title: Polyamines promote root elongation and growth by increasing root cell division in regenerated Virginia pine (Pinus virginiana Mill.) plantlets.
abstract: Polyamines have been demonstrated to play an important role in adventitious root formation and development in plants. Here, we present a detailed analysis of influence of exogenously added polyamines on adventitious root development and its relationship to cold tolerance in Virginia pine (Pinus virginia Mill.). Our results demonstrated that polyamines putrescine (Put), spermidine (Spd), and spermine (Spm) at 0.001 mM improve rooting frequency and promote root elongation. Put, Spd, and Spm at 0.01-1 mM decrease rooting frequency and reduce root elongation root elongation. Measurements of diamine oxidase (DAO, EC 1.4.3.6) and polyamine oxidase (PAO, EC 1.4.3.4) activities showed that higher DAO and PAO enzyme activities were obtained when high concentrations of polyamines were applied and when plantlets were treated for 5-7 week at 4 degrees C and 16 degrees C. Survival rate of plantlets increased with the treatment of polyamines at low temperature. Polyamines increased mitotic index of cells in root tips of regenerated plantlet cultured on medium containing 0.001 microM Put, Spd, or Spm, but did not increase mitotic index in tissues of needle tips of the same plantlets. These results demonstrated that polyamines promote root elongation and growth by increasing root cell division in regenerated Virginia pine plantlets.
authors.affiliation: Department of Biology, Howell Science Complex, East Carolina University, Greenville, NC 27858-4353, USA. tangw@mail.ecu.edu
authors.forename: Wei
authors.initials: W
authors.lastname: Tang
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Newton
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000187:drug effects / Q000378:metabolism; D015317:Biogenic Polyamines / Q000378:metabolism* / Q000494:pharmacology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D008938:Mitosis / Q000187:drug effects / Q000502:physiology*; D008940:Mitotic Index; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000187:drug effects / Q000378:metabolism; D028223:Pinus / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D011700:Putrescine / Q000378:metabolism / Q000494:pharmacology; D012038:Regeneration / Q000187:drug effects / Q000502:physiology*; D013095:Spermidine / Q000378:metabolism / Q000494:pharmacology; D013096:Spermine / Q000378:metabolism / Q000494:pharmacology; D015996:Survival Rate; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D000097667:Polyamine Oxidase
chemical_list: D006631:Amine Oxidase (Copper-Containing); D015317:Biogenic Polyamines; D000587:Oxidoreductases Acting on CH-NH Group Donors; D011700:Putrescine; D013095:Spermidine; D013096:Spermine; D000097667:Polyamine Oxidase