Plastid transformation in Lesquerella fendleri, an oilseed Brassicacea

A plastid transformation protocol was developed for Lesquerella fendleri, a species with a high capacity for plant regeneration in tissue culture. Transformation vector pZS391B carried an aadA16gfp marker gene conferring streptomycin-spectinomycin resistance and green fluorescence under UV light. Biolistic transformation of 51 Lesquerella leaf samples, followed by spectinomycin selection, yielded two transplastomic clones. The AAD-GFP fusion protein, the marker gene product, was localized to chloroplasts by confocal laser microscopy. Fertile plants and seed progeny were obtained in line Lf-pZS391B-1. In the 51 samples a large number (108) of spontaneous mutants were identified. In five of the lines spectinomycin resistance was localized to a conserved stem structure by sequencing 16S rRNA genes. Success in L. fendleri, a wild oilseed species, extends plastid transformation beyond Arabidopsis thaliana in the Brassicaceae family.