Increased resistance to oxidative stress in transgenic plants by targeting mannitol biosynthesis to chloroplasts

• Published in: Plant physiology (Bethesda) 1997-04, Vol.113 (4), p.1177-1183
• Main Authors: Shen, B. (The University of Arizona, Tucson, AZ.), Jensen, R.G, Bohnert, H.J
• Format: Article
• Language: English
• Subjects: ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; ANALISIS CUANTITATIVO; ANALYSE QUANTITATIVE; BACTERIA; Biological and medical sciences; BIOSINTESIS; BIOSYNTHESE; BIOSYNTHESIS; Carbon Dioxide - metabolism; CHEMICAL COMPOSITION; CHLOROPHYLLE; CHLOROPHYLLS; CHLOROPLASTE; CHLOROPLASTS; Chloroplasts - metabolism; CLOROFILAS; CLOROPLASTO; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; Enzymes; ENZYMIC ACTIVITY; Escherichia coli - genetics; EXPRESION GENICA; EXPRESSION DES GENES; FEUILLE; FOTOSINTESIS; Fundamental and applied biological sciences. Psychology; GENE; GENE EXPRESSION; GENE TRANSFER; GENES; Genes, Bacterial; GENETIC REGULATION; GENETICA; GENETICS; GENETIQUE; GENOTIPOS; GENOTYPE; GENOTYPES; HOJAS; Hydroxyl radicals; Kinetics; LEAVES; MANITOL; MANNITOL; Mannitol - metabolism; MANNITOL-1-PHOSPHATE DEHYDROGENASE; Mesophyll cells; Metabolism; Metabolism. Physicochemical requirements; METHYL VIOLOGEN; NET ASSIMILATION RATE; Nicotiana - physiology; NICOTIANA TABACUM; Oxidative Stress; OXIDOREDUCTASES; OXIDORREDUCTASAS; OXIGENO; OXYDOREDUCTASE; OXYGEN; OXYGENE; PHOTOSYNTHESE; PHOTOSYNTHESIS; Plant cells; Plant Leaves; Plant physiology and development; PLANTAS TRANSGENICAS; PLANTE TRANSGENIQUE; Plants; Plants, Genetically Modified - physiology; Plants, Toxic; QUANTITATIVE ANALYSIS; REACTIVE OXYGEN SPECIES; Recombinant Proteins - biosynthesis; STRESS RESPONSE; Sugar Alcohol Dehydrogenases - biosynthesis; Sugar Alcohol Dehydrogenases - genetics; Superoxides; TRANSFERENCIA DE GENES; TRANSFERT DE GENE; TRANSGENIC PLANTS; Whole Plant, Environmental, and Stress Physiology; WILD RELATIVES
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.113.4.1177

To investigate the potential role of a polyol, mannitol, in oxidative stress protection, a bacterial mannitol-1-phosphate dehydrogenase gene was targeted to chloroplasts by the addition of an amino-terminal transit peptide. Transgenic tobacco (Nicotiana tabacum) lines accumulate mannitol at concentrations ranging from 2.5 to 7 micromoles/g fresh weight. Line BS1-31 accumulated approximately 100 mM mannitol in chloroplasts and was identical to the wild type in phenotype and photosynthetic performance. The presence of mannitol in chloroplasts resulted in an increased resistance to methyl viologen (MV)-induced oxidative stress, documented by the increased retention of chlorophyll in transgenic leaf tissue following MV treatment. In the presence of MV, isolated mesophyll cells of BS1-31 exhibited higher CO2 fixation than the wild type. When the hydroxyl radical probe dimethyl sulfoxide was introduced into cells, the initial formation rate of methane sulfinic acid was significantly lower in cells containing mannitol in the chloroplast compartment than in wild-type cells, indicating an increased hydroxyl radical-scavenging capacity in BS1-31 tobacco. We suggest that the chloroplast location of mannitol can supplement endogenous radical-scavenging mechanisms and reduce oxidative damage of cells by hydroxyl radicals