J B Power

University of Nottingham, Nottigham, England, United Kingdom

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Publications (224)558.26 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Gibberellins (GAs) control many aspects of plant development, including seed germination, shoot growth, flower induction and growth and fruit expansion. Leaf explants of Solanum nigrum (Black Nightshade; Solanaceae) were used for Agrobacterium-mediated delivery of GA-biosynthetic genes to determine the influence of their encoded enzymes on the production of bioactive GAs and plant stature in this species. Constructs were prepared containing the neomycin phosphotransferase (nptII) gene for kanamycin resistance as a selectable marker, and the GA-biosynthetic genes, their expression under the control of the CaMV 35S promoter. The GA-biosynthetic genes comprised AtGA20ox1, isolated from Arabidopsis thaliana, the product from which catalyses the formation of C(19)-GAs, and MmGA3ox1 and MmGA3ox2, isolated from Marah macrocarpus, which encode functionally different GA 3-oxidases that convert C(19)-GAs to biologically active forms. Increase in stature was observed in plants transformed with AtGA20ox1, MmGA3ox2 and MmGA3ox1 + MmGA3ox2, their presence and expression being confirmed by PCR and RT-PCR, respectively, accompanied by an increase in GA(1) content. Interestingly, MmGA3ox1 alone did not induce a sustained increase in plant height, probably because of only a marginal increase in bioactive GA(1) content in the transformed plants. The results are discussed in the context of regulating plant stature, since this strategy would decrease the use of chemicals to promote plant growth.
    No preview · Article · Jan 2012 · Plant Cell Reports
  • C. G. Silva · M. R. Davey · J. B. Power

    No preview · Article · Aug 2011 · Planta Medica
  • Source
    A. Chaudhury · J. B. Power · M. R. Davey
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    ABSTRACT: High frequency direct plant regeneration from leaf and petal explants was accomplished for the first time in Streptocarpus varieties. The shoot induction frequency varied with respect to the benzylaminopurine (BAP) concentration added to the Murashige and Skoog (MS) medium. MS medium with 0.5 mg l−1 BAP exhibited the highest (69.9%) plant regeneration frequency with an average of 186 shoots per explant. A higher concentration of BAP inhibited shoot bud induction and plant regeneration along with necrosis of explants. Petal explants derived from the varieties ‘Branwen’ (pink and white) and ‘Chorus Line’ (violet and white) displayed plant regeneration frequency of 22.2–47.4% (within a total of 12 weeks) on MS medium containing 2.0 mg l−1 α-naphthaleneacetic acid and 0.5 mg l−1 BAP for 8 weeks followed by 4 weeks on MS medium with 1.0 mg l−1 BAP. Scanning electron microscopy confirmed direct plant regeneration without callus. Regenerated plants from leaf explants with well-developed leaves and roots were hardened and successfully transferred to pots in glasshouse exhibiting 86% survival at the end of 4–6 weeks. Whereas, regenerated plants from flower petal explants upon transfer to pots in glasshouse exhibited 75–82% survival at the end of 4–6 weeks. Key wordscluster-direct plant regeneration-flower petal- Streptocarpus
    Full-text · Article · Jun 2010
  • Davey MR · Anthony P · Patel D · Power JB

