A soybean (Glycine max) polyubiquitin promoter gives strong constitutive expression in transgenic soybean

Abstract

The success of plant genetic transformation relies greatly on the strength and specificity of the promoters used to drive genes of interest. In this study, we analyzed gfp gene expression mediated by a polyubiquitin promoter (Gmubi) from soybean (Glycine max) in stably transformed soybean tissues. Strong GFP expression was observed in stably transformed proliferative embryogenic tissues. In whole transgenic plants, GFP expression was observed in root tips, main and lateral roots, cotyledons and plumules in young plants as well as in leaf veins, petioles, flower petals, pollen, pods and developing seeds in mature plants. GFP expression was localized mainly in epidermal cells, leaf mesophyll, procambium and vascular tissues. Introduction of an intron-less version of the Gmubi promoter (Gmupri) displayed almost the same GFP expression pattern albeit at lower intensities. The Gmubi promoter showed high levels of constitutive expression and represents an alternative to viral promoters for driving gene expression in soybean.

Isolation and Characterization of a Polyubiquitin Gene and Its Promoter Region fromMesembryanthemum crystallinum

“…In other plants, promoter activities of upstream regions of ubiquitin genes have been reported. 9,13,16,17,[22][23][24][25] In all cases, the lengths of the ubiquitin promoters tested were shorter than 2.3 kb without 5…”

“…The promoters of polyubiquitin genes have been isolated and characterized by transient assays and in transgenic plants for several monocots and dicots. [5][6][7]9,[11][12][13][14][15][16][17] Some of these promoters support constitutive expression 11,13) and are used extensively to direct transgene expression in Lotus japonicus.…”

Strategies for Improvement of Soybean Regeneration via Somatic Embryogenesis and Genetic Transformation

“…Several studies about soybean transformation via particle bombardment using embryogenic tissues have been published (Finer & McMullen, 1991;Finer et al, 1992;Stewart et al, 1996;Droste et al, 2002;Homrich et al, 2008;Schmidt et al, 2008;Wu et al, 2008;Li et al, 2009;Hernandez-Garcia et al, 2009;Xing et al, 2010).…”

“…Sato et al (1993) proved that somatic embryo proliferation occurred from single epidermal cells of existing somatic embryos. Using proliferative embryos as target tissue many studies succeed in regenerating completely transformed plants (Finer & McMullen, 1991;Finer et al, 1992;Stewart et al, 1996;Trick & Finer, 1998;Droste et al, 2002;Homrich et al, 2008;Schmidt et al, 2008;Wu et al, 2008;Li et al, 2009;Hernandez-Garcia et al, 2009;Xing et al, 2010;Wiebke-Strohm et al, 2011).…”

“…Even after more than two decades, the stable transformation of soybean cannot yet be considered as routine because it depends on the ability to bring together efficient transformation and regeneration techniques. Two methods have been successfuly used: particle bombardment Finer & McMullen, 1991;Christou & McCabe, 1992;Finer et al, 1992;Stewart et al, 1996;Aragão et al, 2000;Droste et al, 2002;Homrich et al, 2008;Wu et al, 2008;Li et al, 2009;Hernandez-Garcia et al, 2009;Xing et al, 2010;Viana et al, 2011) and Agrobacterium tumefaciens system Trick & Finer, 1998;Aragão et al, 2000;Yan et al, 2000;Ko et al, 2003Ko et al, , 2004Paz et al, 2006;Hong et al, 2007;Miklos et al, 2007;Liu et al, 2008;Wang & Xu, 2008;Wiebke-Strohm et al, 2011).…”