TRANSIENT EXPRESSION OF MARKER GENES IN IMMATURE ZYGOTIC EMBRYOS OF SPRING WHEAT (TRITICUM-AESTIVUM) THROUGH MICROPROJECTILE BOMBARDMENT

Transient expression of marker genes (cat and uidA) delivered by the Biolistics microprojectile bombardment technique has been detected in immature zygotic embryos of wheat (Triticum aestivum L.). The DNA expression vectors that gave maximal expression of both cat (pCaMVI1CN) and uidA (pCaMVI1GusN) genes had an alcohol dehydrogenase (Adh1) intron 1 cloned in between the cauliflower mosaic virus (CaMV35S) promoter and the coding region of the gene. Detection of chloramphenicol acetyltransferase (CAT) activity in response to cat gene was complicated by the presence of an inhibitor of CAT activity as well as an endogenous CAT-like activity. The results of enzymatic assays were confirmed by an ELISA technique using CAT-specific antibodies, whereas the beta-glucuronidase (GUS) activity following the introduction of the uidA gene was confirmed by both histochemical and fluorometric techniques.