EFFECT OF PROMOTER-LEADER SEQUENCES ON TRANSIENT REPORTER GENE-EXPRESSION IN PARTICLE BOMBARDED PEA (PISUM-SATIVUM L) TISSUES

Particle bombardment was used to deliver plasmids containing promoter-beta-glucuronidase (GUS) gene constructs into intact pea embryo axes, leaves and roots. Transient GUS enzyme activity was influenced by the promoter-leader sequence driving the GUS gene, as measured by fluorometric and histochemical assays. In most cases, the untranslated leader sequence from RNA 4 of alfalfa mosaic virus (referred to here as 'AMV') significantly increased GUS activity when included between the promoter (nopaline synthase (NOS), cauliflower mosaic virus 35S (35S), or the tandem 35S promoter (35S-35S)) and the GUS coding sequence. The 35S-35S-AMV promoter-leader sequence produced 4- to 10-fold greater levels of transient GUS activity in these pea tissues than the 35S promoter alone. Particle bombardment is a simple and rapid method for the assessment of vector constructs in pea tissues.