Camelina Mutants Exhibit Resistance to Inhibitor Herbicides

Camelina (Camelina sativa L.) is a member of the mustard family that has recently gained interest from researchers because of its high seed oil content with low input requirements. However, just like other crops in the mustard family, it is also highly sensitive to residues of inhibitor herbicides. Thus, Dustin Walsh of Washington State University and colleagues conducted a study to select and characterize camelina mutant plants with increased resistance to acetolactate synthase (ALS) inhibitor herbicides.

Walsh and team developed mutant seeds by soaking them in a mutagenic compound. The seeds were then planted and screened for resistance to herbicides imazethapyr and sulfosulfuron. Five lines exhibited resistance, and four of which looked the same and showed resistance to imazethapyr. The other line showed resistance to sulfosulfuron. All five lines appears to be controlled by a single co-dominant gene. Further analyses confirmed the mutant plants' improved resistance to herbicides. When the lines were compared with the wild type, it was discovered that significantly higher doses of herbicides are needed by the mutant lines to reduce plant growth by half.

Through sequence analysis of the ALS genes from the sulfosulfuron resistant line, eight different genes were identified and one was found to be linked with the highest level of resistance through amino acid shift, which has been previously exhibited in yeast and tobacco ALS inhibitor resistance.

Subscribers of Molecular Breeding may get a copy of the research paper at http://www.springerlink.com/content/g1347w06t1557447/fulltext.pdf.