Differential Activity of Wheat Histone H4 Promoter in Transgenic Maize

Abstract

The recent methodology of introducing foreign genes into the genome of monocot cereal plants, including maize, is based on a variety of experimental approaches. Several laboratories have demonstrated the potentials in the use of microprojectile bombardment to transform embryogenic maize tissue cultures (Fromm et al. 1990; Gordon-Kamm et al. 1990; Walters et al. 1992). Furthermore, the production of transgenic maize plants expressing agronomically significant traits was also achieved by this method (Koziel et al. 1993). Regeneration of fertile transgenic maize plants was recently reported by D’Halluin et al. (1992) too, who electroporated plasmid molecules into wounded tissues of immature zygotic embryos or of embryogenic callus cultures. Both of these methods are proposed to be widely applicable for transformation of different breeding stocks. However, the regeneration capability was shown to be genotype-dependent by several tissue culture studies (Tomes and Smith 1985; Lupotto 1986; Petersen et al. 1992).