    No preview · Article · Jan 2010
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    ABSTRACT: Supplementation of semi-solid R2 culture medium with a commercial bovine haemoglobin (Hb) solution (Erythrogen™) at 1:50-1:500 (v:v), had beneficial effects on the growth, following cryopreservation, of cells of the Indica rice, Oryza sativa cv. Pusa Basmati 1. The mean absorbance, as assessed by triphenyl tetrazolium chloride reduction, of rice cells at 8 d post-thawing, was increased by up to 60% (P < 0.05), compared to cells recovered in the absence of Hb. Eryihrogen™ (1:50-1:500 v:v) promoted an increase in biomass, of up to 25% over control (P < 0.05), at 24 d post-thawing. Cell suspensions, re-established by transfer to liquid medium of cells initially thawed and cultured with Erythrogen™ for 24 d, exhibited increased (up to 2-fold) growth rates over a subsequent 20-d period, compared to cells recovered without Hb.
    No preview · Article · Jul 2009 · Artificial Cells Blood Substitutes and Biotechnology
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    ABSTRACT: Global production of ornamental plants is increasing each year with fierce competition between producers, stimulated by increasing consumer demand. Innovations are required in terms of new products at competitive prices to attract consumers. Thus, the industry is under constant pressure to create novel traits. Manipulating the concentration of endogenous growth regulators, such as gibberellins (GAs), in plants can potentially modify shoot architecture. In this investigation, genes from the GA metabolic pathway have been expressed ectopically using the CaMV 35S constitutive promoter in Solanum nigrum and Nicotiana sylvestris. Plants showed statistically significant alteration to their architecture (t-test at 0.01 probability). The feasibility of using tissue-specific promoters was also evaluated in relation to the modification of stature. The technology may lead to decreased dependence on chemical growth regulators, over which there are concerns in relation to human health and potential environmental consequences.
    No preview · Article · Feb 2009 · Acta horticulturae
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    ABSTRACT: Random amplified polymorphic DNA (RAPD) analysis was applied to eight commercial cultivars of pineapple, two intergroup hybrids and two wild species. Morphologically, pineapple is divided into the Cayenne, Queen, Spanish, Maipure and Abacaxi groups. Members of the first three groups have been analysed in this study. The cultivars ‘Tradsithong’, ‘Phuket’, ‘Sawee’ and ‘Tainan’, with spiny leaves, form the Queen group. In ‘Pattavia’, ‘Nanglae’ and ‘Petburi no. 2’ (Cayenne group), spines are confined to the leaf tips. ‘Intrachitdang’ is normally placed in the Spanish group, which is morphologically similar to the Queen group, but with inferior quality fruit. DNA amplification products were compared from 16 arbitrary 10-mer primers from which a dendrogram was constructed. The results confirmed morphological classifications for seven of the eight commercial cultivars, with the Queen and Cayenne groups as separate clusters. However, the cv. ‘Intrachitdang’ was more closely related to the Cayenne group. Two hybrids from reciprocal Cayenne × Queen group crosses, were more closely allied to the Queen group. The two wild species were outside the groups. RAPD analysis can be exploited to investigate relationships within pineapple germplasm.
    No preview · Article · Jun 2008 · Plant Breeding
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    ABSTRACT: Gibberellins (GAs) are endogenous hormones that play a predominant role in regulating plant stature by increasing cell division and elongation in stem internodes. The product of the GA 2-oxidase gene from Phaseolus coccineus (PcGA2ox1) inactivates C(19)-GAs, including the bioactive GAs GA(1 )and GA(4), by 2beta-hydroxylation, reducing the availability of these GAs in plants. The PcGA2ox1 gene was introduced into Solanum melanocerasum and S. nigrum (Solanaceae) by Agrobacterium-mediated transformation with the aim of decreasing the amounts of bioactive GA in these plants and thereby reducing their stature. The transgenic plants exhibited a range of dwarf phenotypes associated with a severe reduction in the concentrations of the biologically active GA(1) and GA(4). Flowering and fruit development were unaffected. The transgenic plants contained greater concentrations of chlorophyll b (by 88%) and total chlorophyll (11%), although chlorophyll a and carotenoid contents were reduced by 8 and 50%, respectively. This approach may provide an alternative to the application of chemical growth retardants for reducing the stature of plants, particularly ornamentals, in view of concerns over the potential environmental and health hazards of such compounds.
    No preview · Article · Apr 2008 · Plant Cell Reports
  • MR. Davey · Anthony P. · Prentice R. · Patel D. · Power J. B. · Lowe K.C.

    No preview · Article · Jan 2008
  • P. Sipen · P. Anthony · M. R. Davey · J. B. Power

