TARGETED GENE INACTIVATION IN PETUNIA BY PCR-BASED SELECTION OF TRANSPOSON INSERTION MUTANTS

Establishment of loss-of-function pheno-types is often a key step in d etermining the biological function of a gene. We describe a procedure to obtain mutant petunia plants in which a specific gene with known se quence is inactivated by the transposable element dTphl. Leaves are co llected from batches of 1000 plants with highly active dTphl elements, pooled according to a three-dimensional matrix, and screened by PCR u sing a transposon- and a gene-specific primer. In this way individual plants with a dTphl insertion can be identified by analysis of about 3 0 PCRs. We found insertion alleles for various genes at a frequency of about 1 in 1000 plants. The plant population can be preserved by self ing all the plants, so that it can be screened for insertions in many genes over a prolonged period.