Sym Gene Testing

The hypothesized importance of sym genes to plants also predicts that their function should have changed little over time. That is, the sym genes of liverworts should work similarly to those of flowering plants. Scientists tested this prediction by using Agrobacterium to introduce a functional liverwort sym gene into an angiosperm possessing a nonfunctional version of the gene that could not form mycorrhizae. The investigators then applied fungal spores to the roots of transgenic plants and a control group of mutant plants. After several weeks, mycorrhizae were present in the transgenic plants--the result of the liverwort sym gene functioning normally. The control plants had no mycorrhizae. -Biology book pg 360

http://oregonstate.edu/dept/nursery-weeds/weedspeciespage/liverwort/female_sporocarp_750.JPG