Phillip Morris

Publications (159) View all

• Article: Genetic transformation of Dichanthium annulatum (Forssk)--an apomictic tropical forage grass.

  S J Dalton, A J E Bettany, V Bhat, M G Gupta, K Bailey, E Timms, P Morris
  [show abstract] [hide abstract]
  ABSTRACT: Eleven Dichanthium annulatum (Forssk) plants were regenerated from embryogenic callus co-transformed with two plasmids encoding either the hygromycin phosphotransferase gene (hph) or the beta-glucuronidase (GUS) gene (uidA). Analysis of these putative transformants showed that three plants were transformed with the hph gene, showed the presence of the hph transcript and expressed hygromycin resistance after transfer to soil. Two of these also contained the uidA gene but did not express GUS and were shown to be the same transformation event. All three of the transformants set seed. Hygromycin resistance varied from 68-100% in the progeny of the three transformants. Transgene transmission appeared to have been mainly through apomixis.
  Plant Cell Reports 07/2003; 21(10):974-80. · 2.27 Impact Factor
• Article: Agrobacterium tumefaciens-mediated transformation of Festuca arundinacea (Schreb.) and Lolium multiflorum (Lam.).

  A J E Bettany, S J Dalton, E Timms, B Manderyck, M S Dhanoa, P Morris
  [show abstract] [hide abstract]
  ABSTRACT: Agrobacterium tumefaciens strain LBA4404 carrying plasmid pTOK233 encoding the hygromycin resistance (hph) and beta-glucuronidase (uidA) genes has been used to transform two agronomic grass species: tall fescue (Festuca arundinacea) and Italian ryegrass (Lolium multiflorum). Embryogenic cell suspension colonies or young embryogenic calli were co-cultured with Agrobacterium in the presence of acetosyringone. Colonies were grown under hygromycin selection with cefotaxime and surviving colonies plated on embryogenesis media. Eight Lolium (six independent lines) and two Festuca plants (independent lines) were regenerated and established in soil. All plants were hygromycin-resistant, but histochemical determination of GUS activity showed that only one Festuca plant and one Lolium plant expressed GUS. Three GUS-negative transgenic L. multiflorum and the two F. arundinacea plants were vernalised and allowed to flower. All three Lolium plants were male- and female-fertile, but the Festuca plants failed to produce seed. Progeny analysis of L. multiflorum showed a 24-68% inheritance of the hph and uidA genes in the three lines with no significant difference between paternal and maternal gene transmission. However, significant differences were noted between the paternal and maternal expression of hygromycin resistance.
  Plant Cell Reports 02/2003; 21(5):437-44. · 2.27 Impact Factor
• Article: Effect of selectable gene to reporter gene ratio on the frequency of co-transformation and co-expression of uidA and hpt transgenes in protoplast-derived plants of tall fescue

  A. J. E. Bettany, S .J. Dalton, E. Timms, M.S. Dhanoa, P. Morris
  [show abstract] [hide abstract]
  ABSTRACT: Forty-six independent transformed plants were regenerated under hygromycin selection from cell-suspension derived protoplasts of Festuca arundinacea (Schreb.) after PEG-mediated transformation. Protoplasts were co-transformed with varying molar gene ratios (0.7:1–6:1) of a marker -glucuronidase (uidA) gene and a selective hygromycin (hpt) resistance gene. Logistic regression analysis indicated that, as expected, the proportion of co-transformed plants tended to increase as the proportion of the marker gene was increased. However, although the proportion of plants co-expressing both genes tended to increase up to a molar ratio of 4:1, it appeared to fall at a molar ratio of 6:1. No statistically significant differences were found in the average copy number of the integrated uidA or hpt transgenes, either in GUS expressing, or in non-GUS expressing plants at the different molar ratios. When using naked-DNA gene transformation methods most authors use a molar ratio of 1:1; our data suggest that adding non-selected and selected transgenes at a higher Molar Gene Ratio would probably improve the proportion of plants regenerated which express both transgenes.
  Plant Cell Tissue and Organ Culture 01/2002; 68(2):177-186. · 3.09 Impact Factor
• Article: Particle-inflow-gun-mediated genetic transformation of buffel grass (Cenchrus ciliaris L.): optimizing biological and physical parameters.

  V Bhat, S J Dalton, S Kumar, B V Bhat, M G Gupta, P Morris
  [show abstract] [hide abstract]
  ABSTRACT: The present study was conducted to optimize various biological and physical parameters for developing an efficient and reproducible gene transfer method for genetic transformation of buffel grass. Transformation was carried out using a helium-driven particle inflow gun (PIG). Embryogenic calli produced from mature seeds of buffel grass cv. CC-119 were separately bombarded with four plasmids, containing Actin (pAct1DX), Ubiquitin (pAHC-25; pAHC-27) and CaMV-35S (pCaMVGUS) promoters, coated on tungsten and gold particles. The efficiency of transformation was monitored through transient GUS expression. Different parameters, viz., the type of promoter, type and size of microcarrier, helium gas pressure, distance and time of bombardment, were standardized for delivering DNA into embryogenic calli. Bombardment with plasmid DNA carrying the actin promoter coated on 1.6 micro gold particles, at a helium pressure of 4 bars, a distance of 10 cm for 10 micro sec and 28 mm Hg vacuum in the chamber, produced the best result in transient GUS expression. The Actin promoter was found to be more efficient in driving expression of the GUS gene in buffel grass, followed by Ubiquitin and CaMV-35S promoters. Lower helium pressure was found to be sub-optimal, while higher pressure produced a smaller number of blue spots, probably due to excessive damage to the cells. Maximum of 385 blue spots was observed with gold particles of 1.6 micro size, whereas only 213 blue spots were recorded for tungsten particles of 1.0 micro size. The optimized parameters can be employed for genetic transformation of buffel grass with genes of agronomic importance.
  Journal of applied genetics 02/2001; 42(4):405-12. · 1.66 Impact Factor
• Source

  Available from: ask-force.org

  Article: Chromosomal localization of cotransformed transgenes in the hexaploid cultivated oat Avena sativa L. using fluorescence in situ hybridization.

  J M Leggett, S J Perret, J Harper, P Morris
  [show abstract] [hide abstract]
  ABSTRACT: Fluorescence in situ hybridization (FISH) was used to localize two transgenes (gus and bar), carried on plasmids pACT-1F and pUBA, respectively, on mitotic metaphase squashes of T1 plants of the cultivated hexaploid oat Avena sativa L. cotransformed by microprojectile bombardment of embryogenic callus. Among the eight progeny analysed by FISH in each of two lines, we detected plants null, hetero- and homozygous for the two genes in one line, and plants null and heterozygous for the two genes in the other line. Our results demonstrated that in the two independent transformation events, the gus and bar genes had inserted in the same position relative to each other. In each transformation event, the insertions occurred on D satellite (SAT) chromosomes bearing a C genome translocation.
  Heredity 02/2000; 84 ( Pt 1):46-53. · 4.60 Impact Factor