Transgenic Nicotiana tabacum with tolerance to 2,4-D has previously been produced using a bacterial 2,4-D-dioxygenase gene (tfdA) driven by the 35S promoter of cauliflower mosaic virus. Using promoters from the Pisum sativum plastocyanin gene (petE) and an Arabidopsis thaliana histone gene (H4A), we demonstrate that similar protection from 2,4-D can be obtained in transgenic N. tabacum by targeting expression of tfdA to either meristematic tissues or chloroplast-containing tissues. As with the 35S promoter constructs, the plants are tolerant but not completely resistant; very young seedlings in particular are only slightly protected. However, the levels of tolerance observed could offer a useful degree of protection from accidental spray drift.