Abstract
PREMISE: Stable transformation is the biggest barrier to studying gene function in plants. In most species, transformation requires tissue culture and regeneration methods that may be arduous and cause undesirable genetic changes. Floral dip methods bypass these challenges by directly transforming ovules of developing flowers, but these methods have limited success outside of the Brassicaceae. METHODS AND RESULTS: We demonstrate that floral dip methods are effective for some genotypes of the yellow monkeyflower, Mimulus guttatus, an ecological and evolutionary model system. In genotypes where floral dip failed, we developed an effective floral bud injection method that allows plants to be infiltrated multiple times and reduces floral abscission and male sterility. CONCLUSIONS: Through a combination of floral dip and injection methods, we transformed both coastal perennial and inland annual genotypes of M. guttatus, setting the stage for understanding the molecular genetic underpinnings of local adaptation to the divergent habitats occupied by these distinctive ecotypes.