The Cre-loxP recombination-based reporter system for plant transcriptional expression studies.

To facilitate the characterization of plant genes, the Cre-loxP site-specific recombination system was adapted to make reporter vectors for plant expression studies. This system allows promoter fragments to be cloned into a small vector (univector) and subsequently recombined in vitro with binary vectors containing different reporter genes precisely at near-perfect efficiency. We have constructed univector-adapted vectors with three reporters, beta-glucuronidase, luciferase, and green fluorescent protein, and a BASTA-resistance gene for selection of plant transformants. Expression in plants using the new system was validated by comparison to conventional reporter vectors. These new vectors are efficient and economical alternatives to the other plant reporter vectors currently available. The royalty-free Cre-loxP system serves as a platform for the future expansion of recombination-based cloning vectors for plant research.