    No preview · Article · Apr 2007 · Comparative Biochemistry and Physiology - Part A Molecular & Integrative Physiology
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    ABSTRACT: The localization was determined of the triterpenoids, asiaticoside and madecassoside, in different organs of glasshouse-grown plants and cultured material, including transformed roots, of two phenotypes of Centella asiatica (L.) Urban of Malaysian origin. Methanolic extracts of asiaticoside and madecassoside were prepared for gradient HPLC analysis. The two phenotypes of C. asiatica exhibited differences in terpenoid content that were tissue specific and varied between glasshouse-grown plants and tissue culture-derived material. Terpenoid content was highest in leaves, with asiaticoside (0.79 ± 0.03 and 1.15 ± 0.10 % of dry mass) and madecassoside [0.97 ± 0.06 and 1.65 ± 0.01 %(d.m.)] in the fringed (F) and smooth leaf (S) phenotypes, respectively. Roots of the F-phenotype contained the lowest content of asiaticoside [0.12 ± 0.01 %(d.m.)], whereas petioles of S-phenotype plants contained the lowest content of asiaticoside [0.16 ± 0.01 %(d.m.)] and madecassoside [0.18 ± 0.14 %(d.m.)]. Transformed roots were induced using Agrobacterium rhizogens and their growth was maximal on Murashige and Skoog basal medium supplemented with 60 g dm−3 sucrose. However, asiaticoside and madecassoside were undetectable in transformed roots and undifferentiated callus.
    No preview · Article · Mar 2007 · Biologia Plantarum
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    ABSTRACT: Gravity is an important environmental factor that controls plant growth and development. Studies have shown that the perception of gravity is not only a property of specialized cells, but can also be performed by undifferentiated cultured cells. In this investigation, callus of Arabidopsis thaliana cv. Columbia was used to investigate the initial steps of gravity-related signalling cascades, through altered expression of transcription factors (TFs). TFs are families of small proteins that regulate gene expression by binding to specific promoter sequences. Based on microarray studies, members of the gene families WRKY, MADS-box, MYB, and AP2/EREBP were selected for investigation, as well as members of signalling chains, namely IAA 19 and phosphoinositol-4-kinase. Using qRT-PCR, transcripts were quantified within a period of 30 min in response to hypergravity (8g), clinorotation [2-D clinostat and 3-D random positioning machine (RPM)] and magnetic levitation (ML). The data indicated that (1) changes in gravity induced stress-related signalling, and (2) exposure in the RPM induced changes in gene expression which resemble those of magnetic levitation. Two dimensional clinorotation resulted in responses similar to those caused by hypergravity. It is suggested that RPM and ML are preferable to simulate microgravity than clinorotation.
    No preview · Article · Jan 2007 · Advances in Space Research
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    ABSTRACT: A key requirement to enhance our understanding of the response of biological organisms to different levels of gravity is the availability of experimental systems that can simulate microgravity and hypergravity in ground-based laboratories. This paper compares the results obtained from analysing gene expression profiles of Drosophila in space versus those obtained in a random position machine (RPM) and by centrifugation. The correlation found validates the use of the RPM simulation technique to establish the effects of real microgravity on biological systems. This work is being extended to investigate Drosophila development in another gravity modifying instrument, the levitation magnet.
    No preview · Article · Jan 2007 · Journal of gravitational physiology: a journal of the International Society for Gravitational Physiology
  • Chapter: Lettuce
    M. Davey · P. Anthony · P. Van Hooff · J. Power · K. Lowe

