Agrobacterium tumefaciens-mediated transformation of Oncidium and Odontoglossum orchid species with the ethylene receptor mutant gene etr1-1

Abstract

Oncidium and Odontoglosum orchid species have reduced display lives and are thus commercially less important than Phalaenopsis. One approach to prolonging display life permanently is to transform Oncidium and Odontoglossum with the ethylene receptor mutant gene etr1-1 from Arabidopsis under control of a flower specific promoter; this should reduce their sensitivity to exogenous ethylene. To achieve this it will be necessary to establish an efficient regeneration protocol using somatic embryogenesis and a routine Agrobacterium tumefaciens-mediated transformation procedure. Protocorm-like bodies (PLBs) of both orchid genera were regenerated from leaf tip explants. Leaf tips and PLBs, cultured in liquid and solid media, were compared as targets for genetic transformation. No transgenic shoots were obtained from leaf tips, while PLBs of Oncidium and Odontoglossum cultured on solid medium were successfully transformed with an expression vector containing nptII and gus genes driven by the cauliflower mosaic virus (CaMV) 35S promoter. Applying the A. tumefaciens strain EHA 105, transformation efficiencies of 1.3-2.7% were achieved for the investigated genotypes. Transformation with etr1-1 gene was achieved subsequently. Oncidium 'Sweet Sugar' has been successfully transformed and validated by PCR and Southern analysis.

Overexpression of a 10-deacetylbaccatin III-10 β-O-acetyltransferase gene leads to increased taxol yield in cells of Taxus chinensis

“…The development of transgenic Taxus cells needs an efficient genetic transformation method. The Agrobacterium-mediated transformation system has been commonly applied to engineer many plant species for desirable traits (Li et al 2008;Gelvin 2009;Raffeiner et al 2009;Silva et al 2009;Banyai et al 2010;Espasandin et al 2010;Ma et al 2010;Zia et al 2010). This system is favored over other methods, such as particle bombardment, due to the integration of low numbers of the transgene into the genome, the stability in the host cells, and the high transformation efficiency, etc.…”

Cloning and characterization of a DCEIN2 gene responsive to ethylene and sucrose in cut flower carnation

“…Ethylene is a gaseous molecule that regulates many aspects of plant development and physiology, including flower senescence and organogenesis (Reid et al 1989;O'Neill et al 1993;Clark et al1997;Guo and Ecker 2004;Dias et al 2009;Karami et al 2008;Raffeiner et al 2009;Lavee et al 2010;Ptak et al 2010). In Arabidopsis, ethylene signaling is mediated by a complex multi-component pathway (Kieber 1997;Guo and Ecker 2004).…”

Induction of Somatic Embryogenesis through Overexpression of ATRKD4 Genes in Phalaenopsis “Sogo Vivien”

“…This compound is highly reactive towards biomolecules, which cause damage of plant tissue followed by browning and necrosis (Kuta and Tripathi, 2005). Several studies of genetic transformation using Agrobacterium with transformation targets in the form of protocorm-like bodies (plb) and orchid protocorm obtained transformation effi ciency of 4.3% in Cattleya (Zhang et al, 2010); 1.91% in Phalaenopsis hybrid (Mishiba et al, 2005); 1.7% in Phalaenopsis amabilis (Semiarti et al, 2007); and 1.3 to 2.7% in Oncidium and Odontoglossum (Raffeiner et al, 2009). To improve the transformation effi ciency, there are many studies using a variety of treatments, such as the provision of antioxidants, desiccation of transformation target before and after infection with Agrobacterium, length of co-cultivation time, density of Agrobacterium tumefaciens used in the transformation, temperature of co-cultivation process, and the addition of surfactant at the time of Agrobacterium tumefaciens infection to the explants (Opabode, 2006).…”