|Macnish, A.J. - UC DAVIS PLANT SCIENCES|
|Reid, M.S. - UC DAVIS PLANT SCIENCES|
Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: June 1, 2009
Publication Date: December 1, 2009
Citation: Macnish, A., Reid, M., Jiang, C. 2009. NICOTIANA MUTABILIS-A NOVEL SYSTEM FOR STUDYING ETHYLENE-MEDIATED FLORAL SENESCENCE. Acta Horticulturae. 847: 95-102. Technical Abstract: As its specific epithet indicates, Nicotiana mutabilis, a tobacco species recently discovered in southern Brazil, has flowers that change color during their display life. Opening buds are white, and as the flower ages, the color changes, at first gradually, and then rapidly through light pink to dark pink and even red. The onset of the pigment change is associated with a marked increase in ethylene production, and the change is retarded by treating the flowers with 1-methylcyclopropene, an inhibitor of ethylene action. Expression of the gene encoding chalcone synthase increased substantially in association with increased concentrations of anthocyanins in the petals. Likewise, expression of a homolog of SAG12, a leaf senescence-associated gene first isolated from Arabidopsis, increased as the color change advanced and ethylene production increased. The numerous genetic and experimental tools available for N. tabacum can readily be applied to this close relative, which therefore provides an interesting new model for studying flower senescence.