Multi-functional T-DNA/Ds tomato lines designed for gene cloning and molecular and physical dissection of the tomato genome.

ABSTRACT

In order to make the tomato genome more accessible for molecular analysis and gene cloning, we have produced 405 individual tomato (Lycopersicon esculentum) lines containing a characterized copy of pJasm13, a multifunctional T-DNA/modified Ds transposon element construct. Both the T-DNA and the Ds element in pJasm13 harbor a set of selectable marker genes to monitor excision and reintegration of Ds and additionally, target sequences for rare cutting restriction enzymes (I-PpoI, SfiI, NotI) and for site-specific recombinases (Cre, FLP, R). Blast analysis of flanking genomic sequences of 174 T-DNA inserts revealed homology to transcribed genes in 69 (40%), of which about half are known or putatively identified as genes and ESTs. The map position of 140 individual inserts was determined on the molecular genetic map of tomato. These inserts are distributed over the 12 chromosomes of tomato, allowing targeted and non-targeted transposon tagging, marking of closely linked genes of interest and induction of chromosomal rearrangements including translocations or creation of saturation-deletions or inversions within defined regions linked to the T-DNA insertion site. The different features of pJasm13 were successfully tested in tomato and Arabidopsis thaliana, thus providing a new tool for molecular/genetic dissection studies, including molecular and physical mapping, mutation analysis and cloning strategies in tomato and potentially, in other plants as well.