segments, the point had greater compositional predictable composition (lowest species
turnover). When species with regular frequency of encounter were classified into ‘point’, ‘middle’, ‘bay’, and ‘no trend’
groups it was found that comparatively more ‘point’ species had pelagic eggs and comparatively more ‘bay’ species had demersal
eggs. Beta diversity of rocky-shore fishes along the physical gradient of the Punta Doble peninsula reflects a transition
between exposed and protected rocky shoreline communities. The correlated physical environmental characteristics associated
with exposed and protected habitats are discussed in relation to diversity regulation and dispersal strategies in reef fishes. 相似文献
19.
20.
Anatomical structure and gravitropic response of the creeping shoots of ground-cover chrysanthemum ‘Yuhuajinhua’ 总被引:1,自引:0,他引:1
Shumei Zhang Sumei Chen Fadi Chen Nianjun Teng Weimin Fang Zhiyong Guan 《Plant Growth Regulation》2008,56(2):141-150
The chrysanthemum cultivar ‘Yuhuajinhua’ has a creeping habit. The anatomy and distribution of amyloplasts within ‘Yuhuajinhua’
stems were compared to those typical of non-creeping cultivars. ‘Yuhuajinhua’ stems are similar to those of conventional cultivars;
but except for the pith, the proportion of the various tissues present in the upper side of stems was higher than that in
the lower side. Most of the amyloplasts lie in the centre of the endodermal cells of the ‘Yuhuajinhua’ stems, rather than
at the bottom, as is typical for non-creeping cultivars. When ‘Yuhuajinhua’ plants were oriented horizontally and kept in
the dark, the stems retained their original growth direction, and the endodermis amyloplasts sedimented according to the gravitational
direction. The endodermis amyloplasts responded rapidly to gravistimulation. The content of IAA in the upper side of the ‘Yuhuajinhua’
stems was higher than that in the lower side, associated with the assymetric growth of the stems. 相似文献