Gene Activation by T-DNA Tagging

Agrobacterium -mediated transformation of plants has not only become a useful tool for the introduction of chimeric genes into plants, but it has also recently been utilized in gene tagging (for reviews, see refs. 1 –3 ). T-DNA tagging has proven a powerful genetic approach for the isolation of novel plant genes. Compared with other approaches to gene isolation (for a review, see ref. 4 ), mutagenesis by insertion of defined DNA sequences allows the rapid cloning and characterization of the mutated locus. Furthermore, T-DNA is an ideal gene tag, as it has the potential to insert preferentially into potentially transcribed regions of the genome (5 ).