Transformation of carnation with genes related to ethylene production and perception: towards generation of potted carnations with a longer display time

Abstract

Potted carnation (Dianthus caryophyllus L. cv. Lillipot) plants were transformed with cDNAs for carnation 1-aminocyclopropane-1-carboxylate (ACC) synthase (DC-ACS1, s/aACS transgenes) or ACC oxidase (DC-ACO1, s/aACO transgenes) in sense or antisense orientation or mutated carnation ethylene receptor cDNA (DC-ERS2¢) by Agrobacterium-mediated gene transfer. The presence of acetosyringone at 100 lM in media for shoot culture prior to leaf explant preparation and preculture of Agrobacterium in addition to the conventional method of addition to media for infection and coculture, and the use of water instead of nutrient media for infection and coculture increased the transformation efficiency to 4.0% compared to the 0.1% obtained by the conventional method. PCR analysis as well as Southern blot analysis confirmed the integration of the ethylene-related transgenes. Leaflet segments of cultured shoots of some lines transformed with s/aACO transgenes had less activity to convert ACC to ethylene than that of the non-transformed control plant, indicating that the integrated s/aACO transgenes reduced the expression of endogenous ACC oxidase gene (DC-ACO1) in the cultured shoots.

Regulation of ethylene biosynthesis at the level of 1-aminocyclopropane-1-carboxylate oxidase (ACO) gene

“…An introduction of the ACO gene in antisense orientation has been proved as an efficient method for ethylene suppression and is still in use (Nuñez-Palenius et al 2006;Kinouchi et al 2006;Huang et al 2007;Wang et al 2009). Other studies have demonstrated that the introduction of truncated ACO gene constructs in the sense orientation can result in co-suppression of homologous host genes, and modulate ethylene biosynthesis (Knoester et al 1997;Aida et al 1998;López-Gómez et al 2009).…”

Transgenics in Ornamental Crops:Creating Novelties in Economically Important Cut Flowers

“…Bovy et al 95 introgressed an Arabidopsis thaliana etr1-1 allele into carnation gemone to generate transgenic lines, where its heterologous expression reduced ethylene production and enhanced flower longevity. Kinouchi et al 96 generated transgenic lines in potted carnation harbouring ACC oxidase (DCACO1, s/aACO) or ACC synthase (DC-ACS1, s/aACS) in sense or antisense orientation, or mutated carnation ethylene receptor cDNA (DC-ERS2). Inokuma et al 97 observed reduced ethylene production and longer vase life in the transgenic lines of 'Lillipot' carnation harbouring an sACO transgene.…”