title: Antisense expression of carnation cDNA encoding ACC synthase or ACC oxidase enhances polyamine content and abiotic stress tolerance in transgenic tobacco plants.
abstract: The amount of polyamines (such as putrescine, spermidine, and spermine) increased under environmental stress conditions. We used transgenic technology in an attempt to evaluate their potential for mitigating the adverse effects of several abiotic stresses in plants. Because there is a metabolic competition for S-adenosylmethionine as a precursor between polyamine (PA) and ethylene biosyntheses, it was expected that the antisense-expression of ethylene biosynthetic genes could result in an increase in PA biosynthesis. Antisense constructs of cDNAs for senescence-related 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (CAS) and ACC oxidase (CAO) were isolated from carnation flowers that were introduced into tobacco by Agrobacterium-mediated transformation. Several transgenic lines showed higher PA contents than wild-type plants. The number and weight of seeds also increased. Stress-induced senescence was attenuated in these transgenic plants in terms of total chlorophyll loss and phenotypic changes after oxidative stress with hydrogen peroxide (H2O2), high salinity, acid stress (pH 3.0), and ABA treatment. These results suggest that the transgenic plants with antisense CAS and CAO cDNAs are more tolerant to abiotic stresses than wild-type plants. This shows a positive correlation between PA content and stress tolerance in plants.
authors.affiliation: Department of Biology, Sunchon National University, Korea.
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Wi
authors.forename: Ky Young
authors.initials: KY
authors.lastname: Park
mesh_terms: D000143:Acids / Q000494:pharmacology; D012437:Adenosylmethionine Decarboxylase / Q000378:metabolism; D000594:Amino Acid Oxidoreductases / Q000235:genetics*; D016922:Cellular Senescence / Q000235:genetics; D016373:DNA, Antisense / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D029749:Dianthus / Q000201:enzymology / Q000235:genetics*; D005030:Ethylenes / Q000378:metabolism; D017343:Genes, Plant; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008190:Lyases / Q000235:genetics*; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress; D010937:Plant Growth Regulators / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000502:physiology*; D011073:Polyamines / Q000378:metabolism*; D012492:Salts / Q000494:pharmacology; D012639:Seeds / Q000378:metabolism; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D014170:Transformation, Genetic
chemical_list: D000143:Acids; D016373:DNA, Antisense; D018076:DNA, Complementary; D005030:Ethylenes; D016877:Oxidants; D010937:Plant Growth Regulators; D011073:Polyamines; D012492:Salts; C036216:ethylene; D006861:Hydrogen Peroxide; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase; D008190:Lyases; D012437:Adenosylmethionine Decarboxylase; C021773:1-aminocyclopropanecarboxylate synthase