Gene transfer by particle bombardment

Abstract

Gene transfer into intact cells and tissues by particle bombardment is becoming an important tool in plant molecular biology [17]. The process has been used to stably transform major crop species including corn [7, 9], soybean [19], and cotton [6]. Genes have also been delivered into the chloroplast of Chlamydomonas [2] and the mitochodria of yeast [12]. Recent results indicate that genes can be introduced into the chloroplasts of higher plants [5] and that the foreign DNA can be stably maintained in the chloroplast and inherited by the progeny of the transgenic plants (Pal Maliga, personal communication). In addition to its application for the production of genetically transformed plants, particle bombardment has been used in transient expression experiments for the functional analysis of promoter elements that confer regulation to environmental [3] and tissue specific factors [16, 23 see also chapter by Twell et al., this volume]. These studies indicate that the technique can be utilized for gene expression studies in tissues as diverse as pollen, coleoptile, aleurone, and embryo. Regulatory genes that code for trans-acting factors have also been analyzed following their delivery into intact tissues [8, 18]. Gene transfer by particle bombardment provides a means of circumventing the use of protoplasts in transient assay systems. Therefore, the expression of reporter genes can be monitored directly in tissues which should exert proper regulation upon the introduced gene.