    No preview · Chapter · Dec 2006
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    ABSTRACT: Pineapple plants transformed with the bar gene for bialaphos resistance were evaluated for transgene stability, gene expression and tolerance to glufosinate ammonium, the active ingredient of the herbicide Basta® X, under field conditions. Genetically modified plants of the cv. Phuket were micropropagated, rooted and established in a shade house before transfer to an experimental plot. Seven months after transfer to the field, plants were tolerant to 1600 ml/rai of the herbicide Basta® X (stock concentration 15% w/v glufosinate ammonium), this being twice the dose recommended for field application of the herbicide. Genetically modified plants remained green and healthy following spraying with the herbicide. In contrast, non-transformed pineapple plants of the same cv. became necrotic and died within 21 days of spraying with the herbicide at a reduced concentration of 800 ml/rai. Bar gene stability and expression in clonally-derived plants were assessed by PCR, RT-PCR and Southern analyses at 120, 210, 240, 270 and 380 days following transfer of the plants to the field. The bar gene was stable and expressed in transgenic plants throughout the duration of the trial. Fruit characteristics and yield were not affected by transgene introduction and expression. Transgenic plants tolerant to glufosinate ammonium should facilitate more effective weed control in pineapple plantations without damage to the crop.
    No preview · Article · Jul 2006 · Plant Breeding
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    ABSTRACT: Two hexaploid somatic hybrids [Sh; L. esculentum (+) L. Peruvianum] accessions 6 and 18 were back-crossed with two diploid L. Esculentum cultivars ‘Moneymaker’ (mm) and ‘pusa Ruby’ (pr). Twenty-two plants of the bc2 generation were produced by backcrossing 7 bcl plants (mm x sh, 6, 18) with five tomato cultivars. Fourteen of the bc2 plants were self-fertile, five produced anther cones with anthocyanin pigmentation not present in the parents. A bc3 generation was developed by crossing the four cultivars as female parent with three bc2 generation plants. The bc3 progeny derived from one pollen parent plant were produced without the need to culture immature seeds. They segregated with respect to pigmented anther cones and were self-fertile. The anther cone pigmentation of the pollen parent plant was associated with increased seed set, greater fruit size and an orange-red fruit colour. These features were transmitted to the fertile bc3 generation. Conversely, bc3 offspring involving the other two parent plants were only recovered by culture of immature seeds. The recovery of diploid plants in BCl and self-fertility in BC2 resulted in almost total recovery of the tomato cultivar characteristics (fruit size, colour and number of seeds) by BC3.
    No preview · Article · Apr 2006 · Plant Breeding
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    ABSTRACT: Knowledge of the genetic relationships among landraces is useful to gene bank managers because it permits a better organization of the crop's gene pool management, more efficient sampling of the available germplasm resources and better access to useful genetic variation for breeders. Genetic diversity of 19 landraces of the cultivated mung bean, Vigna radiate, and three weedy and wild relatives including Vigna mungo, Vigna luteola and Vigna radiate var. sublobata, was investigated at the DNA level with the random amplified polymorphic DNA (RAPD) procedure. Sixty random decamer primers were employed in amplification reactions; 28 of these were informative and yielded 246 bands, of which 229 were polymorphic with a mean of 8.2 bands per primer. A genetic distance matrix based on Nei and Li coefficient was converted to a dendrogram and a two-dimensional plot using multidimensional scaling (MDS). The accessions studied were separated into three main clusters, which included V. radiate landraces, V. mungo and V. luteola, respectively. The variation of this cluster supports the view that the genetic distance of V. mungo and V. luteola varies considerably from the accession VO2955 (V. radiata). The multidimensional scaling plot confirmed that V. mungo, V. luteola and most of the accessions of V. radiata formed distinct clusters with no overlap, and two mung bean accessions (PI177493 and VO4134–1 from Turkey and India, respectively) were genetically distant from other V. radiata landraces. V. radiata and V. mungo are positioned in separate botanical species and V. radiata var. sublobata is classified within other V. radiata landraces. Based on the limited range of accessions tested, the approach holds promise for the classification of mung bean germplasm, identification of mung bean landraces and applications of molecular markers to mung bean breeding.
    No preview · Article · Apr 2006 · Plant Breeding
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    ABSTRACT: Pineapple plants of the cv. Phuket transformed with the bar gene for herbicide tolerance were micropropagated, rooted and established in a shade house before transfer to an experimental field plot. Seven months after transfer to the field, plants were tolerant to 1600 ml rai-1 (240 g rai -1) of the herbicide Basta X®, this being twice the dose recommended for field application of the herbicide. In contrast, non-transformed pineapple plants became necrotic and died within 21 days of spraying with the herbicide at 800 ml rai-1. Bar gene stability and expression in clonally-derived plants were assessed by PCR, RT-PCR and Southern analyses at 120, 210 and 380 days following transfer of the plants to the field. The bar gene was stable and expressed in transgenic plants throughout the duration of the trial. Importantly, fruit quality and yield were unaffected by transformation.
    No preview · Article · Feb 2006 · Acta horticulturae
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    ABSTRACT: RAPD markers have been used to develop genetic fingerprints for 12 Ipomoea species and eight lines of I. rubro-coerulea. Out of the 18 primers initially acquired, only 15 were of real use producing fingerprints suitable for analysis. 114 distinct bands were produced by the remaining 15 primers, resulting in a rather high mean of 7.6 bands/primer. Out of the 15 primers used, only three revealed an obvious polymorphism of the eight I. rubro-coerulea lines indicating that some of the I. rubro-coerulea lines show the same high level of polymorphism at the molecular level, as the tested Ipomoea species do. All 15 primers revealed significant polymorphism when only the species of Ipomoea genus were taken into consideration. The dendrogram constructed on the basis of computed genetic distances confirmed the affiliation of the tested Ipomoea species to the morphologically classified sections Pharbitis, Quamoclit and Batatas. The greatest genetic distance seems to be between section Batatas and the other two ornamental sections (Pharbitis and Quamoclit). Considering each section separately, the most homogeneous species structure was found in section Quamoclit while the other two sections showed a rather high heterogeneity of the comprised species. There can be concluded that RAPD analysis proved to be a valuable tool in identifying phylogenetic relationships among Ipomoea species. This kind of information could be of real help in identifying the most interfertil genitors for interspecific crosses required by breeding programs both of I. batatas and of ornamental Ipomoea species.
    Full-text · Article · Jun 2004 · Acta horticulturae
  • Source
    N Jayabalan · P Anthony · M R Davey · J B Power · K C Lowe
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    ABSTRACT: Critical parameters influencing somatic embryogenesis include growth regulators and oxygen supply. Consequently, the present investigation has focused on optimization of a somatic embryogenic system for peanut (Arachis hypogaea L.) through media supplementation with the auxin, picloram. The latter at 30 mg L(-1) was optimal for inducing regeneration of somatic embryos from cultured explants of zygotic embryos. In contrast, somatic embryogenesis did not occur in the absence of this growth regulator. An assessment has also been made of the beneficial effect on somatic embryogenesis and plant regeneration of the commercial hemoglobin (Hb) solution, Erythrogen. Hemoglobin at 1:50 and 1:100 (v:v) stimulated increases in mean fresh weight (up to a maximum of 57% over control), mean number of explants producing somatic embryos (15%) and mean number of somatic embryos per explant (29%).
    Full-text · Article · Mar 2004 · Artificial Cells Blood Substitutes and Biotechnology

Publication Stats

4k Citations
558.26 Total Impact Points


  • 1970-2012
    • University of Nottingham
      • • Division of Plant and Crop Sciences
      • • School of Biosciences
      • • School of Life Sciences
      Nottigham, England, United Kingdom
  • 1975
    • The Royal Institution of Great Britain
      Londinium, England, United Kingdom